progs/demos/multiarb.c

   1
   2 /*
   3  * GL_ARB_multitexture demo
   4  *
   5  * Command line options:
   6  *    -info      print GL implementation information
   7  *
   8  *
   9  * Brian Paul  November 1998  This program is in the public domain.
  10  * Modified on 12 Feb 2002 for > 2 texture units.
  11  */
  12
  13
  14 #include <math.h>
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #include <GL/glut.h>
  19
  20 #include "readtex.c"   /* I know, this is a hack. */
  21
  22 #define TEXTURE_1_FILE "../images/girl.rgb"
  23 #define TEXTURE_2_FILE "../images/reflect.rgb"
  24
  25 #define TEX0 1
  26 #define TEX7 8
  27 #define ANIMATE 10
  28 #define QUIT 100
  29
  30 static GLboolean Animate = GL_TRUE;
  31 static GLint NumUnits = 1;
  32 static GLboolean TexEnabled[8];
  33
  34 static GLfloat Drift = 0.0;
  35 static GLfloat drift_increment = 0.005;
  36 static GLfloat Xrot = 20.0, Yrot = 30.0, Zrot = 0.0;
  37
  38
  39
  40 static void Idle( void )
  41 {
  42    if (Animate) {
  43       GLint i;
  44
  45       Drift += drift_increment;
  46       if (Drift >= 1.0)
  47          Drift = 0.0;
  48
  49       for (i = 0; i < NumUnits; i++) {
  50          glActiveTextureARB(GL_TEXTURE0_ARB + i);
  51          glMatrixMode(GL_TEXTURE);
  52          glLoadIdentity();
  53          if (i == 0) {
  54             glTranslatef(Drift, 0.0, 0.0);
  55             glScalef(2, 2, 2);
  56          }
  57          else if (i == 1) {
  58             glTranslatef(0.0, Drift, 0.0);
  59          }
  60          else {
  61             glTranslatef(0.5, 0.5, 0.0);
  62             glRotatef(180.0 * Drift, 0, 0, 1);
  63             glScalef(1.0/i, 1.0/i, 1.0/i);
  64             glTranslatef(-0.5, -0.5, 0.0);
  65          }
  66       }
  67       glMatrixMode(GL_MODELVIEW);
  68
  69       glutPostRedisplay();
  70    }
  71 }
  72
  73
  74 static void DrawObject(void)
  75 {
  76    GLint i;
  77    GLint j;
  78    static const GLfloat   tex_coords[] = {  0.0,  0.0,  1.0,  1.0,  0.0 };
  79    static const GLfloat   vtx_coords[] = { -1.0, -1.0,  1.0,  1.0, -1.0 };
  80
  81    if (!TexEnabled[0] && !TexEnabled[1])
  82       glColor3f(0.1, 0.1, 0.1);  /* add onto this */
  83    else
  84       glColor3f(1, 1, 1);  /* modulate this */
  85
  86    glBegin(GL_QUADS);
  87
  88    /* Toggle between the vector and scalar entry points.  This is done purely
  89     * to hit multiple paths in the driver.
