// ****************************************************************************************************
// This is a program for teaching Vulkan
// As such, it is deliberately verbose so that it is obvious (as possible, at least) what is being done
//
// Mike Bailey, Oregon State University
// mjb@cs.oregonstate.edu
//
// The class notes for which this program was written can be found here:
// 	http://cs.oregonstate.edu/~mjb/cs519v
//
// Keyboard commands:
// 	'i', 'I': Toggle using the mouse for object rotation
// 	'm', 'M': Toggle display mode (textures vs. colors, for now)
// 	'p', 'P': Pause the animation
// 	'q', 'Q', Esc: exit the program
//
// Latest update: January 28, 2018
// ****************************************************************************************************



// *********
// INCLUDES:
// *********

#ifdef _WIN32
#include <io.h>
#endif
#include <stdlib.h>
#include <stdio.h>
//#include <unistd.h>
#include <math.h>
#ifndef M_PI
#define M_PI  3.14159265f
#endif
#include <stdarg.h>
#include <string.h>
#include <string>
#include <stdbool.h>
#include <assert.h>
#include <signal.h>

#ifndef _WIN32
typedef int errno_t;
int	fopen_s( FILE**, const char *, const char * ); 
#endif

#define GLFW_INCLUDE_VULKAN
#include "glfw3.h"

#define GLM_FORCE_RADIANS
//#define GLM_FORCE_DEPTH_ZERO_TO_ONE
#include "glm/vec2.hpp"
#include "glm/vec3.hpp"
#include "glm/mat4x4.hpp"
#include "glm/gtc/matrix_transform.hpp"
#include "glm/gtc/matrix_inverse.hpp"
//#include "glm/gtc/type_ptr.hpp"

#ifdef _WIN32
#pragma comment(linker, "/subsystem:windows")
#define APP_NAME_STR_LEN 80
#endif

#include "vulkan.h"
#include "vk_sdk_platform.h"

// these are here to flag why addresses are being passed into a vulkan function --
// 1. is it because the function wants to consume the contents of that tructure or array (IN)?
// or, 2. is it because that function is going to fill that staructure or array (OUT)?
#define IN
#define OUT
#define INOUT




// ******************
// DEFINED CONSTANTS:
// ******************

// useful stuff:

#define DEBUGFILE		"VulkanDebug.txt"
#define nullptr			(void *)NULL
#define MILLION			1000000L
#define BILLION			1000000000L
#define TEXTURE_COUNT		1
#define APP_SHORT_NAME		"cube"
#define APP_LONG_NAME		"Vulkan Cube Demo Program"

#define SECONDS_PER_CYCLE	3.f
#define FRAME_LAG		2
#define SWAPCHAINIMAGECOUNT	2


// multiplication factors for input interaction:
// //  (these are known from previous experience)

const float ANGFACT = { M_PI/180.f };
const float SCLFACT = { 0.005f };


// minimum allowable scale factor:

const float MINSCALE = { 0.05f };


// active mouse buttons (or them together):

const int LEFT   = { 4 };
const int MIDDLE = { 2 };
const int RIGHT  = { 1 };


// the allocation callbacks could look like this:
//typedef struct VkAllocationCallbacks {
//void*                                   pUserData;
//PFN_vkAllocationFunction                pfnAllocation;
//PFN_vkReallocationFunction              pfnReallocation;
//PFN_vkFreeFunction                      pfnFree;
//PFN_vkInternalAllocationNotification    pfnInternalAllocation;
//PFN_vkInternalFreeNotification          pfnInternalFree;
//} VkAllocationCallbacks;
// but we are not going to use them for now:
#define PALLOCATOR		(VkAllocationCallbacks *)nullptr


// report on a result return:

#define REPORT(s)		{ PrintVkError( result, s );  fflush(FpDebug); }
#define HERE_I_AM(s)		if( Verbose )  { fprintf( FpDebug, "\n***** %s *****\n", s );  fflush(FpDebug); }


// graphics parameters:

const double FOV =		glm::radians(60.);	// field-of-view angle
const float EYEDIST =		3.;			// eye distance
const float OMEGA =		2.*M_PI;		// angular velocity, radians/sec

#define SPIRV_MAGIC		0x07230203
// if you do an od -x, the magic number looks like this:
// 0000000 0203 0723 . . .

#define NUM_QUEUES_WANTED	1

#define ARRAY_SIZE(a)		(sizeof(a) / sizeof(a[0]))

// these are here for convenience and readability:
#define VK_FORMAT_VEC4		VK_FORMAT_R32G32B32A32_SFLOAT
#define VK_FORMAT_XYZW		VK_FORMAT_R32G32B32A32_SFLOAT
#define VK_FORMAT_VEC3		VK_FORMAT_R32G32B32_SFLOAT
#define VK_FORMAT_STP		VK_FORMAT_R32G32B32_SFLOAT
#define VK_FORMAT_XYZ		VK_FORMAT_R32G32B32_SFLOAT
#define VK_FORMAT_VEC2		VK_FORMAT_R32G32_SFLOAT
#define VK_FORMAT_ST		VK_FORMAT_R32G32_SFLOAT
#define VK_FORMAT_XY		VK_FORMAT_R32G32_SFLOAT
#define VK_FORMAT_FLOAT		VK_FORMAT_R32_SFLOAT
#define VK_FORMAT_S		VK_FORMAT_R32_SFLOAT
#define VK_FORMAT_X		VK_FORMAT_R32_SFLOAT

// my own error codes:
#define VK_FAILURE		(VkResult)( -2000000000 )
#define VK_SHOULD_EXIT		(VkResult)( -2000000001 )
#define VK_ERROR_SOMETHING_ELSE	(VkResult)( -2000000002 )



// ***********************************************
// MY HELPER TYPEDEFS AND STRUCTS FOR VULKAN WORK:
// ***********************************************

typedef VkBuffer		VkDataBuffer;
typedef VkDevice		VkLogicalDevice;
typedef VkDeviceCreateInfo	VkLogicalDeviceCreateInfo;
#define vkCreateLogicalDevice	vkCreateDevice


// holds all the information about a data buffer so it can be encapsulated in one variable:

typedef struct MyBuffer
{
	VkDataBuffer		buffer;
	VkDeviceMemory		vdm;
	VkDeviceSize		size;
} MyBuffer;


typedef struct MyTexture
{
	uint32_t			width;
	uint32_t			height;
	unsigned char *			pixels;
	VkImage				texImage;
	VkImageView			texImageView;
	VkSampler			texSampler;
	VkDeviceMemory			vdm;
} MyTexture;



// bmp file headers:
struct bmfh
{
	short bfType;
	int bfSize;
	short bfReserved1;
	short bfReserved2;
	int bfOffBits;
} FileHeader;


struct bmih
{
	int biSize;
	int biWidth;
	int biHeight;
	short biPlanes;
	short biBitCount;
	int biCompression;
	int biSizeImage;
	int biXPelsPerMeter;
	int biYPelsPerMeter;
	int biClrUsed;
	int biClrImportant;
} InfoHeader;




// *****************************
// STRUCTS FOR THIS APPLICATION:
// *****************************

// uniform variable block:

struct matBuf
{
        glm::mat4 uModelMatrix;
        glm::mat4 uViewMatrix;
        glm::mat4 uProjectionMatrix;
	glm::mat3 uNormalMatrix;
};


// uniform variable block:

struct lightBuf
{
	glm::vec4 uLightPos;
};


// uniform variable block:

struct miscBuf
{
	float uTime;
	int   uMode;
};


// an array of this struct will hold all vertex information:

struct vertex
{
	glm::vec3	position;
	glm::vec3	normal;
	glm::vec3	color;
	glm::vec2	texCoord;
};




// ********************************
// VULKAN-RELATED GLOBAL VARIABLES:
// ********************************

VkCommandBuffer			CommandBuffers[2];			// 2, because of double-buffering
VkPipeline			ComputePipeline;
VkPipelineCache			ComputePipelineCache;
VkPipelineLayout		ComputePipelineLayout;
VkDataBuffer 			DataBuffer;
VkImage				DepthImage;
VkImageView			DepthImageView;
VkDescriptorSetLayout		DescriptorSetLayouts[4];
VkDescriptorSet			DescriptorSets[4];
VkDebugReportCallbackEXT	ErrorCallback = VK_NULL_HANDLE;
VkEvent				Event;
VkFence				Fence;
VkDescriptorPool		DescriptorPool;
VkFramebuffer			Framebuffers[2];
VkCommandPool			GraphicsCommandPool;
VkPipeline			GraphicsPipeline;
VkPipelineCache			GraphicsPipelineCache;
VkPipelineLayout		GraphicsPipelineLayout;
uint32_t			Height;
VkInstance			Instance;
VkExtensionProperties *		InstanceExtensions;
VkLayerProperties *		InstanceLayers;
VkLogicalDevice			LogicalDevice;
GLFWwindow *			MainWindow;
VkPhysicalDevice		PhysicalDevice;
VkPhysicalDeviceProperties	PhysicalDeviceProperties;
uint32_t			PhysicalDeviceCount;
VkPhysicalDeviceFeatures	PhysicalDeviceFeatures;
VkImage *			PresentImages;
VkImageView *			PresentImageViews;	// the swap chain image views
VkQueue				Queue;
VkRect2D			RenderArea;
VkRenderPass			RenderPass; 
VkSemaphore			SemaphoreImageAvailable;
VkSemaphore			SemaphoreRenderFinished;
VkShaderModule			ShaderModuleFragment;
VkShaderModule			ShaderModuleVertex;
VkBuffer			StagingBuffer;
VkDeviceMemory			StagingBufferMemory;
VkSurfaceKHR			Surface;
VkSwapchainKHR			SwapChain;
VkCommandBuffer			TextureCommandBuffer;	// used for transfering texture from staging buffer to actual texture buffer
VkImage				TextureImage;
VkDeviceMemory			TextureImageMemory;
VkCommandPool			TransferCommandPool;
VkDebugReportCallbackEXT	WarningCallback;
uint32_t			Width;


#include "SampleVertexData.cpp"



// *************************************
// APPLICATION-RELATED GLOBAL VARIABLES:
// *************************************

int				ActiveButton;			// current button that is down
FILE *				FpDebug;			// where to send debugging messages
struct lightBuf			Light;				// cpu struct to hold light information
struct matBuf			Matrices;			// cpu struct to hold matrix information
struct miscBuf			Misc;				// cpu struct to hold miscellaneous information information
int				Mode;				// 0 = use colors, 1 = use textures, ...
MyBuffer			MyLightUniformBuffer;
MyTexture			MyPuppyTexture;			// the cute puppy texture struct
MyBuffer			MyMatrixUniformBuffer;
MyBuffer			MyMiscUniformBuffer;
MyBuffer			MyVertexDataBuffer;
bool				NeedToExit;			// true means the program should exit
int				NumRenders;			// how many times the render loop has been called
bool				Paused;				// true means don't animate
float				Scale;				// scaling factor
double				Time;
bool				Verbose;			// true = write messages into a file
int				Xmouse, Ymouse;			// mouse values
float				Xrot, Yrot;			// rotation angles in degrees
bool				UseMouse;			// true = use mouse for interaction, false = animate




// ********************
// FUNCTION PROTOTYPES:
// ********************

VkResult			DestroyAllVulkan( );

//VkBool32			ErrorCallback( VkDebugReportFlagsEXT, VkDebugReportObjectTypeEXT, uint64_t, size_t, int32_t, const char *, const char *, void * );

int				FindMemoryThatIsDeviceLocal( );
int				FindMemoryThatIsHostVisible( );
int				FindMemoryWithTypeBits( uint32_t );

int				FindQueueFamilyThatDoesGraphics( );
int				FindQueueFamilyThatDoesCompute( );
int				FindQueueFamilyThatDoesTransfer( );

void				InitGraphics( );

VkResult			Init01Instance( );

VkResult			Init02CreateDebugCallbacks( );

VkResult			Init03PhysicalDeviceAndGetQueueFamilyProperties( );

VkResult			Init04LogicalDeviceAndQueue( );

VkResult			Init05DataBuffer( VkDeviceSize, VkBufferUsageFlags, OUT MyBuffer * );
VkResult			Init05UniformBuffer( VkDeviceSize, OUT MyBuffer * );
VkResult			Init05MyVertexDataBuffer( VkDeviceSize, OUT MyBuffer * );
VkResult			Fill05DataBuffer( IN MyBuffer, IN void * );

VkResult			Init06CommandPools( );
VkResult			Init06CommandBuffers( );

VkResult			Init07TextureSampler( OUT MyTexture * );
VkResult			Init07TextureBuffer( INOUT MyTexture * );

VkResult			Init07TextureBufferAndFillFromBmpFile( IN std::string, OUT MyTexture * );

VkResult			Init08Swapchain( );

VkResult			Init09DepthStencilImage( );

VkResult			Init10RenderPasses( );

VkResult			Init11Framebuffers( );

VkResult			Init12SpirvShader( std::string, OUT VkShaderModule * );

VkResult			Init13DescriptorSetPool( );
VkResult			Init13DescriptorSetLayouts( );
VkResult			Init13DescriptorSets( );

VkResult			Init14GraphicsPipelineLayout( );
VkResult			Init14GraphicsVertexFragmentPipeline( VkShaderModule, VkShaderModule, VkPrimitiveTopology, OUT VkPipeline * );
VkResult			Init14ComputePipeline( VkShaderModule, OUT VkPipeline * );


VkResult			RenderScene( );
void				UpdateScene( );
//VkBool32			WarningCallback( VkDebugReportFlagsEXT, VkDebugReportObjectTypeEXT, uint64_t, size_t, int32_t, const char *, const char *, void * );

void				PrintVkError( VkResult, std::string = "" );
void				Reset( );

void				InitGLFW( );
void				GLFWErrorCallback( int, const char * );
void				GLFWKeyboard( GLFWwindow *, int, int, int, int );
void				GLFWMouseButton( GLFWwindow *, int, int, int );
void				GLFWMouseMotion( GLFWwindow *, double, double );
double				GLFWGetTime( );

int				ReadInt( FILE * );
short				ReadShort( FILE * );



// *************
// MAIN PROGRAM:
// *************


int
main( int argc, char * argv[ ] )
{
	Width  = 1024;
	Height = 1024;

#ifdef _WIN32
	errno_t err = fopen_s( &FpDebug, DEBUGFILE, "w" );
	if( err != 0 )
	{
		fprintf( stderr, "Cannot open debug print file '%s'\n", DEBUGFILE );
		FpDebug = stderr;
	}
#else
	FpDebug = fopen( DEBUGFILE, "w" );
	if( FpDebug == NULL )
	{
		fprintf( stderr, "Cannot open debug print file '%s'\n", DEBUGFILE );
		FpDebug = stderr;
	}
#endif
	fprintf(FpDebug, "FpDebug: Width = %d ; Height = %d\n", Width, Height);

	Reset( );
	InitGraphics( );


	// loop until the user closes the window:

	while( glfwWindowShouldClose( MainWindow ) == 0 )
	{
		glfwPollEvents( );
		Time = glfwGetTime( );		// elapsed time, in double-precision seconds
		UpdateScene( );
		RenderScene( );
		if( NeedToExit )
			break;
	}

	fprintf(FpDebug, "Closing the GLFW window\n");

	vkQueueWaitIdle( Queue );
	vkDeviceWaitIdle( LogicalDevice );
	DestroyAllVulkan( );
	glfwDestroyWindow( MainWindow );
	glfwTerminate( );
	return 0;
}


void
InitGraphics( )
{
	HERE_I_AM( "InitGraphics" );

	VkResult result = VK_SUCCESS;

	Init01Instance( );

	InitGLFW( );

	Init02CreateDebugCallbacks( );

	Init03PhysicalDeviceAndGetQueueFamilyProperties( );

	Init04LogicalDeviceAndQueue( );

	Init05UniformBuffer( sizeof(Matrices),   &MyMatrixUniformBuffer );
	Fill05DataBuffer( MyMatrixUniformBuffer,(void *) &Matrices );

	Init05UniformBuffer( sizeof(Light),      &MyLightUniformBuffer );
	Fill05DataBuffer( MyLightUniformBuffer,	(void *) &Light );

	Init05UniformBuffer( sizeof(Misc),   	&MyMiscUniformBuffer );
	Fill05DataBuffer( MyMiscUniformBuffer,	(void *) &Misc );

	Init05MyVertexDataBuffer(  sizeof(VertexData), &MyVertexDataBuffer );
	Fill05DataBuffer( MyVertexDataBuffer,			(void *) VertexData );

	Init06CommandPools();
	Init06CommandBuffers();

	Init07TextureSampler( &MyPuppyTexture );
	Init07TextureBufferAndFillFromBmpFile("puppy.bmp", &MyPuppyTexture);

	Init08Swapchain( );

	Init09DepthStencilImage( );

	Init10RenderPasses( );

	Init11Framebuffers( );

	Init12SpirvShader( "sample-vert.spv", &ShaderModuleVertex );
	Init12SpirvShader( "sample-frag.spv", &ShaderModuleFragment );

	Init13DescriptorSetPool( );
	Init13DescriptorSetLayouts();
	Init13DescriptorSets( );

	Init14GraphicsVertexFragmentPipeline( ShaderModuleVertex, ShaderModuleFragment, VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST, &GraphicsPipeline  );
}




// **********************
// CREATING THE INSTANCE:
// **********************

VkResult
Init01Instance( )
{
	HERE_I_AM( "Init01Instance" );

	VkResult result = VK_SUCCESS;

	VkApplicationInfo vai;
		vai.sType = VK_STRUCTURE_TYPE_APPLICATION_INFO;
		vai.pNext = nullptr;
		vai.pApplicationName = "Vulkan Sample";
		vai.applicationVersion = 100;
		vai.pEngineName = "";
		vai.engineVersion = 1;
		vai.apiVersion = VK_MAKE_VERSION(1, 0, 0);


	// these are the layers and extensions we would like to have:

	const char * instanceLayers[ ] =
	{
		////"VK_LAYER_LUNARG_api_dump",
		////"VK_LAYER_LUNARG_core_validation",
		//"VK_LAYER_LUNARG_image",
		"VK_LAYER_LUNARG_object_tracker",
		"VK_LAYER_LUNARG_parameter_validation",
		//"VK_LAYER_NV_optimus"
	};

	const char * instanceExtensions[ ] =
	{
		"VK_KHR_surface",
#ifdef _WIN32
		"VK_KHR_win32_surface",
#endif
		"VK_EXT_debug_report"
		//"VK_KHR_swapchain"
	};

	// see what layers are available:

	uint32_t count;
	vkEnumerateInstanceLayerProperties( &count, (VkLayerProperties *)nullptr );
	InstanceLayers = new VkLayerProperties[ count ];
	result = vkEnumerateInstanceLayerProperties( &count, InstanceLayers );
	REPORT( "vkEnumerateInstanceLayerProperties" );
	if( result != VK_SUCCESS )
	{
		return result;
	}

	fprintf( FpDebug, "\n%d instance layers enumerated:\n", count );
	for( unsigned int i = 0; i < count; i++ )
	{
		fprintf( FpDebug, "0x%08x  %2d  '%s'  '%s'\n",
			InstanceLayers[i].specVersion,
			InstanceLayers[i].implementationVersion,
			InstanceLayers[i].layerName,
			InstanceLayers[i].description );
	}

