add simple cloth

include/bounce/bounce.h

@@ -57,4 +57,6 @@
 #include <bounce/dynamics/world.h>
 #include <bounce/dynamics/world_listeners.h>
 
+#include <bounce/cloth/cloth.h>
+
 #endif

include/bounce/cloth/cloth.h

@@ -0,0 +1,135 @@
+/*
+* Copyright (c) 2016-2016 Irlan Robson http://www.irlan.net
+*
+* 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 B3_CLOTH_H
+#define B3_CLOTH_H
+
+#include <bounce/common/math/vec3.h>
+#include <bounce/collision/distance.h>
+
+struct b3Mesh;
+class b3Draw;
+
+struct b3ClothDef
+{
+	b3ClothDef()
+	{
+		mesh = NULL;
+		density = 0.0f;
+		gravity.SetZero();
+		k1 = 0.9f;
+		k2 = 0.2f;
+		kd = 0.1f;
+		r = 0.0f;
+	}
+
+	// Cloth mesh
+	// Each edge must be shared by at most two triangles (manifold)
+	const b3Mesh* mesh;
+
+	// Cloth density in kilograms per meter squared
+	float32 density;
+
+	// Gravity force
+	b3Vec3 gravity;
+
+	// Streching stiffness
+	float32 k1;
+
+	// Bending stiffness
+	float32 k2;
+	
+	// Damping
+	float32 kd;
+
+	// Cloth thickness
+	float32 r;
+};
+
+struct b3Particle
+{
+	float32 im;
+	b3Vec3 p0;
+	b3Vec3 p;
+	b3Vec3 v;
+};
+
+struct b3C1
+{
+	float32 L;
+	u32 i1;
+	u32 i2;
+};
+
+struct b3C2
+{
+	float32 angle;
+	u32 i1;
+	u32 i2;
+	u32 i3;
+	u32 i4;
+};
+
+class b3Cloth
+{
+public:
+	b3Cloth();
+	~b3Cloth();
+
+	void Initialize(const b3ClothDef& def);
+
+	void Step(float32 dt, u32 iterations);
+
+	u32 GetVertexCount() const
+	{
+		return m_pCount;
+	}
+
+	const b3Particle* GetVertices() const
+	{
+		return m_ps;
+	}
+
+	b3Particle* GetVertices()
+	{
+		return m_ps;
+	}
+
+	void Draw(b3Draw* draw) const;
+private:
+	void SolveC1();
+
+	b3Particle* m_ps;
+	u32 m_pCount;
+	
+	b3C1* m_c1s;
+	u32 m_c1Count;
+	
+	b3C2* m_c2s;
+	u32 m_c2Count;
+
+	float32 m_k1;
+	float32 m_k2;
+	float32 m_kd;
+	float32 m_r;
+	b3Vec3 m_gravity;
+
+	const b3Mesh* m_mesh;
+};
+
+#endif

include/testbed/tests/cloth_test.h

@@ -0,0 +1,79 @@
+/*
+* Copyright (c) 2016-2016 Irlan Robson http://www.irlan.net
+*
+* 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 CLOTH_H
+#define CLOTH_H
+
+extern DebugDraw* g_debugDraw;
+extern Camera g_camera;
+extern Settings g_settings;
+
+class Cloth : public Test
+{
+public:
+	Cloth()
+	{
+		g_camera.m_zoom = 25.0f;
+
+		b3ClothDef def;
+		def.mesh = m_meshes + e_clothMesh;
+		def.density = 0.4f;
+		def.gravity.Set(-10.0f, 1.0f, 0.0f);
+		def.k1 = 0.9f;
+		def.k2 = 0.2f;
+		def.kd = 0.1f;
+		def.r = 1.0f;
+
+		m_cloth.Initialize(def);
+
+		b3Particle* vs = m_cloth.GetVertices();
+		for (u32 i = 0; i < 5; ++i)
+		{
+			vs[i].im = 0.0f;
+		}
+	}
+
+	void Step()
+	{
+		float32 dt = g_settings.hertz > 0.0f ? 1.0f / g_settings.hertz : 0.0f;
+		
+		if (g_settings.pause)
+		{
+			if (g_settings.singleStep)
+				{
+				g_settings.singleStep = false;
+			}
+			else
+			{
+				dt = 0.0f;
+			}
+		}
+
+		m_cloth.Step(dt, g_settings.positionIterations);
+		m_cloth.Draw(g_debugDraw);
+	}
+
+	static Test* Create()
+	{
+		return new Cloth();
+	}
+
+	b3Cloth m_cloth;
+};
+
+#endif

include/testbed/tests/test.h

@@ -116,6 +116,7 @@ public:
 	{
 		e_gridMesh,
 		e_terrainMesh,
+		e_clothMesh,
 		e_maxMeshes,
 	};