Cocos2d：檢測旋轉精靈上的觸摸？

Question

如何檢測旋轉的CCSprite上的觸摸？

我熟悉使用ccTouchesBegan和contentSize，anchorPoint等的一般技術，讓sprite檢測觸摸是否在其邊界內......但我不確定一旦sprite被旋轉一些角度。

我想讓精靈本身檢測觸摸（封裝）並通過委託將事件報告給另一個對象。

如果有人有一些代碼分享...會很好。

Answer 1

嘗試使用CCNode convertTouchToNodeSpaceAR：方法將點轉換爲旋轉座標，然後您可以對精靈邊界進行比較。

我在CCNode上做了這個類，所以它可用於任何CCNode或子類。

@interface CCNode (gndUtils) 

// Lets a node test to see if a touch is in it. 
// Takes into account the scaling/rotation/transforms of all 
// the parents in the parent chain. 
// Note that rotation of a rectangle doesn't produce a rectangle 
// (and we are using a simple rectangle test) 
// so this is testing the smallest rectangle that encloses the rotated node. 
// This does the converstion to view and then world coordinates 
// so if you are testing lots of nodes, do that converstion manually 
// 
// CGPoint touchLoc = [touch locationInView: [touch view]]; // convert to "View" 
// touchLoc = [[CCDirector sharedDirector] convertToGL: touchLoc]; // move to "World" 
// and then use worldPointInNode: method instead for efficiency. 

- (BOOL) touchInNode: (UITouch *) touch; 

// allows a node to test if a world point is in it. 
- (BOOL) worldPointInNode: (CGPoint) worldPoint; 

@end 

和實現：

@implementation CCNode (gndUtils) 

- (BOOL) touchInNode: (UITouch *) touch 
{ 
    CGPoint touchLoc = [touch locationInView: [touch view]];   // convert to "View coordinates" from "window" presumably 
    touchLoc = [[CCDirector sharedDirector] convertToGL: touchLoc];  // move to "cocos2d World coordinates" 

    return [self worldPointInNode: touchLoc]; 
} 

- (BOOL) worldPointInNode: (CGPoint) worldPoint 
{ 
    // scale the bounding rect of the node to world coordinates so we can see if the worldPoint is in the node. 
    CGRect bbox = CGRectMake(0.0f, 0.0f, self.contentSize.width, self.contentSize.height); // get bounding box in local 
    bbox = CGRectApplyAffineTransform(bbox, [self nodeToWorldTransform]);  // convert box to world coordinates, scaling etc. 
    return CGRectContainsPoint(bbox, worldPoint); 
} 
@end 

Answer 2

@爸爸的代碼轉換節點的BBOX到世界各地。對於旋轉的節點，這擴展了bbox，並且可以在實際節點之外但在世界bbox內的觸摸返回true。爲了避免這種情況，將世界點轉換爲節點的座標空間，並測試其中的本地點。

Answer 3

由於苦艾酒說 - 的poundev23真的只檢查BB圍繞旋轉精靈代碼。 我寫正確的代碼（但Cocos2dx - C++） - 希望它可以幫助別人：

CCSize size = this->getContentSize(); 
CCRect rect = CCRect(0, 0, size.width, size.height); 
CCPoint pt = touch->locationInView(); 
pt = CCDirector::sharedDirector()->convertToGL(pt); 
pt = CCPointApplyAffineTransform(pt, this->worldToNodeTransform()); 
bool b = CCRect::CCRectContainsPoint(rect, pt); 

有一個很好的代碼！

編輯： 好的解決方案！我將它轉換爲Objective C.

- (BOOL) containsTouchLocation:(UITouch *) touch 
{ 
    CGSize size = self.contentSize; 
    CGRect rect = CGRectMake(0, 0, size.width, size.height); 
    CGPoint touchLocation = [touch locationInView: [touch view]]; 
    touchLocation = [[CCDirector sharedDirector] convertToGL:touchLocation]; 
    touchLocation = CGPointApplyAffineTransform(touchLocation, self.worldToNodeTransform); 
    bool containsPoint = CGRectContainsPoint(rect, touchLocation); 

    return containsPoint; 
}