tga.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3
   4 #include "tga.h"
   5
   6 TgaImage* readTga(const char* path) {
   7         FILE* tgaFile = fopen(path, "rb");
   8         if (tgaFile == NULL) {
   9                 return NULL;
  10         }
  11
  12         TgaHeader header;
  13
  14         if (fread(&header, sizeof(TgaHeader), 1, tgaFile) != 1) {
  15                 fclose(tgaFile);
  16                 return NULL;
  17         }
  18
  19         GLenum imageFormat;
  20         GLint imageComponents;
  21
  22         switch (header.imageBpp) {
  23                 case 32:
  24                         imageFormat = GL_BGRA_EXT;
  25                         imageComponents = GL_RGBA8;
  26                         break;
  27                 case 24:
  28                         imageFormat = GL_BGR_EXT;
  29                         imageComponents = GL_RGB8;
  30                         break;
  31                 case 8:
  32                         imageFormat = GL_LUMINANCE;
  33                         imageComponents = GL_LUMINANCE8;
  34                         break;
  35                 default:
  36                         fclose(tgaFile);
  37                         return NULL;
  38         }
  39
  40         unsigned long imageSize = header.imageWidth * header.imageHeight * (header.imageBpp >> 3);
  41
  42         GLbyte* bytes = malloc(imageSize * sizeof(GLbyte));
  43         if (bytes == NULL) {
  44                 fclose(tgaFile);
  45                 return NULL;
  46         }
  47
  48         if (fread(bytes, imageSize, 1, tgaFile) != 1) {
  49                 free(bytes);
  50                 fclose(tgaFile);
  51                 return NULL;
  52         }
  53
  54         fclose(tgaFile);
  55
  56         TgaImage* image = malloc(sizeof(TgaImage));
  57         if (image == NULL) {
  58                 return NULL;
  59         }
  60
  61         (*image).header = header;
  62         (*image).imageFormat = imageFormat;
  63         (*image).imageComponents = imageComponents;
  64         (*image).bytes = bytes;
  65
  66         return image;
  67 }