progs/demos/multiarb.c

   1 /*
   2  * GL_ARB_multitexture demo
   3  *
   4  * Command line options:
   5  *    -info      print GL implementation information
   6  *
   7  *
   8  * Brian Paul  November 1998  This program is in the public domain.
   9  * Modified on 12 Feb 2002 for > 2 texture units.
  10  */
  11
  12
  13 #include <math.h>
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <string.h>
  17 #include <GL/glut.h>
  18
  19 #include "readtex.h"
  20
  21 #define TEXTURE_1_FILE "../images/girl.rgb"
  22 #define TEXTURE_2_FILE "../images/reflect.rgb"
  23
  24 #define TEX0 1
  25 #define TEX7 8
  26 #define ANIMATE 10
  27 #define QUIT 100
  28
  29 static GLboolean Animate = GL_TRUE;
  30 static GLint NumUnits = 1;
  31 static GLboolean TexEnabled[8];
  32
  33 static GLfloat Drift = 0.0;
  34 static GLfloat Xrot = 20.0, Yrot = 30.0, Zrot = 0.0;
  35
  36
  37 static void Idle( void )
  38 {
  39    if (Animate) {
  40       GLint i;
  41
  42       Drift = glutGet(GLUT_ELAPSED_TIME) * 0.001;
  43
  44       for (i = 0; i < NumUnits; i++) {
  45          glActiveTextureARB(GL_TEXTURE0_ARB + i);
  46          glMatrixMode(GL_TEXTURE);
  47          glLoadIdentity();
  48          if (i == 0) {
  49             glTranslatef(Drift, 0.0, 0.0);
  50             glScalef(2, 2, 1);
  51          }
  52          else if (i == 1) {
  53             glTranslatef(0.0, Drift, 0.0);
  54          }
  55          else {
  56             float tx = 0.5, ty = 0.5;
  57             glTranslatef(tx, ty, 0.0);
  58             glRotatef(180.0 * Drift, 0, 0, 1);
  59             glScalef(1.0/i, 1.0/i, 1.0/i);
  60             glTranslatef(-tx, -ty + i * 0.1, 0.0);
  61          }
  62       }
  63       glMatrixMode(GL_MODELVIEW);
  64
  65       glutPostRedisplay();
  66    }
  67 }
  68
  69
  70 static void DrawObject(void)
  71 {
  72    static const GLfloat tex_coords[] = {  0.0,  0.0,  1.0,  1.0,  0.0 };
  73    static const GLfloat vtx_coords[] = { -1.0, -1.0,  1.0,  1.0, -1.0 };
  74    GLint i, j;
  75
  76    if (!TexEnabled[0] && !TexEnabled[1])
  77       glColor3f(0.1, 0.1, 0.1);  /* add onto this */
  78    else
  79       glColor3f(1, 1, 1);  /* modulate this */
  80
  81    glBegin(GL_QUADS);
  82    for (j = 0; j < 4; j++ ) {
  83       for (i = 0; i < NumUnits; i++) {
  84          if (TexEnabled[i])
  85             glMultiTexCoord2fARB(GL_TEXTURE0_ARB + i,
  86                                  tex_coords[j], tex_coords[j+1]);
  87       }
  88       glVertex2f( vtx_coords[j], vtx_coords[j+1] );
  89    }
  90    glEnd();
  91 }
  92
  93
  94 static void Display( void )
  95 {
  96    glClear( GL_COLOR_BUFFER_BIT );
  97
  98    glPushMatrix();
  99       glRotatef(Xrot, 1.0, 0.0, 0.0);
 100       glRotatef(Yrot, 0.0, 1.0, 0.0);
 101       glRotatef(Zrot, 0.0, 0.0, 1.0);
 102       glScalef(5.0, 5.0, 5.0);
 103       DrawObject();
 104    glPopMatrix();
 105
 106    glutSwapBuffers();
 107 }
 108
 109
 110 static void Reshape( int width, int height )
 111 {
 112    glViewport( 0, 0, width, height );
 113    glMatrixMode( GL_PROJECTION );
 114    glLoadIdentity();
 115    glFrustum( -1.0, 1.0, -1.0, 1.0, 10.0, 100.0 );
 116    /*glOrtho( -6.0, 6.0, -6.0, 6.0, 10.0, 100.0 );*/
