#include "types.h"
#include "vga.h"
#include "video.h"
#include "2d.h"
#include "math.h"

/******************************************************************************/

/* Affiche une ligne entre les points spécifiés */

void line(u32 x1, u32 y1, u32 x2, u32 y2, u8 color)
{
	s32 dx, dy, sdx, sdy;
	u32 i, dxabs, dyabs, x, y, px, py;

	dx = x2 - x1;		/*  distance horizontale de la line */
	dy = y2 - y1;		/* distance verticale de la line * */
	dxabs = abs(dx);
	dyabs = abs(dy);
	sdx = sgn(dx);
	sdy = sgn(dy);
	x = dyabs >> 1;
	y = dxabs >> 1;
	px = x1;
	py = y1;

	writepxl(px, py, color);

	if (dxabs >= dyabs) {	/* la ligne est plus horizontale que verticale */
		for (i = 0; i < dxabs; i++) {
			y += dyabs;
			if (y >= dxabs) {
				y -= dxabs;
				py += sdy;
			}
			px += sdx;
			writepxl(px, py, color);
		}
	} else {		/* la ligne est plus verticale que horizontale */

		for (i = 0; i < dyabs; i++) {
			x += dxabs;
			if (x >= dyabs) {
				x -= dyabs;
				px += sdx;
			}
			py += sdy;
			writepxl(px, py, color);
		}
	}
}