• Jump To … +
    ./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/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/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-302.js ./demo/temp-aoc-01-1-data.js ./demo/temp-aoc-01-1.js ./demo/temp-inkscapeSvgFilters.js ./demo/temp-lottie.js ./demo/tensorflow-001.js ./demo/tensorflow-002.js ./demo/utilities.js
  • §

    Demo Filters 028

    Stencil (background) filter functionality

  • §

    Run code

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

    Scene setup

    Get a handle to the Canvas wrapper

    const canvas = scrawl.library.canvas.mycanvas;
  • §

    Namespacing boilerplate

    const namespace = 'demo';
    const name = (n) => `${namespace}-${n}`;
    
    
    scrawl.importDomImage('.flowers');
  • §

    Define filters - need to test them all, plus some user-defined filters

    Asset generator

    scrawl.makeNoiseAsset({
    
        name: name('my-noise-generator'),
        width: 400,
        height: 400,
        scale: 60,
    
        sumFunction: 'modular',
        sumAmplitude: 4,
    
        noiseEngine: 'worley-manhattan',
    });
  • §

    Required, otherwise the asset generator doesn’t produce anything for the filter

    scrawl.makePicture({
        name: name('temp-1'),
        asset: name('my-noise-generator'),
        dimensions: [100, 100],
        copyDimensions: ['100%', '100%'],
        method: 'none',
    });
    
    scrawl.makePicture({
        name: name('temp-2'),
        asset: 'iris',
        dimensions: [400, 400],
        copyDimensions: ['100%', '100%'],
        method: 'none',
    });
  • §

    Displace filter

    scrawl.makeFilter({
        name: name('displace'),
        actions: [
            {
                action: 'process-image',
                asset: name('my-noise-generator'),
                width: 400,
                height: 400,
                copyWidth: 400,
                copyHeight: 400,
                lineOut: 'noise-map',
            },
            {
                action: 'displace',
                lineMix: 'noise-map',
                scaleX: 3,
                scaleY: 3,
                transparentEdges: true,
            }
        ],
    });
  • §

    Blend filter

    scrawl.makeFilter({
        name: name('blend'),
        actions: [
            {
                action: 'process-image',
                asset: 'iris',
                width: 400,
                height: 400,
                copyWidth: 400,
                copyHeight: 400,
                lineOut: 'flower',
            },
            {
                action: 'blend',
                lineMix: 'flower',
                blend: 'color-burn',
            }
        ],
    });
  • §

    Compose filter

    scrawl.makeFilter({
        name: name('compose'),
        actions: [
            {
                action: 'process-image',
                asset: 'iris',
                width: 400,
                height: 400,
                copyWidth: 400,
                copyHeight: 400,
                lineOut: 'flower',
            },
            {
                action: 'compose',
                lineMix: 'flower',
                offsetX: 5,
                compose: 'destination-in',
            }
        ],
    });
  • §

    Gray filter

    scrawl.makeFilter({
        name: name('gray'),
        method: 'gray',
  • §

    Grayscale filter

    }).clone({
        name: name('grayscale'),
        method: 'grayscale',
  • §

    Sepia filter

    }).clone({
        name: name('sepia'),
        method: 'sepia',
  • §

    Invert filter

    }).clone({
        name: name('invert'),
        method: 'invert',
  • §

    Red filter

    }).clone({
        name: name('red'),
        method: 'red',
  • §

    Green filter

    }).clone({
        name: name('green'),
        method: 'green',
  • §

    Blue filter

    }).clone({
        name: name('blue'),
        method: 'blue',
  • §

    Notred filter

    }).clone({
        name: name('notred'),
        method: 'notred',
  • §

    Notgreen filter

    }).clone({
        name: name('notgreen'),
        method: 'notgreen',
  • §

    Notblue filter

    }).clone({
        name: name('notblue'),
        method: 'notblue',
  • §

    Cyan filter

    }).clone({
        name: name('cyan'),
        method: 'cyan',
  • §

    Magenta filter

    }).clone({
        name: name('magenta'),
        method: 'magenta',
  • §

    Yellow filter

    }).clone({
        name: name('yellow'),
        method: 'yellow',
  • §

    Edge detect filter

    }).clone({
        name: name('edgeDetect'),
        method: 'edgeDetect',
  • §

    Sharpen filter

    }).clone({
        name: name('sharpen'),
        method: 'sharpen',
    });
  • §

