[Core] Move Rect2 and Transform2D to their own files

Math2D includes Transform2D, which includes Rect2, which includes Vector2.

1 files changed, 240 insertions, 0 deletions

diff --git a/core/math/rect2.cpp b/core/math/rect2.cpp
new file mode 100644
index 0000000000..480bccdff1
--- /dev/null
+++ b/core/math/rect2.cpp
@@ -0,0 +1,240 @@
+/*************************************************************************/
+/*  rect2.cpp                                                            */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2018 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2018 Godot Engine contributors (cf. AUTHORS.md)    */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "transform_2d.h" // Includes rect2.h but Rect2 needs Transform2D
+
+bool Rect2::intersects_segment(const Point2 &p_from, const Point2 &p_to, Point2 *r_pos, Point2 *r_normal) const {
+
+	real_t min = 0, max = 1;
+	int axis = 0;
+	real_t sign = 0;
+
+	for (int i = 0; i < 2; i++) {
+		real_t seg_from = p_from[i];
+		real_t seg_to = p_to[i];
+		real_t box_begin = position[i];
+		real_t box_end = box_begin + size[i];
+		real_t cmin, cmax;
+		real_t csign;
+
+		if (seg_from < seg_to) {
+
+			if (seg_from > box_end || seg_to < box_begin)
+				return false;
+			real_t length = seg_to - seg_from;
+			cmin = (seg_from < box_begin) ? ((box_begin - seg_from) / length) : 0;
+			cmax = (seg_to > box_end) ? ((box_end - seg_from) / length) : 1;
+			csign = -1.0;
+
+		} else {
+
+			if (seg_to > box_end || seg_from < box_begin)
+				return false;
+			real_t length = seg_to - seg_from;
+			cmin = (seg_from > box_end) ? (box_end - seg_from) / length : 0;
+			cmax = (seg_to < box_begin) ? (box_begin - seg_from) / length : 1;
+			csign = 1.0;
+		}
+
+		if (cmin > min) {
+			min = cmin;
+			axis = i;
+			sign = csign;
+		}
+		if (cmax < max)
+			max = cmax;
+		if (max < min)
+			return false;
+	}
+
+	Vector2 rel = p_to - p_from;
+
+	if (r_normal) {
+		Vector2 normal;
+		normal[axis] = sign;
+		*r_normal = normal;
+	}
+
+	if (r_pos)
+		*r_pos = p_from + rel * min;
+
+	return true;
+}
+
+bool Rect2::intersects_transformed(const Transform2D &p_xform, const Rect2 &p_rect) const {
+
+	//SAT intersection between local and transformed rect2
+
+	Vector2 xf_points[4] = {
+		p_xform.xform(p_rect.position),
+		p_xform.xform(Vector2(p_rect.position.x + p_rect.size.x, p_rect.position.y)),
+		p_xform.xform(Vector2(p_rect.position.x, p_rect.position.y + p_rect.size.y)),
+		p_xform.xform(Vector2(p_rect.position.x + p_rect.size.x, p_rect.position.y + p_rect.size.y)),
+	};
+
+	real_t low_limit;
+
+	//base rect2 first (faster)
+
+	if (xf_points[0].y > position.y)
+		goto next1;
+	if (xf_points[1].y > position.y)
+		goto next1;
+	if (xf_points[2].y > position.y)
+		goto next1;
+	if (xf_points[3].y > position.y)
+		goto next1;
+
+	return false;
+
+next1:
+
+	low_limit = position.y + size.y;
+
+	if (xf_points[0].y < low_limit)
+		goto next2;
+	if (xf_points[1].y < low_limit)
+		goto next2;
+	if (xf_points[2].y < low_limit)
+		goto next2;
+	if (xf_points[3].y < low_limit)
+		goto next2;
+
+	return false;
+
+next2:
+
+	if (xf_points[0].x > position.x)
+		goto next3;
+	if (xf_points[1].x > position.x)
+		goto next3;
+	if (xf_points[2].x > position.x)
+		goto next3;
+	if (xf_points[3].x > position.x)
+		goto next3;
+
+	return false;
+
+next3:
+
+	low_limit = position.x + size.x;
+
+	if (xf_points[0].x < low_limit)
+		goto next4;
+	if (xf_points[1].x < low_limit)
+		goto next4;
+	if (xf_points[2].x < low_limit)
+		goto next4;
+	if (xf_points[3].x < low_limit)
+		goto next4;
+
+	return false;
+
+next4:
+
+	Vector2 xf_points2[4] = {
+		position,
+		Vector2(position.x + size.x, position.y),
+		Vector2(position.x, position.y + size.y),
+		Vector2(position.x + size.x, position.y + size.y),
+	};
+
+	real_t maxa = p_xform.elements[0].dot(xf_points2[0]);
+	real_t mina = maxa;
+
+	real_t dp = p_xform.elements[0].dot(xf_points2[1]);
+	maxa = MAX(dp, maxa);
+	mina = MIN(dp, mina);
+
+	dp = p_xform.elements[0].dot(xf_points2[2]);
+	maxa = MAX(dp, maxa);
+	mina = MIN(dp, mina);
+
+	dp = p_xform.elements[0].dot(xf_points2[3]);
+	maxa = MAX(dp, maxa);
+	mina = MIN(dp, mina);
+
+	real_t maxb = p_xform.elements[0].dot(xf_points[0]);
+	real_t minb = maxb;
+
+	dp = p_xform.elements[0].dot(xf_points[1]);
+	maxb = MAX(dp, maxb);
+	minb = MIN(dp, minb);
+
+	dp = p_xform.elements[0].dot(xf_points[2]);
+	maxb = MAX(dp, maxb);
+	minb = MIN(dp, minb);
+
+	dp = p_xform.elements[0].dot(xf_points[3]);
+	maxb = MAX(dp, maxb);
+	minb = MIN(dp, minb);
+
+	if (mina > maxb)
+		return false;
+	if (minb > maxa)
+		return false;
+
+	maxa = p_xform.elements[1].dot(xf_points2[0]);
+	mina = maxa;
+
+	dp = p_xform.elements[1].dot(xf_points2[1]);
+	maxa = MAX(dp, maxa);
+	mina = MIN(dp, mina);
+
+	dp = p_xform.elements[1].dot(xf_points2[2]);
+	maxa = MAX(dp, maxa);
+	mina = MIN(dp, mina);
+
+	dp = p_xform.elements[1].dot(xf_points2[3]);
+	maxa = MAX(dp, maxa);
+	mina = MIN(dp, mina);
+
+	maxb = p_xform.elements[1].dot(xf_points[0]);
+	minb = maxb;
+
+	dp = p_xform.elements[1].dot(xf_points[1]);
+	maxb = MAX(dp, maxb);
+	minb = MIN(dp, minb);
+
+	dp = p_xform.elements[1].dot(xf_points[2]);
+	maxb = MAX(dp, maxb);
+	minb = MIN(dp, minb);
+
+	dp = p_xform.elements[1].dot(xf_points[3]);
+	maxb = MAX(dp, maxb);
+	minb = MIN(dp, minb);
+
+	if (mina > maxb)
+		return false;
+	if (minb > maxa)
+		return false;
+
+	return true;
+}