opengl_x11

Playing with OpenGL
git clone git://bsandro.tech/opengl_x11
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astc.h (4139B)

      1 #pragma once
      2 
      3 #define GL_GLEXT_PROTOTYPES 1
      4 #include <GL/gl.h>
      5 #include <GL/glx.h>
      6 #include <GL/glu.h>
      7 
      8 #define GL_CHECK(x)                                                                           \
      9 x;                                                                                            \
     10 {                                                                                             \
     11     GLenum glError = glGetError();                                                            \
     12     if (glError!=GL_NO_ERROR) {                                                               \
     13         printf("glGetError() = %i (%#.8x) at %s:%i\n", glError, glError, __FILE__, __LINE__); \
     14         exit(EXIT_FAILURE);                                                                   \
     15     }                                                                                         \
     16 }
     17 
     18 #define CHECK_ASTC_FORMAT(bx, by) if (x==bx&&y==by) return GL_COMPRESSED_RGBA_ASTC_##bx##x##by##_KHR;
     19 #define ASTC_EXT ".astc"
     20 #define ASTC_LEN 5
     21 
     22 /* ASTC header declaration. */
     23 typedef struct
     24 {
     25     uint8_t magic[4];
     26     uint8_t blockdim_x;
     27     uint8_t blockdim_y;
     28     uint8_t blockdim_z;
     29     uint8_t xsize[3];
     30     uint8_t ysize[3];
     31     uint8_t zsize[3];
     32 } astc_header;
     33 
     34 static GLenum get_astc_format(uint8_t x, uint8_t y) {
     35     CHECK_ASTC_FORMAT(4,4)
     36     CHECK_ASTC_FORMAT(5,4)
     37     CHECK_ASTC_FORMAT(5,5)
     38     CHECK_ASTC_FORMAT(6,5)
     39     CHECK_ASTC_FORMAT(6,6)
     40     CHECK_ASTC_FORMAT(8,5)
     41     CHECK_ASTC_FORMAT(8,6)
     42     CHECK_ASTC_FORMAT(8,8)
     43     CHECK_ASTC_FORMAT(10,5)
     44     CHECK_ASTC_FORMAT(10,6)
     45     CHECK_ASTC_FORMAT(10,8)
     46     CHECK_ASTC_FORMAT(10,10)
     47     CHECK_ASTC_FORMAT(12,10)
     48     CHECK_ASTC_FORMAT(12,12)
     49     printf("invalid ASTC block size\n");
     50     exit(-1);
     51 }
     52 
     53 static GLuint mkTextureAstc(const char *filename) {
     54     FILE *f = fopen(filename, "rb");
     55     if (f==NULL) {
     56         printf("error loading file %s\n", filename);
     57         exit(EXIT_FAILURE);
     58     }
     59 
     60     fseek(f, 0, SEEK_END);
     61     int64_t fsize = ftell(f);
     62     rewind(f);
     63 
     64     printf("astc file size: %lld bytes\n", fsize);
     65 
     66     uint8_t *data = malloc(fsize);
     67     if (fread(data, 1, fsize, f) != fsize) {
     68         printf("error reading file %s\n", filename);
     69         exit(EXIT_FAILURE);
     70     }
     71 
     72     const astc_header *astc_data = (astc_header *)data;
     73     printf("astc block: %dx%d\n", astc_data->blockdim_x, astc_data->blockdim_y);
     74     GLenum astc_format = get_astc_format(astc_data->blockdim_x, astc_data->blockdim_y);
     75     /* Merge x,y,z-sizes from 3 chars into one integer value. */
     76     GLsizei xsize = astc_data->xsize[0] + (astc_data->xsize[1] << 8) + (astc_data->xsize[2] << 16);
     77     GLsizei ysize = astc_data->ysize[0] + (astc_data->ysize[1] << 8) + (astc_data->ysize[2] << 16);
     78     GLsizei zsize = astc_data->zsize[0] + (astc_data->zsize[1] << 8) + (astc_data->zsize[2] << 16);
     79 
     80     printf("astc dimensions: %dx%d\n", xsize, ysize);
     81 
     82     /* Compute number of blocks in each direction. */
     83     GLsizei xblocks = (xsize + astc_data->blockdim_x - 1) / astc_data->blockdim_x;
     84     GLsizei yblocks = (ysize + astc_data->blockdim_y - 1) / astc_data->blockdim_y;
     85     GLsizei zblocks = (zsize + astc_data->blockdim_z - 1) / astc_data->blockdim_z;
     86 
     87     // maybe we can do just fsize-16 here
     88     GLsizei astc_size = xblocks * yblocks * zblocks << 4;
     89 
     90     printf("astc data size: %lld bytes\n", astc_size);
     91 
     92     GLuint tex;
     93     GL_CHECK(glGenTextures(1, &tex));
     94     GL_CHECK(glBindTexture(GL_TEXTURE_2D, tex));
     95     GL_CHECK(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT)); // GL_REPEAT
     96     GL_CHECK(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT)); // GL_CLAMP_TO_EDGE
     97     //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
     98     GL_CHECK(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST));
     99     GL_CHECK(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST));
    100     GL_CHECK(glCompressedTexImage2D(GL_TEXTURE_2D, 0, astc_format, xsize, ysize, 0, astc_size, (const GLvoid *)astc_data));
    101     //GL_CHECK(glGenerateMipmap(GL_TEXTURE_2D));
    102     GL_CHECK(glEnable(GL_TEXTURE_2D));
    103 
    104     fclose(f);
    105     free(data);
    106     return tex;
    107 }