src/engine/tga.c

   1 /**
   2  * Copyright 2018-2020 Iwo 'Outfrost' Bujkiewicz
   3  *
   4  * This Source Code Form is subject to the terms of the Mozilla Public
   5  * License, v. 2.0. If a copy of the MPL was not distributed with this
   6  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   7  */
   8
   9 #include "tga.h"
  10
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13
  14 TgaImage* readTga(const char* path) {
  15         FILE* tgaFile = fopen(path, "rb");
  16         if (tgaFile == NULL) {
  17                 return NULL;
  18         }
  19
  20         TgaHeader header;
  21
  22         if (fread(&header, sizeof(TgaHeader), 1, tgaFile) != 1) {
  23                 fclose(tgaFile);
  24                 return NULL;
  25         }
  26
  27         GLenum imageFormat;
  28         GLint imageComponents;
  29
  30         switch (header.imageBpp) {
  31                 case 32:
  32                         imageFormat = GL_BGRA;
  33                         imageComponents = GL_RGBA8;
  34                         break;
  35                 case 24:
  36                         imageFormat = GL_BGR;
  37                         imageComponents = GL_RGB8;
  38                         break;
  39                 case 8:
  40                         imageFormat = GL_LUMINANCE;
  41                         imageComponents = GL_LUMINANCE8;
  42                         break;
  43                 default:
  44                         fclose(tgaFile);
  45                         return NULL;
  46         }
  47
  48         unsigned long imageSize = header.imageWidth * header.imageHeight * (header.imageBpp >> 3);
  49
  50         GLbyte* bytes = malloc(imageSize * sizeof(GLbyte));
  51         if (bytes == NULL) {
  52                 fclose(tgaFile);
  53                 return NULL;
  54         }
  55
  56         if (fread(bytes, imageSize, 1, tgaFile) != 1) {
  57                 free(bytes);
  58                 fclose(tgaFile);
  59                 return NULL;
  60         }
  61
  62         fclose(tgaFile);
  63
  64         TgaImage* image = malloc(sizeof(TgaImage));
  65         if (image == NULL) {
  66                 return NULL;
  67         }
  68
  69         (*image).header = header;
  70         (*image).imageFormat = imageFormat;
  71         (*image).imageComponents = imageComponents;
  72         (*image).bytes = bytes;
  73
  74         return image;
  75 }