rel-function.js

/* title: Rel Function categories: relative functions files: head ../point_src/point-content.js pointlist point mouse dragging stroke ../point_src/functions/clamp.js ../point_src/functions/rel.js stage ../point_src/split.js ../point_src/random.js --- The `rel()` function provides _relative_ offset to values, such as the `point.x`. In this example the center point is copied, and offset by `rel(-200)`. */ const boundCaller = function(func) { /* return a function to call the _given_ function. This allows a _dynamic_ value, called every update. For example, ensure the `y` value of a point is the same as `x`: a.y = boundCaller((p, k) => p.x) */ return function relCaller(p, k) { console.log('Call once') return func.bind(p) } } class MainStage extends Stage { canvas='playspace' mounted(){ let offsetValue = -200 this.center.radius = 40 let a = this.a = this.center.copy() a.x = rel(offsetValue) this.dragging.add(a) a.y = boundCaller((p, k) => this.center.y + offsetValue) } draw(ctx){ this.clear(ctx) this.a.pen.fill(ctx, `hsl(90deg 100% 30%)`) this.center.pen.fill(ctx, `hsl(90deg 10% 10%)`) } } ;stage = MainStage.go();