progs/tests/texcompress2.c

   1 /*
   2  * Test texture compression.
   3  */
   4
   5
   6 #include <assert.h>
   7 #include <stdio.h>
   8 #include <GL/glew.h>
   9 #include <GL/glut.h>
  10 #include "readtex.c"
  11
  12 #define IMAGE_FILE "../images/arch.rgb"
  13
  14 static int ImgWidth, ImgHeight;
  15 static GLenum ImgFormat;
  16 static GLenum CompFormat;
  17 static GLfloat EyeDist = 5.0;
  18 static GLfloat Rot = 0.0;
  19 const GLenum Target = GL_TEXTURE_2D;
  20
  21
  22 static void
  23 CheckError(int line)
  24 {
  25    GLenum err = glGetError();
  26    if (err) {
  27       printf("GL Error %d at line %d\n", (int) err, line);
  28    }
  29 }
  30
  31
  32 static const char *
  33 LookupFormat(GLenum format)
  34 {
  35    switch (format) {
  36    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
  37       return "GL_COMPRESSED_RGB_S3TC_DXT1_EXT";
  38    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
  39       return "GL_COMPRESSED_RGBA_S3TC_DXT1_EXT";
  40    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
  41       return "GL_COMPRESSED_RGBA_S3TC_DXT3_EXT";
  42    default:
  43       return "other";
  44    }
  45 }
  46
  47
  48 static void
  49 TestSubTex(void)
  50 {
  51    GLboolean all = 0*GL_TRUE;
  52    GLubyte *buffer;
  53    GLint size, fmt;
  54
  55    glGetTexLevelParameteriv(Target, 0,
  56                             GL_TEXTURE_COMPRESSED_IMAGE_SIZE_ARB, &size);
  57    glGetTexLevelParameteriv(Target, 0, GL_TEXTURE_INTERNAL_FORMAT, &fmt);
  58
  59    buffer = (GLubyte *) malloc(size);
  60    glGetCompressedTexImageARB(Target, 0, buffer);
  61
  62    printf("Testing sub-texture replacement\n");
  63    if (all)
  64       glCompressedTexImage2DARB(Target, 0,
  65                                 fmt, ImgWidth, ImgHeight, 0,
  66                                 size, buffer);
  67    else {
  68       /* bottom half */
  69       glCompressedTexSubImage2DARB(Target, 0,
  70                                    0, 0, /* pos */
  71                                    ImgWidth, ImgHeight / 2,
  72                                    fmt, size/2, buffer);
  73       /* top half */
  74       glCompressedTexSubImage2DARB(Target, 0,
  75                                    0, ImgHeight / 2, /* pos */
  76                                    ImgWidth, ImgHeight / 2,
  77                                    fmt, size/2, buffer + size / 2);
  78    }
  79
  80    free(buffer);
  81 }
  82
  83
  84 static void
  85 TestGetTex(void)
  86 {
  87    GLubyte *buffer;
  88
  89    buffer = (GLubyte *) malloc(3 * ImgWidth * ImgHeight);
  90
  91    glGetTexImage(GL_TEXTURE_2D,
  92                  0,
  93                  GL_RGB,
  94                  GL_UNSIGNED_BYTE,
  95                  buffer);
  96
  97    free(buffer);
  98 }
  99
 100
 101 static void
 102 LoadCompressedImage(const char *file)
 103 {
 104    const GLenum filter = GL_LINEAR;
 105    GLubyte *image;
 106    GLint p;
 107
 108    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 109    glPixelStorei(GL_PACK_ALIGNMENT, 1);
 110
 111    /*
 112     * Load image and scale if needed.
 113     */
 114    image = LoadRGBImage( file, &ImgWidth, &ImgHeight, &ImgFormat );
 115    if (!image) {
 116       printf("Couldn't read %s\n", IMAGE_FILE);
 117       exit(0);
 118    }
 119    printf("Image is %d x %d\n", ImgWidth, ImgHeight);
 120
 121    /* power of two */
 122    assert(ImgWidth == 128 || ImgWidth == 256 || ImgWidth == 512);
 123    assert(ImgWidth == 128 || ImgHeight == 256 || ImgHeight == 512);
 124
 125    if (ImgFormat == GL_RGB)
 126       CompFormat = GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
 127    else
 128       CompFormat = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
 129
 130    if (ImgFormat == GL_RGBA) {
 131       int i, numAlpha = 0;
 132       for (i = 0; i < ImgWidth * ImgHeight; i++) {
 133          if (image[i*4+3] != 0 && image[i*4+3] != 0xff) {
 134             numAlpha++;
 135          }
 136          if (image[i*4+3] == 0)
 137             image[i*4+3] = 4 * i / ImgWidth;
 138       }
 139       printf("Num Alpha !=0,255: %d\n", numAlpha);
 140    }
 141
 142    CompFormat = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
 143
 144
 145    /*
 146     * Give image to OpenGL and have it compress it.
