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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"
#include "imgui/imgui.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_NoMove | 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);
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