progs/tests/texcompsub.c

   1 /*
   2  * Test texture compression.
   3  */
   4
   5
   6 #include <assert.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <GL/glew.h>
  11 #include <GL/glut.h>
  12
  13 #include "texcomp_image.h"
  14
  15 static int ImgWidth = 512;
  16 static int ImgHeight = 512;
  17 static GLenum CompFormat = GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
  18 static GLfloat EyeDist = 5.0;
  19 static GLfloat Rot = 0.0;
  20 const GLenum Target = GL_TEXTURE_2D;
  21
  22
  23 static void
  24 CheckError(int line)
  25 {
  26    GLenum err = glGetError();
  27    if (err) {
  28       printf("GL Error %d at line %d\n", (int) err, line);
  29    }
  30 }
  31
  32 static void
  33 LoadCompressedImage(void)
  34 {
  35    unsigned char ImgDataTemp[ImgSize / 4];
  36    unsigned i;
  37    const GLenum filter = GL_LINEAR;
  38    const int half = ImgSize / 2;
  39
  40    glTexImage2D(Target, 0, CompFormat, ImgWidth, ImgHeight, 0,
  41                 GL_RGB, GL_UNSIGNED_BYTE, NULL);
  42
  43    /* bottom half */
  44    glCompressedTexSubImage2DARB(Target, 0,
  45                                 0, 0, /* pos */
  46                                 ImgWidth, ImgHeight / 2,
  47                                 CompFormat, ImgSize / 2, ImgData /*+ ImgSize / 2*/);
  48
  49    /* top left */
  50    for (i = 0; i < ImgHeight / 8; i++) {
  51       memcpy(&ImgDataTemp[i * ImgWidth], &ImgData[half + i * 2 * ImgWidth], ImgWidth);
  52    }
  53    glCompressedTexSubImage2DARB(Target, 0,
  54                                 0, ImgHeight / 2, /* pos */
  55                                 ImgWidth / 2, ImgHeight / 2,
  56                                 CompFormat, ImgSize / 4, ImgDataTemp);
  57
  58    /* top right */
  59    for (i = 0; i < ImgHeight / 8; i++) {
  60       memcpy(&ImgDataTemp[i * ImgWidth], &ImgData[half + i * 2 * ImgWidth + ImgWidth], ImgWidth);
  61    }
  62    glCompressedTexSubImage2DARB(Target, 0,
  63                                 ImgWidth / 2, ImgHeight / 2, /* pos */
  64                                 ImgWidth / 2, ImgHeight / 2,
  65                                 CompFormat, ImgSize / 4, ImgDataTemp);
  66
  67    glTexParameteri(Target, GL_TEXTURE_MIN_FILTER, filter);
  68    glTexParameteri(Target, GL_TEXTURE_MAG_FILTER, filter);
  69 }
  70
  71 static void
  72 Init()
  73 {
  74    GLint numFormats, formats[100];
  75    GLint p;
  76
  77    if (!glutExtensionSupported("GL_ARB_texture_compression")) {
  78       printf("Sorry, GL_ARB_texture_compression is required.\n");
  79       exit(1);
  80    }
  81    if (!glutExtensionSupported("GL_EXT_texture_compression_s3tc")) {
  82       printf("Sorry, GL_EXT_texture_compression_s3tc is required.\n");
  83       exit(1);
  84    }
  85
  86    printf("GL_VERSION = %s\n", (char *) glGetString(GL_VERSION));
  87    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
  88
  89    glGetIntegerv(GL_NUM_COMPRESSED_TEXTURE_FORMATS_ARB, &numFormats);
  90    glGetIntegerv(GL_COMPRESSED_TEXTURE_FORMATS_ARB, formats);
  91    printf("%d supported compression formats: ", numFormats);
  92    for (p = 0; p < numFormats; p++)
  93       printf("0x%x ", formats[p]);
  94    printf("\n");
  95
  96    glEnable(GL_TEXTURE_2D);
  97
  98    LoadCompressedImage();
  99 }
 100
 101
 102 static void
 103 Reshape( int width, int height )
 104 {
 105    glViewport( 0, 0, width, height );
 106    glMatrixMode( GL_PROJECTION );
 107    glLoadIdentity();
 108    glFrustum(-1, 1, -1, 1, 4, 100);
 109    glMatrixMode( GL_MODELVIEW );
 110    glLoadIdentity();
 111 }
 112
 113
 114 static void
 115 Key( unsigned char key, int x, int y )
 116 {
 117    (void) x;
 118    (void) y;
 119    switch (key) {
 120       case 'd':
 121          EyeDist -= 1.0;
 122          if (EyeDist < 4.0)
 123             EyeDist = 4.0;
 124          break;
 125       case 'D':
 126          EyeDist += 1.0;
 127          break;
 128       case 'z':
 129          Rot += 5.0;
 130          break;
 131       case 'Z':
 132          Rot -= 5.0;
 133          break;
 134       case 27:
 135          exit(0);
 136          break;
 137    }
 138    glutPostRedisplay();
 139 }
 140
 141
 142 static void
 143 Draw( void )
 144 {
 145    glClearColor(0.3, 0.3, .8, 0);
 146    glClear(GL_COLOR_BUFFER_BIT);
 147
 148    CheckError(__LINE__);
 149    glPushMatrix();
 150    glTranslatef(0, 0, -(EyeDist+0.01));
 151    glRotatef(Rot, 0, 0, 1);
 152    glBegin(GL_POLYGON);
 153    glTexCoord2f(0, 0);  glVertex2f(-1, -1);
 154    glTexCoord2f(1, 0);  glVertex2f( 1, -1);
 155    glTexCoord2f(1, 1);  glVertex2f( 1,  1);
 156    glTexCoord2f(0, 1);  glVertex2f(-1,  1);
 157    glEnd();
 158    glPopMatrix();
 159
 160    glutSwapBuffers();
 161 }
 162
 163
 164 int
 165 main( int argc, char *argv[] )
 166 {
 167    glutInit( &argc, argv );
 168    glutInitWindowSize( 600, 600 );
 169
 170    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE);
 171
 172    glutCreateWindow(argv[0]);
 173    glewInit();
 174
 175    glutReshapeFunc( Reshape );
 176    glutKeyboardFunc( Key );
 177    glutDisplayFunc( Draw );
 178
 179    Init();
 180
 181    glutMainLoop();
 182    return 0;
 183 }