Add initial prototype.

3-mid/physics/implement/box2d/contrib/testbed/tests/tiles.cpp

@@ -0,0 +1,159 @@
+// MIT License
+
+// Copyright (c) 2019 Erin Catto
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+#include "test.h"
+
+/// This stress tests the dynamic tree broad-phase. This also shows that tile
+/// based collision is _not_ smooth due to Box2D not knowing about adjacency.
+class Tiles : public Test
+{
+public:
+	enum
+	{
+		e_count = 20
+	};
+
+	Tiles()
+	{
+		m_fixtureCount = 0;
+		b2Timer timer;
+
+		{
+			float a = 0.5f;
+			b2BodyDef bd;
+			bd.position.y = -a;
+			b2Body* ground = m_world->CreateBody(&bd);
+
+#if 1
+			int32 N = 200;
+			int32 M = 10;
+			b2Vec2 position;
+			position.y = 0.0f;
+			for (int32 j = 0; j < M; ++j)
+			{
+				position.x = -N * a;
+				for (int32 i = 0; i < N; ++i)
+				{
+					b2PolygonShape shape;
+					shape.SetAsBox(a, a, position, 0.0f);
+					ground->CreateFixture(&shape, 0.0f);
+					++m_fixtureCount;
+					position.x += 2.0f * a;
+				}
+				position.y -= 2.0f * a;
+			}
+#else
+			int32 N = 200;
+			int32 M = 10;
+			b2Vec2 position;
+			position.x = -N * a;
+			for (int32 i = 0; i < N; ++i)
+			{
+				position.y = 0.0f;
+				for (int32 j = 0; j < M; ++j)
+				{
+					b2PolygonShape shape;
+					shape.SetAsBox(a, a, position, 0.0f);
+					ground->CreateFixture(&shape, 0.0f);
+					position.y -= 2.0f * a;
+				}
+				position.x += 2.0f * a;
+			}
+#endif
+		}
+
+		{
+			float a = 0.5f;
+			b2PolygonShape shape;
+			shape.SetAsBox(a, a);
+
+			b2Vec2 x(-7.0f, 0.75f);
+			b2Vec2 y;
+			b2Vec2 deltaX(0.5625f, 1.25f);
+			b2Vec2 deltaY(1.125f, 0.0f);
+
+			for (int32 i = 0; i < e_count; ++i)
+			{
+				y = x;
+
+				for (int32 j = i; j < e_count; ++j)
+				{
+					b2BodyDef bd;
+					bd.type = b2_dynamicBody;
+					bd.position = y;
+
+					//if (i == 0 && j == 0)
+					//{
+					//	bd.allowSleep = false;
+					//}
+					//else
+					//{
+					//	bd.allowSleep = true;
+					//}
+
+					b2Body* body = m_world->CreateBody(&bd);
+					body->CreateFixture(&shape, 5.0f);
+					++m_fixtureCount;
+					y += deltaY;
+				}
+
+				x += deltaX;
+			}
+		}
+
+		m_createTime = timer.GetMilliseconds();
+	}
+
+	void Step(Settings& settings) override
+	{
+		const b2ContactManager& cm = m_world->GetContactManager();
+		int32 height = cm.m_broadPhase.GetTreeHeight();
+		int32 leafCount = cm.m_broadPhase.GetProxyCount();
+		int32 minimumNodeCount = 2 * leafCount - 1;
+		float minimumHeight = ceilf(logf(float(minimumNodeCount)) / logf(2.0f));
+		g_debugDraw.DrawString(5, m_textLine, "dynamic tree height = %d, min = %d", height, int32(minimumHeight));
+		m_textLine += m_textIncrement;
+
+		Test::Step(settings);
+
+		g_debugDraw.DrawString(5, m_textLine, "create time = %6.2f ms, fixture count = %d",
+			m_createTime, m_fixtureCount);
+		m_textLine += m_textIncrement;
+
+		//b2DynamicTree* tree = &m_world->m_contactManager.m_broadPhase.m_tree;
+
+		//if (m_stepCount == 400)
+		//{
+		//	tree->RebuildBottomUp();
+		//}
+	}
+
+	static Test* Create()
+	{
+		return new Tiles;
+	}
+
+	int32 m_fixtureCount;
+	float m_createTime;
+};
+
+static int testIndex = RegisterTest("Benchmark", "Tiles", Tiles::Create);