progs/demos/paltex.c

   1 /* $Id: paltex.c,v 1.2 1999/11/02 15:09:04 brianp Exp $ */
   2
   3 /*
   4  * Paletted texture demo.  Written by Brian Paul.
   5  * This program is in the public domain.
   6  */
   7
   8 /*
   9  * $Log: paltex.c,v $
  10  * Revision 1.2  1999/11/02 15:09:04  brianp
  11  * new texture image, cleaned-up code
  12  *
  13  * Revision 1.1.1.1  1999/08/19 00:55:40  jtg
  14  * Imported sources
  15  *
  16  * Revision 3.1  1999/03/28 18:20:49  brianp
  17  * minor clean-up
  18  *
  19  * Revision 3.0  1998/02/14 18:42:29  brianp
  20  * initial rev
  21  *
  22  */
  23
  24
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <math.h>
  28 #include <GL/glut.h>
  29
  30
  31 static float Rot = 0.0;
  32
  33
  34 static void Idle( void )
  35 {
  36    Rot += 5.0;
  37    glutPostRedisplay();
  38 }
  39
  40
  41 static void Display( void )
  42 {
  43    glClear( GL_COLOR_BUFFER_BIT );
  44
  45    glPushMatrix();
  46    glRotatef(Rot, 0, 0, 1);
  47
  48    glBegin(GL_POLYGON);
  49    glTexCoord2f(0, 1);  glVertex2f(-1, -0.5);
  50    glTexCoord2f(1, 1);  glVertex2f( 1, -0.5);
  51    glTexCoord2f(1, 0);  glVertex2f( 1,  0.5);
  52    glTexCoord2f(0, 0);  glVertex2f(-1,  0.5);
  53    glEnd();
  54
  55    glPopMatrix();
  56
  57    glutSwapBuffers();
  58 }
  59
  60
  61 static void Reshape( int width, int height )
  62 {
  63    glViewport( 0, 0, width, height );
  64    glMatrixMode( GL_PROJECTION );
  65    glLoadIdentity();
  66    glFrustum( -1.0, 1.0, -1.0, 1.0, 5.0, 25.0 );
  67    glMatrixMode( GL_MODELVIEW );
  68    glLoadIdentity();
  69    glTranslatef( 0.0, 0.0, -7.0 );
  70 }
  71
  72
  73 static void Key( unsigned char key, int x, int y )
  74 {
  75    (void) x;
  76    (void) y;
  77    switch (key) {
  78       case 27:
  79          exit(0);
  80          break;
  81    }
  82    glutPostRedisplay();
  83 }
  84
  85
  86 static void Init( void )
  87 {
  88 #define HEIGHT 8
  89 #define WIDTH 32
  90    static char texture[HEIGHT][WIDTH] = {
  91          "                                ",
  92          "    MMM    EEEE   SSS    AAA    ",
  93          "   M M M  E      S   S  A   A   ",
  94          "   M M M  EEEE    SS    A   A   ",
  95          "   M M M  E         SS  AAAAA   ",
  96          "   M   M  E      S   S  A   A   ",
  97          "   M   M   EEEE   SSS   A   A   ",
  98          "                                "
  99       };
 100    GLubyte table[256][4];
 101    int i;
 102
 103    if (!glutExtensionSupported("GL_EXT_paletted_texture")) {
 104       printf("Sorry, GL_EXT_paletted_texture not supported\n");
 105       exit(0);
 106    }
 107
 108    /* load the color table for each texel-index */
 109    table[' '][0] = 50;
 110    table[' '][1] = 50;
 111    table[' '][2] = 50;
 112    table[' '][3] = 50;
 113    table['M'][0] = 255;
 114    table['M'][1] = 0;
 115    table['M'][2] = 0;
 116    table['M'][3] = 0;
 117    table['E'][0] = 0;
 118    table['E'][1] = 255;
 119    table['E'][2] = 0;
 120    table['E'][3] = 0;
 121    table['S'][0] = 40;
 122    table['S'][1] = 40;
 123    table['S'][2] = 255;
 124    table['S'][3] = 0;
 125    table['A'][0] = 255;
 126    table['A'][1] = 255;
 127    table['A'][2] = 0;
 128    table['A'][3] = 0;
 129
 130 #ifdef GL_EXT_paletted_texture
 131
 132 #if defined(GL_EXT_shared_texture_palette) && defined(USE_SHARED_PALETTE)
 133    printf("Using shared palette\n");
 134    glColorTableEXT(GL_SHARED_TEXTURE_PALETTE_EXT,    /* target */
 135                    GL_RGBA,          /* internal format */
 136                    256,              /* table size */
 137                    GL_RGBA,          /* table format */
 138                    GL_UNSIGNED_BYTE, /* table type */
 139                    table);           /* the color table */
 140    glEnable(GL_SHARED_TEXTURE_PALETTE_EXT);
 141 #else
 142    glColorTableEXT(GL_TEXTURE_2D,    /* target */
 143                    GL_RGBA,          /* internal format */
 144                    256,              /* table size */
 145                    GL_RGBA,          /* table format */
 146                    GL_UNSIGNED_BYTE, /* table type */
 147                    table);           /* the color table */
 148 #endif
 149
 150    glTexImage2D(GL_TEXTURE_2D,       /* target */
 151                 0,                   /* level */
 152                 GL_COLOR_INDEX8_EXT, /* internal format */
 153                 WIDTH, HEIGHT,       /* width, height */
 154                 0,                   /* border */
 155                 GL_COLOR_INDEX,      /* texture format */
 156                 GL_UNSIGNED_BYTE,    /* texture type */
 157                 texture);            /* teh texture */
 158 #endif
 159
 160    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 161    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 162    glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
 163    glEnable(GL_TEXTURE_2D);
 164 }
 165
 166
 167 int main( int argc, char *argv[] )
 168 {
 169    glutInit( &argc, argv );
 170    glutInitWindowPosition( 0, 0 );
 171    glutInitWindowSize( 400, 400 );
 172
 173    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
 174
 175    glutCreateWindow(argv[0]);
 176
 177    Init();
 178
 179    glutReshapeFunc( Reshape );
 180    glutKeyboardFunc( Key );
 181    glutDisplayFunc( Display );
 182    glutIdleFunc( Idle );
 183
 184    glutMainLoop();
 185    return 0;
 186 }