void PEXOCCSetDrawingFunction( PEXOCC context, unsigned int function )
None.
Invoke PEXOCCSetDrawingFunction to set the drawing function attribute of the renderer's pipeline state according to the value specified by function.
Define the drawing function to specify how the implementation, after color approximation, combines newly drawn pixels with existing pixels in the drawable. This function applies only to image planes and to the rendering of all output primitives.
The registered values, derived from Xlib definitions (defined in X.h), for the drawing functions are shown in the following table:
Drawing Functions ----------------------------------------- Symbol Description ----------------------------------------- GXclear all 0's GXand src AND dest GXandReverse src AND (NOT dest) GXcopy src GXandInverted (NOT src) AND dest GXnoop dst GXxor src XOR dest GXor src OR dest GXnor (NOT src) AND (NOT dest) GXequiv (NOT src) XOR dest GXinvert NOT dest GXorReverse src OR (NOT dest) GXcopyInverted NOT src GXorInverted (NOT src) OR dest GXnand (NOT src) OR (NOT dest) GXset all 1's -----------------------------------------
If you enabled echoing with method PEXEchoXORColor, then the drawing function you select is overridden. The drawing functions, except GXcopy, interact with alpha blending, antialiasing, transparency, and plane masking, except for all planes enabled, in an implementation-dependent way.
If you specify an undefined drawing function value, then the implementation issues a BadPEXOutputCommand error.
This function is a member of the global attribute set and affects all output primitives.
For an overview and for a list of output attribute functions, see Output Attribute Functions.