axmol/tests/cpp-tests/Classes/Box2DTestBed/tests/revolute_joint.cpp

// 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"
#include "ImGui/ImGuiPresenter.h"

class RevoluteJoint : public Test
{
public:
    RevoluteJoint()
    {
        b2Body* ground = NULL;
        {
            b2BodyDef bd;
            ground = m_world->CreateBody(&bd);

            b2EdgeShape shape;
            shape.SetTwoSided(b2Vec2(-40.0f, 0.0f), b2Vec2(40.0f, 0.0f));

            b2FixtureDef fd;
            fd.shape = &shape;
            // fd.filter.categoryBits = 2;

            ground->CreateFixture(&fd);
        }

        m_enableLimit = true;
        m_enableMotor = false;
        m_motorSpeed  = 1.0f;

        {
            b2PolygonShape shape;
            shape.SetAsBox(0.25f, 3.0f, b2Vec2(0.0f, 3.0f), 0.0f);

            b2BodyDef bd;
            bd.type = b2_dynamicBody;
            bd.position.Set(-10.0f, 20.0f);
            b2Body* body = m_world->CreateBody(&bd);
            body->CreateFixture(&shape, 5.0f);

            b2RevoluteJointDef jd;
            jd.Initialize(ground, body, b2Vec2(-10.0f, 20.5f));
            jd.motorSpeed     = m_motorSpeed;
            jd.maxMotorTorque = 10000.0f;
            jd.enableMotor    = m_enableMotor;
            jd.lowerAngle     = -0.25f * b2_pi;
            jd.upperAngle     = 0.5f * b2_pi;
            jd.enableLimit    = m_enableLimit;

            m_joint1 = (b2RevoluteJoint*)m_world->CreateJoint(&jd);
        }

        {
            b2CircleShape circle_shape;
            circle_shape.m_radius = 2.0f;

            b2BodyDef circle_bd;
            circle_bd.type = b2_dynamicBody;
            circle_bd.position.Set(5.0f, 30.0f);

            b2FixtureDef fd;
            fd.density         = 5.0f;
            fd.filter.maskBits = 1;
            fd.shape           = &circle_shape;

            m_ball = m_world->CreateBody(&circle_bd);
            m_ball->CreateFixture(&fd);

            b2PolygonShape polygon_shape;
            polygon_shape.SetAsBox(10.0f, 0.5f, b2Vec2(-10.0f, 0.0f), 0.0f);

            b2BodyDef polygon_bd;
            polygon_bd.position.Set(20.0f, 10.0f);
            polygon_bd.type      = b2_dynamicBody;
            polygon_bd.bullet    = true;
            b2Body* polygon_body = m_world->CreateBody(&polygon_bd);
            polygon_body->CreateFixture(&polygon_shape, 2.0f);

            b2RevoluteJointDef jd;
            jd.Initialize(ground, polygon_body, b2Vec2(19.0f, 10.0f));
            jd.lowerAngle     = -0.25f * b2_pi;
            jd.upperAngle     = 0.0f * b2_pi;
            jd.enableLimit    = true;
            jd.enableMotor    = true;
            jd.motorSpeed     = 0.0f;
            jd.maxMotorTorque = 10000.0f;

            m_joint2 = (b2RevoluteJoint*)m_world->CreateJoint(&jd);
        }
    }

    void UpdateUI() override
    {
        // ImGui::SetNextWindowPos(ImVec2(10.0f, 100.0f));
        ImGui::SetNextWindowSize(ImVec2(200.0f, 100.0f));
        ImGui::Begin("Joint Controls", nullptr, ImGuiWindowFlags_NoResize);

        if (ImGui::Checkbox("Limit", &m_enableLimit))
        {
            m_joint1->EnableLimit(m_enableLimit);
        }

        if (ImGui::Checkbox("Motor", &m_enableMotor))
        {
            m_joint1->EnableMotor(m_enableMotor);
        }

        if (ImGui::SliderFloat("Speed", &m_motorSpeed, -20.0f, 20.0f, "%.0f"))
        {
            m_joint1->SetMotorSpeed(m_motorSpeed);
        }

        ImGui::End();
    }

    void Step(Settings& settings) override
    {
        Test::Step(settings);

        float torque1 = m_joint1->GetMotorTorque(settings.m_hertz);
        DrawString(5, m_textLine, "Motor Torque 1= %4.0f", torque1);

        float torque2 = m_joint2->GetMotorTorque(settings.m_hertz);
        DrawString(5, m_textLine, "Motor Torque 2= %4.0f", torque2);
    }

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

    b2Body* m_ball;
    b2RevoluteJoint* m_joint1;
    b2RevoluteJoint* m_joint2;
    float m_motorSpeed;
    bool m_enableMotor;
    bool m_enableLimit;
};

static int testIndex = RegisterTest("Joints", "Revolute", RevoluteJoint::Create);