 117    glMatrixMode( GL_MODELVIEW );
 118    glLoadIdentity();
 119    glTranslatef( 0.0, 0.0, -70.0 );
 120 }
 121
 122
 123 static void ToggleUnit(int unit)
 124 {
 125    TexEnabled[unit] = !TexEnabled[unit];
 126    glActiveTextureARB(GL_TEXTURE0_ARB + unit);
 127    if (TexEnabled[unit])
 128       glEnable(GL_TEXTURE_2D);
 129    else
 130       glDisable(GL_TEXTURE_2D);
 131    printf("Enabled: ");
 132    for (unit = 0; unit < NumUnits; unit++)
 133       printf("%d ", (int) TexEnabled[unit]);
 134    printf("\n");
 135 }
 136
 137
 138 static void ModeMenu(int entry)
 139 {
 140    if (entry >= TEX0 && entry <= TEX7) {
 141       /* toggle */
 142       GLint i = entry - TEX0;
 143       ToggleUnit(i);
 144    }
 145    else if (entry==ANIMATE) {
 146       Animate = !Animate;
 147       if (Animate)
 148          glutIdleFunc(Idle);
 149       else
 150          glutIdleFunc(NULL);
 151    }
 152    else if (entry==QUIT) {
 153       exit(0);
 154    }
 155
 156    glutPostRedisplay();
 157 }
 158
 159
 160 static void Key( unsigned char key, int x, int y )
 161 {
 162    (void) x;
 163    (void) y;
 164    switch (key) {
 165    case 'a':
 166       Animate = !Animate;
 167       break;
 168    case '0':
 169       ToggleUnit(0);
 170       break;
 171    case '1':
 172       ToggleUnit(1);
 173       break;
 174    case '2':
 175       ToggleUnit(2);
 176       break;
 177    case '3':
 178       ToggleUnit(3);
 179       break;
 180    case '4':
 181       ToggleUnit(4);
 182       break;
 183    case '5':
 184       ToggleUnit(5);
 185       break;
 186    case '6':
 187       ToggleUnit(6);
 188       break;
 189    case '7':
 190       ToggleUnit(7);
 191       break;
 192    case 27:
 193       exit(0);
 194       break;
 195    }
 196    glutPostRedisplay();
 197 }
 198
 199
 200 static void SpecialKey( int key, int x, int y )
 201 {
 202    float step = 3.0;
 203    (void) x;
 204    (void) y;
 205
 206    switch (key) {
 207       case GLUT_KEY_UP:
 208          Xrot += step;
 209          break;
 210       case GLUT_KEY_DOWN:
 211          Xrot -= step;
 212          break;
 213       case GLUT_KEY_LEFT:
 214          Yrot += step;
 215          break;
 216       case GLUT_KEY_RIGHT:
 217          Yrot -= step;
 218          break;
 219    }
 220    glutPostRedisplay();
 221 }
 222
 223
 224 static void Init( int argc, char *argv[] )
 225 {
 226    GLuint texObj[8];
 227    GLint size, i;
 228
 229    const char *exten = (const char *) glGetString(GL_EXTENSIONS);
 230    if (!strstr(exten, "GL_ARB_multitexture")) {
 231       printf("Sorry, GL_ARB_multitexture not supported by this renderer.\n");
 232       exit(1);
 233    }
 234
 235    glGetIntegerv(GL_MAX_TEXTURE_UNITS_ARB, &NumUnits);
 236    printf("%d texture units supported\n", NumUnits);
 237    if (NumUnits > 8)
 238       NumUnits = 8;
 239
 240    glGetIntegerv(GL_MAX_TEXTURE_SIZE, &size);
 241    printf("%d x %d max texture size\n", size, size);
 242
 243    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 244
 245    for (i = 0; i < NumUnits; i++) {
 246       if (i < 2)
 247          TexEnabled[i] = GL_TRUE;
 248       else
 249          TexEnabled[i] = GL_FALSE;
 250    }
 251
 252    /* allocate two texture objects */
