gx Graphics Library Center - lbjoseph

The gx Graphics Library, or gxGL, is a 2D memory drawing library based off of the Win32 GDI libraries.

The functionality offered by gxGL allows you to draw in memory almost exactly as you would in a Liberty BASIC graphicbox. The commands are slightly different, but allow for more functionality.

Below you will find documentation for gxGL.

gxGL Resources

gxGL Header This header must be at the top of every program that uses gxGL.
gxGL Library These functions must be at the bottom of every program that uses gxGL.

Setting Up gxGL

It's easy to get started using gxGL. First, you'll have to put the header structures and variables at the top of your program. These are used by gxGL to keep track of your memory drawings.

After that, all you need to do is tell gxGL how big of a canvas you want to draw on.

 Call gx.InitMemoryDrawing CanvasWidth, CanvasHeight 

This tells gxGL to allocate the properly sized surface available so you can begin drawing on it.

Closing gxGL

When your program ends, you need to tell gxGL to clean up after itself. This too is very simple:

 Call gx.Finish 

Once you do this, gxGL deletes all the memory drawings and closes the handles to the resources it needs.

Colors

Colors in gxGL are exactly like the colors in Liberty BASIC commands. You can use one of the 16 colors recognized by LB, or any color in a "R G B" string format.

Graphics Commands

Commands are issued to gxGL with a simple subroutine call:

 Call gx.Draw "cls; fill blue" 

Commands are separated by a semi-colon, and you can put as many commands in a string as you like.

CLS

The CLS command clears the drawing and fills it white.