Constraint built-ins

Constraints relate Float expressions; the solver finds geometry that satisfies them.

float

float() -> Float

Creates a new solver variable.

Use it for a value you want to name now and constrain later.

Returns Float. A variable with no constraints on it yet.

let center = float();
eq(center, (bounds.x0 + bounds.x1) / 2.);

eq

eq(left: Float, right: Float) -> ()

Constrains two linear expressions to be equal.

Argument	Type	Requirement	Description
left	Float	Required, positional	One side of the equality: a literal, parameter, geometry field, or linear combination of them.
right	Float	Required, positional	The other side.

Returns (). Nothing; the constraint is added to the current cell.

eq(inner.x0, outer.x0 + inset);
eq(inner.w, outer.w - 2. * inset);

Conflicting constraints are reported when the cell runs.

dimension

dimension(p: Float, n: Float, value: Float, coord: Float, pstop: Float, nstop: Float, horizontal: Bool) -> ()

Adds an equality constraint together with the dimension label the GUI draws for it.

Argument	Type	Requirement	Description
p	Float	Required, positional	Coordinate on the positive side of the measurement.
n	Float	Required, positional	Coordinate on the negative side.
value	Float	Required, positional	The constraint: p - n must equal this.
coord	Float	Required, positional	Where the dimension line sits, on the perpendicular axis.
pstop	Float	Required, positional	Where the extension line on the positive side ends.
nstop	Float	Required, positional	Where the extension line on the negative side ends.
horizontal	Bool	Required, positional	true for a horizontal measurement, false for vertical.

Returns (). Nothing; the constraint and its label are added to the current cell.

Prefer the GUI for dimensions

The Dimension tool fills in the orientation and label-placement arguments from the edges you click. In hand-written source, use eq unless you want a visible dimension.