Cocos2d 2.0繪製方法錯誤

Question

我使用cocos2d 2.0。我得到一個錯誤：property 'world' not found on object of type 'ColoredCircleSprite *'我在繪圖方法中寫錯了什麼？

-(void) draw 
{ 
    [super draw]; 
    ccGLEnableVertexAttribs(kCCVertexAttribFlag_Position); 
    kmGLPushMatrix(); 
    self.world->DrawDebugData(); 
    kmGLPopMatrix(); 
} 

我試圖做的，因爲圖所示：Cocos2D 2.0 OpenGL errors?

而且我看到了另一種方式做畫法，我必須從self.world->DrawDebugData();行刪除self.，如果我這樣做，我得到另一個錯誤：Use undeclared identifier 'world'。

即ColoredCircleSprite.h代碼：

#import "cocos2d.h" 

@interface ColoredCircleSprite : CCNode <CCRGBAProtocol, CCBlendProtocol> { 
    float  radius_; 
    GLubyte  opacity_; 
    ccColor3B color_; 

    NSUInteger numberOfSegments; 
    GLfloat *circleVertices_; 

    ccBlendFunc blendFunc_; 
} 

@property (nonatomic,readwrite) float radius; 

/** Opacity: conforms to CCRGBAProtocol protocol */ 
@property (nonatomic,readonly) GLubyte opacity; 
/** Opacity: conforms to CCRGBAProtocol protocol */ 
@property (nonatomic,readonly) ccColor3B color; 
/** BlendFunction. Conforms to CCBlendProtocol protocol */ 
@property (nonatomic,readwrite) ccBlendFunc blendFunc; 

/** creates a Circle with color and radius */ 
+ (id) circleWithColor: (ccColor4B)color radius:(GLfloat)r; 

/** initializes a Circle with color and radius */ 
- (id) initWithColor:(ccColor4B)color radius:(GLfloat)r; 

- (BOOL) containsPoint:(CGPoint)point; 

@end 

我只是複製和粘貼代碼cocos2d-iphone.com論壇。 我真的不知道應該有什麼變量，並且應該是否有任何變量。

謝謝。

Answer 1

@interface ColoredCircleSprite : CCSprite 
{ 
    b2World   *mWorld; 
} 
@property(nonatomic,assign) b2World   *world; 
@end 


@implementation ColoredCircleSprite 
@synthesize world = mWorld; 

-(void)initBox2D 
{  
    //create world in right place... 
    self.world = new b2World(gravity); 
} 
@end