	// see what extensions are available:

	vkEnumerateInstanceExtensionProperties( (char *)nullptr, &count, (VkExtensionProperties *)nullptr );
	InstanceExtensions = new VkExtensionProperties[ count ];
	result = vkEnumerateInstanceExtensionProperties( (char *)nullptr, &count, InstanceExtensions );
	REPORT( "vkEnumerateInstanceExtensionProperties" );
	if( result != VK_SUCCESS )
	{
		return result;
	}

	fprintf( FpDebug, "\n%d extensions enumerated:\n", count );
	for( unsigned int i = 0; i < count; i++ )
	{
		fprintf( FpDebug, "0x%08x  '%s'\n",
			InstanceExtensions[i].specVersion,
			InstanceExtensions[i].extensionName );
	}
	

	// create the instance, asking for the layers and extensions:

	VkInstanceCreateInfo vici;
		vici.sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO;
		vici.pNext = nullptr;
		vici.flags = 0;
		vici.pApplicationInfo = &vai;
		vici.enabledLayerCount = sizeof(instanceLayers) / sizeof(char *);
		vici.ppEnabledLayerNames = instanceLayers;
		vici.enabledExtensionCount = sizeof(instanceExtensions) / sizeof(char *);
		vici.ppEnabledExtensionNames = instanceExtensions;
	
	result = vkCreateInstance( IN &vici, PALLOCATOR, OUT &Instance );
	REPORT( "vkCreateInstance" );
	return result;
}



// ***************************
// CREATE THE DEBUG CALLBACKS:
// ***************************

VkResult
Init02CreateDebugCallbacks( )
{
	HERE_I_AM( "Init02CreateDebugCallbacks" );
	
	VkResult result = VK_SUCCESS;

#ifdef NOTDEF
	PFN_vkCreateDebugReportCallbackEXT vkCreateDebugReportCallbackEXT = (PFN_vkCreateDebugReportCallbackEXT)nullptr;
	*(void **) &vkCreateDebugReportCallbackEXT = vkGetInstanceProcAddr( Instance, "vkCreateDebugReportCallbackEXT" );

	VkDebugReportCallbackCreateInfoEXT		vdrcci;
		vdrcci.sType = VK_STRUCTURE_TYPE_DEBUG_REPORT_CREATE_INFO_EXT;
		vdrcci.pNext = nullptr;
		vdrcci.flags = VK_DEBUG_REPORT_ERROR_BIT_EXT;
		vdrcci.pfnCallback = (PFN_vkDebugReportCallbackEXT) &DebugReportCallback;
		vdrcci.pUserData = nullptr;

	result = vkCreateDebugReportCallbackEXT( Instance, IN &vdrcci, PALLOCATOR, OUT &ErrorCallback );
	REPORT( "vkCreateDebugReportCallbackEXT - 1" );

		vdrcci.flags = VK_DEBUG_REPORT_WARNING_BIT_EXT | VK_DEBUG_REPORT_PERFORMANCE_WARNING_BIT_EXT;

	result = vkCreateDebugReportCallbackEXT( Instance, IN &vdrcci, PALLOCATOR, OUT &WarningCallback );
	REPORT( "vkCreateDebugReportCallbackEXT - 2" );
#endif

	return result;
}



#ifdef NOTYET
PFN_vkDebugReportCallbackEXT
DebugReportCallback(VkDebugReportFlagsEXT flags, VkDebugReportObjectTypeEXT objectType,
	uint64_t object, size_t location, int32_t messageCode,
	const char *  pLayerPrefix, const char *  pMessage, void * pUserData)
{
}



VkBool32
ErrorCallback(	VkDebugReportFlagsEXT flags, VkDebugReportObjectTypeEXT objectType,
			uint64_t object, size_t location, int32_t messageCode,
			const char *  pLayerPrefix, const char *  pMessage, void * pUserData )
{
	fprintf( FpDebug, "ErrorCallback: ObjectType = 0x%0x ; object = %ld ; LayerPrefix = '%s' ; Message = '%s'\n", objectType, object, pLayerPrefix, pMessage );
	return VK_TRUE;
}


VkBool32
WarningCallback( VkDebugReportFlagsEXT flags, VkDebugReportObjectTypeEXT objectType,
			uint64_t object, size_t location, int32_t messageCode,
			const char *  pLayerPrefix, const char *  pMessage, void * pUserData )
{
	fprintf( FpDebug, "WarningCallback: ObjectType = 0x%0x ; object = %ld ; LayerPrefix = '%s' ; Message = '%s'\n", objectType, object, pLayerPrefix, pMessage );
	return VK_TRUE;
}
#endif




// *************************************************************
// FINDING THE PHYSICAL DEVICES AND GET QUEUE FAMILY PROPERTIES:
// *************************************************************

VkResult
Init03PhysicalDeviceAndGetQueueFamilyProperties( )
{
	HERE_I_AM( "Init03PhysicalDeviceAndGetQueueFamilyProperties" );

	VkResult result = VK_SUCCESS;

	result = vkEnumeratePhysicalDevices( Instance, OUT &PhysicalDeviceCount, (VkPhysicalDevice *)nullptr ); 
	REPORT( "vkEnumeratePhysicalDevices - 1" );
	if( result != VK_SUCCESS || PhysicalDeviceCount <= 0 )
	{
		fprintf( FpDebug, "Could not count the physical devices\n" );
		return VK_SHOULD_EXIT;
	}

	fprintf(FpDebug, "\n%d physical devices found.\n", PhysicalDeviceCount);

	VkPhysicalDevice * physicalDevices = new VkPhysicalDevice[ PhysicalDeviceCount ];
	result = vkEnumeratePhysicalDevices( Instance, OUT &PhysicalDeviceCount, OUT physicalDevices  );
	REPORT( "vkEnumeratePhysicalDevices - 2" );
	if( result != VK_SUCCESS )
	{
		fprintf( FpDebug, "Could not enumerate the %d physical devices\n", PhysicalDeviceCount );
		return VK_SHOULD_EXIT;
	}

	int discreteSelect   = -1;
	int integratedSelect = -1;
	for( unsigned int i = 0; i < PhysicalDeviceCount; i++ )
	{
		VkPhysicalDeviceProperties vpdp;
		vkGetPhysicalDeviceProperties( IN physicalDevices[i], OUT &vpdp );
		if( result != VK_SUCCESS )
		{
			fprintf( FpDebug, "Could not get the physical device properties of device %d\n", i );
			return VK_SHOULD_EXIT;
		}

		fprintf( FpDebug, " \n\nDevice %2d:\n", i );
		fprintf( FpDebug, "\tAPI version: %d\n", vpdp.apiVersion );
		fprintf( FpDebug, "\tDriver version: %d\n", vpdp.apiVersion );
		fprintf( FpDebug, "\tVendor ID: 0x%04x\n", vpdp.vendorID );
		fprintf( FpDebug, "\tDevice ID: 0x%04x\n", vpdp.deviceID );
		fprintf( FpDebug, "\tPhysical Device Type: %d =", vpdp.deviceType );
		if( vpdp.deviceType == VK_PHYSICAL_DEVICE_TYPE_DISCRETE_GPU )	fprintf( FpDebug, " (Discrete GPU)\n" );
		if( vpdp.deviceType == VK_PHYSICAL_DEVICE_TYPE_INTEGRATED_GPU )	fprintf( FpDebug, " (Integrated GPU)\n" );
		if( vpdp.deviceType == VK_PHYSICAL_DEVICE_TYPE_VIRTUAL_GPU )	fprintf( FpDebug, " (Virtual GPU)\n" );
		if( vpdp.deviceType == VK_PHYSICAL_DEVICE_TYPE_CPU )		fprintf( FpDebug, " (CPU)\n" );
		fprintf( FpDebug, "\tDevice Name: %s\n", vpdp.deviceName );
		fprintf( FpDebug, "\tPipeline Cache Size: %d\n", vpdp.pipelineCacheUUID[0] );
		//fprintf( FpDebug, "?", vpdp.limits );
		//fprintf( FpDebug, "?", vpdp.sparseProperties );

		// need some logical here to decide which physical device to select:

		if( vpdp.deviceType == VK_PHYSICAL_DEVICE_TYPE_DISCRETE_GPU )
			discreteSelect = i;

		if( vpdp.deviceType == VK_PHYSICAL_DEVICE_TYPE_INTEGRATED_GPU )
			integratedSelect = i;
	}

	int which = -1;
	if( discreteSelect >= 0 )
	{
		which = discreteSelect;
		PhysicalDevice = physicalDevices[which];
	}
	else if( integratedSelect >= 0 )
	{
		which = integratedSelect;
		PhysicalDevice = physicalDevices[which];
	}
	else
	{
		fprintf( FpDebug, "Could not select a Physical Device\n" );
		return VK_SHOULD_EXIT;
	}

	vkGetPhysicalDeviceProperties( PhysicalDevice, OUT &PhysicalDeviceProperties );
	fprintf( FpDebug, "Device #%d selected ('%s')\n", which, PhysicalDeviceProperties.deviceName );

	vkGetPhysicalDeviceFeatures( IN PhysicalDevice, OUT &PhysicalDeviceFeatures );

	fprintf( FpDebug, "\nPhysical Device Features:\n");
	fprintf( FpDebug, "geometryShader = %2d\n", PhysicalDeviceFeatures.geometryShader);
	fprintf( FpDebug, "tessellationShader = %2d\n", PhysicalDeviceFeatures.tessellationShader );
	fprintf( FpDebug, "multiDrawIndirect = %2d\n", PhysicalDeviceFeatures.multiDrawIndirect );
	fprintf( FpDebug, "wideLines = %2d\n", PhysicalDeviceFeatures.wideLines );
	fprintf( FpDebug, "largePoints = %2d\n", PhysicalDeviceFeatures.largePoints );
	fprintf( FpDebug, "multiViewport = %2d\n", PhysicalDeviceFeatures.multiViewport );
	fprintf( FpDebug, "occlusionQueryPrecise = %2d\n", PhysicalDeviceFeatures.occlusionQueryPrecise );
	fprintf( FpDebug, "pipelineStatisticsQuery = %2d\n", PhysicalDeviceFeatures.pipelineStatisticsQuery );
	fprintf( FpDebug, "shaderFloat64 = %2d\n", PhysicalDeviceFeatures.shaderFloat64 );
	fprintf( FpDebug, "shaderInt64 = %2d\n", PhysicalDeviceFeatures.shaderInt64 );
	fprintf( FpDebug, "shaderInt16 = %2d\n", PhysicalDeviceFeatures.shaderInt16 );

#ifdef COMMENT
	All of these VkPhysicalDeviceFeatures are VkBool32s:
robustBufferAccess;
fullDrawIndexUint32;
imageCubeArray;
independentBlend;
geometryShader;
tessellationShader;
sampleRateShading;
dualSrcBlend;
logicOp;
multiDrawIndirect;
drawIndirectFirstInstance;
depthClamp;
depthBiasClamp;
fillModeNonSolid;
depthBounds;
wideLines;
largePoints;
alphaToOne;
multiViewport;
samplerAnisotropy;
textureCompressionETC2;
textureCompressionASTC_LDR;
textureCompressionBC;
occlusionQueryPrecise;
pipelineStatisticsQuery;
vertexPipelineStoresAndAtomics;
fragmentStoresAndAtomics;
shaderTessellationAndGeometryPointSize;
shaderImageGatherExtended;
shaderStorageImageExtendedFormats;
shaderStorageImageMultisample;
shaderStorageImageReadWithoutFormat;
shaderStorageImageWriteWithoutFormat;
shaderUniformBufferArrayDynamicIndexing;
shaderSampledImageArrayDynamicIndexing;
shaderStorageBufferArrayDynamicIndexing;
shaderStorageImageArrayDynamicIndexing;
shaderClipDistance;
shaderCullDistance;
shaderFloat64;
shaderInt64;
shaderInt16;
shaderResourceResidency;
shaderResourceMinLod;
sparseBinding;
sparseResidencyBuffer;
sparseResidencyImage2D;
sparseResidencyImage3D;
sparseResidency2Samples;
sparseResidency4Samples;
sparseResidency8Samples;
sparseResidency16Samples;
sparseResidencyAliased;
variableMultisampleRate;
inheritedQueries;
#endif

	VkFormatProperties					vfp;
#ifdef CHOICES
VK_FORMAT_FEATURE_SAMPLED_IMAGE_BIT = 0x00000001,
VK_FORMAT_FEATURE_STORAGE_IMAGE_BIT = 0x00000002,
VK_FORMAT_FEATURE_STORAGE_IMAGE_ATOMIC_BIT = 0x00000004,
VK_FORMAT_FEATURE_UNIFORM_TEXEL_BUFFER_BIT = 0x00000008,
VK_FORMAT_FEATURE_STORAGE_TEXEL_BUFFER_BIT = 0x00000010,
VK_FORMAT_FEATURE_STORAGE_TEXEL_BUFFER_ATOMIC_BIT = 0x00000020,
VK_FORMAT_FEATURE_VERTEX_BUFFER_BIT = 0x00000040,
VK_FORMAT_FEATURE_COLOR_ATTACHMENT_BIT = 0x00000080,
VK_FORMAT_FEATURE_COLOR_ATTACHMENT_BLEND_BIT = 0x00000100,
VK_FORMAT_FEATURE_DEPTH_STENCIL_ATTACHMENT_BIT = 0x00000200,
VK_FORMAT_FEATURE_BLIT_SRC_BIT = 0x00000400,
VK_FORMAT_FEATURE_BLIT_DST_BIT = 0x00000800,
VK_FORMAT_FEATURE_SAMPLED_IMAGE_FILTER_LINEAR_BIT = 0x00001000,
VK_FORMAT_FEATURE_SAMPLED_IMAGE_FILTER_CUBIC_BIT_IMG = 0x00002000,
#endif

	fprintf( FpDebug, "\nImage Formats Checked:\n" );
	vkGetPhysicalDeviceFormatProperties( PhysicalDevice, IN VK_FORMAT_R32G32B32A32_SFLOAT, &vfp );
	fprintf( FpDebug, "Format VK_FORMAT_R32G32B32A32_SFLOAT: 0x%08x 0x%08x  0x%08x\n",
				vfp.linearTilingFeatures, vfp.optimalTilingFeatures, vfp.bufferFeatures );
	vkGetPhysicalDeviceFormatProperties( PhysicalDevice, IN VK_FORMAT_B32G32R32A32_SFLOAT, &vfp );
	fprintf( FpDebug, "Format VK_FORMAT_B32G32R32A32_SFLOAT: 0x%08x 0x%08x  0x%08x\n",
				vfp.linearTilingFeatures, vfp.optimalTilingFeatures, vfp.bufferFeatures );
	vkGetPhysicalDeviceFormatProperties( PhysicalDevice, IN VK_FORMAT_R8G8B8A8_UNORM, &vfp );
	fprintf( FpDebug, "Format VK_FORMAT_R8G8B8A8_UNORM: 0x%08x 0x%08x  0x%08x\n",
				vfp.linearTilingFeatures, vfp.optimalTilingFeatures, vfp.bufferFeatures );
	vkGetPhysicalDeviceFormatProperties( PhysicalDevice, IN VK_FORMAT_B8G8R8A8_UNORM, &vfp );
	fprintf( FpDebug, "Format VK_FORMAT_B8G8R8A8_UNORM: 0x%08x 0x%08x  0x%08x\n",
				vfp.linearTilingFeatures, vfp.optimalTilingFeatures, vfp.bufferFeatures );

	VkPhysicalDeviceMemoryProperties			vpdmp;
	vkGetPhysicalDeviceMemoryProperties( PhysicalDevice, OUT &vpdmp );

	fprintf( FpDebug, "\n%d Memory Types:\n", vpdmp.memoryTypeCount );
	for( unsigned int i = 0; i < vpdmp.memoryTypeCount; i++ )
	{
		VkMemoryType vmt = vpdmp.memoryTypes[i];
		fprintf( FpDebug, "Memory %2d: ", i );
		if( ( vmt.propertyFlags & VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT       ) != 0 )	fprintf( FpDebug, " DeviceLocal" );
		if( ( vmt.propertyFlags & VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT       ) != 0 )	fprintf( FpDebug, " HostVisible" );
		if( ( vmt.propertyFlags & VK_MEMORY_PROPERTY_HOST_COHERENT_BIT      ) != 0 )	fprintf( FpDebug, " HostCoherent" );
		if( ( vmt.propertyFlags & VK_MEMORY_PROPERTY_HOST_CACHED_BIT        ) != 0 )	fprintf( FpDebug, " HostCached" );
		if( ( vmt.propertyFlags & VK_MEMORY_PROPERTY_LAZILY_ALLOCATED_BIT   ) != 0 )	fprintf( FpDebug, " LazilyAllocated" );
		fprintf(FpDebug, "\n");
	}

	fprintf( FpDebug, "\n%d Memory Heaps:\n", vpdmp.memoryHeapCount );
	for( unsigned int  i = 0; i < vpdmp.memoryHeapCount; i++ )
	{
		fprintf(FpDebug, "Heap %d: ", i);
		VkMemoryHeap vmh = vpdmp.memoryHeaps[i];
		fprintf( FpDebug, " size = 0x%08lx", (unsigned long int)vmh.size );
		if( ( vmh.flags & VK_MEMORY_HEAP_DEVICE_LOCAL_BIT  ) != 0 )	fprintf( FpDebug, " DeviceLocal" );	// only one in use
		fprintf(FpDebug, "\n");
	}

	uint32_t count = -1;
	vkGetPhysicalDeviceQueueFamilyProperties( IN PhysicalDevice, &count, OUT (VkQueueFamilyProperties *)nullptr );
	fprintf( FpDebug, "\nFound %d Queue Families:\n", count );

	VkQueueFamilyProperties *vqfp = new VkQueueFamilyProperties[ count ];
	vkGetPhysicalDeviceQueueFamilyProperties( IN PhysicalDevice, &count, OUT vqfp );
	for( unsigned int i = 0; i < count; i++ )
	{
		fprintf( FpDebug, "\t%d: Queue Family Count = %2d  ;   ", i, vqfp[i].queueCount );
		if( ( vqfp[i].queueFlags & VK_QUEUE_GRAPHICS_BIT ) != 0 )	fprintf( FpDebug, " Graphics" );
		if( ( vqfp[i].queueFlags & VK_QUEUE_COMPUTE_BIT  ) != 0 )	fprintf( FpDebug, " Compute " );
		if( ( vqfp[i].queueFlags & VK_QUEUE_TRANSFER_BIT ) != 0 )	fprintf( FpDebug, " Transfer" );
		fprintf(FpDebug, "\n");
	}

	return result;
}

// ************************************
// CREATE THE LOGICAL DEVICE AND QUEUE:
// ************************************

VkResult
Init04LogicalDeviceAndQueue( )
{
	HERE_I_AM( "Init04LogicalDeviceAndQueue" );

	VkResult result = VK_SUCCESS;

	float 	queuePriorities[NUM_QUEUES_WANTED] =
	{
		1.
	};

