cocos2d-iphone – Cocos2d中的旋转剪辑节点

我在这里使用剪切节点： http://www.learn-cocos2d.com/2011/01/cocos2d-gem-clippingnode

ClippingNode.h

#import "cocos2d.h"
@interface ClippingNode : CCNode {
    CGRect clippingRegionInNodeCoordinates;
    CGRect clippingRegion;
}
@property (nonatomic) CGRect clippingRegion;
@end

ClippingNode.m

#import "ClippingNode.h"

@interface ClippingNode (PrivateMethods)
-(void) deviceOrientationChanged:(NSNotification*)notification;
@end

@implementation ClippingNode
-(CGRect) clippingRegion {
    return clippingRegionInNodeCoordinates;
}

-(void) setClippingRegion:(CGRect)region {

    // keep the original region coordinates in case the user wants them back unchanged
    clippingRegionInNodeCoordinates = region;
    self.position = clippingRegionInNodeCoordinates.origin;
    self.contentSize = clippingRegionInNodeCoordinates.size;

    // convert to retina coordinates if needed
    region = CC_RECT_POINTS_TO_PIXELS(region);

    // respect scaling
    clippingRegion = CGRectMake(region.origin.x * scaleX_,region.origin.y * scaleY_,region.size.width * scaleX_,region.size.height * scaleY_);
}

-(void) setScale:(float)newScale {
    [super setScale:newScale];
    // re-adjust the clipping region according to the current scale factor
    [self setClippingRegion:clippingRegionInNodeCoordinates];
}

-(void) deviceOrientationChanged:(NSNotification*)notification {
    // re-adjust the clipping region according to the current orientation
    [self setClippingRegion:clippingRegionInNodeCoordinates];
}

-(void) visit {

    glEnable(GL_SCISSOR_TEST);
    CGPoint worldPosition = [self convertToWorldspace:CGPointZero];
    const CGFloat s = [[CCDirector sharedDirector] contentScaleFactor];
    glScissor((clippingRegion.origin.x) + (worldPosition.x*s),(clippingRegion.origin.y) + (worldPosition.y*s),(clippingRegion.size.width),(clippingRegion.size.height));

    [super visit];

    gldisable(GL_SCISSOR_TEST);

}
@end

但是,我需要剪切一个旋转的CCNode.关于如何完成这项任务的任何想法？

解决方法

由此替换ClippingNode类中的visit方法

-(void) visit
{

    float rotationAngle = 15;

    glPushmatrix();

    CCRenderTexture* renderTexture = [[CCRenderTexture renderTextureWithWidth:512 height:512] retain];

    glEnable(GL_SCISSOR_TEST);
    glScissor(0,clippingRegion.size.width,clippingRegion.size.height);

    [renderTexture begin];

    glPushmatrix();
    glrotatef(rotationAngle,1);
    glTranslatef(-clippingRegion.origin.x,-clippingRegion.origin.y,0);

    [super visit];

    glPopMatrix();

    [renderTexture end];

    gldisable(GL_SCISSOR_TEST);

    renderTexture.sprite.position = CGPointMake(clippingRegion.origin.x,clippingRegion.origin.y);
    renderTexture.sprite.anchorPoint = CGPointMake(0,1);
    renderTexture.sprite.rotation = rotationAngle;
    [renderTexture.sprite visit];

    [renderTexture release];

    glPopMatrix();
}

基本上它创建了一个纹理,用于呈现ClippingNode内容

然后翻译场景,使裁剪区域中的原点现在为(0,0)

通过rotationAngle旋转整个场景

启用剪刀

渲染场景

翻译,旋转和渲染包含纹理的精灵