    Emboss filter

    scrawl.makeFilter({
        name: name('emboss'),
        method: 'emboss',
        angle: 225,
        strength: 10,
        tolerance: 50,
    });
  • §

    Chroma (green screen) filter

    scrawl.makeFilter({
        name: name('chroma'),
        method: 'chroma',
        ranges: [[0, 0, 0, 80, 80, 80], [180, 180, 180, 255, 255, 255]],
    });
  • §

    Brightness filter

    scrawl.makeFilter({
        name: name('brightness'),
        method: 'brightness',
        level: 0.5,
  • §

    Saturation filter

    }).clone({
        name: name('saturation'),
        method: 'saturation',
        level: 1.4,
  • §

    Threshhold filter

    }).clone({
        name: name('threshold'),
        method: 'threshold',
        level: 127,
        lowRed: 100,
        lowGreen: 0,
        lowBlue: 0,
        highRed: 220,
        highGreen: 60,
        highBlue: 60,
    });
  • §

    Swirl filter

    scrawl.makeFilter({
        name: name('swirl'),
        method: 'swirl',
        startX: '50%',
        startY: '50%',
        innerRadius: 0,
        outerRadius: '50%',
        angle: 240,
        easing: 'easeOutSine',
    });
  • §

    Channels filter

    scrawl.makeFilter({
        name: name('channels'),
        method: 'channels',
        red: 0.4,
        green: 0.8,
        blue: 0.6,
  • §

    Channelstep filter

    }).clone({
        name: name('channelstep'),
        method: 'channelstep',
        red: 64,
        green: 64,
        blue: 64,
    });
  • §

    Tiles filter

    scrawl.makeFilter({
        name: name('tiles'),
        method: 'tiles',
        points: 'hex-grid',
        tileHeight: 40,
        tileRadius: 24,
    });
  • §

    Newsprint filter

    scrawl.makeFilter({
        name: name('newsprint'),
        method: 'newsprint',
        width: 2,
    });
  • §

    Tint filter

    scrawl.makeFilter({
        name: name('tint'),
        method: 'tint',
        redInRed: 0.5,
        redInGreen: 1,
        redInBlue: 0.9,
        greenInRed: 0,
        greenInGreen: 0.3,
        greenInBlue: 0.8,
        blueInRed: 0.8,
        blueInGreen: 0.8,
        blueInBlue: 0.4,
    });
  • §

    Offset filter

    scrawl.makeFilter({
        name: name('offset'),
        method: 'offset',
        offsetX: 12,
        offsetY: 12,
        opacity: 0.5,
    });
  • §

    Glitch filter

    scrawl.makeFilter({
        name: name('glitch'),
        method: 'glitch',
        level: 0.3,
        offsetRedMin: -20,
        offsetRedMax: 20,
        offsetBlueMin: 0,
        offsetBlueMax: 15,
        useMixedChannel: false,
        transparentEdges: true,
        step: 4,
    });
  • §

    Offset Channels filter

    scrawl.makeFilter({
        name: name('offsetChannels'),
        method: 'offsetChannels',
        offsetRedX: -12,
        offsetRedY: -8,
        offsetGreenX: 12,
        offsetGreenY: 16,
        offsetBlueX: 5,
        offsetBlueY: -15,
    });
  • §

    Pixellate filter

    scrawl.makeFilter({
        name: name('pixelate'),
        method: 'pixelate',
        tileWidth: 20,
        tileHeight: 20,
        offsetX: 8,
        offsetY: 8,
    });
  • §

    Blur filter

    scrawl.makeFilter({
        name: name('blur'),
        method: 'blur',
        radius: 8,
        passes: 1,
        excludeTransparentPixels: true,
    });
  • §

    Gaussian Blur filter

    scrawl.makeFilter({
        name: name('gaussianBlur'),
        method: 'gaussianBlur',
        radius: 4,
    });
  • §

