// 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/imgui.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_NoMove | 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); g_debugDraw.DrawString(5, m_textLine, "Motor Torque 1= %4.0f", torque1); m_textLine += m_textIncrement; float torque2 = m_joint2->GetMotorTorque(settings.m_hertz); g_debugDraw.DrawString(5, m_textLine, "Motor Torque 2= %4.0f", torque2); m_textLine += m_textIncrement; } 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);