(*RwGetUserDrawCallback(RwUserDraw *userdraw)) (RwUserDraw *userdraw, void *camimage, RwRect *rect, void *data);
Description
Retrieves the call-back function used to render the user-draw.
Arguments
userdraw Pointer to the user-draw.
Return Value
A pointer to the user-draw’s call-back function if successful, and NULL otherwise.
Comments
User-draw call-backs should be declared as follows:
void
callback(RwUserDraw *userdraw, void *camimage,
RwRect *rect, void *data);
Where the call-back’s arguments are:
userdraw Pointer to the user-draw to be rendered.
camimage The camera’s image buffer as returned by RwGetCameraImage() for the current camera. camimage is device dependent. For more information, see Appendix B.
rect Pointer to a rectangle defining the area of the camera’s image buffer into which the call-back may render. This rectangle is specified in viewport space coordinates, i.e., (0, 0) is the origin of the viewport.
data Pointer to the user data of the user-draw being drawn. This value can be obtained by calling RwGetUserDrawData() with userdraw as an argument. data is passed directly to the call-back function for the convenience of the application developer.
Note that the call-back function is always called after all clumps in the scene have been rendered, i.e., when RwEndCameraUpdate() is called. Therefore user-draw rendering always appear in front of clump rendering. In the case of overlapping user-draws, the order of rendering is not defined.
See Also