    AreaAlpha filter

    scrawl.makeFilter({
        name: name('areaAlpha'),
        method: 'areaAlpha',
        tileWidth: 20,
        tileHeight: 20,
        gutterWidth: 20,
        gutterHeight: 20,
        offsetX: 8,
        offsetY: 8,
        areaAlphaLevels: [255, 0, 0, 255],
    });
  • §

    Matrix filter

    scrawl.makeFilter({
        name: name('matrix'),
        method: 'matrix',
        weights: [-1, -1, 0, -1, 1, 1, 0, 1, 1],
  • §

    Matrix5 filter

    }).clone({
        name: name('matrix5'),
        method: 'matrix5',
        weights: [-1, -1, -1, -1, 0, -1, -1, -1, 0, 1, -1, -1, 0, 1, 1, -1, 0, 1, 1, 1, 0, 1, 1, 1, 1],
    });
  • §

    ChannelLevels filter

    scrawl.makeFilter({
        name: name('channelLevels'),
        method: 'channelLevels',
        red: [50, 200],
        green: [60, 220, 150],
        blue: [40, 180],
        alpha: [],
    });
  • §

    Chrome key filter

    scrawl.makeFilter({
        name: name('chromakey'),
        method: 'chromakey',
        red: 0,
        green: 127,
        blue: 0,
        opaqueAt: 0.7,
        transparentAt: 0.5,
    });
  • §

    Alpha to channels filter

    scrawl.makeFilter({
        name: name('alphaToChannels'),
        method: 'alphaToChannels',
        includeRed: false,
        includeGreen: false,
        excludeRed: false,
    });
  • §

    Channels to alpha filter

    scrawl.makeFilter({
        name: name('channelsToAlpha'),
        method: 'channelsToAlpha',
    });
  • §

    Clamp channels filter

    scrawl.makeFilter({
        name: name('clampChannels'),
        method: 'clampChannels',
        lowRed: 0,
        highRed: 64,
        lowGreen: 100,
        highGreen: 200,
        lowBlue: 200,
        highBlue: 255,
    });
  • §

    Corrode filter

    scrawl.makeFilter({
        name: name('corrode'),
        method: 'corrode',
        width: 5,
        height: 5,
        operation: 'lowest',
    });
  • §

