aigo/lib/image.h

#ifndef _IMAGE_H_
#define _IMAGE_H_

#include <SDL/SDL.h>

// get pixel/something in array p of size w*h 
#define PX_(p, x, y, w, h) ((p)[(x)+(y)*(w)])
// get pixel in SDL_Surface i
#define PX(i,x,y) (PX_((uint32_t*)(i)->pixels, (x), (y), (i)->w, (i)->h))
// get color components of pixel value. should probably be done in a nicer way
#define PXR(px) ((px) & 0xff)
#define PXG(px) (((px) & 0xff00) >> 8)
#define PXB(px) (((px) & 0xff0000) >> 16)

//get the grayscale value of the pixel
#define GRAY(px) ((PXR(px) + PXG(px) + PXB(px)) / 3)

// iterate over SDL_Surface s with variables x, y
#define iter_pixels(s,x,y) for (x = 0; x < s->w; x++) for (y = 0; y < s->h; y++)

namespace Image
{

	void threshold(SDL_Surface *image, int lowerBound, int upperBound);
	SDL_Surface *copySurface(SDL_Surface *s);
}

#endif /* ifndef _IMAGE_H_ */