iphone - UIGestureRecognizer不会旋转 Sprite - Cocos2d

Question

有人知道为什么它不会旋转 Sprite 吗？

- (void)ccTouchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [touches anyObject];

        CGPoint center = CGPointMake(CGRectGetMidX([[touch view] bounds]), CGRectGetMidY([[touch view] bounds]));

        CGPoint firstLocation = [touch previousLocationInView:[touch view]];
        CGPoint location = [touch locationInView:[touch view]];

        CGPoint currentTouchPoint = [[CCDirector sharedDirector] convertToGL:location];
        CGPoint previousTouchPoint = [[CCDirector sharedDirector] convertToGL:firstLocation];

        CGPoint line2Start = currentTouchPoint;
        CGPoint line1Start = previousTouchPoint;
        CGPoint line2End = CGPointMake(center.x + (center.x - line2Start.x), center.y + (center.y - line2Start.y));
        CGPoint line1End = CGPointMake(center.x + (center.x - line1Start.x), center.y + (center.y - line1Start.y));

        CGFloat a = line1End.x - line1Start.x;
        CGFloat b = line1End.y - line1Start.y;
        CGFloat c = line2End.x - line2Start.x;
        CGFloat d = line2End.y - line2Start.y;

        CGFloat line1Slope = (line1End.y - line1Start.y) / (line1End.x - line1Start.x);
        CGFloat line2Slope = (line2End.y - line2Start.y) / (line2End.x - line2Start.x);

        CGFloat degs = acosf(((a*c) + (b*d)) / ((sqrt(a*a + b*b)) * (sqrt(c*c + d*d))));

        CGFloat angleInRadians = (line2Slope > line1Slope) ? degs : -degs;

        [g setRotation:angleInRadians];
}

- (void)ccTouchEnded:(UITouch *)touch withEvent:(UIEvent *)event
{
    UIGestureRecognizer *recognizer;
    [recognizer setState:UIGestureRecognizerStateEnded];
}

G是[g setRotation:angleInRadians]中的 Sprite ；

然后，当我添加这个时

[[touch view] setTransform:CGAffineTransformRotate([[touch view] transform], [grinder rotation])];

它旋转整个场景!请问有什么帮助吗？

谢谢!

Answer 1

哥们

下面是 ui-kit 的链接，但它也适用于 cocos2d你需要照顾好协调系统

1)对于cocos2d，原点是左下角

2)对于UIKit，原点是左上角

"Rotate image by Dragging"

希望这对您有帮助祝你好运