/*
 *  Modified by Toweld (2001/12/01) for using in tow bowl tactics
 */

/*   internal.c
 *  Written By: Garrett Banuk <mongoose@mongeese.org>
 *  This is free, just be sure to give me credit when using it
 *  in any of your programs.
 */

/* internal.[c,h] are various routines used internally
 * by SDL_console and DrawText. */

#include <SDL/SDL.h>
#ifndef _SDL_H
	#include <SDL.h>
#endif

/*
 * Return the pixel value at (x, y)
 * NOTE: The surface must be locked before calling this!
 */
Uint32 DT_GetPixel(SDL_Surface *surface, int x, int y)
{
	int bpp = surface->format->BytesPerPixel;
	/* Here p is the address to the pixel we want to retrieve */
	Uint8 *p = (Uint8 *) surface->pixels + y * surface->pitch + x * bpp;

	switch (bpp)
	{
		case 1:
			return *p;
		case 2:
			return *(Uint16 *) p;
		case 3:
			if(SDL_BYTEORDER == SDL_BIG_ENDIAN)
				return p[0] << 16 | p[1] << 8 | p[2];
			else
				return p[0] | p[1] << 8 | p[2] << 16;
		case 4:
			return *(Uint32 *) p;
		default:
			return 0;	/* shouldn't happen, but avoids warnings */
	}
}

/*
 * Set the pixel at (x, y) to the given value
 * NOTE: The surface must be locked before calling this!
 */
void DT_PutPixel(SDL_Surface *surface, int x, int y, Uint32 pixel)
{
	int bpp = surface->format->BytesPerPixel;
	/* Here p is the address to the pixel we want to set */
	Uint8 *p = (Uint8 *) surface->pixels + y * surface->pitch + x * bpp;

	switch (bpp)
	{
		case 1:
			*p = pixel;
			break;
		case 2:
			*(Uint16 *) p = pixel;
			break;
		case 3:
			if(SDL_BYTEORDER == SDL_BIG_ENDIAN)
			{
				p[0] = (pixel >> 16) & 0xff;
				p[1] = (pixel >> 8) & 0xff;
				p[2] = pixel & 0xff;
			}
			else
			{
				p[0] = pixel & 0xff;
				p[1] = (pixel >> 8) & 0xff;
				p[2] = (pixel >> 16) & 0xff;
			}
			break;
		case 4:
			*(Uint32 *) p = pixel;
			break;
		default:
			break;
	}
}
