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engines/crab/Polygon.h

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+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/*
+ * This code is based on the CRAB engine
+ *
+ * Copyright (c) Arvind Raja Yadav
+ *
+ * Licensed under MIT
+ *
+ */
+
+#ifndef CRAB_POLYGON_H
+#define CRAB_POLYGON_H
+
+#include "crab/Rectangle.h"
+#include "crab/vectors.h"
+
+namespace Crab {
+
+//------------------------------------------------------------------------
+// Purpose: The result of a collision
+//------------------------------------------------------------------------
+struct PolygonCollisionResult {
+	// Are the Polygons currently intersecting?
+	bool _intersect;
+
+	// The translation to apply to polygon A to push the polygons apart
+	// Also known as the minimum translation vector
+	Vector2f _mtv;
+
+	PolygonCollisionResult() {
+		_intersect = false;
+	}
+};
+
+//------------------------------------------------------------------------
+// Purpose: A simple 2D Polygon class
+//------------------------------------------------------------------------
+class Polygon2D {
+	void addPoint(const Vector2f &ref, const Common::String &x, const Common::String &y, Vector2f &min, Vector2f &max);
+
+public:
+	// A list of all points
+	Common::Array<Vector2f> _point;
+
+	// A list of all edges
+	Common::Array<Vector2f> _edge;
+
+	Polygon2D() {}
+	Polygon2D(rapidxml::xml_node<char> *node, Rect &bounds) {
+		load(node, bounds);
+	}
+
+	// Returns the approximate axis aligned bounding box of the polygon
+	void load(rapidxml::xml_node<char> *node, Rect &bounds);
+
+	void setEdge();
+
+	Vector2f center() const;
+	void offset(const float &x, const float &y);
+	void offset(const Vector2f &v) {
+		offset(v.x, v.y);
+	}
+
+	// Check if Polygon2D A is going to collide with Polygon2D B for the given velocity
+	// PolyA is this polygon
+	PolygonCollisionResult collide(const Polygon2D &polyB) const;
+
+	// Code for collision with a rectangle
+	PolygonCollisionResult collide(const Rect &rect) const;
+
+	// Find if a point is inside this polygon
+	bool contains(const float &x, const float &y);
+
+	// Calculate the projection of a polygon on an axis and returns it as a [min, max] interval
+	void project(const Vector2f &axis, float &min, float &max) const;
+
+	void draw(const int &xOffset = 0, const int &yOffset = 0,
+			  const uint8 &r = 0, const uint8 &g = 0, const uint8 &b = 0.0f, const uint8 &a = 255);
+};
+
+} // End of namespace Crab
+
+#endif // CRAB_POLYGON_H