Use sphere mesh. Add soft body test.

examples/testbed/framework/sphere_mesh.cpp

@@ -0,0 +1,149 @@
+/*
+* Copyright (c) 2016-2019 Irlan Robson https://irlanrobson.github.io
+*
+* 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.
+*/
+
+#include <testbed/framework/sphere_mesh.h>
+
+// References:
+// https://github.com/caosdoar/spheres
+// https://schneide.blog/2016/07/15/generating-an-icosphere-in-c/
+
+struct smEdge
+{
+	smEdge() { }
+
+	smEdge(u32 _v1, u32 _v2)
+	{
+		v1 = _v1;
+		v2 = _v2;
+	}
+
+	u32 v1, v2;
+};
+
+struct smEdgeVertexPair
+{
+	smEdgeVertexPair() { }
+
+	smEdgeVertexPair(const smEdge& _edge, u32 _vertex)
+	{
+		edge = _edge;
+		vertex = _vertex;
+	}
+
+	smEdge edge;
+	u32 vertex;
+};
+
+struct smEdgeVertexMap
+{
+	smEdgeVertexMap() { }
+
+	smEdgeVertexPair* Find(const smEdge& edge)
+	{
+		for (u32 i = 0; i < pairs.Count(); ++i)
+		{
+			smEdgeVertexPair* pair = pairs.Get(i);
+
+			if ((pair->edge.v1 == edge.v1 && pair->edge.v2 == edge.v2) || 
+				(pair->edge.v1 == edge.v2 && pair->edge.v2 == edge.v1) )
+			{
+				return pair;
+			}
+		}
+		return nullptr;
+	}
+
+	b3StackArray<smEdgeVertexPair, 32> pairs;
+};
+
+// 
+static inline u32 smSubdivideEdge(u32 i1, u32 i2,
+	const b3Vec3& v1, const b3Vec3& v2,
+	smEdgeVertexMap& edgeVertexMap,
+	smMesh& output)
+{
+	smEdge edge(i1, i2);
+
+	smEdgeVertexPair* pair = edgeVertexMap.Find(edge);
+
+	if (pair)
+	{
+		return pair->vertex;
+	}
+
+	smEdge newEdge(i1, i2);
+	u32 newVertex = output.vertices.Count();
+
+	b3Vec3 v = 0.5f * (v1 + v2);
+	float32 len = v.Normalize();
+
+	output.AddVertex(v.x, v.y, v.z);
+
+	smEdgeVertexPair newPair(newEdge, newVertex);
+
+	edgeVertexMap.pairs.PushBack(newPair);
+
+	return newVertex;
+}
+
+// 
+static inline void smSubdivideMesh(smMesh& output, const smMesh& input)
+{
+	output.vertices = input.vertices;
+
+	smEdgeVertexMap edgeVertexMap;
+
+	for (u32 i = 0; i < input.triangleIndices.Count() / 3; ++i)
+	{
+		u32 vi1 = input.triangleIndices[3 * i + 0];
+		u32 vi2 = input.triangleIndices[3 * i + 1];
+		u32 vi3 = input.triangleIndices[3 * i + 2];
+
+		b3Vec3 v1 = input.vertices[vi1];
+		b3Vec3 v2 = input.vertices[vi2];
+		b3Vec3 v3 = input.vertices[vi3];
+
+		u32 vi4 = smSubdivideEdge(vi1, vi2, v1, v2, edgeVertexMap, output);
+		u32 vi5 = smSubdivideEdge(vi2, vi3, v2, v3, edgeVertexMap, output);
+		u32 vi6 = smSubdivideEdge(vi3, vi1, v3, v1, edgeVertexMap, output);
+
+		output.AddTriangle(vi1, vi4, vi6);
+		output.AddTriangle(vi4, vi2, vi5);
+		output.AddTriangle(vi5, vi3, vi6);
+		output.AddTriangle(vi4, vi5, vi6);
+	}
+}
+
+//
+void smCreateMesh(smMesh& output, u32 subdivisions)
+{
+	B3_ASSERT(output.vertices.Count() == 0);
+	B3_ASSERT(output.triangleIndices.Count() == 0);
+
+	smMesh input;
+	input.SetAsIcosahedron();
+
+	for (u32 i = 0; i < subdivisions; ++i)
+	{
+		smMesh subOutput;
+		smSubdivideMesh(subOutput, input);
+		input = subOutput;
+	}
+
+	output = input;
+}