CDC::SetPixel
COLORREF SetPixel( int x, int y, COLORREF crColor );
COLORREF SetPixel( POINT point, COLORREF crColor );
Return Value
An RGB value for the color that the point is actually painted. This value can be different from that specified by crColor if an approximation of that color is used. If the function fails (if the point is outside the clipping region), the return value is -1.
CDC::GetPixel
COLORREF GetPixel( int x, int y ) const;
COLORREF GetPixel( POINT point ) const;
Return Value
For either version of the function, an RGB color value for the color of the given point. It is -1 if the coordinates do not specify a point in the clipping region.