  90     */
  91    if ( Drift > 0.49 ) {
  92       for (j = 0; j < 4; j++ ) {
  93          for (i = 0; i < NumUnits; i++)
  94             glMultiTexCoord2fARB(GL_TEXTURE0_ARB + i,
  95                                  tex_coords[j], tex_coords[j+1]);
  96          glVertex2f( vtx_coords[j], vtx_coords[j+1] );
  97       }
  98    }
  99    else {
 100       for (j = 0; j < 4; j++ ) {
 101          for (i = 0; i < NumUnits; i++)
 102             glMultiTexCoord2fvARB(GL_TEXTURE0_ARB + i, & tex_coords[j]);
 103          glVertex2fv( & vtx_coords[j] );
 104       }
 105    }
 106
 107    glEnd();
 108 }
 109
 110
 111
 112 static void Display( void )
 113 {
 114    static GLint T0 = 0;
 115    static GLint Frames = 0;
 116    GLint t;
 117
 118    glClear( GL_COLOR_BUFFER_BIT );
 119
 120    glPushMatrix();
 121       glRotatef(Xrot, 1.0, 0.0, 0.0);
 122       glRotatef(Yrot, 0.0, 1.0, 0.0);
 123       glRotatef(Zrot, 0.0, 0.0, 1.0);
 124       glScalef(5.0, 5.0, 5.0);
 125       DrawObject();
 126    glPopMatrix();
 127
 128    glutSwapBuffers();
 129
 130    Frames++;
 131
 132    t = glutGet(GLUT_ELAPSED_TIME);
 133    if (t - T0 >= 250) {
 134       GLfloat seconds = (t - T0) / 1000.0;
 135       drift_increment = 2.2 * seconds / Frames;
 136       T0 = t;
 137       Frames = 0;
 138    }
 139 }
 140
 141
 142 static void Reshape( int width, int height )
 143 {
 144    glViewport( 0, 0, width, height );
 145    glMatrixMode( GL_PROJECTION );
 146    glLoadIdentity();
 147    glFrustum( -1.0, 1.0, -1.0, 1.0, 10.0, 100.0 );
 148    /*glOrtho( -6.0, 6.0, -6.0, 6.0, 10.0, 100.0 );*/
 149    glMatrixMode( GL_MODELVIEW );
 150    glLoadIdentity();
 151    glTranslatef( 0.0, 0.0, -70.0 );
 152 }
 153
 154
 155 static void ModeMenu(int entry)
 156 {
 157    if (entry >= TEX0 && entry <= TEX7) {
 158       /* toggle */
 159       GLint i = entry - TEX0;
 160       TexEnabled[i] = !TexEnabled[i];
 161       glActiveTextureARB(GL_TEXTURE0_ARB + i);
 162       if (TexEnabled[i])
 163          glEnable(GL_TEXTURE_2D);
 164       else
 165          glDisable(GL_TEXTURE_2D);
 166       printf("Enabled: ");
 167       for (i = 0; i < NumUnits; i++)
 168          printf("%d ", (int) TexEnabled[i]);
 169       printf("\n");
 170    }
 171    else if (entry==ANIMATE) {
 172       Animate = !Animate;
 173    }
 174    else if (entry==QUIT) {
 175       exit(0);
 176    }
 177
 178    glutPostRedisplay();
 179 }
 180
 181
 182 static void Key( unsigned char key, int x, int y )
 183 {
 184    (void) x;
 185    (void) y;
 186    switch (key) {
 187       case 27:
 188          exit(0);
 189          break;
 190    }
 191    glutPostRedisplay();
 192 }
 193
 194
 195 static void SpecialKey( int key, int x, int y )
 196 {
 197    float step = 3.0;
 198    (void) x;
 199    (void) y;
 200
 201    switch (key) {
 202       case GLUT_KEY_UP:
 203          Xrot += step;
 204          break;
 205       case GLUT_KEY_DOWN:
 206          Xrot -= step;
 207          break;
 208       case GLUT_KEY_LEFT:
 209          Yrot += step;
 210          break;
 211       case GLUT_KEY_RIGHT:
 212          Yrot -= step;
 213          break;
 214    }
 215    glutPostRedisplay();
 216 }
 217
 218
 219 static void Init( int argc, char *argv[] )
 220 {
 221    GLuint texObj[8];
 222    GLint size, i;
 223
 224    const char *exten = (const char *) glGetString(GL_EXTENSIONS);
 225    if (!strstr(exten, "GL_ARB_multitexture")) {
 226       printf("Sorry, GL_ARB_multitexture not supported by this renderer.\n");
 227       exit(1);
 228    }
 229
 230    glGetIntegerv(GL_MAX_TEXTURE_UNITS_ARB, &NumUnits);
 231    printf("%d texture units supported\n", NumUnits);