 147     */
 148    glTexImage2D(Target, 0, CompFormat, ImgWidth, ImgHeight, 0,
 149                 ImgFormat, GL_UNSIGNED_BYTE, image);
 150    CheckError(__LINE__);
 151
 152    free(image);
 153
 154    glGetTexLevelParameteriv(Target, 0, GL_TEXTURE_INTERNAL_FORMAT, &p);
 155    printf("Compressed Internal Format: %s (0x%x)\n", LookupFormat(p), p);
 156    assert(p == CompFormat);
 157
 158    printf("Original size:   %d bytes\n", ImgWidth * ImgHeight * 3);
 159    glGetTexLevelParameteriv(Target, 0, GL_TEXTURE_COMPRESSED_IMAGE_SIZE_ARB, &p);
 160    printf("Compressed size: %d bytes\n", p);
 161
 162    glTexParameteri(Target, GL_TEXTURE_MIN_FILTER, filter);
 163    glTexParameteri(Target, GL_TEXTURE_MAG_FILTER, filter);
 164
 165    if (0)
 166       TestSubTex();
 167    else
 168       TestGetTex();
 169
 170 }
 171
 172
 173 static void
 174 Init(const char *file)
 175 {
 176    GLint numFormats, formats[100];
 177    GLint p;
 178
 179    if (!glutExtensionSupported("GL_ARB_texture_compression")) {
 180       printf("Sorry, GL_ARB_texture_compression is required.\n");
 181       exit(1);
 182    }
 183    if (!glutExtensionSupported("GL_EXT_texture_compression_s3tc")) {
 184       printf("Sorry, GL_EXT_texture_compression_s3tc is required.\n");
 185       exit(1);
 186    }
 187
 188    printf("GL_VERSION = %s\n", (char *) glGetString(GL_VERSION));
 189    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
 190
 191    glGetIntegerv(GL_NUM_COMPRESSED_TEXTURE_FORMATS_ARB, &numFormats);
 192    glGetIntegerv(GL_COMPRESSED_TEXTURE_FORMATS_ARB, formats);
 193    printf("%d supported compression formats: ", numFormats);
 194    for (p = 0; p < numFormats; p++)
 195       printf("0x%x ", formats[p]);
 196    printf("\n");
 197
 198    LoadCompressedImage(file);
 199
 200    glEnable(GL_TEXTURE_2D);
 201
 202    if (ImgFormat == GL_RGBA) {
 203       glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 204       glEnable(GL_BLEND);
 205    }
 206 }
 207
 208
 209 static void
 210 Reshape( int width, int height )
 211 {
 212    glViewport( 0, 0, width, height );
 213    glMatrixMode( GL_PROJECTION );
 214    glLoadIdentity();
 215    glFrustum(-1, 1, -1, 1, 4, 100);
 216    glMatrixMode( GL_MODELVIEW );
 217    glLoadIdentity();
 218 }
 219
 220
 221 static void
 222 Key( unsigned char key, int x, int y )
 223 {
 224    (void) x;
 225    (void) y;
 226    switch (key) {
 227       case 'd':
 228          EyeDist -= 1.0;
 229          if (EyeDist < 4.0)
 230             EyeDist = 4.0;
 231          break;
 232       case 'D':
 233          EyeDist += 1.0;
 234          break;
 235       case 'z':
 236          Rot += 5.0;
 237          break;
 238       case 'Z':
 239          Rot -= 5.0;
 240          break;
 241       case 27:
 242          exit(0);
 243          break;
 244    }
 245    glutPostRedisplay();
 246 }
 247
 248
 249 static void
 250 Draw( void )
 251 {
 252    glClearColor(0.3, 0.3, .8, 0);
 253    glClear(GL_COLOR_BUFFER_BIT);
 254
 255    glPushMatrix();
 256    glTranslatef(0, 0, -(EyeDist+0.01));
 257    glRotatef(Rot, 0, 0, 1);
 258    glBegin(GL_POLYGON);
 259    glTexCoord2f(0, 0);  glVertex2f(-1, -1);
 260    glTexCoord2f(1, 0);  glVertex2f( 1, -1);
 261    glTexCoord2f(1, 1);  glVertex2f( 1,  1);
 262    glTexCoord2f(0, 1);  glVertex2f(-1,  1);
 263    glEnd();
 264    glPopMatrix();
 265
 266    glutSwapBuffers();
 267 }
 268
 269
 270 int
 271 main( int argc, char *argv[] )
 272 {
 273    glutInit( &argc, argv );
 274    glutInitWindowSize( 600, 600 );
 275
 276    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE);
 277
 278    glutCreateWindow(argv[0]);
 279    glewInit();
 280
 281    glutReshapeFunc( Reshape );
 282    glutKeyboardFunc( Key );
 283    glutDisplayFunc( Draw );
 284
 285    if (argc > 1)
 286       Init(argv[1]);
 287    else
 288       Init(IMAGE_FILE);
 289
 290    glutMainLoop();
 291    return 0;
 292 }