Introduction to the Language of Tactile Graphics

Biblos uses its own programming language with which all tactile graphics can be drawn. It is a true vector graphics programming language with which you can draw any type of tactile graph or image. Every tactile graph is an object in which you use this programming language that traces more or less complex figures within a graphic area.

This language is structured on basic principles of procedural programming. It has basic instructions, some syntax rules and keywords. You can use global and local variables and has the ability to structure procedures and functions.

All basic instructions have the same structure:

- Instruction(Parameters)

The number and type of parameters depend on the instruction used. For example, the instruction to draw a point is:

- Dot(32,64)

Values 32 and 64 refer to the X and Y coordinates where the point is plotted.

A line of code can accommodate only one instruction, one variable, one procedure, one keyword, one comment, etc. If you don't have any programming experience, it is useful to use the guided insertion windows, available in the Insert menu, for the first time.

You can insert comment lines into the code lines. To add a comment line you need to enter the "//" characters at the beginning of the line:

- // This is a comment line

Almost all instructions need one or more pairs of X and Y coordinates, which indicate the points in the graph area. The X coordinate always indicates the axis of the abscissaes, i.e. the horizontal points of the graph. The Y coordinate always indicates the axis of the ordinates, i.e. the vertical points. The origin is always at the "x 0" and "y 0" points. The 0 coordinate for the x-axis always equals the left side of the graph. The coordinate 0 for the ordinates always equals the upper side. Therefore, the coordinates of the "X 0" and "Y 0" points indicate the point at the top left of the touch graph. For visible lines to be drawn, the X and Y values must be positive only. The right and bottom limits of the graph depend on the values configured in the Braille settings.