summaryrefslogtreecommitdiff
path: root/progs/demos/paltex.c
blob: e33a8ee0759e9b80269d68ba62cbf20cb9949a14 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
/* $Id: paltex.c,v 1.1 1999/08/19 00:55:40 jtg Exp $ */

/*
 * Paletted texture demo.  Written by Brian Paul.  This file in public domain.
 */

/*
 * $Log: paltex.c,v $
 * Revision 1.1  1999/08/19 00:55:40  jtg
 * Initial revision
 *
 * Revision 3.1  1999/03/28 18:20:49  brianp
 * minor clean-up
 *
 * Revision 3.0  1998/02/14 18:42:29  brianp
 * initial rev
 *
 */


#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#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, -1);
   glTexCoord2f(1, 1);  glVertex2f( 1, -1);
   glTexCoord2f(1, 0);  glVertex2f( 1,  1);
   glTexCoord2f(0, 0);  glVertex2f(-1,  1);
   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, -15.0 );
}


static void Key( unsigned char key, int x, int y )
{
   (void) x;
   (void) y;
   switch (key) {
      case 27:
         exit(0);
         break;
   }
   glutPostRedisplay();
}


static void SpecialKey( int key, int x, int y )
{
   (void) x;
   (void) y;
   switch (key) {
      case GLUT_KEY_UP:
         break;
      case GLUT_KEY_DOWN:
         break;
      case GLUT_KEY_LEFT:
         break;
      case GLUT_KEY_RIGHT:
         break;
   }
   glutPostRedisplay();
}


static void Init( void )
{
   GLubyte texture[8][8] = {  /* PT = Paletted Texture! */
      {  0,   0,   0,   0,   0,   0,   0,   0},
      {  0, 100, 100, 100,   0, 180, 180, 180},
      {  0, 100,   0, 100,   0,   0, 180,   0},
      {  0, 100,   0, 100,   0,   0, 180,   0},
      {  0, 100, 100, 100,   0,   0, 180,   0},
      {  0, 100,   0,   0,   0,   0, 180,   0},
      {  0, 100,   0,   0,   0,   0, 180,   0},
      {  0, 100, 255,   0,   0,   0, 180, 250},
   };

   GLubyte table[256][4];
   int i;

   if (!glutExtensionSupported("GL_EXT_paletted_texture")) {
      printf("Sorry, GL_EXT_paletted_texture not supported\n");
      exit(0);
   }

   /* put some wacky colors into the texture palette */
   for (i=0;i<256;i++) {
      table[i][0] = i;
      table[i][1] = 0;
      table[i][2] = 127 + i / 2;
      table[i][3] = 255;
   }

#ifdef GL_EXT_paletted_texture

#if defined(GL_EXT_shared_texture_palette) && defined(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 */
                8, 8,                /* 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 );
   glutSpecialFunc( SpecialKey );
   glutDisplayFunc( Display );
   glutIdleFunc( Idle );

   glutMainLoop();
   return 0;
}