// 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
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

#include "test.h"

// This is a test of collision filtering.
// There is a triangle, a box, and a circle.
// There are 6 shapes. 3 large and 3 small.
// The 3 small ones always collide.
// The 3 large ones never collide.
// The boxes don't collide with triangles (except if both are small).
const int16	k_smallGroup = 1;
const int16 k_largeGroup = -1;

const uint16 k_triangleCategory = 0x0002;
const uint16 k_boxCategory = 0x0004;
const uint16 k_circleCategory = 0x0008;

const uint16 k_triangleMask = 0xFFFF;
const uint16 k_boxMask = 0xFFFF ^ k_triangleCategory;
const uint16 k_circleMask = 0xFFFF;

class CollisionFiltering : public Test
{
public:
	CollisionFiltering()
	{
		// Ground body
		{
			b2EdgeShape shape;
			shape.SetTwoSided(b2Vec2(-40.0f, 0.0f), b2Vec2(40.0f, 0.0f));

			b2FixtureDef sd;
			sd.shape = &shape;
			sd.friction = 0.3f;

			b2BodyDef bd;
			b2Body* ground = m_world->CreateBody(&bd);
			ground->CreateFixture(&sd);
		}

		// Small triangle
		b2Vec2 vertices[3];
		vertices[0].Set(-1.0f, 0.0f);
		vertices[1].Set(1.0f, 0.0f);
		vertices[2].Set(0.0f, 2.0f);
		b2PolygonShape polygon;
		polygon.Set(vertices, 3);

		b2FixtureDef triangleShapeDef;
		triangleShapeDef.shape = &polygon;
		triangleShapeDef.density = 1.0f;

		triangleShapeDef.filter.groupIndex = k_smallGroup;
		triangleShapeDef.filter.categoryBits = k_triangleCategory;
		triangleShapeDef.filter.maskBits = k_triangleMask;

		b2BodyDef triangleBodyDef;
		triangleBodyDef.type = b2_dynamicBody;
		triangleBodyDef.position.Set(-5.0f, 2.0f);

		b2Body* body1 = m_world->CreateBody(&triangleBodyDef);
		body1->CreateFixture(&triangleShapeDef);

		// Large triangle (recycle definitions)
		vertices[0] *= 2.0f;
		vertices[1] *= 2.0f;
		vertices[2] *= 2.0f;
		polygon.Set(vertices, 3);
		triangleShapeDef.filter.groupIndex = k_largeGroup;
		triangleBodyDef.position.Set(-5.0f, 6.0f);
		triangleBodyDef.fixedRotation = true; // look at me!

		b2Body* body2 = m_world->CreateBody(&triangleBodyDef);
		body2->CreateFixture(&triangleShapeDef);

		{
			b2BodyDef bd;
			bd.type = b2_dynamicBody;
			bd.position.Set(-5.0f, 10.0f);
			b2Body* body = m_world->CreateBody(&bd);

			b2PolygonShape p;
			p.SetAsBox(0.5f, 1.0f);
			body->CreateFixture(&p, 1.0f);

			b2PrismaticJointDef jd;
			jd.bodyA = body2;
			jd.bodyB = body;
			jd.enableLimit = true;
			jd.localAnchorA.Set(0.0f, 4.0f);
			jd.localAnchorB.SetZero();
			jd.localAxisA.Set(0.0f, 1.0f);
			jd.lowerTranslation = -1.0f;
			jd.upperTranslation = 1.0f;

			m_world->CreateJoint(&jd);
		}

		// Small box
		polygon.SetAsBox(1.0f, 0.5f);
		b2FixtureDef boxShapeDef;
		boxShapeDef.shape = &polygon;
		boxShapeDef.density = 1.0f;
		boxShapeDef.restitution = 0.1f;

		boxShapeDef.filter.groupIndex = k_smallGroup;
		boxShapeDef.filter.categoryBits = k_boxCategory;
		boxShapeDef.filter.maskBits = k_boxMask;

		b2BodyDef boxBodyDef;
		boxBodyDef.type = b2_dynamicBody;
		boxBodyDef.position.Set(0.0f, 2.0f);

		b2Body* body3 = m_world->CreateBody(&boxBodyDef);
		body3->CreateFixture(&boxShapeDef);

		// Large box (recycle definitions)
		polygon.SetAsBox(2.0f, 1.0f);
		boxShapeDef.filter.groupIndex = k_largeGroup;
		boxBodyDef.position.Set(0.0f, 6.0f);

		b2Body* body4 = m_world->CreateBody(&boxBodyDef);
		body4->CreateFixture(&boxShapeDef);

		// Small circle
		b2CircleShape circle;
		circle.m_radius = 1.0f;

		b2FixtureDef circleShapeDef;
		circleShapeDef.shape = &circle;
		circleShapeDef.density = 1.0f;

		circleShapeDef.filter.groupIndex = k_smallGroup;
		circleShapeDef.filter.categoryBits = k_circleCategory;
		circleShapeDef.filter.maskBits = k_circleMask;

		b2BodyDef circleBodyDef;
		circleBodyDef.type = b2_dynamicBody;
		circleBodyDef.position.Set(5.0f, 2.0f);
		
		b2Body* body5 = m_world->CreateBody(&circleBodyDef);
		body5->CreateFixture(&circleShapeDef);

		// Large circle
		circle.m_radius *= 2.0f;
		circleShapeDef.filter.groupIndex = k_largeGroup;
		circleBodyDef.position.Set(5.0f, 6.0f);

		b2Body* body6 = m_world->CreateBody(&circleBodyDef);
		body6->CreateFixture(&circleShapeDef);
	}

	static Test* Create()
	{
		return new CollisionFiltering;
	}
};

static int testIndex = RegisterTest("Examples", "Collision Filtering", CollisionFiltering::Create);
