#pragma pack(push,1)

typedef struct {

  unsigned char  idLength;

  unsigned char  colormapType;

  unsigned char  imageType;

  unsigned char  colormapIndex[2];

  unsigned char  colormapLength[2];

  unsigned char  colormapSize;

  unsigned char  xOrigin[2];

  unsigned char  yOrigin[2];

  unsigned char  width[2];

  unsigned char  height[2];

  unsigned char  pixelSize;

  unsigned char  attributes;

} TgaHeader;

#pragma pack(pop)

unsigned short getLEU16(unsigned char *c)

    { return c[0] | ((unsigned short)c[1] << 8); }

void setLEU16(unsigned char *c, unsigned short i)

    { c[0] = i; c[1] = i >> 8; }

int imageLoadTga(const char *path, int *outWidth, int *outHeight, unsigned char **pixels) {

  *outWidth = *outHeight = 0; *pixels = NULL;

  FILE *f = fopen(path, "rb");

    if (!f) {

    fprintf(stderr, "Cannot open for read: %s\n", path);

    fflush(stderr);

    return FALSE;

  }

  TgaHeader header = {};

  fread(&header, sizeof(header), 1, f); // todo: endianess

  //printf("%d %d %d %d %d\n", header.imageType, header.width, header.height, header.colormapType, header.pixelSize);

  if ( header.imageType != 2

    || !header.width

    || !header.height

    || header.colormapType

    || (header.pixelSize != 24 && header.pixelSize != 32)

  ) {

    fprintf(stderr, "Unsupported format. Only uncompressed 24 or 32 bits TGA are supported: %s\n", path);

    fflush(stderr);

    return FALSE;

  }

  fseek(f, header.idLength, SEEK_CUR);

  int w = *outWidth = getLEU16(header.width);

  int h = *outHeight = getLEU16(header.height);

  int rowSize = w*4;

  int size = h*rowSize;

  *pixels = (unsigned char*)calloc(1, size);

  unsigned char *row = *pixels + size;

  for(unsigned short r = h; r; --r, row -= rowSize) {

    for(unsigned char *c = row - rowSize; c < row; c += 4) {

      c[2] = fgetc(f);

      c[1] = fgetc(f);

      c[0] = fgetc(f);

      c[3] = header.pixelSize == 32 ? fgetc(f) : 255;

    }

  }

  fclose(f);

  return TRUE;

}

int imageSaveTga(const char *path, int width, int height, const unsigned char *pixels) {

  if (width <= 0 || height <= 0 || width > 0xffff || height > 0xffff || !pixels) return FALSE;

  FILE *f = fopen(path, "wb");

  if (!f) {

    fprintf(stderr, "Cannot open file for write: %s\n", path);

    fflush(stderr);

    return FALSE;

  }

  TgaHeader header = {};

  header.imageType = 2;

  setLEU16(header.width, width);

  setLEU16(header.height, height);

  header.pixelSize = 32;

  fwrite(&header, sizeof(header), 1, f); // todo: endianess

  int rowSize = width*4;

  int size = height*rowSize;

  const unsigned char *row = pixels + size;

  for(unsigned short r = height; r; --r, row -= rowSize) {

    for(const unsigned char *c = row - rowSize; c < row; c += 4) {

      fputc(c[2], f);

      fputc(c[1], f);

      fputc(c[0], f);

      fputc(c[3], f);

    }

  }

  fclose(f);

  return TRUE;

}