BresenhamModified

function scrBresenhamModified(x1, y1, x2, y2, grid){
	// Источник : http://eugen.dedu.free.fr/projects/bresenham/
	var ystep, xstep;
	var error;
	var errorprev;
	var _y = y1, _x = x1;
	var ddy, ddx;
	var dx = x2 - x1;
	var dy = y2 - y1;
	var arr = [];
	var width = ds_grid_width(grid);
	var height = ds_grid_height(grid);

	array_push(arr, [x1, y1]);
	if (dy < 0){
		ystep = -1;
		dy = -dy;
	}
	else {
		ystep = 1;
	}
	if (dx < 0){
		xstep = -1;
		dx = -dx;
	}
	else {
		xstep = 1;
	}

	ddy = 2 * dy;  // Для точности - используем двойные значения
	ddx = 2 * dx;
	if (ddx >= ddy){
		errorprev = dx;
		error = dx;  // Стартуем в центре
		for (i=0 ; i < dx ; i++){  // Не используя первую точку, т.к. уже включена
			if _y >= 0 and _y < height
			and _x >= 0 and _x < width
			and  ds_grid_get(grid, _x, _y) > 0 {
			    _x += xstep;
			    error += ddy;
			    if (error > ddx){
				    _y += ystep;
				    error -= ddx;
				    //
				    if (error + errorprev < ddx)
					and _x >= 0 and _x < width
					and _y-ystep >= 0 and _y - ystep < height
					and ds_grid_get(grid, _x, _y-ystep) > 0
					{  // bottom square also
				        array_push(arr, [_x, _y-ystep]);
					}
				    else if (error + errorprev > ddx)
					and _y >= 0 and _y < height
					and _x-xstep >= 0 and _x - xstep < width
					and ds_grid_get(grid, _x-xstep, _y) > 0
					{  // left square also
				        array_push(arr, [_x-xstep, _y]);
					}
				    else{  // corner: bottom and left squares also
						if _y-ystep >= 0 and _y - ystep < height
						and _y >= 0 and _y < height
						and ds_grid_get(grid, _x-xstep, _y) > 0

						{
							array_push(arr, [_x-xstep, _y]);
						}
						if _y-ystep >= 0 and _y - ystep < height
						and _x >= 0 and _x < width
						and ds_grid_get(grid, _x, _y-ystep) > 0
						{
							array_push(arr, [_x, _y-ystep]);
						}
					}
			    }
				if _y >= 0 and _y < height
				and _x >= 0 and _x < width
				and ds_grid_get(grid, _x, _y) > 0
				 {
					array_push(arr, [_x, _y])
				}
			    errorprev = error;
			}
		}
	}
	else{  // Тоже самое
		errorprev = dy;
		error = dy;
		for (i=0 ; i < dy ; i++){
			if _y >= 0 and _y < height
			and _x >= 0 and _x < width
			and ds_grid_get(grid, _x, _y) > 0 {
			    _y += ystep;
			    error += ddx;
			    if (error > ddy){
				    _x += xstep;
				    error -= ddy;
				    if (error + errorprev < ddy)
					and _x-xstep >= 0 and _x - xstep < width
					and _y >= 0 and _y < height
					and ds_grid_get(grid, _x-xstep, _y) > 0
					{
				        array_push(arr, [_x-xstep, _y]);
					}
				    else if (error + errorprev > ddy)
					and _y-ystep >= 0 and _y - ystep < height
					and _x >= 0 and _x < width
					and ds_grid_get(grid, _x, _y-ystep) > 0
					{
						array_push(arr, [_x, _y-ystep]);
					}
				    else{
						if _x-xstep >= 0 and _x - xstep < width
						and _y >= 0 and _y < height
						and ds_grid_get(grid, _x-xstep, _y) > 0
						{
							array_push(arr, [_x-xstep, _y]);
						}
						if _x >= 0 and _x < width
						and _y-ystep >= 0 and _y - ystep < height
						and ds_grid_get(grid, _x, _y-ystep) > 0
						{
							array_push(arr, [_x, _y-ystep]);
						}
				    }
			    }
				if _y >= 0 and _y < height
				and _x >= 0 and _x < width
				and ds_grid_get(grid, _x, _y) > 0
				{
					array_push(arr, [_x, _y])
				}
			    errorprev = error;
			}
		}
	}
	return arr
}