	VkDeviceQueueCreateInfo				vdqci[NUM_QUEUES_WANTED];
		vdqci[0].sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO;
		vdqci[0].pNext = nullptr;
		vdqci[0].flags = 0;
		vdqci[0].queueFamilyIndex = FindQueueFamilyThatDoesGraphics( );
		vdqci[0].queueCount = 1;		// how many queues to create
		vdqci[0].pQueuePriorities = queuePriorities;	// array of queue priorities [0.,1.]


	const char * myDeviceLayers[ ] =
	{
		////"VK_LAYER_LUNARG_api_dump",
		////"VK_LAYER_LUNARG_core_validation",
		//"VK_LAYER_LUNARG_image",
		"VK_LAYER_LUNARG_object_tracker",
		"VK_LAYER_LUNARG_parameter_validation",
		//"VK_LAYER_NV_optimus"
	};

	const char * myDeviceExtensions[ ] =
	{
		"VK_KHR_surface",
#ifndef _WIN32
		"VK_KHR_win32_surface",
#endif
		"VK_EXT_debug_report"
		//"VK_KHR_swapchain"
	};


	// see what device layers are available:

	uint32_t layerCount;
	vkEnumerateDeviceLayerProperties(PhysicalDevice, &layerCount, (VkLayerProperties *)nullptr);
	VkLayerProperties * deviceLayers = new VkLayerProperties[layerCount];
	result = vkEnumerateDeviceLayerProperties( PhysicalDevice, &layerCount, deviceLayers);
	REPORT("vkEnumerateDeviceLayerProperties");
	if (result != VK_SUCCESS)
	{
		return result;
	}

	fprintf(FpDebug, "\n%d physical device layers enumerated:\n", layerCount);
	for (unsigned int i = 0; i < layerCount; i++)
	{
		fprintf(FpDebug, "0x%08x  %2d  '%s'  '%s'\n",
			deviceLayers[i].specVersion,
			deviceLayers[i].implementationVersion,
			deviceLayers[i].layerName,
			deviceLayers[i].description);


		// see what device extensions are available:

		uint32_t extensionCount;
		vkEnumerateDeviceExtensionProperties(PhysicalDevice, deviceLayers[i].layerName, &extensionCount, (VkExtensionProperties *)nullptr);
		VkExtensionProperties * deviceExtensions = new VkExtensionProperties[extensionCount];
		result = vkEnumerateDeviceExtensionProperties(PhysicalDevice, deviceLayers[i].layerName, &extensionCount, deviceExtensions);
		//REPORT("vkEnumerateDeviceExtensionProperties");
		if (result != VK_SUCCESS)
		{
			return result;
		}

		fprintf(FpDebug, "\t%d device extensions enumerated for '%s':\n", extensionCount, deviceLayers[i].layerName );
		for (unsigned int ii = 0; ii < extensionCount; ii++)
		{
			fprintf(FpDebug, "\t0x%08x  '%s'\n",
				deviceExtensions[ii].specVersion,
				deviceExtensions[ii].extensionName);
		}
		fprintf(FpDebug, "\n");
	}


	VkDeviceCreateInfo   vdci;
		vdci.sType = VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO;
		vdci.pNext = nullptr;
		vdci.flags = 0;
		vdci.queueCreateInfoCount = NUM_QUEUES_WANTED;		// # of device queues, each of which can create multiple queues
		vdci.pQueueCreateInfos = IN &vdqci[0];			// array of VkDeviceQueueCreateInfo's
		vdci.enabledLayerCount = sizeof(myDeviceLayers) / sizeof(char *);
		//vdci.enabledLayerCount = 0;
		vdci.ppEnabledLayerNames = myDeviceLayers;
		vdci.enabledExtensionCount = 0;
		vdci.ppEnabledExtensionNames = (const char **)nullptr;			// no extensons
		//vdci.enabledExtensionCount = sizeof(myDeviceExtensions) / sizeof(char *);
		//vdci.ppEnabledExtensionNames = myDeviceExtensions;
		vdci.pEnabledFeatures = IN &PhysicalDeviceFeatures;	// already created

	result = vkCreateLogicalDevice( PhysicalDevice, IN &vdci, PALLOCATOR, OUT &LogicalDevice );
	REPORT( "vkCreateLogicalDevice" );

	
	// get the queue for this logical device:
	
	vkGetDeviceQueue( LogicalDevice, 0, 0,  OUT &Queue );
				// queueFamilyIndex, queueIndex
	return result;
}


// *********************
// CREATE A DATA BUFFER:
// *********************

// This just creates the data buffer -- filling it with data uses the Fill05DataBuffer function
// Use this for vertex buffers, index buffers, uniform buffers, and textures

VkResult
Init05DataBuffer( VkDeviceSize size, VkBufferUsageFlags usage, OUT MyBuffer * pMyBuffer )
{
	HERE_I_AM( "Init05DataBuffer" );

	VkResult result = VK_SUCCESS;

	VkBufferCreateInfo  vbci;
		vbci.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
		vbci.pNext = nullptr;
		vbci.flags = 0;
		vbci.size = size;
		vbci.usage = usage;
#ifdef CHOICES
VK_USAGE_TRANSFER_SRC_BIT
VK_USAGE_TRANSFER_DST_BIT
VK_USAGE_UNIFORM_TEXEL_BUFFER_BIT
VK_USAGE_STORAGE_TEXEL_BUFFER_BIT
VK_USAGE_UNIFORM_BUFFER_BIT
VK_USAGE_STORAGE_BUFFER_BIT
VK_USAGE_INDEX_BUFFER_BIT
VK_USAGE_VERTEX_BUFFER_BIT
VK_USAGE_INDIRECT_BUFFER_BIT
#endif
		vbci.queueFamilyIndexCount = 0;
		vbci.pQueueFamilyIndices = (const uint32_t *)nullptr;
		vbci.sharingMode = VK_SHARING_MODE_EXCLUSIVE;	// can only use CONCURRENT if .queueFamilyIndexCount > 0
#ifdef CHOICES
VK_SHARING_MODE_EXCLUSIVE
VK_SHARING_MODE_CONCURRENT
#endif

	pMyBuffer->size = size;
	result = vkCreateBuffer ( LogicalDevice, IN &vbci, PALLOCATOR,  OUT &pMyBuffer->buffer );
	REPORT( "vkCreateBuffer" );

	VkMemoryRequirements			vmr;
	vkGetBufferMemoryRequirements( LogicalDevice, IN pMyBuffer->buffer, OUT &vmr );		// fills vmr
	if( Verbose )
	{
		fprintf( FpDebug, "Buffer vmr.size = %lld\n", vmr.size );
		fprintf( FpDebug, "Buffer vmr.alignment = %lld\n", vmr.alignment );
		fprintf( FpDebug, "Buffer vmr.memoryTypeBits = 0x%08x\n", vmr.memoryTypeBits );
		fflush( FpDebug );
	}

	VkMemoryAllocateInfo			vmai;
		vmai.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
		vmai.pNext = nullptr;
		vmai.allocationSize = vmr.size;
		vmai.memoryTypeIndex = FindMemoryThatIsHostVisible( );

	VkDeviceMemory				vdm;
	result = vkAllocateMemory( LogicalDevice, IN &vmai, PALLOCATOR, OUT &vdm );
	REPORT( "vkAllocateMemory" );
	pMyBuffer->vdm = vdm;

	result = vkBindBufferMemory( LogicalDevice, pMyBuffer->buffer, IN vdm, 0 );		// 0 is the offset
	REPORT( "vkBindBufferMemory" );

	return result;
}



// ***********************
// CREATE A VERTEX BUFFER:
// ***********************
// this allocates space for a data buffer, but doesn't yet fill it:

VkResult
Init05MyVertexDataBuffer( IN VkDeviceSize size, OUT MyBuffer * pMyBuffer )
{
	VkResult result = Init05DataBuffer( size, VK_BUFFER_USAGE_VERTEX_BUFFER_BIT, pMyBuffer );		// fills pMyBuffer
	REPORT( "InitDataBuffer" );
	return result;
}



// ************************
// CREATE A UNIFORM BUFFER:
// ************************
// this allocates space for a data buffer, but doesn't yet fill it:

VkResult
Init05UniformBuffer( VkDeviceSize size, MyBuffer * pMyBuffer )
{
	VkResult result = Init05DataBuffer( size, VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, OUT pMyBuffer );	// fills pMyBuffer
	return result;
}


// *******************
// FILL A DATA BUFFER:
// *******************

VkResult
Fill05DataBuffer( IN MyBuffer myBuffer, IN void * data )
{
	// the size of the data had better match the size that was used to Init the buffer!

	void * pGpuMemory;
	vkMapMemory( LogicalDevice, IN myBuffer.vdm, 0, VK_WHOLE_SIZE, 0, &pGpuMemory );	// 0 and 0 are offset and flags
	memcpy( pGpuMemory, data, (size_t)myBuffer.size );
	vkUnmapMemory( LogicalDevice, IN myBuffer.vdm );
	return VK_SUCCESS;

	// the way shown here makes it happen immediately
	//
	// but, we could use vkCmdUpdateBuffer( CommandBuffer, myBuffer.buffer, 0, myBuffer.size, data );
	// instead, except that this requires use of the CommandBuffer
	// which might not be so bad since we are using the CommandBuffer at that moment to draw anyway
}





// *************************
// CREATE A TEXTURE SAMPLER:
// *************************

VkResult
Init07TextureSampler( MyTexture * pMyTexture )
{
	HERE_I_AM( "Init07TextureSampler" );

	VkResult result = VK_SUCCESS;
	
	VkSamplerCreateInfo					vsci;
		vsci.sType = VK_STRUCTURE_TYPE_SAMPLER_CREATE_INFO;
		vsci.pNext = nullptr;
		vsci.flags = 0;
		vsci.magFilter = VK_FILTER_LINEAR;
		vsci.minFilter = VK_FILTER_LINEAR;
		vsci.mipmapMode = VK_SAMPLER_MIPMAP_MODE_LINEAR;
		vsci.addressModeU = VK_SAMPLER_ADDRESS_MODE_REPEAT;
		vsci.addressModeV = VK_SAMPLER_ADDRESS_MODE_REPEAT;
		vsci.addressModeW = VK_SAMPLER_ADDRESS_MODE_REPEAT;
#ifdef CHOICES
VK_SAMPLER_ADDRESS_MODE_REPEAT
VK_SAMPLER_ADDRESS_MODE_MIRRORED_REPEAT
VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE
VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_BORDER
VK_SAMPLER_ADDRESS_MODE_MIRROR_CLAMP_TO_EDGE
#endif
		vsci.mipLodBias = 0.;
		vsci.anisotropyEnable = VK_FALSE;
		vsci.maxAnisotropy = 1.;
		vsci.compareEnable = VK_FALSE;
		vsci.compareOp = VK_COMPARE_OP_NEVER;
#ifdef CHOICES
VK_COMPARE_OP_NEVER
VK_COMPARE_OP_LESS
VK_COMPARE_OP_EQUAL
VK_COMPARE_OP_LESS_OR_EQUAL
VK_COMPARE_OP_GREATER
VK_COMPARE_OP_NOT_EQUAL
VK_COMPARE_OP_GREATER_OR_EQUAL
VK_COMPARE_OP_ALWAYS
#endif
		vsci.minLod = 0.;
		vsci.maxLod = 0.;
		vsci.borderColor = VK_BORDER_COLOR_FLOAT_OPAQUE_BLACK;
#ifdef CHOICES
VK_BORDER_COLOR_FLOAT_TRANSPARENT_BLACK
VK_BORDER_COLOR_INT_TRANSPARENT_BLACK
VK_BORDER_COLOR_FLOAT_OPAQUE_BLACK
VK_BORDER_COLOR_INT_OPAQUE_BLACK
VK_BORDER_COLOR_FLOAT_OPAQUE_WHITE
VK_BORDER_COLOR_INT_OPAQUE_WHITE
#endif
		vsci.unnormalizedCoordinates = VK_FALSE;	// VK_TRUE means we are use raw texels as the index
								// VK_FALSE means we are uing the usual 0. - 1.

	result = vkCreateSampler( LogicalDevice, IN &vsci, PALLOCATOR, OUT &pMyTexture->texSampler );
	REPORT( "vkCreateSampler" );
	return result;
}



// ************************
// CREATE A TEXTURE BUFFER:
// ************************

// assume we get to here and have in a MyTexture struct:
// 	* an unsigned char array, holding the pixel rgba
//	* width  is the number of texels in s
//	* height is the number of texels in t

VkResult
Init07TextureBuffer( INOUT MyTexture * pMyTexture)
{
	HERE_I_AM( "Init07TextureBuffer" );

	VkResult result = VK_SUCCESS;

	uint32_t texWidth = pMyTexture->width;;
	uint32_t texHeight = pMyTexture->height;
	unsigned char *texture = pMyTexture->pixels;
	VkDeviceSize textureSize = texWidth * texHeight * 4;		// rgba, 1 byte each

	VkImage  stagingImage;
	VkImage  textureImage;


	// *******************************************************************************
	// this first {...} is to create the staging image:
	// *******************************************************************************
	{
		VkImageCreateInfo			vici;
			vici.sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO;
			vici.pNext = nullptr;
			vici.flags = 0;
#ifdef CHOICES
VK_IMAGE_CREATE_SPARSE_BINDING_BIT
VK_IMAGE_CREATE_SPARSE_RESIDENCY_BIT
VK_IMAGE_CREATE_SPARSE_ALIASED_BIT
VK_IMAGE_CREATE_MUTABLE_FORMAT_BIT
VK_IMAGE_CREATE_CUBE_COMPATIBLE_BIT
VK_IMAGE_CREATE_BIND_SFR_BIT_KHX
VK_IMAGE_CREATE_2D_ARRAY_COMPATIBLE_BIT_KHR
#endif
			vici.imageType = VK_IMAGE_TYPE_2D;
			vici.format = VK_FORMAT_R8G8B8A8_UNORM;
			vici.extent.width = texWidth;
			vici.extent.height = texHeight;
			vici.extent.depth = 1;
			vici.mipLevels = 1;
				vici.arrayLayers = 1;
				vici.samples = VK_SAMPLE_COUNT_1_BIT;
				vici.tiling = VK_IMAGE_TILING_LINEAR;
	#ifdef CHOICES
	VK_IMAGE_TILING_OPTIMAL
	VK_IMAGE_TILING_LINEAR
	#endif
				vici.usage = VK_IMAGE_USAGE_TRANSFER_SRC_BIT;
	#ifdef CHOICES
	VK_IMAGE_USAGE_TRANSFER_SRC_BIT
	VK_IMAGE_USAGE_TRANSFER_DST_BIT
	VK_IMAGE_USAGE_SAMPLED_BIT
	VK_IMAGE_USAGE_STORAGE_BIT
	VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT
	VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT
	VK_IMAGE_USAGE_TRANSIENT_ATTACHMENT_BIT
	VK_IMAGE_USAGE_INPUT_ATTACHMENT_BIT
	#endif
				vici.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
				vici.initialLayout = VK_IMAGE_LAYOUT_PREINITIALIZED;
	#ifdef CHOICES
	VK_IMAGE_LAYOUT_UNDEFINED
	VK_IMAGE_LAYOUT_PREINITIALIZED
	#endif
				vici.queueFamilyIndexCount = 0;
				vici.pQueueFamilyIndices = (const uint32_t *)nullptr;

			result = vkCreateImage(LogicalDevice, IN &vici, PALLOCATOR, OUT &stagingImage);	// allocated, but not filled
			REPORT("vkCreateImage");

			VkMemoryRequirements			vmr;
			vkGetImageMemoryRequirements(LogicalDevice, IN stagingImage, OUT &vmr);

			if (Verbose)
			{
				fprintf(FpDebug, "Image vmr.size = %lld\n", vmr.size);
				fprintf(FpDebug, "Image vmr.alignment = %lld\n", vmr.alignment);
				fprintf(FpDebug, "Image vmr.memoryTypeBits = 0x%08x\n", vmr.memoryTypeBits);
				fflush(FpDebug);
			}

			VkMemoryAllocateInfo			vmai;
				vmai.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
				vmai.pNext = nullptr;
				vmai.allocationSize = vmr.size;
				vmai.memoryTypeIndex = FindMemoryThatIsHostVisible();	// because we want to mmap it

			VkDeviceMemory				vdm;
			result = vkAllocateMemory(LogicalDevice, IN &vmai, PALLOCATOR, OUT &vdm);
			REPORT("vkAllocateMemory");
			pMyTexture->vdm = vdm;

			result = vkBindImageMemory(LogicalDevice, IN stagingImage, IN vdm, 0);	// 0 = offset
			REPORT("vkBindImageMemory");


			// we have now created the staging image -- fill it with the pixel data:

			VkImageSubresource			vis;
				vis.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
				vis.mipLevel = 0;
				vis.arrayLayer = 0;

			VkSubresourceLayout			vsl;
			vkGetImageSubresourceLayout(LogicalDevice, stagingImage, IN &vis, OUT &vsl);

			if (Verbose)
			{
				fprintf(FpDebug, "Subresource Layout:\n");
				fprintf(FpDebug, "\toffset = %lld\n", vsl.offset);
				fprintf(FpDebug, "\tsize = %lld\n", vsl.size);
				fprintf(FpDebug, "\trowPitch = %lld\n", vsl.rowPitch);
				fprintf(FpDebug, "\tarrayPitch = %lld\n", vsl.arrayPitch);
				fprintf(FpDebug, "\tdepthPitch = %lld\n", vsl.depthPitch);
				fflush(FpDebug);
			}

			void * gpuMemory;
			vkMapMemory(LogicalDevice, vdm, 0, VK_WHOLE_SIZE, 0, OUT &gpuMemory);
								// 0 and 0 = offset and memory map flags

			if (vsl.rowPitch == 4 * texWidth)
			{
				memcpy(gpuMemory, (void *)texture, (size_t)textureSize);
			}
			else
			{
				unsigned char *gpuBytes = (unsigned char *)gpuMemory;
				for (unsigned int y = 0; y < texHeight; y++)
				{
					memcpy(&gpuBytes[y * vsl.rowPitch], &texture[4 * y * texWidth], (size_t)(4*texWidth) );
				}
			}

			vkUnmapMemory(LogicalDevice, vdm);

		}
		// *******************************************************************************


		// *******************************************************************************
		// this second {...} is to create the actual texture image:
		// *******************************************************************************
		{
			VkImageCreateInfo			vici;
				vici.sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO;
				vici.pNext = nullptr;
				vici.flags = 0;
				vici.imageType = VK_IMAGE_TYPE_2D;
				vici.format = VK_FORMAT_R8G8B8A8_UNORM;
				vici.extent.width  = texWidth;
				vici.extent.height = texHeight;
				vici.extent.depth = 1;
				vici.mipLevels = 1;
				vici.arrayLayers = 1;
				vici.samples = VK_SAMPLE_COUNT_1_BIT;
				vici.tiling = VK_IMAGE_TILING_OPTIMAL;
				vici.usage = VK_IMAGE_USAGE_TRANSFER_DST_BIT | VK_IMAGE_USAGE_SAMPLED_BIT;
						// because we are transfering into it and will eventual sample from it
				vici.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
				vici.initialLayout = VK_IMAGE_LAYOUT_PREINITIALIZED;
				vici.queueFamilyIndexCount = 0;
				vici.pQueueFamilyIndices = (const uint32_t *)nullptr;

			result = vkCreateImage(LogicalDevice, IN &vici, PALLOCATOR, OUT &textureImage);	// allocated, but not filled
			REPORT("vkCreateImage");

