private function line(xstart: Float, ystart: Float, xend: Float, yend: Float, sprite: Sprite): Void {
        var x0 = Math.round(xstart);
        var y0 = Math.round(ystart);
        var x1 = Math.round(xend);
        var y1 = Math.round(yend);
        sprite.x = x0;
        sprite.y = y0;
        var dx = Math.abs(x1 - x0);
        var dy = Math.abs(y1 - y0);
        var sx : Int;
        var sy : Int;
        if (x0 < x1) sx = 1; else sx = -1;
        if (y0 < y1) sy = 1; else sy = -1;
        var err = dx - dy;

        while (true) {
            //setPixel(x0,y0)
            if (x0 == x1 && y0 == y1) {
                sprite.x = xend;
                sprite.y = yend;
                break;
            }
            var e2 = 2 * err;
            if (e2 > -dy) {
                err -= dy;
                x0 += sx;
                sprite.x = x0;
                if (map.collides(sprite)) {
                    sprite.y -= 1;
                    if (!map.collides(sprite)) {
                        continue;
                    }
                    else {
                        sprite.y -= 1;
                        if (!map.collides(sprite)) {
                            continue;
                        }
                        else {
                            sprite.y -= 1;
                            if (!map.collides(sprite)) {
                                continue;
                            }
                            sprite.y += 1;
                        }
                        sprite.y += 1;
                    }
                    sprite.y += 1;
                    sprite.x -= sx;
                    if (sx < 0) sprite.hitFrom(Direction.RIGHT);
                    else sprite.hitFrom(Direction.LEFT);
                    while (true) {
                        if (y0 == y1) {
                            sprite.y = yend;
                            return;
                        }
                        y0 += sy;
                        sprite.y = y0;
                        if (map.collides(sprite)) {
                            sprite.y -= sy;
                            if (sy < 0) sprite.hitFrom(Direction.DOWN);
                            else sprite.hitFrom(Direction.UP);
                            return;
                        }
                    }
                    return;
                }
            }
            if (e2 < dx) {
                err += dx;
                y0 += sy;
                sprite.y = y0;
                if (map.collides(sprite)) {
                    sprite.y -= sy;
                    if (sy < 0) sprite.hitFrom(Direction.DOWN);
                    else sprite.hitFrom(Direction.UP);
                    while (true) {
                        if (x0 == x1) {
                            sprite.x = xend;
                            return;
                        }
                        x0 += sx;
                        sprite.x = x0;
                        if (map.collides(sprite)) {
                            sprite.y -= 1;
                            if (!map.collides(sprite)) {
                                continue;
                            }
                            else {
                                sprite.y -= 1;
                                if (!map.collides(sprite)) {
                                    continue;
                                }
                                else {
                                    sprite.y -= 1;
                                    if (!map.collides(sprite)) {
                                        continue;
                                    }
                                    sprite.y += 1;
                                }
                                sprite.y += 1;
                            }
                            sprite.y += 1;
                            sprite.x -= sx;
                            if (sx < 0) sprite.hitFrom(Direction.RIGHT);
                            else sprite.hitFrom(Direction.LEFT);
                            return;
                        }
                    }
                    return;
                }
            }
        }
}