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POProblem to detect diamond shape in box2d
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Id
5660020
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AcceptedAnswerId
0
AnswerCount
1
ClosedDate
CommentCount
4
CommunityOwnedDate
CreationDate
2011-04-14T07:38:18
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0
LastActivityDate
2011-11-08T16:23:16.680
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0
OwnerUserId
599866
ParentId
0
PostTypeId
1
Score
1
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550
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text
Body
I make a simple game. It has many diamond image and one ball. when ball touch with diamond shape then collision occur. in my application when ball touch on the edge then collision working correctly but when ball touch on the corner then collision is not working. Code is hear.. <pre><code>- (id)init { if ((self=[super init])) { CGSize winSize = [CCDirector sharedDirector].winSize; self.isTouchEnabled = YES; self.isAccelerometerEnabled=YES; // Create a world b2Vec2 gravity = b2Vec2(0.0f, 0.0f); bool doSleep = true; _world = new b2World(gravity, doSleep); // Create edges around the entire screen b2BodyDef groundBodyDef; groundBodyDef.position.Set(0,0); _groundBody = _world->CreateBody(&groundBodyDef); b2PolygonShape groundBox; b2FixtureDef groundBoxDef; groundBoxDef.shape = &groundBox; groundBox.SetAsEdge(b2Vec2(0,0), b2Vec2(winSize.width/PTM_RATIO, 0)); _bottomFixture = _groundBody->CreateFixture(&groundBoxDef); groundBox.SetAsEdge(b2Vec2(0,0), b2Vec2(0, winSize.height/PTM_RATIO)); _groundBody->CreateFixture(&groundBoxDef); groundBox.SetAsEdge(b2Vec2(0, winSize.height/PTM_RATIO), b2Vec2(winSize.width/PTM_RATIO, winSize.height/PTM_RATIO)); _groundBody->CreateFixture(&groundBoxDef); groundBox.SetAsEdge(b2Vec2(winSize.width/PTM_RATIO, winSize.height/PTM_RATIO), b2Vec2(winSize.width/PTM_RATIO, 0)); _groundBody->CreateFixture(&groundBoxDef); // Create sprite and add it to the layer CCSprite *ball = [CCSprite spriteWithFile:@"ball1.png" rect:CGRectMake(0, 0, 16,16)]; // ball.position = ccp(180, 400); ball.tag = 1; // Create ball body b2BodyDef ballBodyDef; ballBodyDef.type = b2_dynamicBody; ballBodyDef.position.Set(180/PTM_RATIO, 450/PTM_RATIO); ballBodyDef.userData = ball; ballBody = _world->CreateBody(&ballBodyDef); // Create circle shape b2CircleShape circle; circle.m_radius = 16/PTM_RATIO; //circle.m_radius = 50/PTM_RATIO; // Create shape definition and add to body b2FixtureDef ballShapeDef; ballShapeDef.shape = &circle; ballShapeDef.density = 1.0f; ballShapeDef.friction = 0.0f; // We don't want the ball to have friction! ballShapeDef.restitution = 0.0f; _ballFixture = ballBody->CreateFixture(&ballShapeDef); // Give shape initial impulse... b2Vec2 force = b2Vec2(0, 0); ballBody->ApplyLinearImpulse(force, ballBodyDef.position); for(int i = 0; i < 5; i++) { static int padding=25; CCSprite *block = [CCSprite spriteWithFile:@"diamond2.png"]; int xOffset = padding+block.contentSize.width/5+((block.contentSize.width+padding)*i); block.position = ccp(xOffset, 250); block.tag = 2; [self addChild:block]; // Create block body b2BodyDef blockBodyDef; // blockBodyDef.type = b2_dynamicBody; blockBodyDef.position.Set(xOffset/PTM_RATIO, 400/PTM_RATIO); blockBodyDef.userData = block; b2Body *blockBody = _world->CreateBody(&blockBodyDef); // Create block shape b2PolygonShape blockShape; blockShape.SetAsBox(block.contentSize.width/PTM_RATIO/8, block.contentSize.height/PTM_RATIO/8 ); // Create shape definition and add to body b2FixtureDef blockshapeDef; blockshapeDef.shape = &blockShape; blockshapeDef.density = 0.0; blockshapeDef.friction = 10.0; blockshapeDef.restitution = 0.1f; blockBody->CreateFixture(&blockshapeDef); } [self addChild:ball]; // Create contact listener _contactListener = new MyContactListener(); _world->SetContactListener(_contactListener); [[SimpleAudioEngine sharedEngine] playBackgroundMusic:@"background-music-aac.caf"]; [self schedule:@selector(tick:)]; } return self; </code></pre> } <pre><code>- (void)tick:(ccTime) dt { // bool blockFound = false; _world->Step(dt, 10, 10); for(b2Body *b = _world->GetBodyList(); b; b=b->GetNext()) { if (b->GetUserData() != NULL) { CCSprite *sprite = (CCSprite *)b->GetUserData(); if (sprite.tag == 1) { static int maxSpeed = 20; b2Vec2 velocity = b->GetLinearVelocity(); float32 speed = velocity.Length(); // When the ball is greater than max speed, slow it down by // applying linear damping. This is better for the simulation // than raw adjustment of the velocity. if (speed > maxSpeed) { b->SetLinearDamping(0.2); } else if (speed < maxSpeed) { b->SetLinearDamping(0.0); } } sprite.position = ccp(b->GetPosition().x * PTM_RATIO, b->GetPosition().y * PTM_RATIO); sprite.rotation = 1 * CC_RADIANS_TO_DEGREES(b->GetAngle()); } } } </code></pre> Plz help me for detect correct collsion detection near corner of the diamond shape....
Tags
<iphone><cocos2d-iphone><box2d>
Title
Problem to detect diamond shape in box2d
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1. This table or related slice is empty.
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1. This table or related slice is empty.
PostTypePostTypeId
1. PTQuestion
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1. This table or related slice is empty.
UserOwnerUserId
1. USJasmit
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1. This table or related slice is empty.
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1. PO
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 PostTypePostTypeId
 PTAnswer
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1. This table or related slice is empty.
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