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/* $Id: paltex.c,v 1.4 2000/06/27 17:12:10 brianp Exp $ */
/*
* Paletted texture demo. Written by Brian Paul.
* This program is in the public domain.
*/
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#define GL_GLEXT_LEGACY
#include <GL/glut.h>
static float Rot = 0.0;
static void Idle( void )
{
Rot += 5.0;
glutPostRedisplay();
}
static void Display( void )
{
glClear( GL_COLOR_BUFFER_BIT );
glPushMatrix();
glRotatef(Rot, 0, 0, 1);
glBegin(GL_POLYGON);
glTexCoord2f(0, 1); glVertex2f(-1, -0.5);
glTexCoord2f(1, 1); glVertex2f( 1, -0.5);
glTexCoord2f(1, 0); glVertex2f( 1, 0.5);
glTexCoord2f(0, 0); glVertex2f(-1, 0.5);
glEnd();
glPopMatrix();
glutSwapBuffers();
}
static void Reshape( int width, int height )
{
glViewport( 0, 0, width, height );
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
glFrustum( -1.0, 1.0, -1.0, 1.0, 5.0, 25.0 );
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
glTranslatef( 0.0, 0.0, -7.0 );
}
static void Key( unsigned char key, int x, int y )
{
(void) x;
(void) y;
switch (key) {
case 27:
exit(0);
break;
}
glutPostRedisplay();
}
static void Init( void )
{
#define HEIGHT 8
#define WIDTH 32
static char texture[HEIGHT][WIDTH] = {
" ",
" MMM EEEE SSS AAA ",
" M M M E S S A A ",
" M M M EEEE SS A A ",
" M M M E SS AAAAA ",
" M M E S S A A ",
" M M EEEE SSS A A ",
" "
};
GLubyte table[256][4];
if (!glutExtensionSupported("GL_EXT_paletted_texture")) {
printf("Sorry, GL_EXT_paletted_texture not supported\n");
exit(0);
}
/* load the color table for each texel-index */
table[' '][0] = 50;
table[' '][1] = 50;
table[' '][2] = 50;
table[' '][3] = 50;
table['M'][0] = 255;
table['M'][1] = 0;
table['M'][2] = 0;
table['M'][3] = 0;
table['E'][0] = 0;
table['E'][1] = 255;
table['E'][2] = 0;
table['E'][3] = 0;
table['S'][0] = 40;
table['S'][1] = 40;
table['S'][2] = 255;
table['S'][3] = 0;
table['A'][0] = 255;
table['A'][1] = 255;
table['A'][2] = 0;
table['A'][3] = 0;
#ifdef GL_EXT_paletted_texture
#if defined(GL_EXT_shared_texture_palette) && defined(USE_SHARED_PALETTE)
printf("Using shared palette\n");
glColorTableEXT(GL_SHARED_TEXTURE_PALETTE_EXT, /* target */
GL_RGBA, /* internal format */
256, /* table size */
GL_RGBA, /* table format */
GL_UNSIGNED_BYTE, /* table type */
table); /* the color table */
glEnable(GL_SHARED_TEXTURE_PALETTE_EXT);
#else
glColorTableEXT(GL_TEXTURE_2D, /* target */
GL_RGBA, /* internal format */
256, /* table size */
GL_RGBA, /* table format */
GL_UNSIGNED_BYTE, /* table type */
table); /* the color table */
#endif
glTexImage2D(GL_TEXTURE_2D, /* target */
0, /* level */
GL_COLOR_INDEX8_EXT, /* internal format */
WIDTH, HEIGHT, /* width, height */
0, /* border */
GL_COLOR_INDEX, /* texture format */
GL_UNSIGNED_BYTE, /* texture type */
texture); /* teh texture */
#endif
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
glEnable(GL_TEXTURE_2D);
}
int main( int argc, char *argv[] )
{
glutInit( &argc, argv );
glutInitWindowPosition( 0, 0 );
glutInitWindowSize( 400, 400 );
glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
glutCreateWindow(argv[0]);
Init();
glutReshapeFunc( Reshape );
glutKeyboardFunc( Key );
glutDisplayFunc( Display );
glutIdleFunc( Idle );
glutMainLoop();
return 0;
}
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