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  ./demo/canvas-001.js ./demo/canvas-002.js ./demo/canvas-003.js ./demo/canvas-004.js ./demo/canvas-005.js ./demo/canvas-006.js ./demo/canvas-007.js ./demo/canvas-008.js ./demo/canvas-009.js ./demo/canvas-010.js ./demo/canvas-011.js ./demo/canvas-012.js ./demo/canvas-013.js ./demo/canvas-014.js ./demo/canvas-015.js ./demo/canvas-015a.js ./demo/canvas-016.js ./demo/canvas-017.js ./demo/canvas-018.js ./demo/canvas-019.js ./demo/canvas-019a.js ./demo/canvas-020.js ./demo/canvas-021.js ./demo/canvas-022.js ./demo/canvas-023.js ./demo/canvas-024.js ./demo/canvas-025.js ./demo/canvas-026.js ./demo/canvas-027.js ./demo/canvas-028.js ./demo/canvas-029.js ./demo/canvas-030.js ./demo/canvas-031.js ./demo/canvas-032.js ./demo/canvas-033.js ./demo/canvas-034.js ./demo/canvas-035.js ./demo/canvas-036.js ./demo/canvas-037.js ./demo/canvas-038.js ./demo/canvas-039.js ./demo/canvas-040.js ./demo/canvas-041.js ./demo/canvas-042.js ./demo/canvas-043.js ./demo/canvas-044.js ./demo/canvas-045.js ./demo/canvas-046.js ./demo/canvas-047.js ./demo/canvas-048.js ./demo/canvas-049.js ./demo/canvas-050.js ./demo/canvas-051.js ./demo/canvas-052.js ./demo/canvas-053.js ./demo/canvas-054.js ./demo/canvas-055.js ./demo/canvas-056.js ./demo/canvas-058.js ./demo/canvas-059.js ./demo/canvas-060.js ./demo/canvas-061.js ./demo/canvas-062.js ./demo/canvas-063.js ./demo/canvas-064.js ./demo/core-001.js ./demo/delaunator-001.js ./demo/delaunator-002.js ./demo/dom-001.js ./demo/dom-002.js ./demo/dom-003.js ./demo/dom-004.js ./demo/dom-005.js ./demo/dom-006.js ./demo/dom-007.js ./demo/dom-008.js ./demo/dom-009.js ./demo/dom-010.js ./demo/dom-011.js ./demo/dom-012.js ./demo/dom-013.js ./demo/dom-015.js ./demo/dom-016.js ./demo/dom-017.js ./demo/dom-018.js ./demo/filters-001.js ./demo/filters-002.js ./demo/filters-002a.js ./demo/filters-003.js ./demo/filters-004.js ./demo/filters-005.js ./demo/filters-006.js ./demo/filters-007.js ./demo/filters-008.js ./demo/filters-009.js ./demo/filters-010.js ./demo/filters-011.js ./demo/filters-012.js ./demo/filters-013.js ./demo/filters-014.js ./demo/filters-015.js ./demo/filters-016.js ./demo/filters-017.js ./demo/filters-018.js ./demo/filters-019.js ./demo/filters-020.js ./demo/filters-021.js ./demo/filters-022.js ./demo/filters-023.js ./demo/filters-024.js ./demo/filters-025.js ./demo/filters-026.js ./demo/filters-027.js ./demo/filters-028.js ./demo/filters-101.js ./demo/filters-102.js ./demo/filters-103.js ./demo/filters-104.js ./demo/filters-105.js ./demo/filters-501.js ./demo/filters-502.js ./demo/filters-503.js ./demo/filters-504.js ./demo/filters-505.js ./demo/mediapipe-001.js ./demo/mediapipe-002.js ./demo/mediapipe-003.js ./demo/modules-001.js ./demo/modules-002.js ./demo/modules-003.js ./demo/modules-004.js ./demo/modules-005.js ./demo/modules-006.js ./demo/packets-001.js ./demo/packets-002.js ./demo/particles-001.js ./demo/particles-002.js ./demo/particles-003.js ./demo/particles-004.js ./demo/particles-005.js ./demo/particles-006.js ./demo/particles-007.js ./demo/particles-008.js ./demo/particles-009.js ./demo/particles-010.js ./demo/particles-011.js ./demo/particles-012.js ./demo/particles-013.js ./demo/particles-014.js ./demo/particles-015.js ./demo/particles-016.js ./demo/rapier-001.js ./demo/snippets-001.js ./demo/snippets-002.js ./demo/snippets-003.js ./demo/snippets-004.js ./demo/snippets-005.js ./demo/snippets-006.js ./demo/tensorflow-001.js ./demo/tensorflow-002.js ./demo/utilities.js

