ElasticBody.h
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- /*
- * Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com
- *
- * 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 ELASTIC_BODY_H
- #define ELASTIC_BODY_H
- class ElasticBody : public Test
- {
- public:
- b2Body* bodies[64];
- b2Body* m_ground;
- b2Body* m_elev;
- b2PrismaticJoint* m_joint_elev;
- /// Main...
- ElasticBody()
- {
- /// Bottom static body
- {
- b2PolygonDef sd;
- sd.SetAsBox(50.0f, 2.0f);
- sd.friction = 0.1f;
- sd.restitution = 0.1f;
- b2BodyDef bd;
- bd.position.Set(-1.0f, -7.5f);
- m_ground = m_world->CreateBody(&bd);
- m_ground->CreateFixture(&sd);
- }
- /// Upper static body
- {
- b2PolygonDef sd;
- sd.SetAsBox(20.0f, 0.50f,b2Vec2(0.f,0.f),0.047f*b2_pi);
- sd.friction = 0.01f;
- sd.restitution = 0.001f;
- b2BodyDef bd;
- bd.position.Set(-20.f, 93.0f);
- b2Body* g = m_world->CreateBody(&bd);
- g->CreateFixture(&sd);
- sd.SetAsBox(15.f, 0.50f,b2Vec2(-15.0f,12.5f),0.0f);
- g->CreateFixture(&sd);
- sd.SetAsBox(20.f,0.5f,b2Vec2(0.0f,-25.0f),-0.5f);
- g->CreateFixture(&sd);
- }
- /// Left channel left wall
- {
- b2PolygonDef sd;
- sd.SetAsBox(0.7f, 55.0f);
- sd.friction = 0.1f;
- sd.restitution = 0.1f;
- b2BodyDef bd;
- bd.position.Set(-49.3f, 50.0f);
- b2Body* g = m_world->CreateBody(&bd);
- g->CreateFixture(&sd);
- }
- /// Right wall
- {
- b2PolygonDef sd;
- sd.SetAsBox(0.7f, 55.0f);
- sd.friction = 0.1f;
- sd.restitution = 0.1f;
- b2BodyDef bd;
- bd.position.Set(45.f, 50.0f);
- b2Body* g = m_world->CreateBody(&bd);
- g->CreateFixture(&sd);
- }
- /// Left channel right upper wall
- {
- b2PolygonDef sd;
- sd.SetAsBox(0.5f, 20.0f);
- sd.friction = 0.05f;
- sd.restitution = 0.01f;
- b2BodyDef bd;
- bd.position.Set(-42.0f, 70.0f);
- bd.angle = -0.03f*b2_pi;
- b2Body* g = m_world->CreateBody(&bd);
- g->CreateFixture(&sd);
- }
- /// Left channel right lower wall
- {
- b2PolygonDef sd;
- sd.SetAsBox(0.50f, 23.0f);
- sd.friction = 0.05f;
- sd.restitution = 0.01f;
- b2BodyDef bd;
- bd.position.Set(-44.0f, 27.0f);
- b2Body* g = m_world->CreateBody(&bd);
- g->CreateFixture(&sd);
- /// Bottom motors
- b2CircleDef cd;
- cd.radius = 3.0f;
- cd.density = 15.0f;
- cd.friction = 1.f;
- cd.restitution = 0.2f;
- /// 1.
- bd.position.Set(-40.0f,2.5f);
- b2Body* body = m_world->CreateBody(&bd);
- body->CreateFixture(&cd);
- body->SetMassFromShapes();
- b2RevoluteJointDef jr;
- jr.Initialize (g,body,body->GetWorldCenter()+b2Vec2(0.f,1.f));
- jr.maxMotorTorque = 30000.f;
- jr.enableMotor = true;
- jr.motorSpeed = 20.f;
- m_world->CreateJoint(&jr);
- /// 1. left down
- bd.position.Set(-46.0f,-2.5f);
- cd. radius = 1.5f; jr.motorSpeed = -20.f;
- body = m_world->CreateBody(&bd);
- body->CreateFixture(&cd);
- sd.SetAsBox(2.0f, 0.50f);
- body->CreateFixture(&sd);
- body->SetMassFromShapes();
- jr.Initialize (g,body,body->GetWorldCenter());
- m_world->CreateJoint(&jr);
- /// 2.
