Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 | 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 7x 7x 7x 7x 7x 7x 7x 7x 7x 7x 7x 7x 7x 7x 7x 7x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 7x 7x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x | // Animations targeting LineElement. See ../Animations.ts for the
// abstract base + registry mechanics.
import {Animation, AllAnimations, IAnimationStep, registerAnimation} from "../Animations";
import {GeomElement} from "../GeomElement";
import {Slate} from "../../Slate";
import {LineElement} from "./LineElement";
// Default trace rate in px/ms. Calibrated for unhurried teaching: a
// typical 100-px construction line draws over ~400 ms; 200-px lines
// take ~800 ms. Authors who want snappier transitions raise the rate
// via slate.animationConfig.rates["Line.straightEdgeConnect"].
const DEFAULT_LINE_RATE_PX_PER_MS = 0.25;
// Common helper: trace the target line from A toward B by driving
// drawProgress. Used by both StraightEdgeConnect (the canonical
// straightedge stroke between two existing points) and
// StraightEdgeExtend (same shape, just visually framed as extending
// past an endpoint instead of joining two existing ones).
function traceLine(target: LineElement, rate: number): IAnimationStep {
// duration = length / rate, clamped low so an extremely short
// line still gets a perceptible draw.
const dx = target.B.x - target.A.x;
const dy = target.B.y - target.A.y;
const length = Math.sqrt(dx * dx + dy * dy);
const durationMs = Math.max(120, length / rate);
return {
durationMs,
tick: (progress) => { target.drawProgress = progress; },
finalise: () => {
target.drawProgress = 1;
target.visible = true;
},
};
}
// A.Line.straightEdgeConnect — pencil stroke from A toward B.
// Args: none. Duration = length × default rate (0.5 px/ms).
export class LineStraightEdgeConnectAnimation extends Animation {
public animationMethod = AllAnimations.LINE_STRAIGHT_EDGE_CONNECT;
public name = "Line.straightEdgeConnect";
public elementType = LineElement;
public defaultRate = DEFAULT_LINE_RATE_PX_PER_MS;
public build(target: GeomElement, slate: Slate, args: any): IAnimationStep[] {
return [traceLine(target as LineElement, this.defaultRate)];
}
}
// A.Line.straightEdgeExtend — for Line.extend constructions where one
// endpoint sits on an existing line and the other is the projected
// new endpoint. v1 renders the same trace as StraightEdgeConnect;
// future richer variants might pivot a straightedge guide against the
// existing line first.
export class LineStraightEdgeExtendAnimation extends Animation {
public animationMethod = AllAnimations.LINE_STRAIGHT_EDGE_EXTEND;
public name = "Line.straightEdgeExtend";
public elementType = LineElement;
public defaultRate = DEFAULT_LINE_RATE_PX_PER_MS;
public build(target: GeomElement, slate: Slate, args: any): IAnimationStep[] {
return [traceLine(target as LineElement, this.defaultRate)];
}
}
registerAnimation(new LineStraightEdgeConnectAnimation());
registerAnimation(new LineStraightEdgeExtendAnimation());
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