    Curve weights filter

    scrawl.makeFilter({
        name: name('curveWeights'),
        method: 'curveWeights',
        useMixedChannel: false,
        weights: [255, 2, 0, 0, 255, 5, -1, 0, 253, 8, -2, 0, 252, 11, -3, 0, 250, 14, -4, 0, 249, 16, -5, 1, 247, 19, -6, 1, 246, 22, -7, 1, 244, 24, -8, 1, 243, 26, -9, 1, 241, 29, -10, 0, 239, 31, -11, 0, 238, 33, -12, 0, 236, 35, -13, 0, 235, 37, -14, 0, 233, 39, -15, 0, 232, 41, -16, 1, 230, 43, -17, 1, 229, 45, -18, 1, 227, 46, -19, 1, 225, 48, -20, 1, 224, 50, -21, 1, 222, 51, -22, 0, 221, 53, -23, 0, 219, 54, -24, 0, 218, 56, -25, 0, 216, 57, -26, 0, 214, 58, -27, 1, 213, 60, -28, 1, 211, 61, -29, 1, 209, 62, -30, 1, 208, 63, -31, 0, 206, 64, -32, 0, 205, 65, -33, 0, 203, 66, -34, 0, 201, 68, -35, 0, 200, 68, -36, 0, 198, 69, -37, 1, 196, 70, -38, 1, 195, 71, -39, 1, 193, 72, -40, 1, 191, 73, -41, 1, 190, 73, -42, 0, 188, 74, -43, 0, 186, 75, -44, 0, 185, 75, -45, 0, 183, 76, -46, 0, 181, 77, -47, 0, 180, 77, -48, 1, 178, 78, -49, 1, 176, 78, -50, 1, 175, 79, -51, 1, 173, 80, -52, 1, 171, 80, -53, 1, 169, 80, -54, 0, 167, 81, -55, 0, 166, 81, -56, 0, 164, 81, -57, 0, 162, 82, -58, 0, 160, 82, -59, 1, 159, 82, -60, 1, 157, 82, -61, 1, 155, 83, -62, 1, 153, 83, -63, 0, 151, 83, -64, 0, 149, 83, -65, 0, 148, 83, -66, 0, 146, 83, -67, 0, 144, 84, -68, 0, 142, 84, -69, 1, 140, 84, -70, 1, 138, 84, -71, 1, 136, 84, -72, 1, 134, 84, -73, 1, 132, 84, -74, 0, 130, 84, -75, 0, 128, 84, -76, 0, 126, 84, -77, 0, 124, 84, -78, 0, 122, 84, -79, 0, 120, 84, -80, 1, 118, 83, -81, 1, 116, 83, -82, 1, 114, 83, -83, 1, 112, 83, -84, 1, 110, 83, -85, 1, 108, 83, -86, 0, 106, 82, -86, 0, 104, 82, -87, 0, 101, 82, -88, 0, 99, 82, -88, 0, 97, 82, -89, 1, 95, 81, -90, 1, 93, 81, -91, 1, 90, 81, -91, 1, 88, 80, -92, 0, 86, 80, -93, 0, 83, 80, -93, 0, 81, 79, -94, 0, 79, 79, -95, 0, 76, 79, -96, 0, 74, 78, -96, 1, 71, 78, -97, 1, 69, 78, -98, 1, 66, 77, -98, 1, 64, 77, -99, 1, 61, 76, -100, 0, 59, 76, -100, 0, 56, 76, -101, 0, 53, 75, -102, 0, 51, 75, -102, 0, 48, 74, -103, 0, 45, 74, -104, 1, 42, 73, -104, 1, 40, 73, -105, 1, 37, 72, -105, 1, 34, 72, -106, 1, 31, 71, -107, 1, 28, 71, -107, 0, 25, 70, -108, 0, 22, 70, -109, 0, 19, 69, -109, 0, 16, 69, -110, 0, 13, 68, -111, 1, 10, 68, -111, 1, 7, 67, -112, 1, 4, 67, -112, 1, 1, 66, -113, 0, -2, 65, -114, 0, -5, 65, -114, 0, -8, 64, -115, 0, -11, 64, -115, 0, -14, 63, -116, 0, -17, 62, -117, 1, -20, 62, -117, 1, -23, 61, -118, 1, -26, 61, -118, 1, -29, 60, -119, 1, -32, 59, -119, 0, -35, 59, -120, 0, -38, 58, -121, 0, -41, 58, -121, 0, -44, 57, -122, 0, -46, 56, -122, 0, -49, 56, -123, 1, -52, 55, -123, 1, -55, 54, -124, 1, -57, 54, -124, 1, -60, 53, -125, 1, -62, 52, -125, 1, -65, 52, -126, 0, -68, 51, -126, 0, -70, 51, -127, 0, -73, 50, -127, 0, -75, 49, -128, 0, -77, 49, -128, 1, -80, 48, -129, 1, -82, 47, -129, 1, -85, 47, -129, 1, -87, 46, -130, 0, -89, 45, -130, 0, -92, 45, -131, 0, -94, 44, -131, 0, -96, 43, -132, 0, -98, 43, -132, 0, -100, 42, -132, 1, -103, 41, -133, 1, -105, 41, -133, 1, -107, 40, -134, 1, -109, 39, -134, 1, -111, 39, -134, 0, -113, 38, -134, 0, -115, 37, -135, 0, -118, 37, -135, 0, -120, 36, -135, 0, -122, 35, -136, 0, -124, 35, -136, 1, -126, 34, -136, 1, -128, 33, -136, 1, -130, 33, -137, 1, -131, 32, -137, 1, -134, 31, -137, 1, -136, 31, -137, 0, -137, 30, -137, 0, -139, 29, -137, 0, -141, 29, -138, 0, -143, 28, -138, 0, -145, 27, -138, 1, -147, 27, -138, 1, -149, 26, -138, 1, -151, 26, -138, 1, -152, 25, -138, 0, -154, 24, -138, 0, -156, 24, -138, 0, -158, 23, -138, 0, -160, 23, -138, 0, -161, 22, -138, 0, -163, 21, -138, 1, -165, 21, -138, 1, -167, 20, -137, 1, -169, 20, -137, 1, -170, 19, -137, 1, -172, 18, -137, 0, -174, 18, -136, 0, -176, 17, -136, 0, -177, 17, -136, 0, -179, 16, -135, 0, -181, 16, -135, 0, -183, 15, -134, 1, -184, 15, -134, 1, -186, 14, -133, 1, -188, 14, -133, 1, -189, 13, -132, 1, -191, 13, -131, 1, -193, 12, -130, 0, -194, 12, -130, 0, -196, 11, -129, 0, -198, 11, -128, 0, -199, 10, -127, 0, -201, 10, -126, 1, -203, 9, -124, 1, -204, 9, -123, 1, -206, 8, -122, 1, -208, 8, -120, 0, -209, 8, -119, 0, -211, 7, -117, 0, -212, 7, -115, 0, -214, 6, -114, 0, -216, 6, -112, 0, -217, 6, -110, 1, -219, 5, -107, 1, -220, 5, -105, 1, -222, 5, -102, 1, -223, 4, -100, 1, -225, 4, -97, 0, -227, 4, -94, 0, -228, 3, -91, 0, -230, 3, -87, 0, -231, 3, -84, 0, -233, 3, -80, 0, -234, 2, -76, 1, -236, 2, -72, 1, -238, 2, -68, 1, -239, 2, -63, 1, -241, 2, -59, 1, -242, 1, -54, 1, -244, 1, -49, 0, -245, 1, -44, 0, -247, 1, -39, 0, -248, 1, -34, 0, -250, 1, -29, 0, -251, 1, -24, 1, 3, 1, -18, 1, 2, 1, -13, 1, 1, 1, -8, 1, 0, 0, -2, 0],
    });
  • §

