+box2d

1 files changed, 115 insertions, 0 deletions

diff --git a/src/3rdparty/Box2D/Rope/b2Rope.h b/src/3rdparty/Box2D/Rope/b2Rope.h
new file mode 100644
index 0000000..40be9e7
--- /dev/null
+++ b/src/3rdparty/Box2D/Rope/b2Rope.h
@@ -0,0 +1,115 @@
+/*
+* Copyright (c) 2011 Erin Catto http://www.box2d.org
+*
+* This software is provided 'as-is', without any express or implied
+* warranty.  In no event will the authors be held liable for any damages
+* arising from the use of this software.
+* Permission is granted to anyone to use this software for any purpose,
+* including commercial applications, and to alter it and redistribute it
+* freely, subject to the following restrictions:
+* 1. The origin of this software must not be misrepresented; you must not
+* claim that you wrote the original software. If you use this software
+* in a product, an acknowledgment in the product documentation would be
+* appreciated but is not required.
+* 2. Altered source versions must be plainly marked as such, and must not be
+* misrepresented as being the original software.
+* 3. This notice may not be removed or altered from any source distribution.
+*/
+
+#ifndef B2_ROPE_H
+#define B2_ROPE_H
+
+#include "Box2D/Common/b2Math.h"
+
+class b2Draw;
+
+/// 
+struct b2RopeDef
+{
+	b2RopeDef()
+	{
+		vertices = nullptr;
+		count = 0;
+		masses = nullptr;
+		gravity.SetZero();
+		damping = 0.1f;
+		k2 = 0.9f;
+		k3 = 0.1f;
+	}
+
+	///
+	b2Vec2* vertices;
+
+	///
+	int32 count;
+
+	///
+	float32* masses;
+
+	///
+	b2Vec2 gravity;
+
+	///
+	float32 damping;
+
+	/// Stretching stiffness
+	float32 k2;
+
+	/// Bending stiffness. Values above 0.5 can make the simulation blow up.
+	float32 k3;
+};
+
+/// 
+class b2Rope
+{
+public:
+	b2Rope();
+	~b2Rope();
+
+	///
+	void Initialize(const b2RopeDef* def);
+
+	///
+	void Step(float32 timeStep, int32 iterations);
+
+	///
+	int32 GetVertexCount() const
+	{
+		return m_count;
+	}
+
+	///
+	const b2Vec2* GetVertices() const
+	{
+		return m_ps;
+	}
+
+	///
+	void Draw(b2Draw* draw) const;
+
+	///
+	void SetAngle(float32 angle);
+
+private:
+
+	void SolveC2();
+	void SolveC3();
+
+	int32 m_count;
+	b2Vec2* m_ps;
+	b2Vec2* m_p0s;
+	b2Vec2* m_vs;
+
+	float32* m_ims;
+
+	float32* m_Ls;
+	float32* m_as;
+
+	b2Vec2 m_gravity;
+	float32 m_damping;
+
+	float32 m_k2;
+	float32 m_k3;
+};
+
+#endif