generate convex hull/cluster using 'G' while the tests are running

examples/testbed/tests/convex_hull.h

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+/*
+* 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 CONVEX_HULL_H
+#define CONVEX_HULL_H
+
+class ConvexHull : public Test
+{
+public:
+	enum
+	{
+		// Half to avoid generation failure due to many vertices
+		e_count = B3_MAX_HULL_VERTICES / 2
+	};
+
+	ConvexHull()
+	{
+		b3BoxHull box;
+		box.SetIdentity();
+
+		b3Vec3 tetra[4];
+		b3Vec3 v1(-1.0f, 0.0f, 0.0f);
+		b3Vec3 v2(1.0f, 0.0f, 0.0f);
+		b3Vec3 v3(0.0f, 0.0f, -1.0f);
+		b3Vec3 v4 = 0.5f * (v1 + v2 + v3);
+		v4.y += 2.0f;
+
+		tetra[0] = v1;
+		tetra[1] = v2;
+		tetra[2] = v3;
+		tetra[3] = v4;
+
+		// Minkowski sum of box and tetrahedron
+		m_count = 0;
+		for (u32 i = 0; i < box.vertexCount; ++i)
+		{
+			for (u32 j = 0; j < 4; ++j)
+			{
+				b3Vec3 p = box.vertices[i] - tetra[j];
+				
+				m_points[m_count++] = p;
+			}
+		}
+	}
+
+	~ConvexHull()
+	{
+
+	}
+
+	void KeyDown(int button)
+	{
+		if (button == GLFW_KEY_G)
+		{
+			Generate();
+		}
+	}
+
+	void Generate()
+	{
+		m_count = 0;
+		for (u32 i = 0; i < e_count; ++i)
+		{
+			// Clamp to force coplanarities.
+			// This will stress the generation code.
+			float32 x = 3.0f * RandomFloat(-1.0f, 1.0f);
+			float32 y = 3.0f * RandomFloat(-1.0f, 1.0f);
+			float32 z = 3.0f * RandomFloat(-1.0f, 1.0f);
+
+			b3Vec3 p(x, y, z);
+			m_points[m_count++] = p;
+		}
+	}
+
+	void Step()
+	{
+		b3QHull hull;
+		hull.Set(m_points, m_count);
+
+		b3HullShape shape;
+		shape.m_hull = &hull;
+
+		g_draw->DrawSolidShape(&shape, b3Color_white, b3Transform_identity);
+		
+		g_draw->DrawString(b3Color_white, "G - Generate a random convex hull");
+	}
+
+	static Test* Create()
+	{
+		return new ConvexHull();
+	}
+
+	u32 m_count;
+	b3Vec3 m_points[e_count];
+};
+
+#endif