This page was last updated: September 9, 2025
I created a summary document describing the steps in using Texture Mapping. It is called Texturing Steps. Check it out. It might help you on this project!
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| Sphere (venus.bmp) | Torus (saturn.bmp) | OBJ Cow (pluto.bmp) |
The goal of this project is to display the Osu* geometric objects and an OBJ object, without textures and with lit textures.
When you are done with this assignment, you will understand how to read texture images into your program, how to store them in GPU memory, and how to stretch them onto various objects in your scene. Your future graphics programs will forever be better because you learned this!
| Object # | What It Is |
|---|---|
| 0 | An OsuSphere |
| 1 | An OsuCube |
| 2 | An OsuCylinder |
| 3 | An OsuCone |
| 4 | An OsuTorus |
| 5 | An OBJ object |
I personally enjoy using NASA's planetary texture images. If you like that too, click here.
For example:
// in the globals:
GLuint SphereDL, CubeDL, ..., ObjDL;; // display lists
GLuint SphereTex, CubeTex, ..., ObjTex; // texture objects
. . .
// at the end of InitGraphics( ):
int width, height;
char *file = (char *)"spheretex.bmp";
unsigned char *texture = BmpToTexture( file, &width, &height );
if( texture == NULL )
fprintf( stderr, "Cannot open texture '%s'\n", file );
else
fprintf( stderr, "Opened '%s': width = %d ; height = %d\n", file, width, height );
glGenTextures( 1, &SphereTex );
glBindTexture( GL_TEXTURE_2D, SphereTex );
glPixelStorei( GL_UNPACK_ALIGNMENT, 1 );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexImage2D( GL_TEXTURE_2D, 0, 3, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, texture );
. . .
// in InitLists( ):
SphereDL = glGenLists( 1 );
glNewList( SphereDL, GL_COMPILE );
SetMaterial( ????? );
glBindTexture( GL_TEXTURE_2D, SphereTex ); // SphereTex must have already been created when this is called
OsuSphere( ??, 64, 64 );
glEndList( );
. . .
// THE OBJ OBJECT NEEDS TO BE TREATED DIFFERENTLY FROM THE Osu* OBJECTS:
GLuint dl = LoadObjMtlFiles( (char *)"dino.obj" );
ObjDL = glGenLists( 1 );
glNewList( ObjDL, GL_COMPILE );
SetMaterial( ????? );
glBindTexture( GL_TEXTURE_2D, ObjTex ); // ObjTex must have already been created when this is called
glCallList( dl ); // a dl can CallList another dl that has been previously created
glEndList( );
. . .
// in Display( ):
if( << we-are-in-texture-mode >> )
glEnable( GL_TEXTURE_2D );
else
glDisable( GL_TEXTURE_2D );
glEnable( GL_LIGHTING );
glEnable( GL_LIGHT0 );
SetPointLight( GL_LIGHT0, ????? );
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
if( << we-want-to-display-the-sphere >> )
{
glCallList( SphereDL );
}
. . .
if( << we-want-to-display-the-OBJ-object >> )
{
glCallList( ObjDL );
}
. . .
glDisable( GL_TEXTURE_2D );
glDisable( GL_LIGHTING );
Use Canvas to turn in:
#include "setmaterial.cpp" #include "setlight.cpp" #include "osusphere.cpp" #include "osucube.cpp" #include "osucylindercone.cpp" #include "osutorus.cpp" #include "bmptotexture.cpp" #include "loadobjmtlfiles.cpp" //#include "keytime.cpp" //#include "glslprogram.cpp"
Set a constant called something like MS_PER_CYCLE that specifies the number of milliseconds per animation cycle. Then, in your Idle Function, query the number of milliseconds since your program started and turn that into a floating point number between 0. and 1. that indicates how far through the animation cycle you are.
// in the globals: float Time; // in Animate( ): int ms = glutGet( GLUT_ELAPSED_TIME ); ms %= MS_PER_CYCLE; Time = (float)ms / (float)MS_PER_CYCLE; // [0.,1.)Then use Time to animate the light position.
| Item | Points |
| Able to toggle between drawing the 6 objects | 20 |
| Draw the objects with the correct textures | 30 |
| Lighting the textures works | 30 |
| The light source moves | 20 |
| Potential Total | 100 |
Joe Graphics, being somewhat lazy and a lousy typist, always looks for ways to automate repetitive operations into a for-loop. Here is what he did for this project. He first created a struct with all the object information listed:
struct object
{
char* name;
char* file;
int displayList;
char key;
unsigned int texObject;
};
He then populated an array of that struct like this:
struct object Objects[ ] =
{
{ "Sphere", "spheretex.bmp", 0, '0', 0 },
. . .
{ "Obj", "objtex.bmp", 0, '5', 0 },
};
const int NUMOBJECTS = sizeof(Objects) / sizeof(struct object);
This allowed some setup operations to be put in a for-loop:
// must be done before the obj display list is created:
GLuint dl = LoadObjMtlFiles((char*)"dino.obj");
for (int i = 0; i < NUMOBJECTS; i++)
{
Objects[i].displayList = glGenLists(1);
glNewList( Objects[i].displayList, GL_COMPILE );
glBindTexture( ??? );
switch( i )
{
case 0:
OsuSphere(1.f, 128, 32); break;
case 1:
OsuCube(1.f); break;
case 2:
OsuCylinder(0.5f, 1.f, 128, 32); break;
case 3:
OsuCone(1.f, .2f, 1., 128, 32); break;
case 4:
OsuTorus(0.25f, 1.f, 128, 128); break;
case 5:
glCallList(dl); break;
}
glEndList();
}
He then created a global variable:
// in the globals:
int NowObject;
. . .
// in Reset( ):
NowObject = 0;
. . .
// in Keyboard( ):
switch( c )
{
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
NowObject = key - '0'; // turn the ascii character into an integer
return;
. . .
. . .
// in Display( ):
glCallList( Objects[NowObject].displayList );
There is absolutely no requirement that you do it this way! If this makes no sense to you, then just do everything an-object-at-a-time. It will work fine either way.