Your First TGI Application

In this section, we move on to the more practical aspects of writing graphical applications using TGI. This section is the basic chapter and we will talk about the vital concepts including the lifecycle of a graphical application. After reading this section, you will see the basics of the TGI coordinate system, the basic graphic objects used by TGI, the drawing surfaces and how to write a graphical application using TGI.

In order to write a graphical application, a good understanding of the drawing surfaces and coordinate systems is required. We will start by talking about these concepts and how they are represented in TGI. Next, you'll learn step-by-step how to write a graphical application in javascript using TGI. We will discuss the following topics:

• Adding TUval library to your application,
• Methods of obtaining a drawing surface,
• How to create Pen and Brush objects,
• How to use pencil and brush objects to draw shapes,

At the end of this section we will talk about some basic graphic objects and members. These objects are used in the examples throughout this document and include:

• Color
• PointF
• RectangleF
• SizeF