GlgMain.h File Reference

#include "GlgApi.h"

Functions
int	GlgMain (int argc, char *argv[], GlgAppContext context)
	A prototype for the cross-platform program entry point that handles argc and argv parameters the same way on all platforms. More...

Function Documentation

GlgMain()

int GlgMain	(	int	argc,
		char *	argv[],
		GlgAppContext	context
	)

A prototype for the cross-platform program entry point that handles argc and argv parameters the same way on all platforms.

Parameters

argc	Number of command line parameters.
argv	Command line parameter list.
context	An application context: Windows: hInstance parameter of the WinMain entry point. X11 and Gtk: (GlgAppContext)0

Returns

Exit code on Windows, GLG_EXIT_OK on X11 and in Gtk.

On Linux/Unix, GlgMain supplies the main entry point.

On Windows, GlgMain supplies the WinMain entry point and parses its lpCmdLine argument to extract cross-platform argc and argv arguments.

To use GlgMain, include the GlgMain.h file and use GlgMain in the program as shown in the example below.

Example

The following C code demonstrates an example of a GLG application code that uses GLG Generic API to display a GLG drawing in a cross-platform way. This code can compiled and used without any changes in either the X11, Gtk or Windows environment:

#include "GlgMain.h"
 
int GlgMain( int argc, char * argv[], GlgAppContext context )
{
   // Initialize the Toolkit and let it process command-line arguments.
   GlgInit( False, app_context, argc, argv );       
 
   // Load and display a drawing.
   GlgObject viewport = GlgLoadWidgetFromFile( "drawing.g" );
   GlgInitialDraw( viewport );
 
   // Code to add an input callback and install a timer to update the drawing with data should be placed here.
   ...
   
   // Process events.
   int exit_code = GlgMainLoop();
 
   return exit_code;
}

The following is the C++ version of the example that displays a GLG drawing in a cross-platform way:

#include "GlgMain.h"
 
int GlgMain( int argc, char * argv[], GlgAppContext init_context )
{
   // Initialize the Toolkit and let it process command-line arguments.
   GlgSessionC glg_session( False, init_context, argc, argv );
 
   // Load and display a drawing.
   GlgObjectC viewport;
   viewport.LoadWidget( "drawing.g" );
   viewport.InitialDraw();
 
   // Process events.
   int exit_code = glg_session.MainLoop( glg_session.app_context );
 
   return exit_code;
}