/* * Paletted texture demo. Written by Brian Paul. * This program is in the public domain. */ #include <stdio.h> #include <stdlib.h> #include <math.h> #include <string.h> #ifdef _WIN32 #include <windows.h> #endif #include <GL/glew.h> #include <GL/glut.h> static float Rot = 0.0; static GLboolean Anim = 1; static void Idle( void ) { float t = glutGet(GLUT_ELAPSED_TIME) * 0.001; /* in seconds */ Rot = t * 360 / 4; /* 1 rotation per 4 seconds */ glutPostRedisplay(); } static void Display( void ) { /* draw background gradient */ glDisable(GL_TEXTURE_2D); glBegin(GL_POLYGON); glColor3f(1.0, 0.0, 0.2); glVertex2f(-1.5, -1.0); glColor3f(1.0, 0.0, 0.2); glVertex2f( 1.5, -1.0); glColor3f(0.0, 0.0, 1.0); glVertex2f( 1.5, 1.0); glColor3f(0.0, 0.0, 1.0); glVertex2f(-1.5, 1.0); glEnd(); glPushMatrix(); glRotatef(Rot, 0, 0, 1); glEnable(GL_TEXTURE_2D); 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(); glOrtho( -1.5, 1.5, -1.0, 1.0, -1.0, 1.0 ); glMatrixMode( GL_MODELVIEW ); glLoadIdentity(); } static void Key( unsigned char key, int x, int y ) { (void) x; (void) y; switch (key) { case 27: exit(0); break; case 's': Rot += 0.5; break; case ' ': Anim = !Anim; if (Anim) glutIdleFunc( Idle ); else glutIdleFunc( NULL ); break; } glutPostRedisplay(); } static void Init( void ) { #define HEIGHT 8 #define WIDTH 32 /* 257 = HEIGHT * WIDTH + 1 (for trailing '\0') */ static char texture[257] = {"\ \ 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 */ memset(table, 0, 256*4); table[' '][0] = 255; table[' '][1] = 255; table[' '][2] = 255; table[' '][3] = 64; table['M'][0] = 255; table['M'][1] = 0; table['M'][2] = 0; table['M'][3] = 255; table['E'][0] = 0; table['E'][1] = 255; table['E'][2] = 0; table['E'][3] = 255; table['S'][0] = 0; table['S'][1] = 0; table['S'][2] = 255; table['S'][3] = 255; table['A'][0] = 255; table['A'][1] = 255; table['A'][2] = 0; table['A'][3] = 255; #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); /* the 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); glEnable(GL_BLEND); glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); #undef HEIGHT #undef WIDTH } /* * Color ramp test */ static void Init2( void ) { #define HEIGHT 32 #define WIDTH 256 static char texture[HEIGHT][WIDTH]; GLubyte table[256][4]; int i, j; if (!glutExtensionSupported("GL_EXT_paletted_texture")) { printf("Sorry, GL_EXT_paletted_texture not supported\n"); exit(0); } for (j = 0; j < HEIGHT; j++) { for (i = 0; i < WIDTH; i++) { texture[j][i] = i; } } for (i = 0; i < 255; i++) { table[i][0] = i; table[i][1] = 0; table[i][2] = 0; table[i][3] = 255; } #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); glEnable(GL_BLEND); glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); } int main( int argc, char *argv[] ) { glutInit( &argc, argv ); glutInitWindowPosition( 0, 0 ); glutInitWindowSize( 400, 300 ); glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE ); glutCreateWindow(argv[0]); glewInit(); Init(); (void) Init2; /* silence warning */ glutReshapeFunc( Reshape ); glutKeyboardFunc( Key ); glutDisplayFunc( Display ); if (Anim) glutIdleFunc( Idle ); glutMainLoop(); return 0; }