chess_tga_image.h

#ifndef __CHESS_TGA_IMAGE_H__
#define __CHESS_TGA_IMAGE_H__

enum TGATypes {
  TGA_NODATA = 0,
  TGA_INDEXED = 1,
  TGA_RGB = 2,
  TGA_GRAYSCALE = 3,
  TGA_INDEXED_RLE = 9,
  TGA_RGB_RLE = 10,
  TGA_GRAYSCALE_RLE = 11
};

// image data formats
#define IMAGE_RGB       0
#define IMAGE_RGBA      1
#define IMAGE_LUMINANCE 2

// image data types
#define IMAGE_DATA_UNSIGNED_BYTE 0

// pixel data transfer from file to screen:
// these masks arr AND'd with the imageDesc in the TGA header,
// bit 4 is left-to-right ordering
// bit 5 is top-to-bottom
#define BOTTOM_LEFT  0x00       // first pixel is bottom left corner
#define BOTTOM_RIGHT 0x10       // first pixel is bottom right corner
#define TOP_LEFT     0x20       // first pixel is top left corner
#define TOP_RIGHT    0x30       // first pixel is top right corner

// TGA header
struct TGAHeader {
  unsigned char  idLength;		
  unsigned char  colorMapType;	
  unsigned char  imageTypeCode;	
  unsigned char  colorMapSpec[5];	
  unsigned short xOrigin;			
  unsigned short yOrigin;			
  unsigned short width;			
  unsigned short height;			
  unsigned char  bpp;				
  unsigned char  imageDesc;	
};

struct RGBA_t {
  unsigned char r;
  unsigned char g;
  unsigned char b;
  unsigned char a;
};

struct RGB_t {
  unsigned char r;
  unsigned char g;
  unsigned char b;
};

class TargaImage {
private:
  unsigned char  colorDepth;
  unsigned char  imageDataType;
  unsigned char  imageDataFormat;
  unsigned char* imageData;
  unsigned short width;
  unsigned short height;	
  unsigned long  imageSize;

  // swap the red and blue components in the image data
  void swapRedBlue();

public:
  TargaImage();
  virtual ~TargaImage();

  // loading and unloading
  bool load(const char* filename);
  void release();

  // flips image vertically
  bool flipVertical();

  unsigned short getWidth() { return width; };
  unsigned short getHeight() { return height; };
  unsigned char getImageFormat() { return imageDataFormat; };

  // converts RGB format to RGBA format and vice versa
  bool convertRGBAToRGB();
  bool convertRGBToRGBA(unsigned char alphaValue);

  // returns the current image data
  unsigned char* getImage() { return imageData; };
};

#endif // __CHESS_TGA_IMAGE_H__