- §

  # Demo Canvas 030

  Polyline entity functionality

  - Note that the Polyline entity remains experimental technology and may be subject to breaking changes in future minor updates
- §

  Run code

      import * as scrawl from '../source/scrawl.js'

      import { reportSpeed, killPolylineArtefact } from './utilities.js';

- §

  #### Scene setup

      const canvas = scrawl.library.artefact.mycanvas;

- §

  Build some coordinate arrays …

      const absoluteCoords = [[100, 200], [200, 400], [300, 300], [400, 400], [500, 200], [240, 100]];

      const relativeCoords = [['50%', 'center'], ['40%', '10%'], ['20%', '40%'], ['25%', '80%'], ['70%', '75%'], ['85%', '60%']];

- §

  … And a third coordinate array using Wheel entitys

      absoluteCoords.forEach((item, index) => {

          const [x, y] = item;

          scrawl.makeWheel({

              name: `pin-${index}`,

              startX: x,
              startY: y,

              radius: 20,

              handleX: 'center',
              handleY: 'center',

              shadowColor: 'black',
              fillStyle: 'darkgreen',
              method: 'fill',
          });
      });

      const pivotCoords = ['pin-0', 'pin-1', 'pin-2', 'pin-3', 'pin-4', 'pin-5'];

- §

  Add another Wheel entity to act as a (potential) pivot for the Polyline

      scrawl.makeWheel({

          name: 'pivot-wheel',

          start: [50, 50],

          radius: 20,

          handleX: 'center',
          handleY: 'center',

          shadowColor: 'black',
          fillStyle: 'darkred',
          method: 'fill',
      });

- §

  Define the Polyline entity

      const myline = scrawl.makePolyline({

          name: 'my-polyline',

- §

  The `pins` attribute takes an array with elements which are:

  - [x, y] coordinate arrays, where values can be absolute (Numbers) and/or relative (String%) values
  - Artefact objects, or their name-String values
  - (`set` function will also accept an object with attributes: `index, x, y` - to be used by tweens) pins: absoluteCoords,

          pins: absoluteCoords,

- §

  Tension gives us the curviness of the line:

  - 0 - straight lines connecting the pins
  - 0.4ish - reasonable looking curves
  - 1 - exaggerated curves
  - negative values - add loops at the pins

          tension: 0,

- §

  Whether to connect all the pins (true), or run from first to last pin only (false)

          closed: false,

- §

  The starting position is the top left corner of the box which tightly encloses the Shape - regardless of the positions of any artefacts which may be used as pins. Handles and offsets should work as expected

  - This functionality changes when the `mapToPins` flag is set; now the start coordinate maps directly to the first coordinate supplied in the `pins` array. Handle and offset values can no longer be relied on.

          startX: 0,
          startY: 0,

- §

  The `precision` attribute determines the accuracy for positioning artefacts on the path when they have set their `constantPathSpeed` flag to `true`

  - Natural path speed leads to slower progression around tight corners; constant path speed attempts to even out these variations across the length of the path.
  - The default precision value is `10`; decreasing the value increases the positioning accuracy. The more accurate the positioning, the greater the computational (and memory) burden.

          precision: 0.05,

          pivot: 'pivot-wheel',
          lockTo: 'start',

          mapToPins: false,

          strokeStyle: 'orange',
          lineWidth: 6,

          lineCap: 'round',
          lineJoin: 'round',

          shadowColor: 'black',

          method: 'draw',

- §

  Note: the bounding box dimensions reflect the minimum/maximum coordinates of all the pins used to construct the shape. It will only reflect the actual shape of the Shape when `useAsPath` attribute is set to `true`

          showBoundingBox: true,

- §

  Note: when using a Polyline entity as a pivot for other artefacts, set the `useAsPath` flag to true

  - It generates more accurate results - particularly when the Polyline is flipped, rolled and/or scaled, and when underlying pins (particularly when those pins are artefacts) update their coordinates.

          useAsPath: true,

          bringToFrontOnDrag: false,
      });