    Flood filter

    scrawl.makeFilter({
        name: name('flood'),
        method: 'flood',
        alpha: 100,
    });
  • §

    Random noise filter

    scrawl.makeFilter({
        name: name('randomNoise'),
        method: 'randomNoise',
        width: 10,
        height: 10,
        level: 0.7,
    });
  • §

    Reduce palette filter

    scrawl.makeFilter({
        name: name('reducePalette'),
        method: 'reducePalette',
    });
    
    scrawl.makeGradient({
        name: name('red-to-blue'),
        endX: '100%',
    
        colors: [
            [0, 'red'],
            [999, 'blue']
        ],
    });
  • §

    Map to gradient filter

    const myFilter = scrawl.makeFilter({
    
        name: name('mapToGradient'),
        method: 'mapToGradient',
    
        gradient: name('red-to-blue'),
    });
  • §

    Bespoke (drop shadow) filter

    scrawl.makeFilter({
        name: name('dropShadow'),
        actions: [
            {
                action: 'gaussian-blur',
                lineIn: 'source-alpha',
                lineOut: 'shadow',
                radius: 2, 
            },
            {
                action: 'compose',
                lineIn: 'source',
                lineMix: 'shadow',
                offsetX: 6,
                offsetY: 6,
            }
        ],
    });
  • §

    Bespoke (red border) filter

    scrawl.makeFilter({
        name: name('redBorder'),
        actions: [
            {
                action: 'gaussian-blur',
                lineIn: 'source-alpha',
                lineOut: 'border',
                radius: 2,
            },
            {
                action: 'flood',
                lineIn: 'border',
                lineOut: 'border',
                red: 255,
            },
            {
                action: 'compose',
                lineIn: 'source',
                lineMix: 'border',
            }
        ],
    });
  • §

    Scene entitys

    const piccy = scrawl.makePicture({
    
        name: name('background'),
    
        asset: 'iris',
    
        width: '100%',
        height: '100%',
    
        copyWidth: '100%',
        copyHeight: '100%',
    
        method: 'fill',
    });
    
    const group = scrawl.makeGroup({
        name: name('mouse-group'),
        host: canvas.get('baseName'),
    });
    
    const outlineGroup = scrawl.makeGroup({
        name: name('outline-group'),
        host: canvas.get('baseName'),
    });
  • §

