RGBA from a specific pixel in CCSprite (takes much time)

Question

I have tried McDevon's (How to get RGBA color of a specific pixel in CCSprite) approach, but it is taking too much time to process and so my app is lacking smooth movements.

My app has some pieces that are moved around the screen by user touch. I want to check for every move if the pixel is of a certain color.

When I tried McDevon's, the app starts to skip some of the sprite's movements, almost printing only its final place of move.

Here's McDevon's:

-(BOOL)checkPixel: (CCSprite*)background : (CGFloat)x :(CGFloat)y{
BOOL result = FALSE;

CGPoint location;
location = ccp(x * CC_CONTENT_SCALE_FACTOR(), y * CC_CONTENT_SCALE_FACTOR());

UInt8 data[4];

CCRenderTexture* renderTexture = [[CCRenderTexture alloc] initWithWidth:background.boundingBox.size.width * CC_CONTENT_SCALE_FACTOR()
                                                                 height:background.boundingBox.size.height * CC_CONTENT_SCALE_FACTOR()
                                                            pixelFormat:kCCTexture2DPixelFormat_RGBA8888];

[renderTexture begin];
[background draw];

glReadPixels((GLint)location.x,(GLint)location.y, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, data);

[renderTexture end];
[renderTexture release];

NSLog(@"R: %d, G: %d, B: %d, A: %d", data[0], data[1], data[2], data[3]);

if((data[0]==0)&&(data[1]==0)&&(data[2]==0)){
    result = TRUE;
}

return result;

}

Here's a piece of my code:

    futurePos = ccpAdd(sprite.position, translation);

    // Check Area on pixels
    if([self checkPixel:background :futurePos.x :futurePos.y]){
            sprite.position = futurePos;
    }

Any ideas to make it faster / smoothier? Thanks!

Answer 1

Best solution:

I extracted the RAW image data into 8 bit array. But instead of using 24 bits (RGB) images I am now using monochromatic bitmap images.

Super fast. I just have to convert the image layers to single bmp file.