			VkMemoryRequirements			vmr;
			vkGetImageMemoryRequirements(LogicalDevice, IN textureImage, OUT &vmr);

			if( Verbose )
			{
				fprintf( FpDebug, "Texture vmr.size = %lld\n", vmr.size );
				fprintf( FpDebug, "Texture vmr.alignment = %lld\n", vmr.alignment );
				fprintf( FpDebug, "Texture vmr.memoryTypeBits = 0x%08x\n", vmr.memoryTypeBits );
				fflush( FpDebug );
			}

			VkMemoryAllocateInfo			vmai;
				vmai.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
				vmai.pNext = nullptr;
				vmai.allocationSize = vmr.size;
				vmai.memoryTypeIndex = FindMemoryThatIsDeviceLocal( );	// because we want to sample from it

			VkDeviceMemory				vdm;
			result = vkAllocateMemory(LogicalDevice, IN &vmai, PALLOCATOR, OUT &vdm);
			REPORT("vkAllocateMemory");

			result = vkBindImageMemory( LogicalDevice, IN textureImage, IN vdm, 0 );	// 0 = offset
			REPORT( "vkBindImageMemory" );
		}
		// *******************************************************************************


		// copy pixels from the staging image to the texture:

		VkCommandBufferBeginInfo		vcbbi;
			vcbbi.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
			vcbbi.pNext = nullptr;
			vcbbi.flags = VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT;
			vcbbi.pInheritanceInfo = (VkCommandBufferInheritanceInfo *)nullptr;

		result = vkBeginCommandBuffer( TextureCommandBuffer, IN &vcbbi);
		REPORT( "Init07TextureBuffer -- vkBeginCommandBuffer" );


		// *******************************************************************************
		// transition the staging buffer layout:
		// *******************************************************************************
		{
			VkImageSubresourceRange			visr;
				visr.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
				visr.baseMipLevel = 0;
				visr.levelCount = 1;
				visr.baseArrayLayer = 0;
				visr.layerCount = 1;
				
			VkImageMemoryBarrier			vimb;
				vimb.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
				vimb.pNext = nullptr;
				vimb.oldLayout = VK_IMAGE_LAYOUT_PREINITIALIZED;
				vimb.newLayout = VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL;
				vimb.srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
				vimb.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
				vimb.image = stagingImage;
				vimb.srcAccessMask = VK_ACCESS_HOST_WRITE_BIT;
				vimb.dstAccessMask = VK_ACCESS_TRANSFER_READ_BIT;
				vimb.subresourceRange = visr;


			vkCmdPipelineBarrier( TextureCommandBuffer,
					VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT, VK_PIPELINE_STAGE_TRANSFER_BIT, 0,
					0, (VkMemoryBarrier *)nullptr,
					0, (VkBufferMemoryBarrier *)nullptr,
					1, IN &vimb );
		}
		// *******************************************************************************



		// *******************************************************************************
		// transition the texture buffer layout:
		// *******************************************************************************
		{
			VkImageSubresourceRange			visr;
				visr.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
				visr.baseMipLevel = 0;
				visr.levelCount = 1;
				visr.baseArrayLayer = 0;
				visr.layerCount = 1;

			VkImageMemoryBarrier			vimb;
				vimb.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
				vimb.pNext = nullptr;
				vimb.oldLayout = VK_IMAGE_LAYOUT_PREINITIALIZED;
				vimb.newLayout = VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL;
				vimb.srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
				vimb.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
				vimb.image = textureImage;
				vimb.srcAccessMask = VK_ACCESS_TRANSFER_READ_BIT;
				vimb.dstAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
				vimb.subresourceRange = visr;

			vkCmdPipelineBarrier(TextureCommandBuffer,
				VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT, VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT, 0,
				0, (VkMemoryBarrier *)nullptr,
				0, (VkBufferMemoryBarrier *)nullptr,
				1, IN &vimb);

			// now do the final image transfer:

			VkImageSubresourceLayers		visl;
				visl.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
				visl.baseArrayLayer = 0;
				visl.mipLevel = 0;
				visl.layerCount = 1;

			VkOffset3D				vo3;
				vo3.x = 0;
				vo3.y = 0;
				vo3.z = 0;

			VkExtent3D				ve3;
				ve3.width = texWidth;
				ve3.height = texHeight;
				ve3.depth = 1;

			VkImageCopy				vic;
				vic.srcSubresource = visl;
				vic.srcOffset = vo3;
				vic.dstSubresource = visl;
				vic.dstOffset = vo3;
				vic.extent = ve3;

			vkCmdCopyImage(TextureCommandBuffer,
				stagingImage, VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL,
				textureImage, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
				1, IN &vic);
		}
	// *******************************************************************************


	// *******************************************************************************
	// transition the texture buffer layout a second time:
	// *******************************************************************************
		{
			VkImageSubresourceRange			visr;
				visr.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
				visr.baseMipLevel = 0;
				visr.levelCount = 1;
				visr.baseArrayLayer = 0;
				visr.layerCount = 1;

			VkImageMemoryBarrier			vimb;
				vimb.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
				vimb.pNext = nullptr;
				vimb.oldLayout = VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL;
				vimb.newLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
				vimb.srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
				vimb.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
				vimb.image = textureImage;
				vimb.srcAccessMask = VK_ACCESS_TRANSFER_READ_BIT;
				vimb.dstAccessMask = VK_ACCESS_SHADER_READ_BIT | VK_ACCESS_INPUT_ATTACHMENT_READ_BIT;
				vimb.subresourceRange = visr;

			vkCmdPipelineBarrier(TextureCommandBuffer,
				VK_PIPELINE_STAGE_TRANSFER_BIT, VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT, 0,
				0, (VkMemoryBarrier *)nullptr,
				0, (VkBufferMemoryBarrier *)nullptr,
				1, IN &vimb);
		}
		// *******************************************************************************

		result = vkEndCommandBuffer( TextureCommandBuffer );
		REPORT("Init07TextureBuffer -- vkEndCommandBuffer");

		VkSubmitInfo				vsi;
			vsi.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
			vsi.pNext = nullptr;
			vsi.commandBufferCount = 1;
			vsi.pCommandBuffers = &TextureCommandBuffer;
			vsi.waitSemaphoreCount = 0;
			vsi.pWaitSemaphores = (VkSemaphore *)nullptr;
			vsi.signalSemaphoreCount = 0;
			vsi.pSignalSemaphores = (VkSemaphore *)nullptr;
			vsi.pWaitDstStageMask = (VkPipelineStageFlags *)nullptr;

		result = vkQueueSubmit( Queue, 1, IN &vsi, VK_NULL_HANDLE );
		if (Verbose)		REPORT("vkQueueSubmit");

		result = vkQueueWaitIdle( Queue );
		if (Verbose)		REPORT("vkQueueWaitIdle");


		// create an image view for the texture image:

		VkImageSubresourceRange			visr;
			visr.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
			visr.baseMipLevel = 0;
			visr.levelCount = 1;
			visr.baseArrayLayer = 0;
			visr.layerCount = 1;

		VkImageViewCreateInfo			vivci;
			vivci.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
			vivci.pNext = nullptr;
			vivci.flags = 0;
			vivci.image = textureImage;
			vivci.viewType = VK_IMAGE_VIEW_TYPE_2D;
			vivci.format = VK_FORMAT_R8G8B8A8_UNORM;
			vivci.components.r = VK_COMPONENT_SWIZZLE_R;
			vivci.components.g = VK_COMPONENT_SWIZZLE_G;
			vivci.components.b = VK_COMPONENT_SWIZZLE_B;
			vivci.components.a = VK_COMPONENT_SWIZZLE_A;
			vivci.subresourceRange = visr;

		result = vkCreateImageView(LogicalDevice, IN &vivci, PALLOCATOR, OUT &pMyTexture->texImageView);
		REPORT("vkCreateImageView");

		return result;
	}



	// ***************************************
	// CREATE A TEXTURE IMAGE FROM A BMP FILE:
	// ***************************************

	VkResult
	Init07TextureBufferAndFillFromBmpFile( IN std::string filename, OUT MyTexture * pMyTexture )
	{
		HERE_I_AM( "Init07TextureBufferAndFillFromBmpFile" );

		VkResult result = VK_SUCCESS;

		const int birgb = { 0 };

		FILE * fp;
	#ifdef _WIN32
		errno_t err = fopen_s( &fp, filename.c_str( ), "rb" );
		if( err != 0 )
		{
			fprintf( stderr, "Cannot open BMP file '%s'\n", filename.c_str( ) );
			return VK_FAILURE;
		}
	#else
		fp = fopen( filename.c_str( ), "rb" );
		if( fp == NULL )
		{
			fprintf( stderr, "Cannot open BMP file '%s'\n", filename.c_str( ) );
			return VK_FAILURE;
		}
	#endif

		FileHeader.bfType = ReadShort( fp );

		// if bfType is not 0x4d42, the file is not a bmp:

		if( FileHeader.bfType != 0x4d42 )
		{
			fprintf( FpDebug, "Wrong type of file: 0x%0x\n", FileHeader.bfType );
			fclose( fp );
			return VK_FAILURE;
		}


		FileHeader.bfSize = ReadInt( fp );
		FileHeader.bfReserved1 = ReadShort( fp );
		FileHeader.bfReserved2 = ReadShort( fp );
		FileHeader.bfOffBits = ReadInt( fp );

		InfoHeader.biSize = ReadInt( fp );
		InfoHeader.biWidth = ReadInt( fp );
		InfoHeader.biHeight = ReadInt( fp );

		uint32_t texWidth  = InfoHeader.biWidth;
		uint32_t texHeight = InfoHeader.biHeight;

		InfoHeader.biPlanes = ReadShort( fp );
		InfoHeader.biBitCount = ReadShort( fp );
		InfoHeader.biCompression = ReadInt( fp );
		InfoHeader.biSizeImage = ReadInt( fp );
		InfoHeader.biXPelsPerMeter = ReadInt( fp );
		InfoHeader.biYPelsPerMeter = ReadInt( fp );
		InfoHeader.biClrUsed = ReadInt( fp );
		InfoHeader.biClrImportant = ReadInt( fp );

		fprintf( FpDebug, "Image size found: %d x %d\n", texWidth, texHeight );

		unsigned char * texture = new unsigned char[ 4 * texWidth * texHeight ];

		// extra padding bytes:

		int numExtra =  4*(( (3*InfoHeader.biWidth)+3)/4) - 3*InfoHeader.biWidth;

		// we do not support compression:

		if( InfoHeader.biCompression != birgb )
		{
			fprintf( FpDebug, "Wrong type of image compression: %d\n", InfoHeader.biCompression );
			fclose( fp );
			return VK_FAILURE;
		}

		rewind( fp );
		fseek( fp, 14+40, SEEK_SET );

		if( InfoHeader.biBitCount == 24 )
		{
			unsigned char *tp = texture;
			for( unsigned int t = 0; t < texHeight; t++ )
			{
				for( unsigned int s = 0; s < texWidth; s++, tp += 4 )
				{
					*(tp+3) = 255;			// a
					*(tp+2) = fgetc( fp );		// b
					*(tp+1) = fgetc( fp );		// g
					*(tp+0) = fgetc( fp );		// r
				}

				for( int e = 0; e < numExtra; e++ )
				{
					fgetc( fp );
				}
			}
		}
		fclose( fp );

		pMyTexture->width = texWidth;
		pMyTexture->height = texHeight;
		pMyTexture->pixels = texture;

		result = Init07TextureBuffer( INOUT pMyTexture );
		REPORT( "Init07TextureBuffer" );

		return result;
	}



	int
	ReadInt( FILE *fp )
	{
		unsigned char b3, b2, b1, b0;
		b0 = fgetc( fp );
		b1 = fgetc( fp );
		b2 = fgetc( fp );
		b3 = fgetc( fp );
		return ( b3 << 24 )  |  ( b2 << 16 )  |  ( b1 << 8 )  |  b0;
	}


	short
	ReadShort( FILE *fp )
	{
		unsigned char b1, b0;
		b0 = fgetc( fp );
		b1 = fgetc( fp );
		return ( b1 << 8 )  |  b0;
	}


	
	// ************************
	// CREATING THE SWAP CHAIN:
	// ************************

	VkResult
	Init08Swapchain( )
	{
		HERE_I_AM( "Init08Swapchain" );

		VkResult result = VK_SUCCESS;

		VkSurfaceCapabilitiesKHR		vsc;

		vkGetPhysicalDeviceSurfaceCapabilitiesKHR( PhysicalDevice, Surface, OUT &vsc );
	#ifdef ELEMENTS
	vsc.uint32_t                         minImageCount;
	vsc.uint32_t                         maxImageCount;
	vsc.VkExtent2D                       currentExtent;
	vsc.VkExtent2D                       minImageExtent;
	vsc.VkExtent2D                       maxImageExtent;
	vsc.uint32_t                         maxImageArrayLayers;
	vsc.VkSurfaceTransformFlagsKHR       supportedTransforms;
	vsc.VkSurfaceTransformFlagBitsKHR    currentTransform;
	vsc.VkCompositeAlphaFlagsKHR         supportedCompositeAlpha;
	vsc.VkImageUsageFlags                supportedUsageFlags;
	#endif

		VkExtent2D surfaceRes = vsc.currentExtent;
		fprintf( FpDebug, "\nSurface resolution for swap chain = %d, %d\n",
			surfaceRes.width, surfaceRes.height );

	#ifdef ELEMENTS
	surfaceRes.width
	surfaceRes.height;
	#endif

		VkSwapchainCreateInfoKHR		vscci;
			vscci.sType = VK_STRUCTURE_TYPE_SWAPCHAIN_CREATE_INFO_KHR;
			vscci.pNext = nullptr;
			vscci.flags = 0;
			vscci.surface = Surface;			// ???
			vscci.minImageCount = 2;			// double buffering
			vscci.imageFormat = VK_FORMAT_B8G8R8A8_UNORM;
			vscci.imageColorSpace = VK_COLORSPACE_SRGB_NONLINEAR_KHR;
			vscci.imageExtent.width = surfaceRes.width;
			vscci.imageExtent.height = surfaceRes.height;
			vscci.imageUsage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT;
			vscci.preTransform = VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR;
			vscci.compositeAlpha = VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR;
			vscci.imageArrayLayers = 1;
			vscci.imageSharingMode = VK_SHARING_MODE_EXCLUSIVE;
			vscci.queueFamilyIndexCount = 0;
			vscci.pQueueFamilyIndices = (const uint32_t *)nullptr;
			vscci.presentMode = VK_PRESENT_MODE_MAILBOX_KHR;
			//vscci.oldSwapchain = (VkSwapchainKHR *)nullptr;	// what if there is no old swapchain? ???
			vscci.oldSwapchain = VK_NULL_HANDLE;			// what if there is no old swapchain? ???
			vscci.clipped = true;
		
		result = vkCreateSwapchainKHR( LogicalDevice, IN &vscci, PALLOCATOR, OUT &SwapChain );
		REPORT( "vkCreateSwapchainKHR" );


		uint32_t imageCount;
		result = vkGetSwapchainImagesKHR( LogicalDevice, IN SwapChain, OUT &imageCount, (VkImage *)nullptr );	// 0 
		REPORT( "vkGetSwapchainImagesKHR - 0" );
		if( imageCount != 2 )
		{
			fprintf( FpDebug, "imageCount return from vkGetSwapchainImages = %d; should have been 2\n", imageCount );
			return result;
		}

		PresentImages = new VkImage[ imageCount ];
		result = vkGetSwapchainImagesKHR( LogicalDevice, SwapChain, OUT &imageCount, PresentImages );	// 0 
		REPORT( "vkGetSwapchainImagesKHR - 1" );


		// present views for the double-buffering:

		PresentImageViews = new VkImageView[ imageCount ];	// better be 2
		for( unsigned int i = 0; i < imageCount; i++ )
		{
			VkImageViewCreateInfo		vivci;
			vivci.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
			vivci.pNext = nullptr;
			vivci.flags = 0;
			vivci.viewType = VK_IMAGE_VIEW_TYPE_2D;
			vivci.format = VK_FORMAT_B8G8R8A8_UNORM;
			vivci.components.r = VK_COMPONENT_SWIZZLE_R;
			vivci.components.g = VK_COMPONENT_SWIZZLE_G;
			vivci.components.b = VK_COMPONENT_SWIZZLE_B;
			vivci.components.a = VK_COMPONENT_SWIZZLE_A;
			vivci.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
			vivci.subresourceRange.baseMipLevel = 0;
			vivci.subresourceRange.levelCount = 1;
			vivci.subresourceRange.baseArrayLayer = 0;
			vivci.subresourceRange.layerCount = 1;
			vivci.image = PresentImages[i];

			result = vkCreateImageView( LogicalDevice, IN &vivci, PALLOCATOR, OUT &PresentImageViews[i] );
			REPORT( "vkCreateImageView" );
		}

		return result;
	}


	
	// *************************************
	// CREATING THE DEPTH AND STENCIL IMAGE:
	// *************************************

	VkResult
	Init09DepthStencilImage( )
	{
		HERE_I_AM( "Init09DepthStencilImage" );
		
		VkResult result = VK_SUCCESS;
		
		VkExtent3D ve3d = { Width, Height, 1 };

		VkImageCreateInfo			vici;
			vici.sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO;
			vici.pNext = nullptr;
			vici.flags = 0;
			vici.imageType = VK_IMAGE_TYPE_2D;
			vici.format = VK_FORMAT_D32_SFLOAT_S8_UINT;
			vici.extent = ve3d;
			vici.mipLevels = 1;
			vici.arrayLayers = 1;
		vici.samples = VK_SAMPLE_COUNT_1_BIT;
		vici.tiling = VK_IMAGE_TILING_OPTIMAL;
		vici.usage = VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT;
		vici.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
		vici.queueFamilyIndexCount = 0;
		vici.pQueueFamilyIndices = (const uint32_t *)nullptr;
		vici.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;

	result = vkCreateImage( LogicalDevice, IN &vici, PALLOCATOR, &DepthImage );
	REPORT( "vkCreateImage" );

	VkMemoryRequirements			vmr;
	vkGetImageMemoryRequirements( LogicalDevice, IN DepthImage, OUT &vmr );

	VkMemoryAllocateInfo			vmai;
		vmai.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
		vmai.pNext = nullptr;
		vmai.allocationSize = vmr.size;
		vmai.memoryTypeIndex = FindMemoryThatIsDeviceLocal( );

	VkDeviceMemory imageMemory;
	result = vkAllocateMemory( LogicalDevice, IN &vmai, PALLOCATOR, OUT &imageMemory );
	REPORT( "vkAllocateMemory" );

	result = vkBindImageMemory( LogicalDevice, DepthImage, imageMemory, 0 );	// 0 is the offset
	REPORT( "vkBindImageMemory" );

