A ParametrIQ CAD drawing is a PiQ Lang program. The .piq file is a list of PiQ Lang lines, and everything you draw with the mouse is saved as them. So anything you draw can be written, read and changed as text, and anything you write can be opened and drawn on. Here is the language in five minutes. Type along in the Playground: it runs each statement you type and shows its value.

Definitions, not copies

A variable is a name for a value, made with =. It keeps its definition, not the value it had when it was made:

WIDTH=50
DEPTH=WIDTH/2
WIDTH=80
DEPTH

DEPTH is 40: "half of WIDTH", always. That is what makes a design parametric: a whole drawing is defined from a few variables, and changing them redraws it. See Variables.

Points that follow

A drawing is built on points, P and a number. Every drawing starts with four, the corners of the box: P0 at the origin, P1 L to its right, P2 W above P1, and P3 to the left of P2. A new point keeps its definition too, so a point made from other points moves when they do: P4=DOWN(P0,WALL) is always WALL below P0. See Points.

A whole design

Put together, a dozen lines define the blank for a tray: a base L by W, creased, with a wall WALL high on each side, its outline cut.

WALL=40,"Wall height"
P4=DOWN(P0,WALL)
P5=DOWN(P1,WALL)
P6=RIGHT(P1,WALL)
P7=RIGHT(P2,WALL)
P8=UP(P2,WALL)
P9=UP(P3,WALL)
P10=LEFT(P3,WALL)
P11=LEFT(P0,WALL)
POLYLINE @1,[P0,P1,P2,P3],TRUE,1
POLYLINE @2,[P0,P4,P5,P1,P6,P7,P2,P8,P9,P3,P10,P11],TRUE,0
L=300

Nothing in it is at a fixed position except P0: every corner is worked out from the box's size and WALL. Change L to 500, and the blank is redrawn for a tray 500 long. The "Wall height" after WALL labels the variable: ParametrIQ CAD shows the label in the Variables panel and asks for it by that name. See A whole design.

Where next

• The PiQ Lang primer goes on to loops and choices, functions of your own and drawings within drawings.
• Expressions lists every operator and function, and Interactive every command.
• Templates written this way run unchanged through the ParametrIQ SaaS API, so your own programs can make the same drawing at any size.