- cd.radius = 3.0f; jr.motorSpeed = 20.f;
- bd.position.Set(-32.0f,2.5f);
- body = m_world->CreateBody(&bd);
- body->CreateFixture(&cd);
- body->SetMassFromShapes();
- jr.Initialize (g,body,body->GetWorldCenter()+b2Vec2(0.f,1.f));
- m_world->CreateJoint(&jr);
- /// 3.
- jr.motorSpeed = 20.f;
- bd.position.Set(-24.0f,1.5f);
- body = m_world->CreateBody(&bd);
- body->CreateFixture(&cd);
- body->SetMassFromShapes();
- jr.Initialize (g,body,body->GetWorldCenter()+b2Vec2(0.f,1.f));
- m_world->CreateJoint(&jr);
- /// 4.
- bd.position.Set(-16.0f,0.8f);
- body = m_world->CreateBody(&bd);
- body->CreateFixture(&cd);
- body->SetMassFromShapes();
- jr.Initialize (g,body,body->GetWorldCenter()+b2Vec2(0.f,1.f));
- m_world->CreateJoint(&jr);
- /// 5.
- bd.position.Set(-8.0f,0.5f);
- body = m_world->CreateBody(&bd);
- body->CreateFixture(&cd);
- body->SetMassFromShapes();
- jr.Initialize (g,body,body->GetWorldCenter()+b2Vec2(0.f,1.f));
- m_world->CreateJoint(&jr);
- /// 6.
- bd.position.Set(0.0f,0.1f);
- body = m_world->CreateBody(&bd);
- body->CreateFixture(&cd);
- body->SetMassFromShapes();
- jr.Initialize (g,body,body->GetWorldCenter()+b2Vec2(0.f,1.f));
- m_world->CreateJoint(&jr);
- /// 7.
- bd.position.Set(8.0f,-0.5f);
- body = m_world->CreateBody(&bd);
- body->CreateFixture(&cd);
- sd.SetAsBox(3.7f, 0.5f);
- body->CreateFixture(&sd);
- body->SetMassFromShapes();
- jr.Initialize (g,body,body->GetWorldCenter()+b2Vec2(0.f,1.f));
- m_world->CreateJoint(&jr);
- /// 8. right rotator
- sd.SetAsBox(5.f, 0.5f);
- sd.density = 2.0f;
- bd.position.Set(18.0f,1.f);
- b2Body* rightmotor = m_world->CreateBody(&bd);
- rightmotor->CreateFixture(&sd);
- sd.SetAsBox(4.5f, 0.5f, b2Vec2(0.f,0.f),b2_pi/3.f);
- rightmotor->CreateFixture(&sd);
- sd.SetAsBox(4.5f, 0.5f, b2Vec2(0.f,0.f),b2_pi*2.f/3.f);
- rightmotor->CreateFixture(&sd);
- cd.radius = 4.2f;
- rightmotor->CreateFixture(&cd);
- rightmotor->SetMassFromShapes();
- jr.Initialize (g,rightmotor,rightmotor->GetWorldCenter());
- jr.maxMotorTorque = 70000.f;
- jr.motorSpeed = -4.f;
- m_world->CreateJoint(&jr);
- /// 9. left rotator
- sd.SetAsBox(8.5f, 0.5f);
- sd.density = 2.0f;
- bd.position.Set(-34.0f,17.f);
- body = m_world->CreateBody(&bd);
- body->CreateFixture(&sd);
- sd.SetAsBox(8.5f, 0.5f, b2Vec2(0.f,0.f),b2_pi*.5f);
- body->CreateFixture(&sd);
- cd.radius = 7.f;
- cd.friction = 0.9f;
- body->CreateFixture(&cd);
- body->SetMassFromShapes();
- jr.Initialize (g,body,body->GetWorldCenter());
- jr.maxMotorTorque = 100000.f;
- jr.motorSpeed = -5.f;
- m_world->CreateJoint(&jr);
- /// big compressor
- sd.SetAsBox(3.0f,4.f);
- sd.density = 10.0f;