	VkImageViewCreateInfo			vivci;
		vivci.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
		vivci.pNext = nullptr;
		vivci.flags = 0;
		vivci.image = DepthImage;
		vivci.viewType = VK_IMAGE_VIEW_TYPE_2D;
		vivci.format = vici.format;
		vivci.components.r = VK_COMPONENT_SWIZZLE_IDENTITY;
		vivci.components.g = VK_COMPONENT_SWIZZLE_IDENTITY;
		vivci.components.b = VK_COMPONENT_SWIZZLE_IDENTITY;
		vivci.components.a = VK_COMPONENT_SWIZZLE_IDENTITY;
		vivci.subresourceRange.aspectMask = VK_IMAGE_ASPECT_DEPTH_BIT;
		vivci.subresourceRange.baseMipLevel = 0;
		vivci.subresourceRange.levelCount = 1;
		vivci.subresourceRange.baseArrayLayer = 0;
		vivci.subresourceRange.layerCount = 1;

		result = vkCreateImageView( LogicalDevice, IN &vivci, PALLOCATOR, OUT &DepthImageView );
		REPORT("vkCreateImageView");
		return result;
}




// **************************
// CREATING THE RENDERPASSES:
// **************************

VkResult
Init10RenderPasses( )
{
	HERE_I_AM( "Init10RenderPasses" );

	VkResult result = VK_SUCCESS;

	// need 2 - one for the color and one for the depth/stencil
	VkAttachmentDescription				vad[2];
		vad[0].format = VK_FORMAT_B8G8R8A8_UNORM;;
		vad[0].samples = VK_SAMPLE_COUNT_1_BIT;
		vad[0].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
		vad[0].storeOp = VK_ATTACHMENT_STORE_OP_STORE;
		vad[0].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
		vad[0].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
		vad[0].initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
		vad[0].finalLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
		vad[0].flags = 0;
		//vad[0].flags = VK_ATTACHMENT_DESCRIPTION_MAT_ALIAS_BIT;

		vad[1].format = VK_FORMAT_D32_SFLOAT_S8_UINT;
		vad[1].samples = VK_SAMPLE_COUNT_1_BIT;
		vad[1].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
		vad[1].storeOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
		vad[1].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
		vad[1].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
		vad[1].initialLayout = VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;
		vad[1].finalLayout = VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;
		vad[1].flags = 0;
		//vad[1].flags = VK_ATTACHMENT_DESCRIPTION_MAT_ALIAS_BIT;

	VkAttachmentReference				colorReference;
		colorReference.attachment = 0;
		colorReference.layout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;

	VkAttachmentReference				depthReference;
		depthReference.attachment = 1;
		depthReference.layout = VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;

	VkSubpassDescription				vsd;
		vsd.flags = 0;
		vsd.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
		vsd.inputAttachmentCount = 0;
		vsd.pInputAttachments = (VkAttachmentReference *)nullptr;
		vsd.colorAttachmentCount = 1;
		vsd.pColorAttachments = &colorReference;
		vsd.pResolveAttachments = (VkAttachmentReference *)nullptr;
		vsd.pDepthStencilAttachment = &depthReference;
		vsd.preserveAttachmentCount = 0;
		vsd.pPreserveAttachments = (uint32_t *)nullptr;

	VkRenderPassCreateInfo				vrpci;
		vrpci.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO;
		vrpci.pNext = nullptr;
		vrpci.flags = 0;
		vrpci.attachmentCount = 2;		// color and depth/stencil
		vrpci.pAttachments = vad;
		vrpci.subpassCount = 1;
		vrpci.pSubpasses = &vsd;
		vrpci.dependencyCount = 0;			// ********************* ERROR ?
		vrpci.pDependencies = (VkSubpassDependency *)nullptr;

	result = vkCreateRenderPass( LogicalDevice, IN &vrpci, PALLOCATOR, OUT &RenderPass );
	REPORT( "vkCreateRenderPass" );
		//vgpci.renderPass = RenderPass;

	return result;
}


// ************************
// CREATE THE FRAMEBUFFERS:
// ************************

VkResult
Init11Framebuffers( )
{
	HERE_I_AM( "Init11Framebuffers" );

	VkResult result = VK_SUCCESS;
	VkImageView frameBufferAttachments[2];		// color + depth/stencil

	VkFramebufferCreateInfo				vfbci;
		vfbci.sType = VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO;
		vfbci.pNext = nullptr;
		vfbci.flags = 0;
		vfbci.renderPass = RenderPass;
		vfbci.attachmentCount = 2;
		vfbci.pAttachments =  frameBufferAttachments;
		vfbci.width = Width;
		vfbci.height = Height;
		vfbci.layers = 1;

	frameBufferAttachments[0] = PresentImageViews[0];
	frameBufferAttachments[1] = DepthImageView;
	result = vkCreateFramebuffer( LogicalDevice, IN &vfbci, PALLOCATOR, OUT &Framebuffers[0] );
	REPORT( "vkCreateFrameBuffer - 0" );

	frameBufferAttachments[0] = PresentImageViews[1];
	frameBufferAttachments[1] = DepthImageView;
	result = vkCreateFramebuffer( LogicalDevice, IN &vfbci, PALLOCATOR, OUT &Framebuffers[1] );
	REPORT( "vkCreateFrameBuffer - 1" );

	return result;
}



// *******************************
// CREATE THE COMMAND BUFFER POOL:
// *******************************

// Note: need a separate command buffer for each thread!

VkResult
Init06CommandPools( )
{
	HERE_I_AM( "Init06CommandPools" );

	VkResult result = VK_SUCCESS;

	{
		VkCommandPoolCreateInfo				vcpci;
			vcpci.sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO;
			vcpci.pNext = nullptr;
			vcpci.flags =     VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT
					| VK_COMMAND_POOL_CREATE_TRANSIENT_BIT;
			vcpci.queueFamilyIndex = FindQueueFamilyThatDoesGraphics( );

		result = vkCreateCommandPool( LogicalDevice, IN &vcpci, PALLOCATOR, OUT &GraphicsCommandPool );
		REPORT( "vkCreateCommandPool -- Graphics" );
	}

	{
		VkCommandPoolCreateInfo				vcpci;
			vcpci.sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO;
			vcpci.pNext = nullptr;
			vcpci.flags =     VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT
					| VK_COMMAND_POOL_CREATE_TRANSIENT_BIT;
			vcpci.queueFamilyIndex = FindQueueFamilyThatDoesTransfer( );

		result = vkCreateCommandPool( LogicalDevice, IN &vcpci, PALLOCATOR, OUT &TransferCommandPool );
		REPORT( "vkCreateCommandPool -- Transfer" );
	}

	return result;
}



// ***************************
// CREATE THE COMMAND BUFFERS:
// ***************************

VkResult
Init06CommandBuffers( )
{
	HERE_I_AM( "Init06CommandBuffers" );

	VkResult result = VK_SUCCESS;

	// allocate 2 command buffers for the double-buffered rendering:

	{
		VkCommandBufferAllocateInfo			vcbai;
			vcbai.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
			vcbai.pNext = nullptr;
			vcbai.commandPool = GraphicsCommandPool;
			vcbai.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY;
			vcbai.commandBufferCount = 2;		// 2, because of double-buffering

		result = vkAllocateCommandBuffers( LogicalDevice, IN &vcbai, OUT &CommandBuffers[0] );
		REPORT( "vkAllocateCommandBuffers - 1" );
	}


	// allocate 1 command buffer for the transfering pixels from a staging buffer to a texture buffer:

	{
		VkCommandBufferAllocateInfo			vcbai;
			vcbai.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
			vcbai.pNext = nullptr;
			vcbai.commandPool = TransferCommandPool;
			vcbai.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY;
			vcbai.commandBufferCount = 1;

		result = vkAllocateCommandBuffers( LogicalDevice, IN &vcbai, OUT &TextureCommandBuffer );
		REPORT( "vkAllocateCommandBuffers - 2" );
	}

	return result;
}



// ****************************************
// READ A SPIR-V SHADER MODULE FROM A FILE:
// ****************************************

VkResult
Init12SpirvShader( std::string filename, VkShaderModule * pShaderModule )
{
	HERE_I_AM( "Init12SpirvShader" );

	FILE *fp;
	(void) fopen_s( &fp, filename.c_str(), "rb");
	if( fp == NULL )
	{
		fprintf( FpDebug, "Cannot open shader file '%s'\n", filename.c_str( ) );
		return VK_SHOULD_EXIT;
	}
	uint32_t magic;
	fread( &magic, 4, 1, fp );
	if( magic != SPIRV_MAGIC )
	{
		fprintf( FpDebug, "Magic number for spir-v file '%s is 0x%08x -- should be 0x%08x\n", filename.c_str( ), magic, SPIRV_MAGIC );
		return VK_SHOULD_EXIT;
	}

	fseek( fp, 0L, SEEK_END );
	int size = ftell( fp );
	rewind( fp );
	unsigned char *code = new unsigned char [size];
	fread( code, size, 1, fp );
	fclose( fp );

	VkShaderModuleCreateInfo		vsmci;
		vsmci.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
		vsmci.pNext = nullptr;
		vsmci.flags = 0;
		vsmci.codeSize = size;
		vsmci.pCode = (uint32_t *)code;

	VkResult result = vkCreateShaderModule( LogicalDevice, &vsmci, PALLOCATOR, pShaderModule );
	REPORT( "vkCreateShaderModule" );
	fprintf(FpDebug, "Shader Module '%s' successfully loaded\n", filename.c_str());
	delete [ ] code;
	return result;
}



// *****************************
// CREATE A DESCRIPTOR SET POOL:
// *****************************

VkResult
Init13DescriptorSetPool()
{
	HERE_I_AM( "Init13DescriptorSetPool" );

	VkResult result = VK_SUCCESS;

	VkDescriptorPoolSize				vdps[4];
		vdps[0].type = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
		vdps[0].descriptorCount = 1;
		vdps[1].type = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
		vdps[1].descriptorCount = 1;
		vdps[2].type = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
		vdps[2].descriptorCount = 1;
		vdps[3].type = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
		vdps[3].descriptorCount = 1;
#ifdef CHOICES
VkDescriptorType:
VK_DESCRIPTOR_TYPE_SAMPLER
VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE
VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER
VK_DESCRIPTOR_TYPE_STORAGE_IMAGE
VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER
VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER
VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER
VK_DESCRIPTOR_TYPE_STORAGE_BUFFER
VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC
VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC
VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT
#endif

	VkDescriptorPoolCreateInfo			vdpci;
		vdpci.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
		vdpci.pNext = nullptr;
		vdpci.flags = 0;
#ifdef CHOICES
0
VK_DESCRIPTOR_POOL_CREATE_FREE_DESCRIPTOR_SET_BIT
#endif
		vdpci.maxSets = 4;
		vdpci.poolSizeCount = 4;
		vdpci.pPoolSizes = &vdps[0];

	result = vkCreateDescriptorPool(LogicalDevice, IN &vdpci, PALLOCATOR, OUT &DescriptorPool);
	REPORT("vkCreateDescriptorPool");

	return result;
}



// *********************************
// CREATING A DESCRIPTOR SET LAYOUT:
// *********************************

// A DS is a set of resources bound into the pipeline as a group.
// Multiple sets can be bound at one time.
// Each set has a layout, which describes the order and type of data in that set.
// The pipeline layout consists of multiple DS layouts.

#ifdef CODE_THAT_THIS_WILL_BE_DESCRIBING
layout( std140, set = 0, binding = 0 ) uniform matrixBuf
{
        mat4 uModelMatrix;
        mat4 uViewMatrix;
        mat4 uProjectionMatrix;
	mat3 uNormalMatrix;
} Matrices;

layout( std140, set = 1, binding = 0 ) uniform lightBVuf
{
	vec4 uLightPos;
} Light;

layout( std140, set = 2, binding = 0 ) uniform miscBuf
{
        float uTime;
	int   uMode;
} Misc;

layout ( set = 3, binding = 0 ) uniform sampler2D uSampler;
#endif



VkResult
Init13DescriptorSetLayouts( )
{
	HERE_I_AM( "Init13DescriptorSetLayouts" );

	VkResult result = VK_SUCCESS;

	// arrays of >= 1 layouts:
	//DS #0:
	VkDescriptorSetLayoutBinding		MatrixSet[1];
		MatrixSet[0].binding            = 0;
		MatrixSet[0].descriptorType     = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
		MatrixSet[0].descriptorCount    = 1;
		MatrixSet[0].stageFlags         = VK_SHADER_STAGE_VERTEX_BIT;
		MatrixSet[0].pImmutableSamplers = (VkSampler *)nullptr;

	// DS #1:
	VkDescriptorSetLayoutBinding		LightSet[1];
		LightSet[0].binding            = 0;
		LightSet[0].descriptorType     = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
		LightSet[0].descriptorCount    = 1;
		LightSet[0].stageFlags         = VK_SHADER_STAGE_VERTEX_BIT | VK_SHADER_STAGE_FRAGMENT_BIT;
		LightSet[0].pImmutableSamplers = (VkSampler *)nullptr;

	//DS #2:
	VkDescriptorSetLayoutBinding		MiscSet[1];
		MiscSet[0].binding            = 0;
		MiscSet[0].descriptorType     = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
		MiscSet[0].descriptorCount    = 1;
		MiscSet[0].stageFlags         = VK_SHADER_STAGE_VERTEX_BIT | VK_SHADER_STAGE_FRAGMENT_BIT;
		MiscSet[0].pImmutableSamplers = (VkSampler *)nullptr;

	// DS #3:
	VkDescriptorSetLayoutBinding		TexSamplerSet[1];
		TexSamplerSet[0].binding            = 0;
		TexSamplerSet[0].descriptorType     = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
							// uniform sampler2D uSampler
							// vec4 rgba = texture( uSampler, vST );
		TexSamplerSet[0].descriptorCount    = 1;
		TexSamplerSet[0].stageFlags         = VK_SHADER_STAGE_FRAGMENT_BIT;
		TexSamplerSet[0].pImmutableSamplers = (VkSampler *)nullptr;

#ifdef CHOICES
VkDescriptorType:
VK_DESCRIPTOR_TYPE_SAMPLER
VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE
VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER
VK_DESCRIPTOR_TYPE_STORAGE_IMAGE
VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER
VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER
VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER
VK_DESCRIPTOR_TYPE_STORAGE_BUFFER
VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC
VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC
VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT
#endif

	VkDescriptorSetLayoutCreateInfo			vdslc0;
		vdslc0.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;
		vdslc0.pNext = nullptr;
		vdslc0.flags = 0;
		vdslc0.bindingCount = 1;
		vdslc0.pBindings = &MatrixSet[0];

	VkDescriptorSetLayoutCreateInfo			vdslc1;
		vdslc1.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;
		vdslc1.pNext = nullptr;
		vdslc1.flags = 0;
		vdslc1.bindingCount = 1;
		vdslc1.pBindings = &LightSet[0];

	VkDescriptorSetLayoutCreateInfo			vdslc2;
		vdslc2.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;
		vdslc2.pNext = nullptr;
		vdslc2.flags = 0;
		vdslc2.bindingCount = 1;
		vdslc2.pBindings = &MiscSet[0];

	VkDescriptorSetLayoutCreateInfo			vdslc3;
		vdslc3.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;
		vdslc3.pNext = nullptr;
		vdslc3.flags = 0;
		vdslc3.bindingCount = 1;
		vdslc3.pBindings = &TexSamplerSet[0];

	result = vkCreateDescriptorSetLayout( LogicalDevice, &vdslc0, PALLOCATOR, OUT &DescriptorSetLayouts[0] );
	REPORT( "vkCreateDescriptorSetLayout - 0" );

	result = vkCreateDescriptorSetLayout( LogicalDevice, &vdslc1, PALLOCATOR, OUT &DescriptorSetLayouts[1] );
	REPORT( "vkCreateDescriptorSetLayout - 1" );

	result = vkCreateDescriptorSetLayout( LogicalDevice, &vdslc2, PALLOCATOR, OUT &DescriptorSetLayouts[2] );
	REPORT( "vkCreateDescriptorSetLayout - 2" );

	result = vkCreateDescriptorSetLayout( LogicalDevice, &vdslc3, PALLOCATOR, OUT &DescriptorSetLayouts[3] );
	REPORT( "vkCreateDescriptorSetLayout - 3" );

	return result;
}




// ***********************************
// ALLOCATE AND WRITE DESCRIPTOR SETS:
// ***********************************

VkResult
Init13DescriptorSets( )
{
	HERE_I_AM( "Init13DescriptorSets" );

	VkResult result = VK_SUCCESS;

	VkDescriptorSetAllocateInfo			vdsai;
		vdsai.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
		vdsai.pNext = nullptr;
		vdsai.descriptorPool = DescriptorPool;
		vdsai.descriptorSetCount = 4;
		vdsai.pSetLayouts = DescriptorSetLayouts;


	result = vkAllocateDescriptorSets( LogicalDevice, IN &vdsai, OUT &DescriptorSets[0] );
	REPORT( "vkAllocateDescriptorSets" );

	VkDescriptorBufferInfo				vdbi0;
		vdbi0.buffer = MyMatrixUniformBuffer.buffer;
		vdbi0.offset = 0;	// bytes
		vdbi0.range = sizeof(Matrices);

	VkDescriptorBufferInfo				vdbi1;
		vdbi1.buffer = MyLightUniformBuffer.buffer;
		vdbi1.offset = 0;	// bytes
		vdbi1.range = sizeof(Light);

	VkDescriptorBufferInfo				vdbi2;
		vdbi2.buffer = MyMiscUniformBuffer.buffer;
		vdbi2.offset = 0;	// bytes
		vdbi2.range = sizeof(Misc);

	VkDescriptorImageInfo				vdii0;
		vdii0.sampler   = MyPuppyTexture.texSampler;
		vdii0.imageView = MyPuppyTexture.texImageView;
		vdii0.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;

	VkWriteDescriptorSet				vwds0;
		// ds 0:
		vwds0.sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
		vwds0.pNext = nullptr;
		vwds0.dstSet = DescriptorSets[0];
		vwds0.dstBinding = 0;
		vwds0.dstArrayElement = 0;
		vwds0.descriptorCount = 1;
		vwds0.descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
		vwds0.pBufferInfo = &vdbi0;
		vwds0.pImageInfo = (VkDescriptorImageInfo *)nullptr;
		vwds0.pTexelBufferView = (VkBufferView *)nullptr;

		// ds 1:
	VkWriteDescriptorSet				vwds1;
		vwds1.sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
		vwds1.pNext = nullptr;
		vwds1.dstSet = DescriptorSets[1];
		vwds1.dstBinding = 0;
		vwds1.dstArrayElement = 0;
		vwds1.descriptorCount = 1;
		vwds1.descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
		vwds1.pBufferInfo = &vdbi1;
		vwds1.pImageInfo = (VkDescriptorImageInfo *)nullptr;
		vwds1.pTexelBufferView = (VkBufferView *)nullptr;

	VkWriteDescriptorSet				vwds2;
		// ds 2:
		vwds2.sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
		vwds2.pNext = nullptr;
		vwds2.dstSet = DescriptorSets[2];
		vwds2.dstBinding = 0;
		vwds2.dstArrayElement = 0;
		vwds2.descriptorCount = 1;
		vwds2.descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
		vwds2.pBufferInfo = &vdbi2;
		vwds2.pImageInfo = (VkDescriptorImageInfo *)nullptr;
		vwds2.pTexelBufferView = (VkBufferView *)nullptr;

