Shapes in sprite kit - objective-c

Question

How do you make a circle or another shape in sprite kit I have seen some that use CGPath but i haven't really ever used CGPath ever . I was able to make a square with SKSpritenode but I can't seem to make triangles or circles.

Answer 1

This creates an SKShapeNode and sets its path property to a circle path with radius 16.
SKShapeNode *shape = [SKShapeNode node];
CGRect rect = CGRectMake(0, 0, 32, 32);
shape.path = [self circleInRect:rect];
shape.strokeColor = [SKColor greenColor];
shape.fillColor = [SKColor redColor];
shape.position = CGPointMake(100,100);
[self addChild:shape];
This method returns a CGPath object initialized with a oval path
- (CGPathRef) circleInRect:(CGRect)rect
{
// Adjust position so path is centered in shape
CGRect adjustedRect = CGRectMake(rect.origin.x-rect.size.width/2, rect.origin.y-rect.size.height/2, rect.size.width, rect.size.height);
UIBezierPath *bezierPath = [UIBezierPath bezierPathWithOvalInRect:adjustedRect];
return bezierPath.CGPath;
}
Here's a triangle path...
- (CGPathRef) triangleInRect:(CGRect)rect
{
CGFloat offsetX = CGRectGetMidX(rect);
CGFloat offsetY = CGRectGetMidY(rect);
UIBezierPath* bezierPath = [UIBezierPath bezierPath];
[bezierPath moveToPoint: CGPointMake(offsetX, 0)];
[bezierPath addLineToPoint: CGPointMake(-offsetX, offsetY)];
[bezierPath addLineToPoint: CGPointMake(-offsetX, -offsetY)];
[bezierPath closePath];
return bezierPath.CGPath;
}

Answer 2

Code snippet to create Triangle using Sprite Kit
SKShapeNode* leftContainer = [SKShapeNode node];
leftContainer.position = CGPointMake(CGRectGetMidX(self.frame),
CGRectGetMidY(self.frame));
CGMutablePathRef pathLeftContainer = CGPathCreateMutable();
// Move to position and Draws line to form a triangle
CGPathMoveToPoint(pathLeftContainer, NULL, 60, 100);
CGPathAddLineToPoint(pathLeftContainer, 0, 120, 160);
CGPathAddLineToPoint(pathLeftContainer, 0,180,100);
CGPathAddLineToPoint(pathLeftContainer, 0,60,100);
[leftContainer setPath:pathLeftContainer];
leftContainer.lineWidth = 10.0;
leftContainer.strokeColor = [UIColor redColor];
leftContainer.physicsBody = [SKPhysicsBody bodyWithEdgeChainFromPath:leftContainer.path];
leftContainer.physicsBody.dynamic = FALSE;
[leftContainer.physicsBody setAllowsRotation:FALSE];
[self addChild:leftContainer];
CGPathRelease(pathLeftContainer);
Code snippet to create Circle using Sprite Kit
SKShapeNode* leftContainer = [SKShapeNode node];
leftContainer.position = CGPointMake(CGRectGetMidX(self.frame),
CGRectGetMidY(self.frame));
CGMutablePathRef pathLeftContainer = CGPathCreateMutable();
// Draw circle with radius 20
CGPathAddArc(pathLeftContainer, NULL, 0, 20, 20, 0, 2*M_PI, true);
[leftContainer setPath:pathLeftContainer];
leftContainer.lineWidth = 10.0;
leftContainer.strokeColor = [UIColor redColor];
leftContainer.physicsBody = [SKPhysicsBody bodyWithEdgeChainFromPath:leftContainer.path];
leftContainer.physicsBody.dynamic = FALSE;
[leftContainer.physicsBody setAllowsRotation:FALSE];
[self addChild:leftContainer];
CGPathRelease(pathLeftContainer);