# ReadPixelFast (x,y,[buffer])

# Parameters

x - y-coordinate of pixel y - y-coordinate of pixel buffer (optional) - name of buffer to read colour value from, e.g. BackBuffer()

# Description

Reads a color value from either the current buffer or the specified buffer, and returns it. The returned colour value is in the form of an integer than contains the alpha, red, green and blue values of the pixel. IMPORTANT: You *must* use this command on a locked buffer, otherwise the command will fail. See LockBuffer. Also, you must make sure that the coordinates that you are reading from are valid, otherwise you will end up reading garbage values. WARNING: By not following the above advice, you may cause your computer to crash. See also: GetColor, ReadPixel.

# Example

; ReadPixelFast/WritePixeFast Example ; ----------------------------------- Graphics 640,480,16 Print "Press a key to read color values" WaitKey() ; Load and draw an image on to the screen - can be anything pic=LoadImage("media/blitz_pic.bmp") DrawImage pic,0,0 ; Initialise an array big enough to fit all the color information of the screen Dim pix(GraphicsWidth(),GraphicsHeight()) ; Lock buffer before using ReadPixelFast LockBuffer ; Use ReadPixel to get all the color information of the screen For y=0 To GraphicsHeight() For x=0 To GraphicsWidth() pix(x,y)=ReadPixelFast(x,y) Next Next ; Lock buffer after using ReadPixelFast UnlockBuffer Cls Locate 0,0 Print "Press a key to write pixels" Print "Once this has finished, you can then press a key to end the program" WaitKey() ; Lock buffer before using WritePixelFast LockBuffer ; Use WritePixel to redraw the screen using the color information we got earlier For y=0 To GraphicsHeight() For x=0 To GraphicsWidth() WritePixelFast x,y,pix(x,GraphicsHeight()-y) ; get y array value in backwards order, to flip screen Next Next ; Unlock buffer after using WritePixelFast UnlockBuffer WaitKey()

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