		// ds 3:
	VkWriteDescriptorSet				vwds3;
		vwds3.sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
		vwds3.pNext = nullptr;
		vwds3.dstSet = DescriptorSets[3];
		vwds3.dstBinding = 0;
		vwds3.dstArrayElement = 0;
		vwds3.descriptorCount = 1;
		vwds3.descriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
		vwds3.pBufferInfo = (VkDescriptorBufferInfo *)nullptr;
		vwds3.pImageInfo = &vdii0;
		vwds3.pTexelBufferView = (VkBufferView *)nullptr;

	uint32_t copyCount = 0;

	// this could have been done with one call and an array of VkWriteDescriptorSets:

	vkUpdateDescriptorSets( LogicalDevice, 1, IN &vwds0, IN copyCount, (VkCopyDescriptorSet *)nullptr );
	vkUpdateDescriptorSets( LogicalDevice, 1, IN &vwds1, IN copyCount, (VkCopyDescriptorSet *)nullptr );
	vkUpdateDescriptorSets( LogicalDevice, 1, IN &vwds2, IN copyCount, (VkCopyDescriptorSet *)nullptr );
	vkUpdateDescriptorSets( LogicalDevice, 1, IN &vwds3, IN copyCount, (VkCopyDescriptorSet *)nullptr );

	return VK_SUCCESS;
}

// *************************
// CREATE A PIPELINE LAYOUT:
// *************************

VkResult
Init14GraphicsPipelineLayout( )
{
	HERE_I_AM( "Init14GraphicsPipelineLayout" );

	VkResult result = VK_SUCCESS;

	VkPipelineLayoutCreateInfo			vplci;
		vplci.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
		vplci.pNext = nullptr;
		vplci.flags = 0;
		vplci.setLayoutCount = 4;
		vplci.pSetLayouts = &DescriptorSetLayouts[0];
		vplci.pushConstantRangeCount = 0;
		vplci.pPushConstantRanges = (VkPushConstantRange *)nullptr;

	result = vkCreatePipelineLayout( LogicalDevice, IN &vplci, PALLOCATOR, OUT &GraphicsPipelineLayout );
	REPORT( "vkCreatePipelineLayout" );

	return result;
}



// *****************************
// CREATING A GRAPHICS PIPELINE:
// *****************************


#ifdef COMMENT
struct matBuf
{
        glm::mat4 uModelMatrix;
        glm::mat4 uViewMatrix;
        glm::mat4 uProjectionMatrix;
} Matrices;

struct lightBuf
{
	glm::vec4 uLightPos;
} Light;

struct miscBuf
{
	float uTime;
	int   uMode;
} Misc;

struct vertex
{
	glm::vec3	position;
	glm::vec3	normal;
	glm::vec3	color;
	glm::vec2	texCoord;
} Vertices;
#endif


VkResult
Init14GraphicsVertexFragmentPipeline( VkShaderModule vertexShader, VkShaderModule fragmentShader, VkPrimitiveTopology topology, OUT VkPipeline *pGraphicsPipeline  )
{
#ifdef ASSUMPTIONS
		vvibd[0].inputRate = VK_VERTEX_INPUT_RATE_VERTEX;
		vprsci.depthClampEnable = VK_FALSE;
		vprsci.rasterizerDiscardEnable = VK_FALSE;
		vprsci.polygonMode = VK_POLYGON_MODE_FILL;
		vprsci.cullMode = VK_CULL_MODE_NONE;	// best to do this because of the projectionMatrix[1][1] *= -1.;
		vprsci.frontFace = VK_FRONT_FACE_COUNTER_CLOCKWISE;
		vpmsci.rasterizationSamples = VK_SAMPLE_COUNT_ONE_BIT;
		vpcbas.blendEnable = VK_FALSE;
		vpcbsci.logicOpEnable = VK_FALSE;
	VkDynamicState					vds[ ] = { VK_DYNAMIC_STATE_VIEWPORT, VK_DYNAMIC_STATE_SCISSOR };
		vpdssci.depthTestEnable = VK_TRUE;
		vpdssci.depthWriteEnable = VK_TRUE;
		vpdssci.depthCompareOp = VK_COMPARE_OP_LESS;
#endif

		HERE_I_AM( "Init14GraphicsVertexFragmentPipeline" );

		VkResult result = VK_SUCCESS;

	VkPipelineLayoutCreateInfo				vplci;
		vplci.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
		vplci.pNext = nullptr;
		vplci.flags = 0;
		vplci.setLayoutCount = 4;
		vplci.pSetLayouts = DescriptorSetLayouts;
		vplci.pushConstantRangeCount = 0;
		vplci.pPushConstantRanges = (VkPushConstantRange *)nullptr;

	result = vkCreatePipelineLayout( LogicalDevice, IN &vplci, PALLOCATOR, OUT &GraphicsPipelineLayout );
	REPORT( "vkCreatePipelineLayout" );

	VkPipelineShaderStageCreateInfo				vpssci[2];
		vpssci[0].sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
		vpssci[0].pNext = nullptr;
		vpssci[0].flags = 0;
		vpssci[0].stage = VK_SHADER_STAGE_VERTEX_BIT;
#ifdef BITS
VK_SHADER_STAGE_VERTEX_BIT
VK_SHADER_STAGE_TESSELLATION_CONTROL_BIT
VK_SHADER_STAGE_TESSELLATION_EVALUATION_BIT
VK_SHADER_STAGE_GEOMETRY_BIT
VK_SHADER_STAGE_FRAGMENT_BIT
VK_SHADER_STAGE_COMPUTE_BIT
VK_SHADER_STAGE_ALL_GRAPHICS
VK_SHADER_STAGE_ALL
#endif
		vpssci[0].module = vertexShader;
		vpssci[0].pName = "main";
		vpssci[0].pSpecializationInfo = (VkSpecializationInfo *)nullptr;

		vpssci[1].sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
		vpssci[1].pNext = nullptr;
		vpssci[1].flags = 0;
		vpssci[1].stage = VK_SHADER_STAGE_FRAGMENT_BIT;
		vpssci[1].module = fragmentShader;
		vpssci[1].pName = "main";
		vpssci[1].pSpecializationInfo = (VkSpecializationInfo *)nullptr;

	VkVertexInputBindingDescription			vvibd[1];	// an array containing one of these per buffer being used
		vvibd[0].binding = 0;		// which binding # this is
		vvibd[0].stride = sizeof( struct vertex );		// bytes between successive 
		vvibd[0].inputRate = VK_VERTEX_INPUT_RATE_VERTEX;
#ifdef CHOICES
VK_VERTEX_INPUT_RATE_VERTEX
VK_VERTEX_INPUT_RATE_INSTANCE
#endif

#ifdef COMMENT
struct vertex
{
	glm::vec3	position;
	glm::vec3	normal;
	glm::vec3	color;
	glm::vec2	texCoord;
} Vertices;
#endif
	VkVertexInputAttributeDescription		vviad[4];		// an array containing one of these per vertex attribute in all bindings
		// 4 = vertex, normal, color, texture coord
		vviad[0].location = 0;			// location in the layout decoration
		vviad[0].binding = 0;			// which binding description this is part of
		vviad[0].format = VK_FORMAT_VEC3;	// x, y, z
		vviad[0].offset = offsetof( struct vertex, position );			// 0
#ifdef EXTRAS_DEFINED_AT_THE_TOP
VK_FORMAT_VEC4 = VK_FORMAT_R32G32B32A32_SFLOAT
VK_FORMAT_XYZW = VK_FORMAT_R32G32B32A32_SFLOAT
VK_FORMAT_VEC3 = VK_FORMAT_R32G32B32_SFLOAT
VK_FORMAT_STP = VK_FORMAT_R32G32B32_SFLOAT
VK_FORMAT_XYZ = VK_FORMAT_R32G32B32_SFLOAT
VK_FORMAT_VEC2 = VK_FORMAT_R32G32_SFLOAT
VK_FORMAT_ST = VK_FORMAT_R32G32_SFLOAT
VK_FORMAT_XY = VK_FORMAT_R32G32_SFLOAT
VK_FORMAT_FLOAT = VK_FORMAT_R32_SFLOAT
VK_FORMAT_S = VK_FORMAT_R32_SFLOAT
VK_FORMAT_X = VK_FORMAT_R32_SFLOAT
#endif

		vviad[1].location = 1;
		vviad[1].binding = 0;
		vviad[1].format = VK_FORMAT_VEC3;	// nx, ny, nz
		vviad[1].offset = offsetof( struct vertex, normal );			// 12

		vviad[2].location = 2;
		vviad[2].binding = 0;
		vviad[2].format = VK_FORMAT_VEC3;	// r, g, b
		vviad[2].offset = offsetof( struct vertex, color );			// 24

		vviad[3].location = 3;
		vviad[3].binding = 0;
		vviad[3].format = VK_FORMAT_VEC2;	// s, t
		vviad[3].offset = offsetof( struct vertex, texCoord );			// 36


	VkPipelineVertexInputStateCreateInfo			vpvisci;			// used to describe the input vertex attributes
		vpvisci.sType = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO;
		vpvisci.pNext = nullptr;
		vpvisci.flags = 0;
		vpvisci.vertexBindingDescriptionCount = 1;
		vpvisci.pVertexBindingDescriptions = vvibd;
		vpvisci.vertexAttributeDescriptionCount = 4;
		vpvisci.pVertexAttributeDescriptions = vviad;

	VkPipelineInputAssemblyStateCreateInfo			vpiasci;
		vpiasci.sType = VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO;
		vpiasci.pNext = nullptr;
		vpiasci.flags = 0;
		vpiasci.topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST;;
#ifdef CHOICES
			VK_PRIMITIVE_TOPOLOGY_POINT_LIST
			VK_PRIMITIVE_TOPOLOGY_LINE_LIST
			VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST
			VK_PRIMITIVE_TOPOLOGY_LINE_STRIP
			VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP
			VK_PRIMITIVE_TOPOLOGY_TRIANGLE_FAN
			VK_PRIMITIVE_TOPOLOGY_LINE_LIST_WITH_ADJACENCY
			VK_PRIMITIVE_TOPOLOGY_LINE_STRIP_WITH_ADJACENCY
			VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST_WITH_ADJACENCY
			VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP_WITH_ADJACENCY
#endif
		vpiasci.primitiveRestartEnable = VK_FALSE;

	VkPipelineTessellationStateCreateInfo			vptsci;
		vptsci.sType = VK_STRUCTURE_TYPE_PIPELINE_TESSELLATION_STATE_CREATE_INFO;
		vptsci.pNext = nullptr;
		vptsci.flags = 0;
		vptsci.patchControlPoints = 0;		// number of patch control points

	// VkPipelineGeometryStateCreateInfo			vpgsci;
		// vptsci.sType = VK_STRUCTURE_TYPE_PIPELINE_TESSELLATION_STATE_CREATE_INFO;
		// vptsci.pNext = nullptr;
		// vptsci.flags = 0;

	VkViewport						vv;
		vv.x = 0;
		vv.y = 0;
		vv.width = (float)Width;
		vv.height = (float)Height;
		vv.minDepth = 0.0f;
		vv.maxDepth = 1.0f;

	// scissoring:
	VkRect2D						vr;
		vr.offset.x = 0;
		vr.offset.y = 0;
		vr.extent.width = Width;
		vr.extent.height = Height;

	VkPipelineViewportStateCreateInfo			vpvsci;
		vpvsci.sType = VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO;
		vpvsci.pNext = nullptr;
		vpvsci.flags = 0;
		vpvsci.viewportCount = 1;
		vpvsci.pViewports = &vv;
		vpvsci.scissorCount = 1;
		vpvsci.pScissors = &vr;

	VkPipelineRasterizationStateCreateInfo			vprsci;
		vprsci.sType = VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_STATE_CREATE_INFO;
		vprsci.pNext = nullptr;
		vprsci.flags = 0;
		vprsci.depthClampEnable = VK_FALSE;
		vprsci.rasterizerDiscardEnable = VK_FALSE;
		vprsci.polygonMode = VK_POLYGON_MODE_FILL;
#ifdef CHOICES
VK_POLYGON_MODE_FILL
VK_POLYGON_MODE_LINE
VK_POLYGON_MODE_POINT
#endif
		vprsci.cullMode = VK_CULL_MODE_NONE;	// recommend this because of the projMatrix[1][1] *= -1.;
#ifdef CHOICES
VK_CULL_MODE_NONE
VK_CULL_MODE_FRONT_BIT
VK_CULL_MODE_BACK_BIT
VK_CULL_MODE_FRONT_AND_BACK_BIT
#endif
		vprsci.frontFace = VK_FRONT_FACE_COUNTER_CLOCKWISE;
#ifdef CHOICES
VK_FRONT_FACE_COUNTER_CLOCKWISE
VK_FRONT_FACE_CLOCKWISE
#endif
		vprsci.depthBiasEnable = VK_FALSE;
		vprsci.depthBiasConstantFactor = 0.f;
		vprsci.depthBiasClamp = 0.f;
		vprsci.depthBiasSlopeFactor = 0.f;
		vprsci.lineWidth = 1.f;

	VkPipelineMultisampleStateCreateInfo			vpmsci;
		vpmsci.sType = VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO;
		vpmsci.pNext = nullptr;
		vpmsci.flags = 0;
		vpmsci.rasterizationSamples = VK_SAMPLE_COUNT_1_BIT;
		vpmsci.sampleShadingEnable = VK_FALSE;
		vpmsci.minSampleShading = 0;
		vpmsci.pSampleMask = (VkSampleMask *)nullptr;
		vpmsci.alphaToCoverageEnable = VK_FALSE;
		vpmsci.alphaToOneEnable = VK_FALSE;

	VkPipelineColorBlendAttachmentState			vpcbas;
		vpcbas.colorWriteMask = 	VK_COLOR_COMPONENT_R_BIT
					    |	VK_COLOR_COMPONENT_G_BIT
					    |	VK_COLOR_COMPONENT_B_BIT
					    |	VK_COLOR_COMPONENT_A_BIT;
		vpcbas.blendEnable = VK_FALSE;
		vpcbas.srcColorBlendFactor = VK_BLEND_FACTOR_SRC_COLOR;
		vpcbas.dstColorBlendFactor = VK_BLEND_FACTOR_ONE_MINUS_SRC_COLOR;
		vpcbas.colorBlendOp = VK_BLEND_OP_ADD;
		vpcbas.srcAlphaBlendFactor = VK_BLEND_FACTOR_ONE;
		vpcbas.dstAlphaBlendFactor = VK_BLEND_FACTOR_ZERO;
		vpcbas.alphaBlendOp = VK_BLEND_OP_ADD;

	VkPipelineColorBlendStateCreateInfo			vpcbsci;
		vpcbsci.sType = VK_STRUCTURE_TYPE_PIPELINE_COLOR_BLEND_STATE_CREATE_INFO;
		vpcbsci.pNext = nullptr;
		vpcbsci.flags = 0;
		vpcbsci.logicOpEnable = VK_FALSE;
		vpcbsci.logicOp = VK_LOGIC_OP_COPY;
#ifdef CHOICES
VK_LOGIC_OP_CLEAR
VK_LOGIC_OP_AND
VK_LOGIC_OP_AND_REVERSE
VK_LOGIC_OP_COPY
VK_LOGIC_OP_AND_INVERTED
VK_LOGIC_OP_NO_OP
VK_LOGIC_OP_XOR
VK_LOGIC_OP_OR
VK_LOGIC_OP_NOR
VK_LOGIC_OP_EQUIVALENT
VK_LOGIC_OP_INVERT
VK_LOGIC_OP_OR_REVERSE
VK_LOGIC_OP_COPY_INVERTED
VK_LOGIC_OP_OR_INVERTED
VK_LOGIC_OP_NAND
VK_LOGIC_OP_SET
#endif
		vpcbsci.attachmentCount = 1;
		vpcbsci.pAttachments = &vpcbas;
		vpcbsci.blendConstants[0] = 0;
		vpcbsci.blendConstants[1] = 0;
		vpcbsci.blendConstants[2] = 0;
		vpcbsci.blendConstants[3] = 0;

	VkDynamicState				vds[ ] = { VK_DYNAMIC_STATE_VIEWPORT, VK_DYNAMIC_STATE_SCISSOR };
#ifdef CHOICES
VK_DYNAMIC_STATE_VIEWPORT	--	vkCmdSetViewort( )
VK_DYNAMIC_STATE_SCISSOR	--	vkCmdSetScissor( )
VK_DYNAMIC_STATE_LINE_WIDTH	--	vkCmdSetLineWidth( )
VK_DYNAMIC_STATE_DEPTH_BIAS	--	vkCmdSetDepthBias( )
VK_DYNAMIC_STATE_BLEND_CONSTANTS	--	vkCmdSetBendConstants( )
VK_DYNAMIC_STATE_DEPTH_BOUNDS	--	vkCmdSetDepthZBounds( )
VK_DYNAMIC_STATE_STENCIL_COMPARE_MASK	--	vkCmdSetStencilCompareMask( )
VK_DYNAMIC_STATE_STENCIL_WRITE_MASK	--	vkCmdSetStencilWriteMask( )
VK_DYNAMIC_STATE_STENCIL_REFERENCE	--	vkCmdSetStencilReferences( )
#endif
	VkPipelineDynamicStateCreateInfo			vpdsci;
		vpdsci.sType = VK_STRUCTURE_TYPE_PIPELINE_DYNAMIC_STATE_CREATE_INFO;
		vpdsci.pNext = nullptr;
		vpdsci.flags = 0;
		vpdsci.dynamicStateCount = 0;			// leave turned off for now
		vpdsci.pDynamicStates = vds;

	VkStencilOpState					vsosf;	// front
		vsosf.failOp = VK_STENCIL_OP_KEEP;
		vsosf.passOp = VK_STENCIL_OP_KEEP;
		vsosf.depthFailOp = VK_STENCIL_OP_KEEP;
#ifdef CHOICES
VK_STENCIL_OP_KEEP
VK_STENCIL_OP_ZERO
VK_STENCIL_OP_REPLACE
VK_STENCIL_OP_INCREMENT_AND_CLAMP
VK_STENCIL_OP_DECREMENT_AND_CLAMP
VK_STENCIL_OP_INVERT
VK_STENCIL_OP_INCREMENT_AND_WRAP
VK_STENCIL_OP_DECREMENT_AND_WRAP
#endif
		vsosf.compareOp = VK_COMPARE_OP_NEVER;
#ifdef CHOICES
VK_COMPARE_OP_NEVER
VK_COMPARE_OP_LESS
VK_COMPARE_OP_EQUAL
VK_COMPARE_OP_LESS_OR_EQUAL
VK_COMPARE_OP_GREATER
VK_COMPARE_OP_NOT_EQUAL
VK_COMPARE_OP_GREATER_OR_EQUAL
VK_COMPARE_OP_ALWAYS
#endif
		vsosf.compareMask = ~0;
		vsosf.writeMask = ~0;
		vsosf.reference = 0;

