pinball.cpp

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// 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 Pinball : public Test
{
public:
        Pinball()
        {
                // Ground body
                b2Body* ground = NULL;
                {
                        b2BodyDef bd;
                        ground = m_world->CreateBody(&bd);

                        b2Vec2 vs[5];
                        vs[0].Set(-8.0f, 6.0f);
                        vs[1].Set(-8.0f, 20.0f);
                        vs[2].Set(8.0f, 20.0f);
                        vs[3].Set(8.0f, 6.0f);
                        vs[4].Set(0.0f, -2.0f);

                        b2ChainShape loop;
                        loop.CreateLoop(vs, 5);
                        b2FixtureDef fd;
                        fd.shape = &loop;
                        fd.density = 0.0f;
                        ground->CreateFixture(&fd);
                }

                // Flippers
                {
                        b2Vec2 p1(-2.0f, 0.0f), p2(2.0f, 0.0f);

                        b2BodyDef bd;
                        bd.type = b2_dynamicBody;

                        bd.position = p1;
                        b2Body* leftFlipper = m_world->CreateBody(&bd);

                        bd.position = p2;
                        b2Body* rightFlipper = m_world->CreateBody(&bd);

                        b2PolygonShape box;
                        box.SetAsBox(1.75f, 0.1f);

                        b2FixtureDef fd;
                        fd.shape = &box;
                        fd.density = 1.0f;

                        leftFlipper->CreateFixture(&fd);
                        rightFlipper->CreateFixture(&fd);

                        b2RevoluteJointDef jd;
                        jd.bodyA = ground;
                        jd.localAnchorB.SetZero();
                        jd.enableMotor = true;
                        jd.maxMotorTorque = 1000.0f;
                        jd.enableLimit = true;

                        jd.motorSpeed = 0.0f;
                        jd.localAnchorA = p1;
                        jd.bodyB = leftFlipper;
                        jd.lowerAngle = -30.0f * b2_pi / 180.0f;
                        jd.upperAngle = 5.0f * b2_pi / 180.0f;
                        m_leftJoint = (b2RevoluteJoint*)m_world->CreateJoint(&jd);

                        jd.motorSpeed = 0.0f;
                        jd.localAnchorA = p2;
                        jd.bodyB = rightFlipper;
                        jd.lowerAngle = -5.0f * b2_pi / 180.0f;
                        jd.upperAngle = 30.0f * b2_pi / 180.0f;
                        m_rightJoint = (b2RevoluteJoint*)m_world->CreateJoint(&jd);
                }

                // Circle character
                {
                        b2BodyDef bd;
                        bd.position.Set(1.0f, 15.0f);
                        bd.type = b2_dynamicBody;
                        bd.bullet = true;

                        m_ball = m_world->CreateBody(&bd);

                        b2CircleShape shape;
                        shape.m_radius = 0.2f;

                        b2FixtureDef fd;
                        fd.shape = &shape;
                        fd.density = 1.0f;
                        m_ball->CreateFixture(&fd);
                }

                m_button = false;
        }

        void Step(Settings& settings) override
        {
                if (m_button)
                {
                        m_leftJoint->SetMotorSpeed(20.0f);
                        m_rightJoint->SetMotorSpeed(-20.0f);
                }
                else
                {
                        m_leftJoint->SetMotorSpeed(-10.0f);
                        m_rightJoint->SetMotorSpeed(10.0f);
                }

                Test::Step(settings);

                g_debugDraw.DrawString(5, m_textLine, "Press 'a' to control the flippers");
                m_textLine += m_textIncrement;

        }

        void Keyboard(int key) override
        {
                switch (key)
                {
                case GLFW_KEY_A:
                        m_button = true;
                        break;
                }
        }

        void KeyboardUp(int key) override
        {
                switch (key)
                {
                case GLFW_KEY_A:
                        m_button = false;
                        break;
                }
        }

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

        b2RevoluteJoint* m_leftJoint;
        b2RevoluteJoint* m_rightJoint;
        b2Body* m_ball;
        bool m_button;
};

static int testIndex = RegisterTest("Examples", "Pinball", Pinball::Create);