捏放大CCParallaxNode

Question

如何實現捏縮放到parallax scrolling node？

Answer 1

這裏的解決方案：

- (void)handlePitchZoom:(NSSet *)touches withEvent:(UIEvent *)event { 

    UITouch* touch1 = [[[event allTouches] allObjects] objectAtIndex:0]; 
    UITouch* touch2 = [[[event allTouches] allObjects] objectAtIndex:1]; 

    // calculate scale value 
    double prevDistance = ccpDistance([touch1 previousLocationInView:[touch1 view]], [touch2 previousLocationInView:[touch2 view]]); 
    double newDistance = ccpDistance([touch1 locationInView:[touch1 view]], [touch2 locationInView:[touch2 view]]); 

    CGFloat relation = newDistance/prevDistance; 
    CGFloat newScale = self.scale * relation; 

    if ((newScale >= minScale) && (newScale <= maxScale)) { 

     CGPoint touch1Location = [parallaxNode convertTouchToNodeSpace:touch1]; 
     CGPoint touch2Location = [parallaxNode convertTouchToNodeSpace:touch2]; 

     // calculate center point between two touches 
     CGPoint centerPoint = ccpMidpoint(touch1Location, touch2Location); 

     // store center point location (ScrollableView space) 
     CGPoint centerPointInParentNodeSpace = [self convertPoint:centerPoint fromNode:parallaxNode]; 
     CGPoint oldPoint = ccp(centerPointInParentNodeSpace.x * (self.scale), centerPointInParentNodeSpace.y * (self.scale)); 
     self.scale = newScale; 

     CGPoint newPoint = ccp(centerPointInParentNodeSpace.x * (self.scale), centerPointInParentNodeSpace.y * (self.scale)); 
     CGPoint diff = ccp(oldPoint.x - newPoint.x , oldPoint.y - newPoint.y); 

     [parallaxNode setPosition:ccp(parallaxNode.position.x + (diff.x*(1/self.scale)), parallaxNode.position.y + (diff.y*(1/self.scale)))]; 
    } 

希望這將幫助別人......