	VkStencilOpState					vsosb;	// back
		vsosb.failOp = VK_STENCIL_OP_KEEP;
		vsosb.passOp = VK_STENCIL_OP_KEEP;
		vsosb.depthFailOp = VK_STENCIL_OP_KEEP;
		vsosb.compareOp = VK_COMPARE_OP_NEVER;
		vsosb.compareMask = ~0;
		vsosb.writeMask = ~0;
		vsosb.reference = 0;

	VkPipelineDepthStencilStateCreateInfo			vpdssci;
		vpdssci.sType = VK_STRUCTURE_TYPE_PIPELINE_DEPTH_STENCIL_STATE_CREATE_INFO;
		vpdssci.pNext = nullptr;
		vpdssci.flags = 0;
		vpdssci.depthTestEnable = VK_TRUE;
		vpdssci.depthWriteEnable = VK_TRUE;
		vpdssci.depthCompareOp = VK_COMPARE_OP_LESS;
#ifdef CHOICES
VK_COMPARE_OP_NEVER
VK_COMPARE_OP_LESS
VK_COMPARE_OP_EQUAL
VK_COMPARE_OP_LESS_OR_EQUAL
VK_COMPARE_OP_GREATER
VK_COMPARE_OP_NOT_EQUAL
VK_COMPARE_OP_GREATER_OR_EQUAL
VK_COMPARE_OP_ALWAYS
#endif
		vpdssci.depthBoundsTestEnable = VK_FALSE;
		vpdssci.front = vsosf;
		vpdssci.back  = vsosb;
		vpdssci.minDepthBounds = 0.;
		vpdssci.maxDepthBounds = 1.;
		vpdssci.stencilTestEnable = VK_FALSE;



	VkGraphicsPipelineCreateInfo				vgpci;
		vgpci.sType = VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO;
		vgpci.pNext = nullptr;
		vgpci.flags = 0;
#ifdef CHOICES
VK_PIPELINE_CREATE_DISABLE_OPTIMIZATION_BIT
VK_PIPELINE_CREATE_ALLOW_DERIVATIVES_BIT
VK_PIPELINE_CREATE_DERIVATIVE_BIT
#endif
		vgpci.stageCount = 2;				// number of stages in this pipeline
		vgpci.pStages = vpssci;
		vgpci.pVertexInputState = &vpvisci;
		vgpci.pInputAssemblyState = &vpiasci;
		vgpci.pTessellationState = (VkPipelineTessellationStateCreateInfo *)nullptr;		// &vptsci
		vgpci.pViewportState = &vpvsci;
		vgpci.pRasterizationState = &vprsci;
		vgpci.pMultisampleState = &vpmsci;
		vgpci.pDepthStencilState = &vpdssci;
		vgpci.pColorBlendState = &vpcbsci;
		vgpci.pDynamicState = (VkPipelineDynamicStateCreateInfo *) nullptr;
		//vgpci.pDynamicState = &vpdsci;
		vgpci.layout = IN GraphicsPipelineLayout;
		vgpci.renderPass = IN RenderPass;
		vgpci.subpass = 0;				// subpass number
		vgpci.basePipelineHandle = (VkPipeline) VK_NULL_HANDLE;
		vgpci.basePipelineIndex = 0;

	result = vkCreateGraphicsPipelines( LogicalDevice, VK_NULL_HANDLE, 1, IN &vgpci, PALLOCATOR, OUT pGraphicsPipeline );
	REPORT( "vkCreateGraphicsPipelines" );

	return result;
}






// *************************
// SETUP A COMPUTE PIPELINE:
// *************************

VkResult
Init14ComputePipeline( VkShaderModule computeShader, OUT VkPipeline * pComputePipeline  )
{
	HERE_I_AM( "Init14ComputePipeline" );

	VkResult result = VK_SUCCESS;

	VkPipelineShaderStageCreateInfo			vpssci;
		vpssci.sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
		vpssci.pNext = nullptr;
		vpssci.flags = 0;
		vpssci.stage = VK_SHADER_STAGE_COMPUTE_BIT;
		vpssci.module = computeShader;
		vpssci.pName = "main";
		vpssci.pSpecializationInfo = (VkSpecializationInfo *)nullptr;

	VkPipelineLayoutCreateInfo				vplci;
		vplci.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
		vplci.pNext = nullptr;
		vplci.flags = 0;
		vplci.setLayoutCount = 1;
		vplci.pSetLayouts = DescriptorSetLayouts;
		vplci.pushConstantRangeCount = 0;
		vplci.pPushConstantRanges = (VkPushConstantRange *)nullptr;

	result = vkCreatePipelineLayout( LogicalDevice, IN &vplci, PALLOCATOR, OUT &ComputePipelineLayout );
	REPORT( "vkCreatePipelineLayout" );

	VkComputePipelineCreateInfo			vcpci[1];
		vcpci[0].sType = VK_STRUCTURE_TYPE_COMPUTE_PIPELINE_CREATE_INFO;
		vcpci[0].pNext = nullptr;
		vcpci[0].flags = 0;
		vcpci[0].stage = vpssci;
		vcpci[0].layout = ComputePipelineLayout;
		vcpci[0].basePipelineHandle = VK_NULL_HANDLE;
		vcpci[0].basePipelineIndex = 0;

	result = vkCreateComputePipelines( LogicalDevice, VK_NULL_HANDLE, 1, &vcpci[0], PALLOCATOR, pComputePipeline );
	REPORT( "vkCreateComputePipelines" );
	return result;
}

#ifdef SAMPLE_CODE
vkBeginRenderPass( );
vkCmdBindPipeline( CommandBuffer, VK_PIPELINE_BIND_POINT_COMPUTE, ComputePipelines[0] );
vkCmdDispatch( CommandBuffer, numWGx, numWGy, numWQz );
vkEndRenderPass( );
#endif




// **********************************
// CREATING AND SUBMITTING THE FENCE:
// **********************************

VkResult
InitFence( )
{
	VkFenceCreateInfo			vfci;
		vfci.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
		vfci.pNext = nullptr;
		vfci.flags = 0;

	vkCreateFence( LogicalDevice, &vfci, PALLOCATOR, &Fence );


	VkSubmitInfo				vsi;
		vsi.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
		vsi.pNext = nullptr;
		vsi.waitSemaphoreCount = 0;					// ??? uint32_t
		vsi.pWaitSemaphores = (VkSemaphore *)nullptr;			// ??????
		vsi.pWaitDstStageMask = (VkPipelineStageFlags *)nullptr;	// ?????
		vsi.commandBufferCount = 1;
		vsi.pCommandBuffers = CommandBuffers;
		vsi.signalSemaphoreCount = 0;					// ?????
		vsi.pSignalSemaphores = (VkSemaphore *)nullptr;			// ?????

	VkResult result = vkQueueSubmit( Queue, 1, IN &vsi, IN Fence );
		// Fence can be VK_NULL_HANDLE if have no fence
	REPORT( "vkQueueSubmit" );

#ifdef SAMPLE_CODE
	result = vkWaitForFences( LogicalDevice, 1, pFences, VK_TRUE, timeout );
	REPORT( "vkWaitForFences" );
#endif

	return result;
}

#ifdef SAMPLE_CODE
	vkDestroyFence( LogicalDevice, Fence, nullptr );
#endif




// ***************
// PUSH CONSTANTS:
// ***************
//
// Push Constants are uniform variables in a shader.
// There is one Push Constant block per pipeline.
// Push Constants are "injected" into the pipeline.
// They are not necessarily backed by device memory, although they could be.

#ifdef COMMENT
layout( push_constant ) uniform myPushConstants_t
{
	int a;
	float b;
	int c;
} MyPushConstants;
#endif

#ifdef SAMPLE_CODE
	VkPushConstantRange				vpcr[1];
		vpcr.stageFlags = VK_SHADER_STAGE_ALL;
		vpcr.offset = 0;
		vpcr.size = << in bytes >>

	VkPipelineLayoutCreateInfo		vplci;
		vplci.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
		vplci.pNext = nullptr;
		vplci.flags = 0;
		vplci.setLayoutCount = << length of array .pSetLayouts >>
		vplci.pSetLayouts = << array of type VkDescriptorSetLayout >>
		vplci.pushConstantRangeCount = << length of array pPushConstantRanges >>
		vplci.pPushConstantRanges = << array of type VkPushConstantRange >>

	result = vkCreatePipelineLayout( LogicalDevice, &vplci, PALLOCATOR, &PipelineLayout );
#endif

#ifdef SAMPLE_CODE
	vkCmdPushConstants( CommandBuffer, PipelineLayout, VK_SHADER_STAGE_ALL, offset, size, void *values );
#endif



// *************************
// SPECIALIZATION CONSTANTS:
// *************************
//
// Specialization Constants "specialize" a shader.
// I.e., these constants get compiled-in.
// Typically, the final code generation comes late, with calls to
// 	vkCreateComputePipelines( )
// 	vkCreateGraphicsPipelines( )
// The compiler can make code-generation decisions based on Specialization Constants.
// Specialization constants are good for:
// 	branching (~ #ifdef)
// 	switch
// 	loop unrolling
// 	constant folding
// 	operator simplification

#ifdef SAMPLE_CODE
layout( constant_id = 1 ) const bool  USE_HALF_ANGLE = true;
layout( constant_id = 2 ) const float G = -9.8f;


	VkSpecializationMapEntity			vsme[1];
		vsme[0].constantId = << the constant_id in the layout line, uint32_t >>
		vsme[0].offset = << how far into the raw data this constant is, bytes >>
		vsme[0].size = << size of this SC in the raw data >>

	VkSpecializationInfo				vsi;
		vsi.mapEntryCount = << number of SCs to be set >>
		vsi.pmapEntries = << array of VkSpecializationMapEntry elements >>
		vsi.dataSize = << in bytes >>
		vsi.pData = << the raw data, void * >>
#endif



// *******************************
// HANDLING A VULKAN ERROR RETURN:
// *******************************

struct errorcode
{
	VkResult	resultCode;
	std::string	meaning;
}
ErrorCodes[ ] =
{
	{ VK_NOT_READY,				"Not Ready"			},
	{ VK_TIMEOUT,				"Timeout"			},
	{ VK_EVENT_SET,				"Event Set"			},
	{ VK_EVENT_RESET,			"Event Reset"			},
	{ VK_INCOMPLETE,			"Incomplete"			},
	{ VK_ERROR_OUT_OF_HOST_MEMORY,		"Out of Host Memory"		},
	{ VK_ERROR_OUT_OF_DEVICE_MEMORY,	"Out of Device Memory"		},
	{ VK_ERROR_INITIALIZATION_FAILED,	"Initialization Failed"		},
	{ VK_ERROR_DEVICE_LOST,			"Device Lost"			},
	{ VK_ERROR_MEMORY_MAP_FAILED,		"Memory Map Failed"		},
	{ VK_ERROR_LAYER_NOT_PRESENT,		"Layer Not Present"		},
	{ VK_ERROR_EXTENSION_NOT_PRESENT,	"Extension Not Present"		},
	{ VK_ERROR_FEATURE_NOT_PRESENT,		"Feature Not Present"		},
	{ VK_ERROR_INCOMPATIBLE_DRIVER,		"Incompatible Driver"		},
	{ VK_ERROR_TOO_MANY_OBJECTS,		"Too Many Objects"		},
	{ VK_ERROR_FORMAT_NOT_SUPPORTED,	"Format Not Supported"		},
	{ VK_ERROR_FRAGMENTED_POOL,		"Fragmented Pool"		},
	{ VK_ERROR_SURFACE_LOST_KHR,		"Surface Lost"			},
	{ VK_ERROR_NATIVE_WINDOW_IN_USE_KHR,	"Native Window in Use"		},
	{ VK_SUBOPTIMAL_KHR,			"Suboptimal"			},
	{ VK_ERROR_OUT_OF_DATE_KHR,		"Error Out of Date"		},
	{ VK_ERROR_INCOMPATIBLE_DISPLAY_KHR,	"Incompatible Display"		},
	{ VK_ERROR_VALIDATION_FAILED_EXT,	"Validation Failed"		},
	{ VK_ERROR_INVALID_SHADER_NV,		"Invalid Shader"		},
	{ VK_ERROR_OUT_OF_POOL_MEMORY_KHR,	"Out of Pool Memory"		},
	{ VK_ERROR_INVALID_EXTERNAL_HANDLE_KHX,	"Invalid External Handle"	},
};

void
PrintVkError( VkResult result, std::string prefix )
{
	if (Verbose  &&  result == VK_SUCCESS)
	{
		fprintf(FpDebug, "%s: %s\n", prefix.c_str(), "Successful");
		fflush(FpDebug);
		return;
	}

	const int numErrorCodes = sizeof( ErrorCodes ) / sizeof( struct errorcode );
	std::string meaning = "";
	for( int i = 0; i < numErrorCodes; i++ )
	{
		if( result == ErrorCodes[i].resultCode )
		{
			meaning = ErrorCodes[i].meaning;
			break;
		}
	}

	fprintf( FpDebug, "\n%s: %s\n", prefix.c_str(), meaning.c_str() );
	fflush(FpDebug);
}






// *******
// FENCES:
// *******

#ifdef SAMPLE_CODE
VkResult
InitFence( )
{
	VkResult result;

	VkFenceCreateInfo				vfci;
		vfci.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
		vfci.pNext = nullptr;
		vfci.flags = VK_FENCE_CREATE_SIGNALED_BIT;	// the only option

	result = vkCreateFence( LogicalDevice, IN &vfci, PALLOCATOR, &Fence );
	REPORT( "vkCreateFence" );


	result = vkGetFenceStatus( LogicalDevice, IN Fence );
#ifdef RESULT
		VK_SUCCESS: 	its signaled
		VK_NOT_READY:	its not signaled
#endif
	REPORT( "vkGetFenceStatus" );


	result = vkWaitForFence( LogicalDevice, fenceCount, pFences, waitForAll, timeout );
#ifdef CHOICES
		waitForAll: VK_TRUE = wait for all fences
			  : VK_FALSE = wait for any fences
		timeout   : uint64_t, timeout in nanoseconds
#endif
#ifdef RESULT
		result:   : VK_SUCCESS = returned because a fence signaled
			  : VK_TIMEOUT = returned because the timeout was exceeded
#endif
	REPORT( "vkWaitForFence" );

	result = vkResetFences( LogicalDevice, count, pFemces );
	REPORT( "vkResetFences" );
}
#endif



// *******
// EVENTS:
// *******
#ifdef SAMPLE_CODE
VkResult
InitEvent( )
{
	VkResult result;

	VkEventCreateInfo			veci;
		veci.sType = VK_STRUCTURE_TYPE_EVENT_CREATE_INFO;
		veci.pNext = nullptr;
		veci.flags = 0;

	VkResult result = vkCreateEvent( LogicalDevice, IN &veci, PALLOCATOR, OUT &Event );
	REPORT( "vkCreateEvent" );

	result = vkSetEvent( LogicalDevice, Event );
	REPORT( "vkSetEvent" );
	result = vkResetEvent( LogicalDevice, Event );
	REPORT( "vkResetEvent" );

	result = vkGetEventStatus( LogicalDevice, Event );
#ifdef RESULTS
		VK_EVENT_SET  : signaled
		VK_EVENT_RESET: not signaled
#endif
	REPORT( "vkGetEventStatus" );


	result = vkCmdSetEvent( CommandBuffer, Event, pipelineStageBits );
	REPORT( "vkCmdSetEvent" );
	result = vkCmdResetEvent( CommandBuffer, Event, pipelineStageBits );
	REPORT( "vkCmdResetEvent" );

	result = vkCmdWaitEvents( CommandBuffer, eventCount, pEvents, srcPipelineStageBits, dstPipelineStageBits,
		memoryBarrierCount, pMemoryBarriers,
		bufferMemoryBarrierCount, pBufferMemoryBarriers,
		imageMemoryBarrierCount, pImageMemoryBarriers );
	REPORT( "vkCmdWaitEvents" );
#endif



// ***********
// SEMAPHORES:
// ***********

VkResult
InitSemaphore( )
{
	VkResult result = VK_SUCCESS;

	VkSemaphoreCreateInfo			vsci;
		vsci.sType = VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;
		vsci.pNext = nullptr;
		vsci.flags = 0;

	result = vkCreateSemaphore( LogicalDevice, IN &vsci, PALLOCATOR, OUT &SemaphoreImageAvailable );
	REPORT( "vkCreateSemaphore -- image available" );

	result = vkCreateSemaphore( LogicalDevice, IN &vsci, PALLOCATOR, OUT &SemaphoreRenderFinished );
	REPORT( "vkCreateSemaphore -- render finished" );

		// vkQueueSubmit waits for one set of semaphores and signals another
		// Can have 2 queues, one for compute and one for graphics
			// Graphics Queue can wait on signal from Compute Queue
			// Then, Compute Queue can wait on signal from Graphics Queue

	return result;
}



VkResult
DestroyAllVulkan( )
{
	VkResult result = VK_SUCCESS;

	result = vkDeviceWaitIdle( LogicalDevice );
	REPORT( "vkWaitIdle" );

