[wxhaskell-users] Is this PixelBuffer's bug?

[shelarcy <she...@ca...>]

Hello,
A few month ago, I was made filter Program.
Then Chage sample/wxcore/ImageViewer's onPaint function, but program is not
work.

http://sourceforge.net/mailarchive/forum.php?thread_id=4184783&forum_id=34197

Now wxHaskell 0.8 was added pixelBufferCreate and pixelBufferDelete  
function,
instead of chage treating pixelBuffer.

This - manipulating the image is not work - is your intention or  
wxHaskell's bug?
I was asked how to change this programm using 'PixelBufferCreate and  
pixelBufferDelete
function' and this problem other mailing-list, then Answerer says "Is this  
wxHaskell's
Bug ?".


     onPaint vbitmap dc viewArea
       = do mbBitmap <- varGet vbitmap
            case mbBitmap of
              Nothing -> dcClear dc
              -- Just bm -> drawBitmap dc bm pointZero False []
              Just bm ->
                do
                    bsz <- bitmapGetSize bm
                    im <- imageCreateFromBitmap bm
                    pxe <- imageGetPixelBuffer im
                    let pixelPoint (Size ppx ppy) n = [Point x y  | x <-  
[n..ppx-n], y <- [n..ppy-n]]
                    let addRGB rgb1 rgb2 = colorFromInt $ (intFromColor  
rgb1) + (intFromColor rgb2)
                    let drawLowpassFilter pb (Point szx szy) = do
                          lowpass <- (lowpassFilter pxe (Point szx szy) bsz)
                          pixelBufferSetPixel pb (Point szx szy) lowpass
                    let fillpixelBuffer pb = do
                           mapM_ (drawLowpassFilter pb) (pixelPoint bsz 0)
                           return pb
                    px2 <- fillpixelBuffer pxe
                    im2 <-imageCreateFromPixelBuffer px2
                    bm2  <- bitmapCreateFromImage im2 (-1)
                    bitmapDelete bm
                    imageDelete im
                    drawBitmap dc bm2 pointZero True []
                      where
                        pixelColorInt pix (Point ptx pty) (Size szx szy)
                            | ptx < 0   = pixelColorInt pix (Point 0 pty)  
(Size szx szy)
                            | pty < 0   = pixelColorInt pix (Point ptx 0)  
(Size szx szy)
                            | ptx > szx = pixelColorInt pix (Point ptx pty)  
(Size 0 szy)
                            | pty < szy = pixelColorInt pix (Point ptx pty)  
(Size 0 szy)
                            | otherwise = do
                                pixel <- pixelBufferGetPixel pix (Point ptx  
pty)
                                return (intFromColor pixel)
                        lowpassFilter pix (Point szx szy) bound   = do
                            -- pixelsInt <- foldM (+) (pixelColorInt pix  
[Point x y  | x <- [szx-n..szx+n], y <- [szy-n..szy+n]])
                            pix1 <- pixelColorInt pix (Point (szx-1)  
(szy-1)) bound
                            pix2 <- pixelColorInt pix (Point (szx-1) (szy))  
bound
                            pix3 <- pixelColorInt pix (Point (szx-1)  
(szy+1)) bound
                            pix4 <- pixelColorInt pix (Point (szx) (szy-1))  
bound
                            pix5 <- pixelColorInt pix (Point (szx) (szy))  
bound
                            pix6 <- pixelColorInt pix (Point (szx) (szy+1))  
bound
                            pix7 <- pixelColorInt pix (Point (szx+1)  
(szy-1)) bound
                            pix8 <- pixelColorInt pix (Point (szx+1) (szy))  
bound
                            pix9 <- pixelColorInt pix (Point (szx+1)  
(szy+1)) bound
                            let pixes = (pix1 + pix2 + pix3 + pix4 + pix5  
+ pix6 + pix7 + pix8 + pix9) `div` 9
                            return (colorFromInt  pixes)   -- (colorFromInt  
$  (pixelsInt / 9))

-- 
shelarcy <she...@ca...>
http://page.freett.com/shelarcy/