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