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read the pen number value of the pixel at a specified x,y location within a certain RastPort.
Source position: agraphics.pas line 2107
function ReadPixel( |
Rp: PRastPort; |
x: LongInt; |
y: LongInt |
):LongInt; |
Rp |
|
A pointer to a RastPort structure |
x |
|
X Coordinate to read |
y |
|
Y Coordinate to read |
The pen number of the pixel at (x,y) is returned. -1 is returned if the pixel cannot be read for some reason.
Combine the bits from each of the bit-planes used to describe a particular RastPort into the pen number selector which that bit combination normally forms for the system hardware selection of pixel color.
|
Change the pen num of one specific pixel in a specified RastPort. |