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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 APPLY_FORCE_H
#define APPLY_FORCE_H
class ApplyForce : public Test
{
public:
ApplyForce()
{
m_world->SetGravity(b2Vec2(0.0f, 0.0f));
const float32 k_restitution = 0.4f;
b2Body* ground;
{
b2BodyDef bd;
bd.position.Set(0.0f, 20.0f);
ground = m_world->CreateBody(&bd);
b2EdgeShape shape;
b2FixtureDef sd;
sd.shape = &shape;
sd.density = 0.0f;
sd.restitution = k_restitution;
// Left vertical
shape.Set(b2Vec2(-20.0f, -20.0f), b2Vec2(-20.0f, 20.0f));
ground->CreateFixture(&sd);
// Right vertical
shape.Set(b2Vec2(20.0f, -20.0f), b2Vec2(20.0f, 20.0f));
ground->CreateFixture(&sd);
// Top horizontal
shape.Set(b2Vec2(-20.0f, 20.0f), b2Vec2(20.0f, 20.0f));
ground->CreateFixture(&sd);
// Bottom horizontal
shape.Set(b2Vec2(-20.0f, -20.0f), b2Vec2(20.0f, -20.0f));
ground->CreateFixture(&sd);
}
{
b2Transform xf1;
xf1.q.Set(0.3524f * b2_pi);
xf1.p = xf1.q.GetXAxis();
b2Vec2 vertices[3];
vertices[0] = b2Mul(xf1, b2Vec2(-1.0f, 0.0f));
vertices[1] = b2Mul(xf1, b2Vec2(1.0f, 0.0f));
vertices[2] = b2Mul(xf1, b2Vec2(0.0f, 0.5f));
b2PolygonShape poly1;
poly1.Set(vertices, 3);
b2FixtureDef sd1;
sd1.shape = &poly1;
sd1.density = 4.0f;
b2Transform xf2;
xf2.q.Set(-0.3524f * b2_pi);
xf2.p = -xf2.q.GetXAxis();
vertices[0] = b2Mul(xf2, b2Vec2(-1.0f, 0.0f));
vertices[1] = b2Mul(xf2, b2Vec2(1.0f, 0.0f));
vertices[2] = b2Mul(xf2, b2Vec2(0.0f, 0.5f));
b2PolygonShape poly2;
poly2.Set(vertices, 3);
b2FixtureDef sd2;
sd2.shape = &poly2;
sd2.density = 2.0f;
b2BodyDef bd;
bd.type = b2_dynamicBody;
bd.angularDamping = 5.0f;
bd.linearDamping = 0.1f;
bd.position.Set(0.0f, 2.0);
bd.angle = b2_pi;
bd.allowSleep = false;
m_body = m_world->CreateBody(&bd);
m_body->CreateFixture(&sd1);
m_body->CreateFixture(&sd2);
}
{
b2PolygonShape shape;
shape.SetAsBox(0.5f, 0.5f);
b2FixtureDef fd;
fd.shape = &shape;
fd.density = 1.0f;
fd.friction = 0.3f;
for (int i = 0; i < 10; ++i)
{
b2BodyDef bd;
bd.type = b2_dynamicBody;
bd.position.Set(0.0f, 5.0f + 1.54f * i);
b2Body* body = m_world->CreateBody(&bd);
body->CreateFixture(&fd);
float32 gravity = 10.0f;
float32 I = body->GetInertia();
float32 mass = body->GetMass();
// For a circle: I = 0.5 * m * r * r ==> r = sqrt(2 * I / m)
float32 radius = b2Sqrt(2.0f * I / mass);
b2FrictionJointDef jd;
jd.localAnchorA.SetZero();
jd.localAnchorB.SetZero();
jd.bodyA = ground;
jd.bodyB = body;
jd.collideConnected = true;
jd.maxForce = mass * gravity;
jd.maxTorque = mass * radius * gravity;
m_world->CreateJoint(&jd);
}
}
}
void Keyboard(unsigned char key)
{
switch (key)
{
case 'w':
{
b2Vec2 f = m_body->GetWorldVector(b2Vec2(0.0f, -200.0f));
b2Vec2 p = m_body->GetWorldPoint(b2Vec2(0.0f, 2.0f));
m_body->ApplyForce(f, p);
}
break;
case 'a':
{
m_body->ApplyTorque(50.0f);
}
break;
case 'd':
{
m_body->ApplyTorque(-50.0f);
}
break;
}
}
static Test* Create()
{
return new ApplyForce;
}
b2Body* m_body;
};
#endif
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