Classic Drawing

Abstract

Drawing pictures is arguably one of the most important application of computer graphics. A graph shows data in a pictorial manner. Computers can be used both to produce data and generate a pictorial representation – a visualisation – of this data, and a graph is a relatively simple pictorial representation. A graph is a simple graphic. But Xlib does not even support the drawing of graphs. However it does have facility to put on the screen lines of different types, and fill areas with colour, together with means supporting interaction between the computer user and those lines and areas. Although such components are simple they can lead to complex results. An outcome can be they provide flexibility for creating pictures but at the cost of more programming effort and required knowledge. In this chapter illustrations of those aspects of Xlib will be given by simple examples.