An introduction to the draw dialect

Draw is a Red dialect created to make it easy to draw two-dimensional geometrical shapes such as circles, rectangles, and animations. It makes use of VID, so the needs 'view has to appear in the header. To start with a simple example, here is how to draw a circle:

;-- see Chapter09/first-draw-example.red:
view [
    base 100x100 cyan draw[
line 20x0 75x50
        pen red 
        circle 35x5020
    ]
]

We draw on a base face and start a draw block. In it, we draw a line from a starting point at 20 x 0 to an end point at 75 x 50. Then, we define a pen with the color red and use it to draw a circle with a radius of 20 and center at 35 x 50:

=> Now answer question 9 from the Questions section.

Instead of a base, you can also add drawings on an existing image.

The draw dialect is very elaborate, here are some of the things you can try out:

• Draw rectangles (box), triangles, polygons, ellipses, curves, arcs, special fonts, and so on
• Set the line-width of the pen...