// 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" #include "ImGui/ImGuiPresenter.h" // This tests distance joints, body destruction, and joint destruction. class DistanceJoint : public Test { public: DistanceJoint() { 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); } { b2BodyDef bd; bd.type = b2_dynamicBody; bd.angularDamping = 0.1f; bd.position.Set(0.0f, 5.0f); b2Body* body = m_world->CreateBody(&bd); b2PolygonShape shape; shape.SetAsBox(0.5f, 0.5f); body->CreateFixture(&shape, 5.0f); m_hertz = 1.0f; m_dampingRatio = 0.7f; b2DistanceJointDef jd; jd.Initialize(ground, body, b2Vec2(0.0f, 15.0f), bd.position); jd.collideConnected = true; m_length = jd.length; m_minLength = m_length; m_maxLength = m_length; b2LinearStiffness(jd.stiffness, jd.damping, m_hertz, m_dampingRatio, jd.bodyA, jd.bodyB); m_joint = (b2DistanceJoint*)m_world->CreateJoint(&jd); } } void UpdateUI() override { // ImGui::SetNextWindowPos(ImVec2(10.0f, 100.0f)); ImGui::SetNextWindowSize(ImVec2(260.0f, 150.0f)); ImGui::Begin("Joint Controls", nullptr, ImGuiWindowFlags_NoResize); if (ImGui::SliderFloat("Length", &m_length, 0.0f, 20.0f, "%.0f")) { m_length = m_joint->SetLength(m_length); } if (ImGui::SliderFloat("Min Length", &m_minLength, 0.0f, 20.0f, "%.0f")) { m_minLength = m_joint->SetMinLength(m_minLength); } if (ImGui::SliderFloat("Max Length", &m_maxLength, 0.0f, 20.0f, "%.0f")) { m_maxLength = m_joint->SetMaxLength(m_maxLength); } if (ImGui::SliderFloat("Hertz", &m_hertz, 0.0f, 10.0f, "%.1f")) { float stiffness; float damping; b2LinearStiffness(stiffness, damping, m_hertz, m_dampingRatio, m_joint->GetBodyA(), m_joint->GetBodyB()); m_joint->SetStiffness(stiffness); m_joint->SetDamping(damping); } if (ImGui::SliderFloat("Damping Ratio", &m_dampingRatio, 0.0f, 2.0f, "%.1f")) { float stiffness; float damping; b2LinearStiffness(stiffness, damping, m_hertz, m_dampingRatio, m_joint->GetBodyA(), m_joint->GetBodyB()); m_joint->SetStiffness(stiffness); m_joint->SetDamping(damping); } ImGui::End(); } static Test* Create() { return new DistanceJoint; } b2DistanceJoint* m_joint; float m_length; float m_minLength; float m_maxLength; float m_hertz; float m_dampingRatio; }; static int testIndex = RegisterTest("Joints", "Distance Joint", DistanceJoint::Create);