tga.c

   1 #include <GL/gl.h>
   2
   3 #include <stdlib.h>
   4 #include <stdio.h>
   5
   6 #include "tga.h"
   7
   8 TGAimage* read_tga(const char* path) {
   9         FILE* tga_file = fopen(path, "rb");
  10         if (tga_file == NULL) {
  11                 return NULL;
  12         }
  13
  14         TGAheader header;
  15
  16         if (fread(&header, sizeof(TGAheader), 1, tga_file) != 1) {
  17                 fclose(tga_file);
  18                 return NULL;
  19         }
  20
  21         GLenum image_format;
  22         GLint image_components;
  23
  24         if (header.image_bpp == 32) {
  25                 image_format = GL_BGRA_EXT;
  26                 image_components = GL_RGBA8;
  27         }
  28         else if (header.image_bpp == 24) {
  29                 image_format = GL_BGR_EXT;
  30                 image_components = GL_RGB8;
  31         }
  32         else if (header.image_bpp == 8) {
  33                 image_format = GL_LUMINANCE;
  34                 image_components = GL_LUMINANCE8;
  35         }
  36         else {
  37                 fclose(tga_file);
  38                 return NULL;
  39         }
  40
  41         unsigned long image_size = header.image_width * header.image_height * (header.image_bpp >> 3);
  42
  43         GLbyte* bytes = malloc(image_size * sizeof(GLbyte));
  44         if (bytes == NULL) {
  45                 fclose(tga_file);
  46                 return NULL;
  47         }
  48
  49         if (fread(bytes, image_size, 1, tga_file) != 1) {
  50                 free(bytes);
  51                 fclose(tga_file);
  52                 return NULL;
  53         }
  54
  55         fclose(tga_file);
  56
  57         TGAimage* image = malloc(sizeof(TGAimage));
  58         if (image == NULL) {
  59                 return NULL;
  60         }
  61
  62         (*image).header = header;
  63         (*image).image_format = image_format;
  64         (*image).image_components = image_components;
  65         (*image).bytes = bytes;
  66
  67         return image;
  68 }