GetPixel
GetPixel Find whether a specified pixel is black or white short horiz ; horizontal position, in local coordinates
short vert ; vertical coordinate
returns Is the point black?
GetPixel returns an indication of whether a pixel associated with a coordinate pair is black or white.
horiz and . . .
vert identify the pixel in question (which hangs below and to the right of
the specified point). These are expressed in the coordinate system of
FALSE White (by convention, "off") TRUE Black (other than the foreground color)
Notes: GetPixel is not sensitive to the size of the GrafPort's portRect and doesn't check to see if the point is in the visRgn; i.e., if an overlapping window
covers the coordinates. Thus, this function may return information about a
pixel that is not part of the current GrafPort (though the return value is always correct with respect to the visible screen).
To check whether a point is owned by the current GrafPort, use: thePoint.h=horiz;
thePoint.v=vert;
. . . it's in the region . . .
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