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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-057.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/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-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/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/temp-000.js ./demo/temp-001.js ./demo/temp-001a.js ./demo/temp-002.js ./demo/temp-003.js ./demo/temp-004.js ./demo/temp-005.js ./demo/temp-006.js ./demo/temp-007.js ./demo/temp-008.js ./demo/temp-009.js ./demo/temp-010.js ./demo/temp-011.js ./demo/temp-012.js ./demo/temp-013.js ./demo/temp-014.js ./demo/temp-015.js ./demo/temp-016.js ./demo/temp-017.js ./demo/temp-018.js ./demo/temp-018a.js ./demo/temp-019.js ./demo/temp-020.js ./demo/temp-021.js ./demo/temp-022.js ./demo/temp-023.js ./demo/temp-024.js ./demo/temp-025.js ./demo/temp-026.js ./demo/temp-027.js ./demo/temp-028.js ./demo/temp-029.js ./demo/temp-030.js ./demo/temp-031.js ./demo/temp-032.js ./demo/temp-033.js ./demo/temp-034.js ./demo/temp-035.js ./demo/temp-036.js ./demo/temp-037.js ./demo/temp-100.js ./demo/temp-101.js ./demo/temp-102.js ./demo/temp-103.js ./demo/temp-104.js ./demo/temp-200.js ./demo/temp-201.js ./demo/temp-301.js ./demo/temp-inkscapeSvgFilters.js ./demo/temp-lottie.js ./demo/tensorflow-001.js ./demo/tensorflow-002.js ./demo/utilities.js
  • §

    Demo Canvas 041

    Access and use a canvas context engine using the makeAnimation factory

  • §

    Run code

    import * as scrawl from '../source/scrawl.js';
    
    import { reportSpeed } from './utilities.js';
  • §

    Ignore pixel ratio considerations

    • Leads to issues when dragging the browser between screens with different pixel ratio densities
    scrawl.setIgnorePixelRatio(true);
  • §

    Scene setup

    const canvas = scrawl.library.canvas.mycanvas;
    
    
    const boxes = [];
    
    const engine = {
    
        width: canvas.get("width"),
        height: canvas.get("height"),
        count: 1000,
    };
  • §

    Setup the display canvas

    canvas.set({
    
        width: engine.width,
        height: engine.height,
        isComponent: true,
    
    }).render();
  • §

    Build and populate our cache Cell with pre-drawn boxes

    canvas.buildCell({
    
        name: 'cache',
        width: 50 * 40,
        height: 50,
        cleared: false,
        compiled: false,
        shown: false,
    });
    
    const source = scrawl.library.cell.cache.element;
    const sourceEngine = scrawl.library.cell.cache.engine;
    
    sourceEngine.fillStyle = 'white';
    sourceEngine.strokeStyle = 'black';
    sourceEngine.lineWidth = 1;
    
    for (let i = 0; i < 40; i++) {
    
        let size = 10 + i,
            delta = Math.floor(size / 2) + 0.5;
    
        sourceEngine.setTransform(1, 0, 0, 1, (50 * i) + 25, 25);
        sourceEngine.fillRect(-delta, -delta, size, size);
        sourceEngine.strokeRect(-delta, -delta, size, size);
    }
  • §

    On start, and UI, create the required number of box objects

    • these are plain JS objects holding data for our box drawing routine
    const buildBoxes = function (boxesRequired) {
    
        let { width, height } = engine,
            size, x, y, dx;
    
        boxes.length = 0;
    
        for (let i = 0; i < boxesRequired; i++) {
    
            size = 10 + Math.random() * 40;
            x = Math.floor(Math.random() * width);
            y = Math.floor(Math.random() * height);
            dx = -1 - Math.random();
    
            boxes.push([x, y, dx, Math.floor(size - 10)]);
        }
    };
  • §

    Use the box data to draw the appropriate box images onto the screen at the required positions

    const drawBoxes = function () {
    
        const engineWidth = engine.width,
            ctx = canvas.base.engine;
    
        let box, x, y, deltaX, boxpos, width;
    
        return function () {
    
            ctx.setTransform(1, 0, 0, 1, 0, 0);
    
            for (let i = 0, iz = boxes.length; i < iz; i++) {
    
                box = boxes[i];
                [x, y, deltaX, boxpos] = box;
                width = boxpos + 10
    
                ctx.drawImage(source, boxpos * 50, 0, 50, 50, x - 25, y - 25, 50, 50);
    
                x += deltaX;
                if (x < -width) x += engineWidth + (width * 2);
                box[0] = x;
            }
        }
    }();
  • §

    Speed reporter

    const report = reportSpeed('#reportmessage', function () {
    
        return `Box count: ${boxes.length}`;
    });
  • §

    The animation loop object

    scrawl.makeAnimation({
    
        name: 'demo-animation',
    
        fn: () => {
    
            if (boxes.length !== engine.count) buildBoxes(engine.count);
    
            canvas.clear();
            drawBoxes();
            canvas.show();
            report();
        },
    });
    
    scrawl.addListener("up", () => engine.count += 1000, canvas.domElement);
  • §

    Development and testing

    console.log(scrawl.library);