 253    glGenTextures(NumUnits, texObj);
 254
 255    /* setup the texture objects */
 256    for (i = 0; i < NumUnits; i++) {
 257
 258       glActiveTextureARB(GL_TEXTURE0_ARB + i);
 259       glBindTexture(GL_TEXTURE_2D, texObj[i]);
 260
 261       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 262       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 263
 264       if (i == 0) {
 265          if (!LoadRGBMipmaps(TEXTURE_1_FILE, GL_RGB)) {
 266             printf("Error: couldn't load texture image\n");
 267             exit(1);
 268          }
 269       }
 270       else if (i == 1) {
 271          if (!LoadRGBMipmaps(TEXTURE_2_FILE, GL_RGB)) {
 272             printf("Error: couldn't load texture image\n");
 273             exit(1);
 274          }
 275       }
 276       else {
 277          /* checker */
 278          GLubyte image[8][8][3];
 279          GLint i, j;
 280          for (i = 0; i < 8; i++) {
 281             for (j = 0; j < 8; j++) {
 282                if ((i + j) & 1) {
 283                   image[i][j][0] = 50;
 284                   image[i][j][1] = 50;
 285                   image[i][j][2] = 50;
 286                }
 287                else {
 288                   image[i][j][0] = 25;
 289                   image[i][j][1] = 25;
 290                   image[i][j][2] = 25;
 291                }
 292             }
 293          }
 294          glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 8, 8, 0,
 295                       GL_RGB, GL_UNSIGNED_BYTE, (GLvoid *) image);
 296       }
 297
 298       /* Bind texObj[i] to ith texture unit */
 299       if (i < 2)
 300          glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
 301       else
 302          glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_ADD);
 303
 304       if (TexEnabled[i])
 305          glEnable(GL_TEXTURE_2D);
 306    }
 307
 308    glShadeModel(GL_FLAT);
 309    glClearColor(0.3, 0.3, 0.4, 1.0);
 310
 311    if (argc > 1 && strcmp(argv[1], "-info")==0) {
 312       printf("GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
 313       printf("GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
 314       printf("GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
 315       printf("GL_EXTENSIONS = %s\n", (char *) glGetString(GL_EXTENSIONS));
 316    }
 317 }
 318
 319
 320 int main( int argc, char *argv[] )
 321 {
 322    GLint i;
 323
 324    glutInit( &argc, argv );
 325    glutInitWindowSize( 300, 300 );
 326    glutInitWindowPosition( 0, 0 );
 327    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
 328    glutCreateWindow(argv[0] );
 329
 330    Init( argc, argv );
 331
 332    glutReshapeFunc( Reshape );
 333    glutKeyboardFunc( Key );
 334    glutSpecialFunc( SpecialKey );
 335    glutDisplayFunc( Display );
 336    if (Animate)
 337       glutIdleFunc(Idle);
 338
 339    glutCreateMenu(ModeMenu);
 340
 341    for (i = 0; i < NumUnits; i++) {
 342       char s[100];
 343       sprintf(s, "Toggle Texture %d", i);
 344       glutAddMenuEntry(s, TEX0 + i);
 345    }
 346    glutAddMenuEntry("Toggle Animation", ANIMATE);
 347    glutAddMenuEntry("Quit", QUIT);
 348    glutAttachMenu(GLUT_RIGHT_BUTTON);
 349
 350    glutMainLoop();
 351    return 0;
 352 }