Question

I draw some Shape with openGL command in CCNode. And now I want deal Gaussian Blur with it.
But I can’t find any way to do this.
Anybody recommend?

.

.major of solve code:

    CCRenderTexture *renderTex = [[CCRenderTexture renderTextureWithWidth:480 height: 320] retain];
    renderTex.position = ccp(size.width/2, size.height/2);
    [renderTex begin];
    //here can put any draw code with opengl
    [curve visit];
    [renderTex end];
    CCTexture2DMutable *mutableTexture=[[[CCTexture2DMutable alloc]
                                        initWithImage:[renderTex getUIImageFromBuffer]]autorelease];

    CGRect rect = CGRectMake(0, 0, [mutableTexture contentSizeInPixels].width, [mutableTexture contentSizeInPixels].height);
    [AWTextureFilter blur:mutableTexture radius:8 rect:rect];
    CCSpriteFrame *frame = [CCSpriteFrame frameWithTexture:mutableTexture rect:rect];
    [[CCSpriteFrameCache sharedSpriteFrameCache]addSpriteFrame:frame name:@"1"];
    CCSprite *blur = [CCSprite spriteWithSpriteFrame:frame];
    [blur setPosition:ccp(size.width/2, size.height/2)];
    blur.opacity=200;
    [self addChild:blur];

Answer 1

you have to:

• render the whole scene to the render target (to the texture), you can use Framebuffer Objects
• then you draw a fullscreen quad with that previuous texture (with the scene) attached.
• in the end you can perform gussian blur effect (or some other postprocessing effect)

some info:

• http://maniacdev.com/2011/07/tutorial-masking-sprites-in-cocos2d-with-ccrendertexture/
• http://www.songho.ca/opengl/gl_fbo.html
• http://www.gamerendering.com/2008/10/11/gaussian-blur-filter-shader/