// 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" // Test the prismatic joint with limits and motor options. class PrismaticJoint : public Test { public: PrismaticJoint() { b2Body* ground = NULL; { b2BodyDef bd; ground = m_world->CreateBody(&bd); b2EdgeShape shape; shape.SetTwoSided(b2Vec2(-40.0f, 0.0f), b2Vec2(40.0f, 0.0f)); ground->CreateFixture(&shape, 0.0f); } m_enableLimit = true; m_enableMotor = false; m_motorSpeed = 10.0f; { b2PolygonShape shape; shape.SetAsBox(1.0f, 1.0f); b2BodyDef bd; bd.type = b2_dynamicBody; bd.position.Set(0.0f, 10.0f); bd.angle = 0.5f * b2_pi; bd.allowSleep = false; b2Body* body = m_world->CreateBody(&bd); body->CreateFixture(&shape, 5.0f); b2PrismaticJointDef pjd; // Horizontal pjd.Initialize(ground, body, bd.position, b2Vec2(1.0f, 0.0f)); pjd.motorSpeed = m_motorSpeed; pjd.maxMotorForce = 10000.0f; pjd.enableMotor = m_enableMotor; pjd.lowerTranslation = -10.0f; pjd.upperTranslation = 10.0f; pjd.enableLimit = m_enableLimit; m_joint = (b2PrismaticJoint*)m_world->CreateJoint(&pjd); } } 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_joint->EnableLimit(m_enableLimit); } if (ImGui::Checkbox("Motor", &m_enableMotor)) { m_joint->EnableMotor(m_enableMotor); } if (ImGui::SliderFloat("Speed", &m_motorSpeed, -100.0f, 100.0f, "%.0f")) { m_joint->SetMotorSpeed(m_motorSpeed); } ImGui::End(); } void Step(Settings& settings) override { Test::Step(settings); float force = m_joint->GetMotorForce(settings.m_hertz); g_debugDraw.DrawString(5, m_textLine, "Motor Force = %4.0f", force); m_textLine += m_textIncrement; } static Test* Create() { return new PrismaticJoint; } b2PrismaticJoint* m_joint; float m_motorSpeed; bool m_enableMotor; bool m_enableLimit; }; static int testIndex = RegisterTest("Joints", "Prismatic", PrismaticJoint::Create);