- bd.position.Set(-16.0f,17.f);
- b2Body *hammerleft = m_world->CreateBody(&bd);
- hammerleft->CreateFixture(&sd);
- hammerleft->SetMassFromShapes();
- b2DistanceJointDef jd;
- jd.Initialize(body, hammerleft, body->GetWorldCenter()+b2Vec2(0.f,6.f), hammerleft->GetWorldCenter() );
- m_world->CreateJoint(&jd);
- bd.position.Set(4.0f,17.f);
- b2Body *hammerright = m_world->CreateBody(&bd);
- hammerright->CreateFixture(&sd);
- hammerright->SetMassFromShapes();
- jd.Initialize(body, hammerright, body->GetWorldCenter()-b2Vec2(0.f,6.f), hammerright->GetWorldCenter() );
- m_world->CreateJoint(&jd);
- /// pusher
- sd.SetAsBox(6.f,0.75f);
- bd.position.Set(-21.0f,9.f);
- b2Body* pusher = m_world->CreateBody(&bd);
- pusher->CreateFixture(&sd);
- sd.SetAsBox(2.f,1.5f,b2Vec2(-5.f,0.f),0.f);
- pusher->SetMassFromShapes();
- pusher->CreateFixture(&sd);
- jd.Initialize(rightmotor,pusher,rightmotor->GetWorldCenter()+b2Vec2(-8.0f,0.f),
- pusher->GetWorldCenter()+b2Vec2(5.0f,0.f) );
- m_world->CreateJoint(&jd);
- }
- /// Static bodies above motors
- {
- b2PolygonDef sd;
- b2CircleDef cd;
- sd.SetAsBox(9.0f, 0.5f);
- sd.friction = 0.05f;
- sd.restitution = 0.01f;
- b2BodyDef bd;
- bd.position.Set(-15.5f, 12.f);
- bd.angle = 0.0;
- b2Body* g = m_world->CreateBody(&bd);
- g->CreateFixture(&sd);
-
- sd.SetAsBox(8.f, 0.5f, b2Vec2(23.f,0.f),0.f);
- g->CreateFixture(&sd);
- /// compressor statics
- sd.SetAsBox(7.0f, 0.5f, b2Vec2(-2.f,9.f),0.f);
- g->CreateFixture(&sd);
- sd.SetAsBox(9.0f, 0.5f, b2Vec2(22.f,9.f),0.f);
- g->CreateFixture(&sd);
- sd.SetAsBox(19.0f, 0.5f, b2Vec2(-9.f,15.f),-0.05f);
- g->CreateFixture(&sd);
- sd.SetAsBox(4.7f, 0.5f, b2Vec2(15.f,11.5f),-0.5f);
- g->CreateFixture(&sd);
- /// below compressor
- sd.SetAsBox(26.0f, 0.3f, b2Vec2(17.f,-4.4f),-0.02f);
- g->CreateFixture(&sd);
- cd.radius = 1.0f; cd.friction = 1.0;
- cd.localPosition = b2Vec2(29.f,-6.f);
- g->CreateFixture(&cd);
- cd.radius = 0.7f;
- cd.localPosition = b2Vec2(-2.f,-4.5f);
- g->CreateFixture(&cd);
- }
- /// Elevator
- {
- b2BodyDef bd;
- b2CircleDef cd;
- b2PolygonDef sd;
- bd.position.Set(40.0f,4.0f);
- m_elev = m_world->CreateBody(&bd);
- sd.SetAsBox(0.5f, 2.5f,b2Vec2(3.0f,-3.0f), 0.f);
- sd.density = 1.f;
- sd.friction = 0.01f;
- m_elev->CreateFixture(&sd);
- sd.SetAsBox(7.0f, 0.5f, b2Vec2(-3.5f,-5.5f), 0.f);
- m_elev->CreateFixture(&sd);
- sd.SetAsBox(0.5f, 2.5f, b2Vec2(-11.f,-3.5f), 0.f);
- m_elev->CreateFixture(&sd);
- m_elev->SetMassFromShapes();
-
- b2PrismaticJointDef jp;
- jp.Initialize(m_ground,m_elev, bd.position, b2Vec2(0.0f, 1.0f));
- jp.lowerTranslation = 0.0f;
- jp.upperTranslation = 100.0f;