- §

  Add some Block entitys which will pivot to our Polyline entity

      absoluteCoords.forEach((item, index) => {

          scrawl.makeBlock({

              name: `block-${index}`,

              width: 20,
              height: 20,

              pivot: 'my-polyline',
              pivotPin: index,
              lockTo: 'pivot',

              handleX: 'center',
              handleY: 'center',

              roll: 45,

              fillStyle: 'lightblue',
              strokeStyle: 'yellow',
              lineWidth: 3,
              method: 'fillThenDraw',
          });
      });

- §

  Testing natural vs constant speeds along the path

      for (let i = 0; i < 10; i++) {

          scrawl.makeWheel({

              name: `normal-ball-${i}`,
              order: 2,

              radius: 10,
              fillStyle: 'lightgreen',
              strokeStyle: 'red',
              method: 'fillThenDraw',

              handle: ['center', 'center'],

              path: 'my-polyline',
              pathPosition: i / 100,
              lockTo: 'path',

              delta: {
                  pathPosition: 0.001,
              },

          }).clone({

              name: `constant-ball-${i}`,
              fillStyle: 'yellow',
              strokeStyle :'blue',

              pathPosition: (i / 100) + 0.5,

              constantSpeedAlongPath: true,
          });
      }

- §

  #### User interaction

  Create the drag-and-drop zone

      scrawl.makeDragZone({
          zone: canvas,
          collisionGroup: canvas.base.name,
          endOn: ['up', 'leave'],

          updateOnStart: {
              shadowBlur: 6,
              shadowOffsetX: 3,
              shadowOffsetY: 3,
          },

          updateOnEnd: {
              shadowBlur: 0,
              shadowOffsetX: 0,
              shadowOffsetY: 0,
          },

          preventTouchDefaultWhenDragging: true,
      });

- §

  #### Scene animation

  Function to display frames-per-second data, and other information relevant to the demo

      const report = reportSpeed('#reportmessage', function () {
          return `Bounding box: ${myline.getBoundingBox().join(', ')}`;
      });

- §

  Create the Display cycle animation

      scrawl.makeRender({

          name: 'demo-animation',
          target: canvas,
          afterShow: report,
      });

- §

  #### More user interaction

      scrawl.makeUpdater({

          event: ['input', 'change'],
          origin: '.controlItem',

          target: myline,

          useNativeListener: true,
          preventDefault: true,

          updates: {

              tension: ['tension', 'float'],
              pivot: ['lockTo', 'raw'],
              closed: ['closed', 'boolean'],
              path: ['useAsPath', 'boolean'],
              map: ['mapToPins', 'boolean'],
              reverse: ['flipReverse', 'boolean'],
              upend: ['flipUpend', 'boolean'],
              roll: ['roll', 'float'],
              scale: ['scale', 'float'],
          },
      });

- §

  Change the coordinate array used by the Polyline

      const updatePins = (e) => {

          e.preventDefault();
          e.returnValue = false;

          const val = e.target.value;

          if (val === 'absolute') myline.set({ pins: absoluteCoords });
          else if (val === 'relative') myline.set({ pins: relativeCoords });
          else if (val === 'artefacts') myline.set({ pins: pivotCoords });
      };
      scrawl.addNativeListener(['input', 'change'], updatePins, '#pins');

- §

  Setup form @ts-expect-error

      document.querySelector('#tension').value = 0;

- §

  @ts-expect-error

      document.querySelector('#pivot').value = 'start';

- §

  @ts-expect-error

      document.querySelector('#closed').value = 0;

- §

  @ts-expect-error

      document.querySelector('#path').value = 1;

- §

  @ts-expect-error

      document.querySelector('#map').value = 0;

- §

  @ts-expect-error

      document.querySelector('#pins').value = 'absolute';

- §

  @ts-expect-error

      document.querySelector('#reverse').value = 0;

- §

  @ts-expect-error

      document.querySelector('#upend').value = 0;

- §

  @ts-expect-error

      document.querySelector('#roll').value = 0;

- §

  @ts-expect-error

      document.querySelector('#scale').value = 1;

- §

  #### Development and testing

      console.log(scrawl.library);

      console.log('Performing tests ...');

      killPolylineArtefact(canvas, 'pin-2', 3000, myline, () => myline.updatePinAt('pin-2', 2));