Add initial prototype.

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

@@ -0,0 +1,133 @@
+// 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"
+
+class Platformer : public Test
+{
+public:
+
+	enum State
+	{
+		e_unknown,
+		e_above,
+		e_below
+	};
+
+	Platformer()
+	{
+		// Ground
+		{
+			b2BodyDef bd;
+			b2Body* ground = m_world->CreateBody(&bd);
+
+			b2EdgeShape shape;
+			shape.SetTwoSided(b2Vec2(-20.0f, 0.0f), b2Vec2(20.0f, 0.0f));
+			ground->CreateFixture(&shape, 0.0f);
+		}
+
+		// Platform
+		{
+			b2BodyDef bd;
+			bd.position.Set(0.0f, 10.0f);
+			b2Body* body = m_world->CreateBody(&bd);
+
+			b2PolygonShape shape;
+			shape.SetAsBox(3.0f, 0.5f);
+			m_platform = body->CreateFixture(&shape, 0.0f);
+
+			m_bottom = 10.0f - 0.5f;
+			m_top = 10.0f + 0.5f;
+		}
+
+		// Actor
+		{
+			b2BodyDef bd;
+			bd.type = b2_dynamicBody;
+			bd.position.Set(0.0f, 12.0f);
+			b2Body* body = m_world->CreateBody(&bd);
+
+			m_radius = 0.5f;
+			b2CircleShape shape;
+			shape.m_radius = m_radius;
+			m_character = body->CreateFixture(&shape, 20.0f);
+
+			body->SetLinearVelocity(b2Vec2(0.0f, -50.0f));
+
+			m_state = e_unknown;
+		}
+	}
+
+	void PreSolve(b2Contact* contact, const b2Manifold* oldManifold) override
+	{
+		Test::PreSolve(contact, oldManifold);
+
+		b2Fixture* fixtureA = contact->GetFixtureA();
+		b2Fixture* fixtureB = contact->GetFixtureB();
+
+		if (fixtureA != m_platform && fixtureA != m_character)
+		{
+			return;
+		}
+
+		if (fixtureB != m_platform && fixtureB != m_character)
+		{
+			return;
+		}
+
+#if 1
+		b2Vec2 position = m_character->GetBody()->GetPosition();
+
+		if (position.y < m_top + m_radius - 3.0f * b2_linearSlop)
+		{
+			contact->SetEnabled(false);
+		}
+#else
+        b2Vec2 v = m_character->GetBody()->GetLinearVelocity();
+        if (v.y > 0.0f)
+		{
+            contact->SetEnabled(false);
+        }
+#endif
+	}
+
+	void Step(Settings& settings) override
+	{
+		Test::Step(settings);
+
+		b2Vec2 v = m_character->GetBody()->GetLinearVelocity();
+        g_debugDraw.DrawString(5, m_textLine, "Character Linear Velocity: %f", v.y);
+		m_textLine += m_textIncrement;
+	}
+
+	static Test* Create()
+	{
+		return new Platformer;
+	}
+
+	float m_radius, m_top, m_bottom;
+	State m_state;
+	b2Fixture* m_platform;
+	b2Fixture* m_character;
+};
+
+static int testIndex = RegisterTest("Examples", "Platformer", Platformer::Create);