- jp.enableLimit = true;
- jp.enableMotor = true;
- jp.maxMotorForce = 10000.f;
- jp.motorSpeed = 0.f;
- m_joint_elev = (b2PrismaticJoint*)m_world->CreateJoint(&jp);
-
- /// Korb
- sd.SetAsBox(2.3f, 0.5f,b2Vec2(1.f,0.0f), 0.0f);
- sd.density = 0.5f;
- bd.position.Set(29.0f,6.5f);
- b2Body* body = m_world->CreateBody(&bd);
- body->CreateFixture(&sd);
- sd.SetAsBox(2.5f, 0.5f,b2Vec2(3.0f,-2.f), b2_pi/2.f);
- body->CreateFixture(&sd);
- sd.SetAsBox(4.6f, 0.5f,b2Vec2(7.8f,-4.0f), 0.f);
- body->CreateFixture(&sd);
- sd.SetAsBox(0.5f, 4.5f,b2Vec2(12.f,0.0f), 0.f);
- body->CreateFixture(&sd);
-
- sd.SetAsBox(0.5f, 0.5f,b2Vec2(13.f,4.0f), 0.f);
- body->CreateFixture(&sd);
- cd.radius = 0.7f; cd.density = 1.f; cd.friction = 0.01f;
- cd.localPosition = b2Vec2(0.f,0.f);
- body->CreateFixture(&cd);
- body->SetMassFromShapes();
- b2RevoluteJointDef jr;
- jr.Initialize(m_elev,body, bd.position);
- jr.enableLimit = true;
- jr.lowerAngle = -0.2f;
- jr.upperAngle = b2_pi*1.1f;
- jr.collideConnected = true;
- m_world->CreateJoint(&jr);
- /// upper body exit
- sd.SetAsBox(14.0f, 0.5f,b2Vec2(-3.5f,-10.0f), 0.0f);
- bd.position.Set(17.5f,96.0f);
- body = m_world->CreateBody(&bd);
- body->CreateFixture(&sd);
- }
- /// "Elastic body" 64 bodies - something like a lin. elastic compound
- /// connected via dynamic forces (springs)
- {
- b2PolygonDef sd;
- sd.SetAsBox(0.55f, 0.55f);
- sd.density = 1.5f;
- sd.friction = 0.01f;
- sd.filter.groupIndex = -1;
- b2Vec2 startpoint(30.f,20.f);
- b2BodyDef bd;
- bd.isBullet = false;
- bd.allowSleep = false;
- for (int i = 0; i < 8; ++i)
- {
- for (int j = 0; j < 8; ++j)
- {
- bd.position.Set(j*1.02f, 2.51f + 1.02f * i);
- bd.position += startpoint;
- b2Body* body = m_world->CreateBody(&bd);
- bodies[8*i+j] = body;
- body->CreateFixture(&sd);
- body->SetMassFromShapes();
- }
- }
- }
- }
- /// Apply dynamic forces (springs) and check elevator state
- void Step(Settings* settings)
- {
- Test::Step(settings);
- for (int i=0; i<8; ++i){
- for (int j=0; j<8; ++j){
- b2Vec2 zero(0.0f,0.0f);
- b2Vec2 down(0.0f, -0.5f);
- b2Vec2 up(0.0f, 0.5f);
- b2Vec2 right(0.5f, 0.0f);
- b2Vec2 left(-0.5f, 0.0f);
- int ind = i*8+j;
- int indr = ind+1;
- int indd = ind+8;
- float32 spring = 500.0f;
- float32 damp = 5.0f;
- if (j<7) {
- AddSpringForce(*(bodies[ind]),zero,*(bodies[indr]),zero,spring, damp, 1.0f);
- AddSpringForce(*(bodies[ind]),right,*(bodies[indr]),left,0.5f*spring, damp, 0.0f);
- }
- if (i<7) {
- AddSpringForce(*(bodies[ind]),zero,*(bodies[indd]),zero,spring, damp, 1.0f);
- AddSpringForce(*(bodies[ind]),up,*(bodies[indd]),down,0.5f*spring,damp,0.0f);
- }
