blob: b4fab004a637d81a0dcfa15181454b38556c300e [file] [log] [blame]
/*
* Test vertex arrays and multitexture.
* Press 'a' to toggle vertex arrays on/off.
* When you run this program you should see a square with four colors:
*
* +------+------+
* |yellow| pink |
* +------+------+
* |green | blue |
* +------+------+
*/
#include <assert.h>
#include <math.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "GL/glut.h"
static GLuint Window = 0;
static GLuint TexObj[2];
static GLfloat Angle = 0.0f;
static GLboolean UseArrays = 1, Anim = 0;
static GLfloat VertArray[4][2] = {
{-1.2, -1.2}, {1.2, -1.2}, {1.2, 1.2}, {-1.2, 1.2}
};
static GLfloat Tex0Array[4][2] = {
{0, 0}, {1, 0}, {1, 1}, {0, 1}
};
static GLfloat Tex1Array[4][2] = {
{0, 0}, {1, 0}, {1, 1}, {0, 1}
};
static void init_arrays(void)
{
glVertexPointer(2, GL_FLOAT, 0, VertArray);
glEnableClientState(GL_VERTEX_ARRAY);
glClientActiveTextureARB(GL_TEXTURE0_ARB);
glTexCoordPointer(2, GL_FLOAT, 0, Tex0Array);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glClientActiveTextureARB(GL_TEXTURE1_ARB);
glTexCoordPointer(2, GL_FLOAT, 0, Tex1Array);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
}
static void draw( void )
{
glClear( GL_COLOR_BUFFER_BIT );
glColor3f( 0.0, 0.0, 0.0 );
/* draw first polygon */
glPushMatrix();
glRotatef( Angle, 0.0, 0.0, 1.0 );
if (UseArrays) {
glDrawArrays(GL_POLYGON, 0, 4);
}
else {
glBegin( GL_POLYGON );
glTexCoord2f( 0.0, 0.0 );
glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 0.0, 0.0);
glVertex2f( -1.0, -1.0 );
glTexCoord2f( 1.0, 0.0 );
glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 1.0, 0.0);
glVertex2f( 1.0, -1.0 );
glTexCoord2f( 1.0, 1.0 );
glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 1.0, 1.0);
glVertex2f( 1.0, 1.0 );
glTexCoord2f( 0.0, 1.0 );
glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 0.0, 1.0);
glVertex2f( -1.0, 1.0 );
glEnd();
}
glPopMatrix();
glutSwapBuffers();
}
static void idle( void )
{
Angle += 2.0;
glutPostRedisplay();
}
/* change view Angle, exit upon ESC */
static void key(unsigned char k, int x, int y)
{
(void) x;
(void) y;
switch (k) {
case 'a':
UseArrays = !UseArrays;
printf("UseArrays: %d\n", UseArrays);
break;
case ' ':
Anim = !Anim;
if (Anim)
glutIdleFunc(idle);
else
glutIdleFunc(NULL);
break;
case 27:
glDeleteTextures( 2, TexObj );
glutDestroyWindow(Window);
exit(0);
}
glutPostRedisplay();
}
/* new window size or exposure */
static void reshape( int width, int height )
{
glViewport(0, 0, (GLint)width, (GLint)height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
/* glOrtho( -3.0, 3.0, -3.0, 3.0, -10.0, 10.0 );*/
glFrustum( -2.0, 2.0, -2.0, 2.0, 6.0, 20.0 );
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef( 0.0, 0.0, -8.0 );
}
static void init( void )
{
static int width=8, height=8;
GLubyte tex[64][3];
GLint i, j;
/* generate texture object IDs */
glGenTextures( 2, TexObj );
/*
* setup first texture object
*/
glActiveTextureARB(GL_TEXTURE0_ARB);
glEnable( GL_TEXTURE_2D );
glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_ADD );
glBindTexture( GL_TEXTURE_2D, TexObj[0] );
assert(glIsTexture(TexObj[0]));
/* red over black */
for (i=0;i<height;i++) {
for (j=0;j<width;j++) {
int p = i*width+j;
if (i < height / 2) {
tex[p][0] = 0; tex[p][1] = 0; tex[p][2] = 0;
}
else {
tex[p][0] = 255; tex[p][1] = 0; tex[p][2] = 0;
}
}
}
glTexImage2D( GL_TEXTURE_2D, 0, 3, width, height, 0,
GL_RGB, GL_UNSIGNED_BYTE, tex );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );
/*
* setup second texture object
*/
glActiveTextureARB(GL_TEXTURE1_ARB);
glEnable( GL_TEXTURE_2D );
glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_ADD );
glBindTexture( GL_TEXTURE_2D, TexObj[1] );
assert(glIsTexture(TexObj[1]));
/* left=green, right = blue */
for (i=0;i<height;i++) {
for (j=0;j<width;j++) {
int p = i*width+j;
if (j < width / 2) {
tex[p][0] = 0; tex[p][1] = 255; tex[p][2] = 0;
}
else {
tex[p][0] = 0; tex[p][1] = 0; tex[p][2] = 255;
}
}
}
glTexImage2D( GL_TEXTURE_2D, 0, 3, width, height, 0,
GL_RGB, GL_UNSIGNED_BYTE, tex );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );
}
int main( int argc, char *argv[] )
{
glutInit(&argc, argv);
glutInitWindowPosition(0, 0);
glutInitWindowSize(300, 300);
glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
Window = glutCreateWindow("Texture Objects");
if (!Window) {
exit(1);
}
init();
init_arrays();
glutReshapeFunc( reshape );
glutKeyboardFunc( key );
if (Anim)
glutIdleFunc( idle );
glutDisplayFunc( draw );
glutMainLoop();
return 0;
}