如何在Cocos2d iPhone中扭曲CCSprite？

Question

我试图将我的精灵弯曲到某个角度，但是无法找到正确的方法来做到这一点..我试图研究过程来扭曲存在于Cocos2d 1.00版本中的精灵，但我无法在最新版本中找到它0.99.5 请帮我弄清楚如何在cocos2d中歪斜一个Sprite？

Answer 1

这个版本为0.99.5的CCNode.h和CCNode.m补丁怎么样？此修补程序包含版本0.99.5和版本1.0.0之间的偏差差异。

我还将补丁上传到gist https://gist.github.com/1082368

diff --git a/cocos2d/CCNode.h b/cocos2d/CCNode.h
index d6faaf5..64acdc5 100644
--- a/cocos2d/CCNode.h
+++ b/cocos2d/CCNode.h
@@ -105,6 +107,9 @@ enum {
    // position of the node
    CGPoint position_;
    CGPoint positionInPixels_;
+   
+   // skew angles
+   float skewX_, skewY_;

    // is visible
    BOOL visible_;
@@ -174,6 +179,20 @@ enum {
  @since v0.8
  */
 @property (nonatomic,readwrite) float vertexZ;
+
+/** The X skew angle of the node in degrees.
+ This angle describes the shear distortion in the X direction.
+ Thus, it is the angle between the Y axis and the left edge of the shape
+ The default skewX angle is 0. Positive values distort the node in a CW direction.
+ */
+@property(nonatomic,readwrite,assign) float skewX;
+
+/** The Y skew angle of the node in degrees.
+ This angle describes the shear distortion in the Y direction.
+ Thus, it is the angle between the X axis and the bottom edge of the shape
+ The default skewY angle is 0. Positive values distort the node in a CCW direction.
+ */
+@property(nonatomic,readwrite,assign) float skewY;
 /** The rotation (angle) of the node in degrees. 0 is the default rotation angle. Positive values rotate node CW. */
 @property(nonatomic,readwrite,assign) float rotation;
 /** The scale factor of the node. 1.0 is the default scale factor. It modifies the X and Y scale at the same time. */
diff --git a/cocos2d/CCNode.m b/cocos2d/CCNode.m
index 5392905..569cb22 100644
--- a/cocos2d/CCNode.m
+++ b/cocos2d/CCNode.m
@@ -73,12 +75,32 @@
 #pragma mark CCNode - Transform related properties

 @synthesize rotation = rotation_, scaleX = scaleX_, scaleY = scaleY_;
+@synthesize skewX = skewX_, skewY = skewY_;
 @synthesize position = position_, positionInPixels = positionInPixels_;
 @synthesize anchorPoint = anchorPoint_, anchorPointInPixels = anchorPointInPixels_;
 @synthesize contentSize = contentSize_, contentSizeInPixels = contentSizeInPixels_;
 @synthesize isRelativeAnchorPoint = isRelativeAnchorPoint_;

 // getters synthesized, setters explicit
+
+-(void) setSkewX:(float)newSkewX
+{
+   skewX_ = newSkewX;
+   isTransformDirty_ = isInverseDirty_ = YES;
+#if CC_NODE_TRANSFORM_USING_AFFINE_MATRIX
+   isTransformGLDirty_ = YES;
+#endif
+}
+
+-(void) setSkewY:(float)newSkewY
+{
+   skewY_ = newSkewY;
+   isTransformDirty_ = isInverseDirty_ = YES;
+#if CC_NODE_TRANSFORM_USING_AFFINE_MATRIX
+   isTransformGLDirty_ = YES;
+#endif
+}
+
 -(void) setRotation: (float)newRotation
 {
    rotation_ = newRotation;
@@ -237,6 +259,7 @@

        isRunning_ = NO;

+       skewX_ = skewY_ = 0.0f;
        rotation_ = 0.0f;
        scaleX_ = scaleY_ = 1.0f;
        positionInPixels_ = position_ = CGPointZero;
@@ -615,6 +638,14 @@
    if (rotation_ != 0.0f )
        glRotatef( -rotation_, 0.0f, 0.0f, 1.0f );

+   // skew
+   if ( (skewX_ != 0.0f) || (skewY_ != 0.0f) ) {
+       CGAffineTransform skewMatrix = CGAffineTransformMake( 1.0f, tanf(CC_DEGREES_TO_RADIANS(skewY_)), tanf(CC_DEGREES_TO_RADIANS(skewX_)), 1.0f, 0.0f, 0.0f );
+       GLfloat glMatrix[16];
+       CGAffineToGL(&skewMatrix, glMatrix);                                                             
+       glMultMatrixf(glMatrix);
+   }
+   
    // scale
    if (scaleX_ != 1.0f || scaleY_ != 1.0f)
        glScalef( scaleX_, scaleY_, 1.0f );
@@ -757,19 +788,26 @@

        if ( !isRelativeAnchorPoint_ && !CGPointEqualToPoint(anchorPointInPixels_, CGPointZero) )
            transform_ = CGAffineTransformTranslate(transform_, anchorPointInPixels_.x, anchorPointInPixels_.y);
-       
+
        if( ! CGPointEqualToPoint(positionInPixels_, CGPointZero) )
            transform_ = CGAffineTransformTranslate(transform_, positionInPixels_.x, positionInPixels_.y);

        if( rotation_ != 0 )
            transform_ = CGAffineTransformRotate(transform_, -CC_DEGREES_TO_RADIANS(rotation_));

+       if( skewX_ != 0 || skewY_ != 0 ) {
+           // create a skewed coordinate system
+           CGAffineTransform skew = CGAffineTransformMake(1.0f, tanf(CC_DEGREES_TO_RADIANS(skewY_)), tanf(CC_DEGREES_TO_RADIANS(skewX_)), 1.0f, 0.0f, 0.0f);
+           // apply the skew to the transform
+           transform_ = CGAffineTransformConcat(skew, transform_);
+       }
+       
        if( ! (scaleX_ == 1 && scaleY_ == 1) ) 
            transform_ = CGAffineTransformScale(transform_, scaleX_, scaleY_);

        if( ! CGPointEqualToPoint(anchorPointInPixels_, CGPointZero) )
            transform_ = CGAffineTransformTranslate(transform_, -anchorPointInPixels_.x, -anchorPointInPixels_.y);
-       
+               
        isTransformDirty_ = NO;
    }