- int inddr = indd + 1;
- int inddl = indd - 1;
- float32 drdist = sqrtf(2.0f);
- if (i < 7 && j < 7){
- AddSpringForce(*(bodies[ind]),zero,*(bodies[inddr]),zero,spring, damp, drdist);
- }
- if (i < 7 && j > 0){
- AddSpringForce(*(bodies[ind]),zero,*(bodies[inddl]),zero,spring, damp, drdist);
- }
- indr = ind+2;
- indd = ind+8*2;
- if (j<6) {
- AddSpringForce(*(bodies[ind]),zero,*(bodies[indr]),zero,spring, damp, 2.0f);
- }
- if (i<6) {
- AddSpringForce(*(bodies[ind]),zero,*(bodies[indd]),zero,spring,damp,2.0f);
- }
- inddr = indd + 2;
- inddl = indd - 2;
- drdist = sqrtf(2.0f)*2.0f;
- if (i < 6 && j < 6){
- AddSpringForce(*(bodies[ind]),zero,*(bodies[inddr]),zero,spring, damp, drdist);
- }
- if (i < 6 && j > 1){
- AddSpringForce(*(bodies[ind]),zero,*(bodies[inddl]),zero,spring, damp, drdist);
- }
- }
- }
- /// Check if bodies are near elevator
- /// Look if the body to lift is near the elevator
- b2Vec2 p1 = bodies[0]->GetWorldCenter();
- b2Vec2 p2 = bodies[63]->GetWorldCenter();
- /// m_elev: elevator prism. joint
- b2Vec2 e = m_elev->GetWorldCenter() + b2Vec2(0.f,7.f);
- // maybe not the best way to do it...
- // Bodies reached the elevator side
- if ( p1.x>e.x || p2.x>e.x ) {
- // go up
- if ( ( p1.y<e.y || p2.y<e.y ) &&
- ( m_joint_elev->GetJointTranslation()<=m_joint_elev->GetLowerLimit()+1.f ) )
- {
- m_joint_elev->SetMotorSpeed(20.f);
- //printf("lift goes up trans: %Gn",m_joint_elev->GetJointTranslation());
- }
- }
- // go down
- if ( (m_joint_elev->GetJointTranslation()>=m_joint_elev->GetUpperLimit()-2.f) )
- {
- m_joint_elev->SetMotorSpeed(-15.f);
- //printf("lift goes down: %Gn",m_joint_elev->GetJointTranslation());
- }
- }
- /// Add a spring force
- void AddSpringForce(b2Body& bA, b2Vec2& localA, b2Body& bB, b2Vec2& localB, float32 k, float32 friction, float32 desiredDist)
- {
- b2Vec2 pA = bA.GetWorldPoint(localA);
- b2Vec2 pB = bB.GetWorldPoint(localB);
- b2Vec2 diff = pB - pA;
- //Find velocities of attach points
- b2Vec2 vA = bA.GetLinearVelocity() - b2Cross(bA.GetWorldVector(localA), bA.GetAngularVelocity());
- b2Vec2 vB = bB.GetLinearVelocity() - b2Cross(bB.GetWorldVector(localB), bB.GetAngularVelocity());
- b2Vec2 vdiff = vB-vA;
- float32 dx = diff.Normalize(); //normalizes diff and puts length into dx
- float32 vrel = vdiff.x*diff.x + vdiff.y*diff.y;
- float32 forceMag = -k*(dx-desiredDist) - friction*vrel;
- diff *= forceMag; // diff *= forceMag
- bB.ApplyForce(diff, bA.GetWorldPoint(localA));
- diff *= -1.0f;
- bA.ApplyForce(diff, bB.GetWorldPoint(localB));
- }
- /// Default constructor
- static Test* Create()
- {
- return new ElasticBody;
- }
- };
- #endif