#ifdef ALL_MY_CREATES
vkCreateBuffer ( ... );
vkCreateCommandPool( ... );
vkCreateComputePipelines( ... );
vkCreateDebugReportCallbackEXT( ... );
vkCreateDescriptorPool( ... );
vkCreateDescriptorSetLayout( ... );
vkCreateEvent( ... );
vkCreateFence( ... );
vkCreateFramebuffer( ... );
vkCreateGraphicsPipelines( ... );
vkCreateImage( ... );
vkCreateImageView( ... );
vkCreateInstance( ... );
vkCreateLogicalDevice( ... );
vkCreatePipelineLayout( ... );
vkCreateRenderPass( ... );
vkCreateSampler( ... );
vkCreateSemaphore( ... );
vkCreateShaderModule( ... );
vkCreateSwapchainKHR( ... );
#endif

	vkDestroyPipelineLayout( LogicalDevice, GraphicsPipelineLayout, PALLOCATOR );
	vkDestroyDescriptorSetLayout( LogicalDevice, DescriptorSetLayouts[0], PALLOCATOR );
	vkDestroyDescriptorSetLayout( LogicalDevice, DescriptorSetLayouts[1], PALLOCATOR );
	vkDestroyDescriptorSetLayout( LogicalDevice, DescriptorSetLayouts[2], PALLOCATOR );
	vkDestroyDescriptorSetLayout( LogicalDevice, DescriptorSetLayouts[3], PALLOCATOR );
	vkDestroyDevice( LogicalDevice, PALLOCATOR );
	vkDestroyInstance( Instance, PALLOCATOR );

	return result;
}


int
FindMemoryThatIsDeviceLocal( )
{
	VkPhysicalDeviceMemoryProperties	vpdmp;
	vkGetPhysicalDeviceMemoryProperties( PhysicalDevice, OUT &vpdmp );
	for( unsigned int i = 0; i < vpdmp.memoryTypeCount; i++ )
	{
		VkMemoryType vmt = vpdmp.memoryTypes[i];
		if( ( vmt.propertyFlags & VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT ) != 0 )
		{
			return i;
		}
	}
	return -1;
}


int
FindMemoryThatIsHostVisible( )
{
	VkPhysicalDeviceMemoryProperties	vpdmp;
	vkGetPhysicalDeviceMemoryProperties( PhysicalDevice, OUT &vpdmp );
	for( unsigned int i = 0; i < vpdmp.memoryTypeCount; i++ )
	{
		VkMemoryType vmt = vpdmp.memoryTypes[i];
		if( ( vmt.propertyFlags & VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT ) != 0 )
		{
			return i;
		}
	}
	return -1;
}


int
FindQueueFamilyThatDoesGraphics( )
{
	uint32_t count = -1;
	vkGetPhysicalDeviceQueueFamilyProperties( IN PhysicalDevice, &count, OUT (VkQueueFamilyProperties *)nullptr );
	VkQueueFamilyProperties *vqfp = new VkQueueFamilyProperties[ count ];
	vkGetPhysicalDeviceQueueFamilyProperties( IN PhysicalDevice, &count, OUT vqfp );
	for( unsigned int i = 0; i < count; i++ )
	{
		if( ( vqfp[i].queueFlags & VK_QUEUE_GRAPHICS_BIT ) != 0 )
			return i;
	}
	return -1;
}


int
FindQueueFamilyThatDoesCompute( )
{
	uint32_t count = -1;
	vkGetPhysicalDeviceQueueFamilyProperties( IN PhysicalDevice, &count, OUT (VkQueueFamilyProperties *)nullptr );
	VkQueueFamilyProperties *vqfp = new VkQueueFamilyProperties[ count ];
	vkGetPhysicalDeviceQueueFamilyProperties( IN PhysicalDevice, &count, OUT vqfp );
	for( unsigned int i = 0; i < count; i++ )
	{
		if( ( vqfp[i].queueFlags & VK_QUEUE_COMPUTE_BIT  ) != 0 )
			return i;
	}
	return -1;
}


int
FindQueueFamilyThatDoesTransfer( )
{
	uint32_t count = -1;
	vkGetPhysicalDeviceQueueFamilyProperties( IN PhysicalDevice, &count, OUT (VkQueueFamilyProperties *)nullptr );
	VkQueueFamilyProperties *vqfp = new VkQueueFamilyProperties[ count ];
	vkGetPhysicalDeviceQueueFamilyProperties( IN PhysicalDevice, &count, OUT vqfp );
	for( unsigned int i = 0; i < count; i++ )
	{
		if( ( vqfp[i].queueFlags & VK_QUEUE_TRANSFER_BIT ) != 0 )
			return i;
	}
	return -1;
}


int
FindMemoryWithTypeBits( uint32_t memoryTypeBits )
{
	VkPhysicalDeviceMemoryProperties	vpdmp;
	vkGetPhysicalDeviceMemoryProperties( PhysicalDevice, OUT &vpdmp );
	for( unsigned int i = 0; i < vpdmp.memoryTypeCount; i++ )
	{
		VkMemoryType vmt = vpdmp.memoryTypes[i];
		if( ( vmt.propertyFlags & (1<<i) ) != 0 )
		{
			return i;
		}
	}
	return 0;
}




// *********************************************
// EXECUTE THE CODE FOR THE RENDERING OPERATION:
// *********************************************

VkResult
RenderScene( )
{
	NumRenders++;
	if (NumRenders <= 2)
		HERE_I_AM( "RenderScene" );
	
	VkResult result = VK_SUCCESS;

	uint32_t nextImageIndex;
	vkAcquireNextImageKHR( LogicalDevice, IN SwapChain, IN UINT64_MAX, IN VK_NULL_HANDLE, IN VK_NULL_HANDLE, OUT &nextImageIndex );
	if( Verbose &&  NumRenders <= 2 )	fprintf(FpDebug, "nextImageIndex = %d\n", nextImageIndex);

	VkCommandBufferBeginInfo		vcbbi;
		vcbbi.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
		vcbbi.pNext = nullptr;
		vcbbi.flags = VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT;
		//vcbbi.flags = VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT;   <----- or could use this one??
		vcbbi.pInheritanceInfo = (VkCommandBufferInheritanceInfo *)nullptr;

	result = vkBeginCommandBuffer( CommandBuffers[nextImageIndex], IN &vcbbi );
	//REPORT( "vkBeginCommandBuffer" );

	VkClearColorValue			vccv;
		vccv.float32[0] = 0.0;
		vccv.float32[1] = 0.0;
		vccv.float32[2] = 0.0;
		vccv.float32[3] = 1.0;

	VkClearDepthStencilValue		vcdsv;
		vcdsv.depth = 1.f;
		vcdsv.stencil = 0;

	VkClearValue				vcv[2];
		vcv[0].color = vccv;
		vcv[1].depthStencil = vcdsv;

	VkOffset2D o2d = { 0, 0 };
	VkExtent2D e2d = { Width, Height };
	VkRect2D r2d = { o2d, e2d };

	VkRenderPassBeginInfo				vrpbi;
		vrpbi.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
		vrpbi.pNext = nullptr;
		vrpbi.renderPass = RenderPass;
		vrpbi.framebuffer = Framebuffers[ nextImageIndex ];
		vrpbi.renderArea = r2d;
		vrpbi.clearValueCount = 2;
		vrpbi.pClearValues = vcv;		// used for VK_ATTACHMENT_LOAD_OP_CLEAR
	vkCmdBeginRenderPass( CommandBuffers[nextImageIndex], IN &vrpbi, IN VK_SUBPASS_CONTENTS_INLINE );
	result = VK_SUCCESS;
	//REPORT("vkCmdBeginRenderPass");

	vkCmdBindPipeline( CommandBuffers[nextImageIndex], VK_PIPELINE_BIND_POINT_GRAPHICS, GraphicsPipeline );
	result = VK_SUCCESS;
	//REPORT("vkCmdBindPipeline");

	VkViewport viewport =
	{
		0.,			// x
		0.,			// y
		(float)Width,
		(float)Height,
		0.,			// minDepth
		1.			// maxDepth
	};

	vkCmdSetViewport( CommandBuffers[nextImageIndex], 0, 1, IN &viewport );		// 0=firstViewport, 1=viewportCount
	result = VK_SUCCESS;
	//REPORT("vkCmdSetViewport");

	VkRect2D scissor =
	{
		0,
		0,
		Width,
		Height
	};

	vkCmdSetScissor( CommandBuffers[nextImageIndex], 0, 1, &scissor );
	result = VK_SUCCESS;
	//REPORT("vkCmdScissor");

	
	vkCmdBindDescriptorSets( CommandBuffers[nextImageIndex], VK_PIPELINE_BIND_POINT_GRAPHICS, GraphicsPipelineLayout, 0, 4, DescriptorSets, 0, (uint32_t *)nullptr );
														    // dynamic offset count, dynamic offsets
	result = VK_SUCCESS;
	//REPORT("vkCmdBindDescriptorSets");

	//vkCmdBindPushConstants( CommandBuffers[nextImageIndex], PipelineLayout, VK_SHADER_STAGE_ALL, offset, size, void *values );

	VkBuffer buffers[1] = { MyVertexDataBuffer.buffer };

	VkDeviceSize offsets[1] = { 0 };

	vkCmdBindVertexBuffers( CommandBuffers[nextImageIndex], 0, 1, buffers, offsets );		// 0, 1 = firstBinding, bindingCount
	result = VK_SUCCESS;
	//REPORT("vkCmdBindVertexBuffers");

	const uint32_t vertexCount = sizeof(VertexData) / sizeof(VertexData[0]);
	const uint32_t instanceCount = 1;
	const uint32_t firstVertex = 0;
	const uint32_t firstInstance = 0;
	vkCmdDraw( CommandBuffers[nextImageIndex], vertexCount, instanceCount, firstVertex, firstInstance );
	result = VK_SUCCESS;
	//REPORT("vkCmdDraw");

	vkCmdEndRenderPass( CommandBuffers[nextImageIndex] );
	result = VK_SUCCESS;
	//REPORT("vkEndRenderPass");

	vkEndCommandBuffer( CommandBuffers[nextImageIndex] );
	result = VK_SUCCESS;
	//REPORT("vkEndCommandBuffer");

	VkFenceCreateInfo			vfci;
		vfci.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
		vfci.pNext = nullptr;
		vfci.flags = 0;

	VkFence renderFence;
	vkCreateFence( LogicalDevice, &vfci, PALLOCATOR, OUT &renderFence );
	result = VK_SUCCESS;
	//REPORT("vkCreateFence");

	VkPipelineStageFlags waitAtBottom = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
#ifdef CHOICES
typedef enum VkPipelineStageFlagBits {
VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT = 0x00000001,
VK_PIPELINE_STAGE_DRAW_INDIRECT_BIT = 0x00000002,
VK_PIPELINE_STAGE_VERTEX_INPUT_BIT = 0x00000004,
VK_PIPELINE_STAGE_VERTEX_SHADER_BIT = 0x00000008,
VK_PIPELINE_STAGE_TESSELLATION_CONTROL_SHADER_BIT = 0x00000010,
VK_PIPELINE_STAGE_TESSELLATION_EVALUATION_SHADER_BIT = 0x00000020,
VK_PIPELINE_STAGE_GEOMETRY_SHADER_BIT = 0x00000040,
VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT = 0x00000080,
VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT = 0x00000100,
VK_PIPELINE_STAGE_LATE_FRAGMENT_TESTS_BIT = 0x00000200,
VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT = 0x00000400,
VK_PIPELINE_STAGE_COMPUTE_SHADER_BIT = 0x00000800,
VK_PIPELINE_STAGE_TRANSFER_BIT = 0x00001000,
VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT = 0x00002000,
VK_PIPELINE_STAGE_HOST_BIT = 0x00004000,
VK_PIPELINE_STAGE_ALL_GRAPHICS_BIT = 0x00008000,
VK_PIPELINE_STAGE_ALL_COMMANDS_BIT = 0x00010000,
VK_PIPELINE_STAGE_COMMAND_PROCESS_BIT_NVX = 0x00020000,
} VkPipelineStageFlagBits;
#endif
	VkQueue presentQueue;
	vkGetDeviceQueue( LogicalDevice, FindQueueFamilyThatDoesGraphics( ), 0, OUT &presentQueue );
					// 0 = queueIndex
	result = VK_SUCCESS;
	//REPORT("vkGetDeviceQueue");

	VkSubmitInfo				vsi;
		vsi.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
		vsi.pNext = nullptr;
///		vsi.waitSemaphoreCount = 1;
		vsi.waitSemaphoreCount = 0;
		vsi.pWaitSemaphores = &SemaphoreImageAvailable;
		vsi.pWaitDstStageMask = &waitAtBottom;
		vsi.commandBufferCount = 1;
		vsi.pCommandBuffers = &CommandBuffers[nextImageIndex];
///		vsi.signalSemaphoreCount = 1;
		vsi.signalSemaphoreCount = 0;
		vsi.pSignalSemaphores = &SemaphoreRenderFinished;

	result = vkQueueSubmit( presentQueue, 1, IN &vsi, IN renderFence );	// 1 = submitCount
	if( Verbose && NumRenders <= 2 )	REPORT("vkQueueSubmit");

	result = vkWaitForFences( LogicalDevice, 1, IN &renderFence, VK_TRUE, UINT64_MAX );	// waitAll, timeout
	if (Verbose && NumRenders <= 2)		REPORT("vkWaitForFences");

	vkDestroyFence( LogicalDevice, renderFence, PALLOCATOR );
	result = VK_SUCCESS;
	//REPORT("vkDestroyFence");

	VkPresentInfoKHR				vpi;
		vpi.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR;
		vpi.pNext = nullptr;
		vpi.waitSemaphoreCount = 0;
		vpi.pWaitSemaphores = (VkSemaphore *)nullptr;
		vpi.swapchainCount = 1;
		vpi.pSwapchains = &SwapChain;
		vpi.pImageIndices = &nextImageIndex;
		vpi.pResults = (VkResult *)nullptr;

	result = vkQueuePresentKHR( presentQueue, IN &vpi );
	if (Verbose && NumRenders <= 2)		REPORT("vkQueuePresentKHR");

	return result;
}




// ***************************
// RESET THE GLOBAL VARIABLES:
// ***************************

void
Reset( )
{
	ActiveButton = 0;
	Mode = 0;
	NeedToExit = false;
	NumRenders = 0;
	Paused = false;
	Scale  = 1.0;
	UseMouse = false;
	Verbose = true;
	Xrot = Yrot = 0.;

	// initialize the matrices:

	glm::vec3  eye(0.,0.,EYEDIST);
	glm::vec3  look(0.,0.,0.);
	glm::vec3  up(0.,1.,0.);
	Matrices.uModelMatrix      = glm::mat4( );		// identity
	Matrices.uViewMatrix       = glm::lookAt( eye, look, up );
	Matrices.uProjectionMatrix = glm::perspective( FOV, (double)Width/(double)Height, 0.1, 1000. );
	Matrices.uProjectionMatrix[1][1] *= -1.;
	Matrices.uNormalMatrix = glm::inverseTranspose(  glm::mat3( Matrices.uModelMatrix )  );


	// initialize the light position:

	Light.uLightPos = glm::vec4( 0., 10., 0., 1. );


	// initialize the misc stuff:

	Misc.uTime = 0.;
	Misc.uMode = Mode;
}



// *****************
// UPDATE THE SCENE:
// *****************

void
UpdateScene( )
{
	// change the object orientation:

	if( UseMouse )
	{
		if( Scale < MINSCALE )
			Scale = MINSCALE;

		Matrices.uModelMatrix = glm::mat4( );		// identity

		Matrices.uModelMatrix = glm::scale(  Matrices.uModelMatrix, glm::vec3(Scale,Scale,Scale) );

		Matrices.uModelMatrix = glm::rotate( Matrices.uModelMatrix, Yrot, glm::vec3( 0.,1.,0.) );
		Matrices.uModelMatrix = glm::rotate( Matrices.uModelMatrix, Xrot, glm::vec3( 1.,0.,0.) );
						// done this way, the Xrot is applied first, then the Yrot, then the Scale

	}
	else
	{
		if( ! Paused )
		{
			const glm::vec3 axis = glm::vec3( 0., 1., 0. );
			Matrices.uModelMatrix      = glm::rotate( glm::mat4( ),  (float)glm::radians( 360.f*Time/SECONDS_PER_CYCLE ),   axis );
		}
	}


	// change the object projection:

	Matrices.uProjectionMatrix = glm::perspective( FOV, (double)Width/(double)Height, 0.1, 1000. );
		Matrices.uProjectionMatrix[1][1] *= -1.;


	// change the normal matrix:

	Matrices.uNormalMatrix = glm::inverseTranspose(  glm::mat3( Matrices.uModelMatrix )  );
	Fill05DataBuffer( MyMatrixUniformBuffer, (void *) &Matrices );


	// possibly change the light position:

	// Fill05DataBuffer( MyLightUniformBuffer, (void*) &Light );	// don't need this now:


	// change the miscellaneous stuff:

	Misc.uTime = (float)Time;
	Misc.uMode = Mode;
	Fill05DataBuffer( MyMiscUniformBuffer, (void *) &Misc );
}



//**********************************************************************
// GLFW WINDOW FUNCTIONS:
//**********************************************************************


void
InitGLFW( )
{
	glfwInit( );

	uint32_t count;
	const char ** extensions = glfwGetRequiredInstanceExtensions (&count);
	fprintf( FpDebug, "\nFound %d GLFW Required Instance Extensions:\n", count );
	for( uint32_t i = 0; i < count; i++ )
	{
		fprintf( FpDebug, "\t%s\n", extensions[ i ] );
	}

	glfwWindowHint( GLFW_CLIENT_API, GLFW_NO_API );
	glfwWindowHint( GLFW_RESIZABLE, GLFW_FALSE );
	MainWindow = glfwCreateWindow( Width, Height, "Vulkan Sample", NULL, NULL );
	VkResult result = glfwCreateWindowSurface( Instance, MainWindow, NULL, &Surface );
	REPORT( "glfwCreateWindowSurface" );

	glfwSetErrorCallback( GLFWErrorCallback );
	glfwSetKeyCallback( MainWindow, GLFWKeyboard );
	glfwSetCursorPosCallback( MainWindow, GLFWMouseMotion );
	glfwSetMouseButtonCallback( MainWindow, GLFWMouseButton );
}



void
GLFWErrorCallback( int error, const char * description )
{
	fprintf( FpDebug, "GLFW Error = %d: '%s'\n", error, description );
}


void
GLFWKeyboard( GLFWwindow * window, int key, int scancode, int action, int mods )
{
	if( action == GLFW_PRESS )
	{
		switch( key )
		{

			case 'i':
			case 'I':
				UseMouse = ! UseMouse;
				break;

			case 'm':
			case 'M':
				Mode++;
				if( Mode >= 2 )
					Mode = 0;
				break;

			case 'p':
			case 'P':
				Paused = ! Paused;
				break;

			case 'q':
			case 'Q':
			case GLFW_KEY_ESCAPE:
				NeedToExit = true;
				break;
		
			case 'v':
			case 'V':
				Verbose = ! Verbose;
				break;

			default:
				fprintf( FpDebug, "Unknow key hit: 0x%04x = '%c'\n", key, key );
				fflush(FpDebug);
		}
	}
}


// **********************************
// PROCESS A MOUSE BUTTON UP OR DOWN:
// **********************************

void
GLFWMouseButton( GLFWwindow *window, int button, int action, int mods )
{
	if( Verbose )		fprintf( FpDebug, "Mouse button = %d; Action = %d\n", button, action );

	int b = 0;		// LEFT, MIDDLE, or RIGHT

	
	// get the proper button bit mask:

	switch( button )
	{
		case GLFW_MOUSE_BUTTON_LEFT:
			b = LEFT;		break;

		case GLFW_MOUSE_BUTTON_MIDDLE:
			b = MIDDLE;		break;

		case GLFW_MOUSE_BUTTON_RIGHT:
			b = RIGHT;		break;

		default:
			b = 0;
			fprintf( FpDebug, "Unknown mouse button: %d\n", button );
	}


	// button down sets the bit, up clears the bit:

	if( action == GLFW_PRESS )
	{
		double xpos, ypos;
		glfwGetCursorPos( window, &xpos, &ypos);
		Xmouse = (int)xpos;
		Ymouse = (int)ypos;
		ActiveButton |= b;		// set the proper bit
	}
	else
	{
		ActiveButton &= ~b;		// clear the proper bit
	}
}


// *************************
// PROCESS A MOUSE MOVEMENT:
// *************************

void
GLFWMouseMotion( GLFWwindow *window, double xpos, double ypos )
{
	int dx = (int)xpos - Xmouse;		// change in mouse coords
	int dy = (int)ypos - Ymouse;

	if( ( ActiveButton & LEFT ) != 0 )
	{
		Xrot += ( ANGFACT*dy );
		Yrot += ( ANGFACT*dx );
	}


	if( ( ActiveButton & MIDDLE ) != 0 )
	{
		Scale += SCLFACT * (float) ( dx - dy );

		// keep object from turning inside-out or disappearing:

		if( Scale < MINSCALE )
			Scale = MINSCALE;
	}

	Xmouse = (int)xpos;			// new current position
	Ymouse = (int)ypos;
}