Add initial prototype.

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

@@ -0,0 +1,253 @@
+// 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 "settings.h"
+#include "test.h"
+
+class EdgeShapesCallback : public b2RayCastCallback
+{
+public:
+	EdgeShapesCallback()
+	{
+		m_fixture = NULL;
+	}
+
+	float ReportFixture(b2Fixture* fixture, const b2Vec2& point,
+						  const b2Vec2& normal, float fraction) override
+	{
+		m_fixture = fixture;
+		m_point = point;
+		m_normal = normal;
+
+		return fraction;
+	}
+
+	b2Fixture* m_fixture;
+	b2Vec2 m_point;
+	b2Vec2 m_normal;
+};
+
+class EdgeShapes : public Test
+{
+public:
+
+	enum
+	{
+		e_maxBodies = 256
+	};
+
+	EdgeShapes()
+	{
+		// Ground body
+		{
+			b2BodyDef bd;
+			b2Body* ground = m_world->CreateBody(&bd);
+
+			float x1 = -20.0f;
+			float y1 = 2.0f * cosf(x1 / 10.0f * b2_pi);
+			for (int32 i = 0; i < 80; ++i)
+			{
+				float x2 = x1 + 0.5f;
+				float y2 = 2.0f * cosf(x2 / 10.0f * b2_pi);
+
+				b2EdgeShape shape;
+				shape.SetTwoSided(b2Vec2(x1, y1), b2Vec2(x2, y2));
+				ground->CreateFixture(&shape, 0.0f);
+
+				x1 = x2;
+				y1 = y2;
+			}
+		}
+
+		{
+		b2Vec2 vertices[3];
+		vertices[0].Set(-0.5f, 0.0f);
+		vertices[1].Set(0.5f, 0.0f);
+		vertices[2].Set(0.0f, 1.5f);
+		m_polygons[0].Set(vertices, 3);
+	}
+
+		{
+			b2Vec2 vertices[3];
+			vertices[0].Set(-0.1f, 0.0f);
+			vertices[1].Set(0.1f, 0.0f);
+			vertices[2].Set(0.0f, 1.5f);
+			m_polygons[1].Set(vertices, 3);
+		}
+
+		{
+			float w = 1.0f;
+			float b = w / (2.0f + b2Sqrt(2.0f));
+			float s = b2Sqrt(2.0f) * b;
+
+			b2Vec2 vertices[8];
+			vertices[0].Set(0.5f * s, 0.0f);
+			vertices[1].Set(0.5f * w, b);
+			vertices[2].Set(0.5f * w, b + s);
+			vertices[3].Set(0.5f * s, w);
+			vertices[4].Set(-0.5f * s, w);
+			vertices[5].Set(-0.5f * w, b + s);
+			vertices[6].Set(-0.5f * w, b);
+			vertices[7].Set(-0.5f * s, 0.0f);
+
+			m_polygons[2].Set(vertices, 8);
+		}
+
+		{
+			m_polygons[3].SetAsBox(0.5f, 0.5f);
+		}
+
+		{
+			m_circle.m_radius = 0.5f;
+		}
+
+		m_bodyIndex = 0;
+		memset(m_bodies, 0, sizeof(m_bodies));
+
+		m_angle = 0.0f;
+	}
+
+	void Create(int32 index)
+	{
+		if (m_bodies[m_bodyIndex] != NULL)
+		{
+			m_world->DestroyBody(m_bodies[m_bodyIndex]);
+			m_bodies[m_bodyIndex] = NULL;
+		}
+
+		b2BodyDef bd;
+
+		float x = RandomFloat(-10.0f, 10.0f);
+		float y = RandomFloat(10.0f, 20.0f);
+		bd.position.Set(x, y);
+		bd.angle = RandomFloat(-b2_pi, b2_pi);
+		bd.type = b2_dynamicBody;
+
+		if (index == 4)
+		{
+			bd.angularDamping = 0.02f;
+		}
+
+		m_bodies[m_bodyIndex] = m_world->CreateBody(&bd);
+
+		if (index < 4)
+		{
+			b2FixtureDef fd;
+			fd.shape = m_polygons + index;
+			fd.friction = 0.3f;
+			fd.density = 20.0f;
+			m_bodies[m_bodyIndex]->CreateFixture(&fd);
+		}
+		else
+		{
+			b2FixtureDef fd;
+			fd.shape = &m_circle;
+			fd.friction = 0.3f;
+			fd.density = 20.0f;
+			m_bodies[m_bodyIndex]->CreateFixture(&fd);
+		}
+
+		m_bodyIndex = (m_bodyIndex + 1) % e_maxBodies;
+	}
+
+	void DestroyBody()
+	{
+		for (int32 i = 0; i < e_maxBodies; ++i)
+		{
+			if (m_bodies[i] != NULL)
+			{
+				m_world->DestroyBody(m_bodies[i]);
+				m_bodies[i] = NULL;
+				return;
+			}
+		}
+	}
+
+	void Keyboard(int key) override
+	{
+		switch (key)
+		{
+		case GLFW_KEY_1:
+		case GLFW_KEY_2:
+		case GLFW_KEY_3:
+		case GLFW_KEY_4:
+		case GLFW_KEY_5:
+			Create(key - GLFW_KEY_1);
+			break;
+
+		case GLFW_KEY_D:
+			DestroyBody();
+			break;
+		}
+	}
+
+	void Step(Settings& settings) override
+	{
+		bool advanceRay = settings.m_pause == 0 || settings.m_singleStep;
+
+		Test::Step(settings);
+		g_debugDraw.DrawString(5, m_textLine, "Press 1-5 to drop stuff");
+		m_textLine += m_textIncrement;
+
+		float L = 25.0f;
+		b2Vec2 point1(0.0f, 10.0f);
+		b2Vec2 d(L * cosf(m_angle), -L * b2Abs(sinf(m_angle)));
+		b2Vec2 point2 = point1 + d;
+
+		EdgeShapesCallback callback;
+
+		m_world->RayCast(&callback, point1, point2);
+
+		if (callback.m_fixture)
+		{
+			g_debugDraw.DrawPoint(callback.m_point, 5.0f, b2Color(0.4f, 0.9f, 0.4f));
+
+			g_debugDraw.DrawSegment(point1, callback.m_point, b2Color(0.8f, 0.8f, 0.8f));
+
+			b2Vec2 head = callback.m_point + 0.5f * callback.m_normal;
+			g_debugDraw.DrawSegment(callback.m_point, head, b2Color(0.9f, 0.9f, 0.4f));
+		}
+		else
+		{
+			g_debugDraw.DrawSegment(point1, point2, b2Color(0.8f, 0.8f, 0.8f));
+		}
+
+		if (advanceRay)
+		{
+			m_angle += 0.25f * b2_pi / 180.0f;
+		}
+	}
+
+	static Test* Create()
+	{
+		return new EdgeShapes;
+	}
+
+	int32 m_bodyIndex;
+	b2Body* m_bodies[e_maxBodies];
+	b2PolygonShape m_polygons[4];
+	b2CircleShape m_circle;
+
+	float m_angle;
+};
+
+static int testIndex = RegisterTest("Geometry", "Edge Shapes", EdgeShapes::Create);