csrTga.h

   1 #pragma pack(push, 1)
   2 struct tga_header
   3 {
   4         char  idlength;
   5         char  colourmaptype;
   6         char  datatypecode;
   7         short int colourmaporigin;
   8         short int colourmaplength;
   9         char  colourmapdepth;
  10         short int x_origin;
  11         short int y_origin;
  12         short width;
  13         short height;
  14         char  bitsperpixel;
  15         char  imagedescriptor;
  16 };
  17 #pragma pack(pop)
  18
  19 // Requires RGBA data. Can write grayscale (comp=1), RGB (comp=3) or RGBA (comp=4)
  20 int csr_tga_write( const char *path, u32 width, u32 height, int comp, u8 *rgba )
  21 {
  22         FILE *fp = fopen( path, "wb" );
  23
  24         if( fp )
  25         {
  26                 struct tga_header header =
  27                 {
  28                         .datatypecode = 2,
  29                         .width = width,
  30                         .height = height,
  31                         .bitsperpixel = comp * 8,
  32                         .imagedescriptor = 0x20
  33                 };
  34
  35                 fwrite( &header, sizeof( struct tga_header ), 1, fp );
  36
  37                 for( u32 i = 0; i < width * height; i ++ )
  38                 {
  39                         u8 *colour = rgba + i*4;
  40                         u8 flipped[4];
  41
  42                         if( comp >= 3 )
  43                         {
  44                                 flipped[0] = colour[2];
  45                                 flipped[1] = colour[1];
  46                                 flipped[2] = colour[0];
  47                                 flipped[3] = colour[3];
  48
  49                                 colour = flipped;
  50                         }
  51
  52                         fwrite( colour, 1, comp, fp );
  53                 }
  54
  55                 fclose( fp );
  56                 return 1;
  57         }
  58         else
  59         {
  60                 return 0;
  61         }
  62 }