geometry

Author: mstop4

current-scripts/Demos/useful-scripts/scripts/geometry_functions/geometry_functions.gml

@@ -0,0 +1,170 @@
+/// @func              get_edge_position(instance, bounding_box)
+/// @desc              Get the closest position of ans instance to the edge of rectangle
+/// @param {Instance}  instance 
+/// @param {Rectangle} bounding_box
+function get_edge_position(_instance, _bounding_box) {
+	var _pos = new Vector2(_instance.x, _instance.y);
+	var _bb_mid = new Vector2(
+		_bounding_box.left + _bounding_box.width()/2,
+		_bounding_box.top + _bounding_box.height()/2
+	);
+
+	var _cur_t1 = -1;
+	var _cur_dist;
+	var _edge = new Vector2(0, 0);
+	var _closest_dist = 1000000;
+	var _closest_pos = new Vector3(-1, -1, -1);
+			
+	if (!collision_rectangle(_bounding_box.left, _bounding_box.top,
+				_bounding_box.right, _bounding_box.bottom,
+				_instance, false, false)) {
+
+		// left
+		_cur_t1 = ray_line_intersect(_bb_mid, _pos, _bounding_box.left_edge());
+				
+		if (_cur_t1 != -1) {
+			_edge.x = _bb_mid.x + lengthdir_x(_cur_t1, point_direction(_bb_mid.x, _bb_mid.y, _pos.x, _pos.y));
+			_edge.y = _bb_mid.y + lengthdir_y(_cur_t1, point_direction(_bb_mid.x, _bb_mid.y, _pos.x, _pos.y));
+			_cur_dist = point_distance(_pos.x, _pos.y, _edge.x, _edge.y);
+		
+			if (_cur_dist < _closest_dist) {
+				_closest_dist = _cur_dist;
+				_closest_pos.x = _edge.x;
+				_closest_pos.y = _edge.y;
+				_closest_pos.z = point_direction(_bb_mid.x, _bb_mid.y, _pos.x, _pos.y);
+			}
+		}
+	
+		// right
+		_cur_t1 = ray_line_intersect(_bb_mid, _pos, _bounding_box.right_edge());
+				
+		if (_cur_t1 != -1) {
+			_edge.x = _bb_mid.x + lengthdir_x(_cur_t1,point_direction(_bb_mid.x, _bb_mid.y, _pos.x, _pos.y));
+			_edge.y = _bb_mid.y + lengthdir_y(_cur_t1,point_direction(_bb_mid.x, _bb_mid.y, _pos.x, _pos.y));
+			_cur_dist = point_distance(_pos.x, _pos.y, _edge.x, _edge.y);
+		
+			if (_cur_dist < _closest_dist) {
+				_closest_dist = _cur_dist;
+				_closest_pos.x = _edge.x;
+				_closest_pos.y = _edge.y;
+				_closest_pos.z = point_direction(_bb_mid.x,_bb_mid.y,_pos.x, _pos.y);
+			}
+		}
+	
+		// top
+		_cur_t1 = ray_line_intersect(_bb_mid, _pos, _bounding_box.top_edge());
+				
+		if (_cur_t1 != -1) {
+			_edge.x = _bb_mid.x + lengthdir_x(_cur_t1,point_direction(_bb_mid.x, _bb_mid.y, _pos.x, _pos.y));
+			_edge.y = _bb_mid.y + lengthdir_y(_cur_t1,point_direction(_bb_mid.x, _bb_mid.y, _pos.x, _pos.y));
+			_cur_dist = point_distance(_pos.x, _pos.y, _edge.x, _edge.y);
+		
+			if (_cur_dist < _closest_dist) {
+				_closest_dist = _cur_dist;
+				_closest_pos.x = _edge.x;
+				_closest_pos.y = _edge.y;
+				_closest_pos.z = point_direction(_bb_mid.x,_bb_mid.y,_pos.x, _pos.y);
+			}
+		}
+	
+		// bottom
+		_cur_t1 = ray_line_intersect(_bb_mid, _pos, _bounding_box.bottom_edge());
+				
+		if (_cur_t1 != -1) {
+			_edge.x = _bb_mid.x + lengthdir_x(_cur_t1,point_direction(_bb_mid.x, _bb_mid.y, _pos.x, _pos.y));
+			_edge.y = _bb_mid.y + lengthdir_y(_cur_t1,point_direction(_bb_mid.x, _bb_mid.y, _pos.x, _pos.y));
+			_cur_dist = point_distance(_pos.x, _pos.gravity_direction, _edge.x, _edge.y);
+		
+			if (_cur_dist < _closest_dist) {
+				_closest_dist = _cur_dist;
+				_closest_pos.x = _edge.x;
+				_closest_pos.y = _edge.y;
+				_closest_pos.z = point_direction(_bb_mid.x,_bb_mid.y,_pos.x, _pos.y);
+			}
+		}
+	}
+
+	return _closest_pos;
+}
+
+/// @func                point_which_side(A, B, P)