 232    if (NumUnits > 8)
 233       NumUnits = 8;
 234
 235    glGetIntegerv(GL_MAX_TEXTURE_SIZE, &size);
 236    printf("%d x %d max texture size\n", size, size);
 237
 238    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 239
 240    for (i = 0; i < NumUnits; i++) {
 241       if (i < 2)
 242          TexEnabled[i] = GL_TRUE;
 243       else
 244          TexEnabled[i] = GL_FALSE;
 245    }
 246
 247    /* allocate two texture objects */
 248    glGenTextures(NumUnits, texObj);
 249
 250    /* setup the texture objects */
 251    for (i = 0; i < NumUnits; i++) {
 252
 253       glActiveTextureARB(GL_TEXTURE0_ARB + i);
 254       glBindTexture(GL_TEXTURE_2D, texObj[i]);
 255
 256       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 257       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 258
 259       if (i == 0) {
 260          if (!LoadRGBMipmaps(TEXTURE_1_FILE, GL_RGB)) {
 261             printf("Error: couldn't load texture image\n");
 262             exit(1);
 263          }
 264       }
 265       else if (i == 1) {
 266          if (!LoadRGBMipmaps(TEXTURE_2_FILE, GL_RGB)) {
 267             printf("Error: couldn't load texture image\n");
 268             exit(1);
 269          }
 270       }
 271       else {
 272          /* checker */
 273          GLubyte image[8][8][3];
 274          GLint i, j;
 275          for (i = 0; i < 8; i++) {
 276             for (j = 0; j < 8; j++) {
 277                if ((i + j) & 1) {
 278                   image[i][j][0] = 50;
 279                   image[i][j][1] = 50;
 280                   image[i][j][2] = 50;
 281                }
 282                else {
 283                   image[i][j][0] = 25;
 284                   image[i][j][1] = 25;
 285                   image[i][j][2] = 25;
 286                }
 287             }
 288          }
 289          glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 8, 8, 0,
 290                       GL_RGB, GL_UNSIGNED_BYTE, (GLvoid *) image);
 291       }
 292
 293       /* Bind texObj[i] to ith texture unit */
 294       if (i < 2)
 295          glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
 296       else
 297          glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_ADD);
 298
 299       if (TexEnabled[i])
 300          glEnable(GL_TEXTURE_2D);
 301    }
 302
 303    glShadeModel(GL_FLAT);
 304    glClearColor(0.3, 0.3, 0.4, 1.0);
 305
 306    if (argc > 1 && strcmp(argv[1], "-info")==0) {
 307       printf("GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
 308       printf("GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
 309       printf("GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
 310       printf("GL_EXTENSIONS = %s\n", (char *) glGetString(GL_EXTENSIONS));
 311    }
 312 }
 313
 314
 315 int main( int argc, char *argv[] )
 316 {
 317    GLint i;
 318
 319    glutInit( &argc, argv );
 320    glutInitWindowSize( 300, 300 );
 321    glutInitWindowPosition( 0, 0 );
 322    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
 323    glutCreateWindow(argv[0] );
 324
 325    Init( argc, argv );
 326
 327    glutReshapeFunc( Reshape );
 328    glutKeyboardFunc( Key );
 329    glutSpecialFunc( SpecialKey );
 330    glutDisplayFunc( Display );
 331    glutIdleFunc( Idle );
 332
 333    glutCreateMenu(ModeMenu);
 334
 335    for (i = 0; i < NumUnits; i++) {
 336       char s[100];
 337       sprintf(s, "Toggle Texture %d", i);
 338       glutAddMenuEntry(s, TEX0 + i);
 339    }
 340    glutAddMenuEntry("Toggle Animation", ANIMATE);
 341    glutAddMenuEntry("Quit", QUIT);
 342    glutAttachMenu(GLUT_RIGHT_BUTTON);
 343
 344    glutMainLoop();
 345    return 0;
 346 }