function can_move(map, cur_x, cur_y, target_x, target_y) { var x_lines = map.x_lines || []; var y_lines = map.y_lines || []; var min_x = min(cur_x, target_x); var max_x = max(cur_x, target_x); var min_y = min(cur_y, target_y); var max_y = max(cur_y, target_y); var dx = target_x - cur_x; var dy = target_y - cur_y; var dydx = dy / (dx + EPS); var dxdy = 1 / dydx; for (var i = 0; i < x_lines.length; i++) { var line = x_lines[i]; var line_x = line[0]; if (max_x < line_x || min_x > line_x || max_y < line[1] || min_y > line[2]) { continue; } var y_intersect = cur_y + (line_x - cur_x) * dydx; if (y_intersect < line[1] || y_intersect > line[2]) { continue; } return false; } for (var i = 0; i < y_lines.length; i++) { var line = y_lines[i]; var line_y = line[0]; if (max_y < line_y || min_y > line_y || max_x < line[1] || min_x > line[2]) { continue; } var x_intersect = cur_x + (line_y - cur_y) * dxdy; if (x_intersect < line[1] || x_intersect > line[2]) { continue; } return false; } return true; }