cocos2d 新手指导

-(void)onSetSprite:(NSString *)fileName position:(CGPoint)point{    _guidePic = [[CCSprite spriteWithSpriteFrameName:fileName] retain];    [_guidePic.texture setAliasTexParameters];    [_guidePic setBlendFunc:(ccBlendFunc){GL_ZERO,GL_ONE_MINUS_SRC_ALPHA}];    [_guidePic setPosition:point];        _target = [CCRenderTexture renderTextureWithWidth:1024 height:768];    [[_target sprite] setBlendFunc:(ccBlendFunc){GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA}];        [_target clear:0.0f g:0.0f b:0.0f a:0.5f];    [_target setPosition:ccp(512,384)];        [self addChild:_target];    [_target begin];    [_guidePic visit];    [_target end];}