正在做物理小游戏, 用到齿轮
Node *drawGear(float r1,float r2,int teeth) { DrawNode *gear = DrawNode::create(); float da=2.0*PI/teeth/4.0; PhysicsBody* gearBody = PhysicsBody::create(); PhysicsMaterial gearMaterial(0.05,0.5,0.05f); gearBody->setGravityEnable(false); Vec2 polyPoint[4]; float angle; for(int i = 0; i < teeth; i++) { int j = 3; angle= i * 2.0 * PI / teeth; Vec2 pos1 = Vec2(r1*cos(angle),r1*sin(angle)); polyPoint[j] = pos1; //gear->drawPoint(pos1,3,Color4F::RED); Vec2 pos2 = Vec2(r2 * cos(angle+da),r2 * sin(angle+da)); polyPoint[--j] = pos2; //gear->drawPoint(pos2,Color4F::BLUE); gear->drawSegment(pos1,pos2,1,Color4F::BLACK); pos1 = Vec2(r2 * cos(angle+da),r2 * sin(angle+da)); //polyPoint[++j] = pos1; //gear->drawPoint(pos1,Color4F::YELLOW); pos2 = Vec2(r2 * cos(angle+2*da),r2 * sin(angle+2*da)); //polyPoint[++j] = pos2; //gear->drawPoint(pos2,Color4F::GREEN); gear->drawSegment(pos1,Color4F::BLACK); pos1 = Vec2(r2 * cos(angle+2*da),r2 * sin(angle+2*da)); polyPoint[--j] = pos1; //gear->drawPoint(pos1,Color4F::GRAY); pos2 = Vec2(r1 * cos(angle+3*da),r1 * sin(angle+3*da)); polyPoint[--j] = pos2; //gear->drawPoint(pos2,Color4F::MAGENTA); gear->drawSegment(pos1,Color4F::BLACK); gear->drawCircle(Vec2::ZERO,r1,60,false,Color4F::BLACK); gearBody->addShape(PhysicsShapeCircle::create(r1,gearMaterial)); gear->drawCircle(Vec2::ZERO,r1/3*2,Color4F::BLACK); gearBody->addShape(PhysicsShapePolygon::create(polyPoint,4,gearMaterial)); } gear->setPhysicsBody(gearBody); return gear; }