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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 Particles 005

  Emit particles from inside an artefact’s area

- §

  Run code

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

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

- §

  #### Scene setup

      const canvas = scrawl.library.artefact.mycanvas;

      scrawl.library.group[canvas.base.name].set({

          order: 1,
      })

- §

  Create draggable entitys which will act as the areas in which particles will be generated by the Emitter entitys

      const dragItems = scrawl.makeGroup({

          name: 'my-drag-items',
          host: canvas.base.name,
          order: 0,
      });

      scrawl.makePhrase({

          name: 'hello',
          group: 'my-drag-items',

          text: 'HELLO!',

          font: 'bold 100px sans-serif',
          lineHeight: 0.8,

          startX: 70,
          startY: 200,

          handleX: 20,
          handleY: 20,

          roll: -30,
          scale: 1.1,

          fillStyle: 'aliceblue',
          method: 'fillThenDraw',

      });

      scrawl.makeShape({

          name: 'myshape',
          group: 'my-drag-items',

          pathDefinition: 'M266.2,703.1 h-178 L375.1,990 l287-286.9 H481.9 C507.4,365,683.4,91.9,911.8,25.5 877,15.4,840.9,10,803.9,10 525.1,10,295.5,313.4,266.2,703.1 z',

          start: [400, 300],
          handle: ['center', 'center'],

          scale: 0.2,
          roll: -90,
          flipUpend: true,
          scaleOutline: false,

          fillStyle: 'aliceblue',
          method: 'fillThenDraw',
      });

- §

  #### Particle physics animation scene

- §

  Create a World object which we can then assign to the particle emitter

      const myWorld = scrawl.makeWorld({

          name: 'demo-world',
          tickMultiplier: 2,
      });

- §

  Create the particle Emitter entity

      scrawl.makeEmitter({

          name: 'emitter-one',
          world: myWorld,

          generationRate: 60,
          killAfterTime: 5,

          rangeZ: 0.3,
          rangeFromZ: 0.1,

- §

  We tell the Emitter to generated its Particles randomly, with initial start coordinates constrained to within the area defined by another artefact - we can set the `generateInArea` attribute by the artefact’s name String, or the artefact object itself.

          generateInArea: 'hello',

- §

  This is the entity the Emitter will be stamping

          artefact: scrawl.makeWheel({

              name: 'particle-wheel-entity',

              radius: 12,

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

              globalCompositeOperation: 'source-atop',

              fillStyle: 'blue',
              strokeStyle: 'white',
              method: 'fillThenDraw',
              visibility: false,

              noUserInteraction: true,
              noPositionDependencies: true,
              noFilters: true,
              noDeltaUpdates: true,
          }),

          stampAction: function (artefact, particle, host) {

              const history = particle.history;

              let remaining, globalAlpha, scale, start, z, roll;

              history.forEach(p => {

                  [remaining, z, ...start] = p;

                  globalAlpha = remaining / 6;
                  scale = 1 + (z / 3);

                  if (globalAlpha > 0 && scale > 0) {

                      roll = globalAlpha * 720;
                      artefact.simpleStamp(host, {start, scale, globalAlpha, roll});
                  }
              });
          },

- §

  Test that we can clone the Emitter entity

      }).clone({

          name: 'emitter-two',
          generateInArea: 'myshape',

          artefact: scrawl.makeBlock({

              name: 'particle-block-entity',

              width: 20,
              height: 20,

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

              fillStyle: 'red',
              method: 'fillThenDraw',
              visibility: false,

              globalCompositeOperation: 'source-atop',

              noUserInteraction: true,
              noPositionDependencies: true,
              noFilters: true,
              noDeltaUpdates: true,
          }),
      });

- §

  #### Scene animation

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

      const particlenames = scrawl.library.particlenames,
          particle = scrawl.library.particle;

      const report = reportSpeed('#reportmessage', function () {

- §

  ParticleHistory arrays are not saved in the Scrawl-canvas library; instead we need to count them in each particle

          let historyCount = 0;
          particlenames.forEach(n => {

              const p = particle[n];
              if (p) historyCount += p.history.length;
          });

          return `    Particles: ${particlenames.length}
          Stamps per display: ${historyCount}`;
      });

- §

  Create the Display cycle animation

      scrawl.makeRender({

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

- §

  #### User interaction

      scrawl.makeDragZone({

          zone: canvas,
          collisionGroup: dragItems,
          endOn: ['up', 'leave'],
          exposeCurrentArtefact: true,
          preventTouchDefaultWhenDragging: true,
      });

- §

  #### Development and testing

      console.log(scrawl.library);