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/*
* Copyright (c) 2006-2009 Erin Catto http://www.box2d.org
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*/
#ifndef SLIDER_CRANK_H
#define SLIDER_CRANK_H
// A motor driven slider crank with joint friction.
class SliderCrank : public Test
{
public:
SliderCrank()
{
b2Body* ground = NULL;
{
b2BodyDef bd;
ground = m_world->CreateBody(&bd);
b2EdgeShape shape;
shape.Set(b2Vec2(-40.0f, 0.0f), b2Vec2(40.0f, 0.0f));
ground->CreateFixture(&shape, 0.0f);
}
{
b2Body* prevBody = ground;
// Define crank.
{
b2PolygonShape shape;
shape.SetAsBox(0.5f, 2.0f);
b2BodyDef bd;
bd.type = b2_dynamicBody;
bd.position.Set(0.0f, 7.0f);
b2Body* body = m_world->CreateBody(&bd);
body->CreateFixture(&shape, 2.0f);
b2RevoluteJointDef rjd;
rjd.Initialize(prevBody, body, b2Vec2(0.0f, 5.0f));
rjd.motorSpeed = 1.0f * b2_pi;
rjd.maxMotorTorque = 10000.0f;
rjd.enableMotor = true;
m_joint1 = (b2RevoluteJoint*)m_world->CreateJoint(&rjd);
prevBody = body;
}
// Define follower.
{
b2PolygonShape shape;
shape.SetAsBox(0.5f, 4.0f);
b2BodyDef bd;
bd.type = b2_dynamicBody;
bd.position.Set(0.0f, 13.0f);
b2Body* body = m_world->CreateBody(&bd);
body->CreateFixture(&shape, 2.0f);
b2RevoluteJointDef rjd;
rjd.Initialize(prevBody, body, b2Vec2(0.0f, 9.0f));
rjd.enableMotor = false;
m_world->CreateJoint(&rjd);
prevBody = body;
}
// Define piston
{
b2PolygonShape shape;
shape.SetAsBox(1.5f, 1.5f);
b2BodyDef bd;
bd.type = b2_dynamicBody;
bd.fixedRotation = true;
bd.position.Set(0.0f, 17.0f);
b2Body* body = m_world->CreateBody(&bd);
body->CreateFixture(&shape, 2.0f);
b2RevoluteJointDef rjd;
rjd.Initialize(prevBody, body, b2Vec2(0.0f, 17.0f));
m_world->CreateJoint(&rjd);
b2PrismaticJointDef pjd;
pjd.Initialize(ground, body, b2Vec2(0.0f, 17.0f), b2Vec2(0.0f, 1.0f));
pjd.maxMotorForce = 1000.0f;
pjd.enableMotor = true;
m_joint2 = (b2PrismaticJoint*)m_world->CreateJoint(&pjd);
}
// Create a payload
{
b2PolygonShape shape;
shape.SetAsBox(1.5f, 1.5f);
b2BodyDef bd;
bd.type = b2_dynamicBody;
bd.position.Set(0.0f, 23.0f);
b2Body* body = m_world->CreateBody(&bd);
body->CreateFixture(&shape, 2.0f);
}
}
}
void Keyboard(unsigned char key)
{
switch (key)
{
case 'f':
m_joint2->EnableMotor(!m_joint2->IsMotorEnabled());
m_joint2->GetBodyB()->SetAwake(true);
break;
case 'm':
m_joint1->EnableMotor(!m_joint1->IsMotorEnabled());
m_joint1->GetBodyB()->SetAwake(true);
break;
}
}
void Step(Settings* settings)
{
Test::Step(settings);
m_debugDraw.DrawString(5, m_textLine, "Keys: (f) toggle friction, (m) toggle motor");
m_textLine += 15;
float32 torque = m_joint1->GetMotorTorque(settings->hz);
m_debugDraw.DrawString(5, m_textLine, "Motor Torque = %5.0f", (float) torque);
m_textLine += 15;
}
static Test* Create()
{
return new SliderCrank;
}
b2RevoluteJoint* m_joint1;
b2PrismaticJoint* m_joint2;
};
#endif
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