/* ************************************************************************** */
/*                                                                            */
/*  ML_vertical_line.c                                                        */
/*  | Project : libmonochrome                                                 */
/*                                                                            */
/*  By: Pierre "PierrotLL" Le Gall <legallpierre89@gmail.com>                 */
/*  Last updated: 2011/11/22                                                  */
/*                                                                            */
/* ************************************************************************** */

#include <monochrome/internals.h>

void ML_vertical_line(int x, int y1, int y2, ML_Color color)
{
    int i, j;
    char checker, byte, *vram = ML_vram_address();
	if(x&~127 || (y1<0 && y2<0) || (y1>63 && y2>63)) return;
	if(y1 > y2)
	{
		int tmp = y1;
		y1 = y2;
		y2 = tmp;
	}
	if(y1 < 0) y1 = 0;
	if(y2 > 63) y2 = 63;

	i = (y1<<4)+(x>>3);
	j = (y2<<4)+(x>>3);
	switch (color)
	{
		case ML_BLACK:
			byte = 128>>(x&7);
			for( ; i<=j ; i+=16)
				vram[i] |= byte;
			break;
		case ML_WHITE:
			byte = ~(128>>(x&7));
			for( ; i<=j ; i+=16)
				vram[i] &= byte;
			break;
		case ML_XOR:
			byte = 128>>(x&7);
			for( ; i<=j ; i+=16)
				vram[i] ^= byte;
			break;
		case ML_CHECKER:
			byte = 128>>(x&7);
			checker = (y1 & 1) ^ (x & 1);
			for( ; i<=j ; i+=16)
			{
				if(checker) vram[i] &= ~byte;
				else vram[i] |= byte;
				checker = !checker;
			}
			break;
		default:
			break;
	}
}