+/// @desc                Returns which side of a line segment AB a point P is on
+///                      0 = on the line
+///                      < 0 = below or left
+///                      > 0 = above or right
+/// @param {LineSegment} line
+/// @param {Vector2}     P
+function point_which_side(_line, _p) {
+	return (_p.x - _line.a.x) * (_line.b.y - _line.y) - (_p.y - _line.a.y) * (_line.b.x - _line.a.x);
+}
+
+/// @func           prune_path(path)
+/// @desc           Removes redundant points in a Path
+/// @param {Path}   path
+/// @param {Object} obstacle
+function prune_path(_path, _obstacle) {
+	var _num_points = path_get_number(_path);
+
+	if (_num_points == 1)
+		return;
+
+	 var _cur = new Vector2(path_get_x(_path, 0), path_get_y(_path, 0));
+	 var _next = new Vector2(0, 0);
+
+	for (var i=1; i<_num_points; i++) {
+		_next.x = path_get_x(_path, i);
+		_next.y = path_get_y(_path, i); 
+	
+		if (!collision_line(_cur.x, _cur.y, _next.x, _next.y, _obstacle, false, true)) {
+			if (i <_num_points-1)
+				path_delete_point(_path,i);
+		}
+	
+		else {
+			_cur.x = _next.x;
+			_cur.y = _next.y;
+		}
+	}
+}
+
+
+/// @func                 ray_line_intersect(origin, target, a, b)
+/// @desc                 Finds the intersection point between a ray and and a line segment
+/// @param {Vector2}      origin
+/// @param {Vector2}      target
+/// @param {LineSegement} line  
+function ray_line_intersect(_origin, _target, _line) {
+	var _ray_dir = point_direction(_origin.x, _origin.y, _target.x, _target.y);
+
+	var _v1 = new Vector2(_origin.x - _line.a.x, _origin.y - _line.a.y);
+	var _v2 = new Vector2(_line.b.x - _line.a.x, _line.b.y - _line.a.y);
+	var _v3 = new Vector2(-lengthdir_y(1, _ray_dir), lengthdir_x(1, _ray_dir));
+
+	var _dot = dot_product(_v2.x, _v2.y, _v3.x, _v3.y);
+
+	if (abs(_dot) == 0)
+		return -1;
+	
+	var _t1 = cross_product_2d(_v2, _v1) / _dot;
+	var _t2 = dot_product(_v1.x, _v1.y, _v3.x, _v3.y) / _dot;
+
+	if (_t1 >= 0 && (_t2 >= 0 && _t2 <= 1))
+		return _t1;
+
+	return -1;
+}
+
+/// @func         ray_reflect(incident_dir, normal_dir)
+/// @desc         Rr = Ri - 2 * N * (Ri . N)
+/// @param {real} incident_dir
+/// @param {real} normal_dir
+function ray_reflect(_incident_dir, _normal_dir) {
+	var _ri = new Vector2(lengthdir_x(1, _incident_dir), lengthdir_y(1, _incident_dir));
+	var _n = new Vector2(lengthdir_x(1, _normal_dir), lengthdir_y(1, _normal_dir));
+
+	var _dot = dot_product(_ri.x, _ri.y, _n.x, _n.y);
+	var _reflect_x = _ri.x - 2 * _n.x * _dot;
+	var _reflect_y = _ri.y - 2 * _n.y * _dot;
+
+	return point_direction(0, 0, _reflect_x, _reflect_y);
+}

current-scripts/Demos/useful-scripts/scripts/geometry_functions/geometry_functions.yy

@@ -0,0 +1,35 @@
+function LineSegment(_ax, _ay, _bx, _by) constructor {
+	a = new Vector2(_ax, _ay);
+	b = new Vector2(_bx, _by);
+}
+
+function Rectangle(_left, _top, _right, _bottom) constructor {
+	left = _left;
+	top = _top;
+	right = _right;
+	bottom = _bottom;
+	
+	function width() {
+		return right - left;
+	}
+	
+	function height() {
+		return bottom - top;
+	}
+	
+	function left_edge() {
+		return new LineSegment(left, top, left, bottom);
+	}
+	
+	function top_edge() {
+		return new LineSegment(left, top, right, top);
+	}
+	
+	function right_edge() {
+		return new LineSegment(right, top, right, bottom);
+	}
+	
+	function bottom_edge() {
+		return new LineSegment(left, _bottom, right, bottom);
+	}
+}