/*
	GraphicsModule_main.c
	
	Apple and Think C Implementation of 'ADgm' screen saver code resource.
	
	This file provides a generic interface for writing a After Dark™ graphics module.
	The function "main" is called by After Dark and passed four parameters:
	
		storage:	A Handle to memory you have allocated.
		blankRgn:	A region covering all screens.
		message:	A value indicating which function to call.
		params:		A pointer to a structure containing useful information.
		
	To use it, write the five routines:
	
	OSErr DoInitialize(Handle *storage, RgnHandle blankRgn, GMParamBlockPtr params);
	OSErr DoClose(Handle storage, RgnHandle blankRgn, GMParamBlockPtr params);
	OSErr DoBlank(Handle storage, RgnHandle blankRgn, GMParamBlockPtr params);
	OSErr DoDrawFrame(Handle storage, RgnHandle blankRgn, GMParamBlockPtr params);
	OSErr DoSetUp(RgnHandle blankRgn, short message, GMParamBlockPtr params);
	
	For more information, consult the programmer's section of the manual.
	
	By Patrick Beard and Bruce Burkhalter and Colin Glassey
	
	©1989,1990,1991 Berkeley Systems, Inc.
*/

#include 
#include "GraphicsModule_Types.h"

#ifdef THINK_C
/* allows use of Global vars with Think C */
#include 
#define OpenGlobals()	RememberA0(); SetUpA4();
#define CloseGlobals()	RestoreA4();
#endif

/* entry point into graphics module */

pascal OSErr 
main(storage, blankRgn, message, params)
	Handle 			*storage;			/* storage allocated by graphics module. */
	RgnHandle 		blankRgn;			/* region to do all drawing in. */
	short 			message;			/* the action to take */
	GMParamBlockPtr params;				/* parameters & services for controlling graphics module */
{
	OSErr err=noErr;

#ifdef THINK_C	
	/* set up globals for strings etc. only for THINK C */
	OpenGlobals();
#endif	

	/* dispatch message to appropriate routine. */
	switch(message) {
		case Initialize:
			err = DoInitialize(storage, blankRgn, params);
			break;
			
		case Close:
			err = DoClose(*storage, blankRgn, params);
			break;
			
		case Blank:
			err = DoBlank(*storage, blankRgn, params);
			break;
			
		case DrawFrame:
			err = DoDrawFrame(*storage, blankRgn, params);		
			break;
		
		/*	Bouncing Ball does not handle the next two messages.	*/
		
		case ModuleSelected:
			/*err=DoSelected(*storage, blankRgn, params);*/		/*Uncomment this is your module handles it*/
			break;
			
		case DoAbout:
			/*err=DoAbout(*storage, blankRgn, params);*/		/*Uncomment this is your module handles it*/
			break;

		default: /* user may have hit a button */
			if(message>=ButtonMessage) {
				/* handle the button */
				err=DoSetUp(blankRgn, message, params);
			}  /* end if */
			break;
			
	} /* end switch */
	
#ifdef THINK_C		
	CloseGlobals();
#endif	

	return err;
}