Hi! Here comes some more notes for the API.
As it is now, most of the drawing functions returns GP_RetCode. It doesn't do any harm, however handling of the return value is inconsistent (especially for primitives that are draw using several other primitives) and generally the returned value is useless. So does anybody object to converting these to return void?
There are however some calls where GP_RetCode has it's meaning:
* GP_Text() - may return invalid string character (for encoding given by font) - now invalid characters are silently converted into spaces
* Functions that opens/saves files - should return if operation has failed
But all other drawing functions (like GP_Line(), GP_Circle(), etc...) should better return void.