    Note: stencil filters cannot be memoized, which makes them slow

    • We can’t memoize what we don’t know, and we have no way of knowing what the canvas behind the entity will look like, or if it has changed since the last Display cycle
    const cog = scrawl.makeCog({
        name: name('cog'),
        group,
        start: ['center', 'center'],
        handle: ['center', 'center'],
        outerRadius: 120,
        innerRadius: 80,
        outerControlsDistance: 20,
        innerControlsDistance: 16,
        points: 12,
        fillStyle: 'red',
        delta: {
            roll: 0.5,
        },
        isStencil: true,
        visibility: false,
    });
    
    cog.clone({
        name: name('cog-outline'),
        group: outlineGroup,
        strokeStyle: 'white',
        lineWidth: 2,
        method: 'draw',
        pivot: name('cog'),
        lockTo: 'pivot',
        isStencil: false,
    });
    
    const block = scrawl.makeBlock({
        name: name('block'),
        group,
        start: ['center', 'center'],
        handle: ['center', 'center'],
        dimensions: [200, 120],
        fillStyle: 'red',
        isStencil: true,
    });
    
    block.clone({
        name: name('block-outline'),
        group: outlineGroup,
        strokeStyle: 'white',
        lineWidth: 2,
        method: 'draw',
        pivot: name('block'),
        lockTo: 'pivot',
        isStencil: false,
    });
  • §

    Cat spritesheet image file taken from https://www.kisspng.com/png-walk-cycle-css-animations-drawing-sprite-sprite-1064760/

    scrawl.importSprite('img/cat-sprite.png');
    
    const cat = scrawl.makePicture({
        name: name('cat'),
        group,
        start: ['center', 'center'],
        handle: ['center', 'center'],
        dimensions: [300, 150],
        roll: 20,
        asset: 'cat-sprite',
        spriteTrack: 'walk',
        spriteFrameDuration: 100,
        isStencil: true,
        visibility: false,
    });
    
    cat.clone({
        name: name('cat-outline'),
        group: outlineGroup,
        strokeStyle: 'white',
        lineWidth: 2,
        method: 'draw',
        pivot: name('cat'),
        lockTo: 'pivot',
        isStencil: false,
    });
    
    let stencil = block;
  • §

    Scene animation

    Function to check whether mouse cursor is over canvas, and lock the reference entity accordingly

    const mouseCheck = function () {
    
        let active = false;
    
        return function () {
    
            if (canvas.here.active !== active) {
    
                active = canvas.here.active;
    
                stencil.set({
                    lockTo: (active) ? 'mouse' : 'start'
                });
            }
        };
    }();
  • §

    For this demo we will suppress touchmove functionality over the canvas

    scrawl.addNativeListener('touchmove', (e) => {
    
        e.preventDefault();
        e.returnValue = false;
    
    }, canvas.domElement);
  • §

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

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

    @ts-expect-error

        return `    globalAlpha - ${globalAlpha.value}`;
    });
  • §

    Create the Display cycle animation

    scrawl.makeRender({
    
        name: name('animation'),
        target: canvas,
        commence: mouseCheck,
        afterShow: report,
    });
  • §

    User interaction

    scrawl.addNativeListener(['input', 'change'], (e) => {
    
        e.preventDefault();
        e.returnValue = false;
    
        let val = e.target.value;
    
        if (val) {
    
            group.setArtefacts({
                filters: [name(val)],
            });
        }
        else {
    
            group.setArtefacts({
                filters: [],
            });
        }
    }, '#filter');
    
    scrawl.addNativeListener(['input', 'change'], (e) => {
    
        e.preventDefault();
        e.returnValue = false;
    
        let val = e.target.value;
    
        if (val) {
    
            group.setArtefacts({
                visibility: false,
            });
    
            outlineGroup.setArtefacts({
                visibility: false,
            });
    
            cat.haltSprite();
  • §

    @ts-expect-error

            stencil = group.getArtefact(name(val));
    
            stencil.set({
                visibility: true,
            });
    
            if (val === 'cat') cat.playSprite();
    
            outlineGroup.getArtefact(name(`${val}-outline`)).set({
                visibility: true,
            });
        }
    }, '#entity');
    
    scrawl.makeUpdater({
    
        event: ['change'],
        origin: '.controlItem',
    
        target: stencil,
    
        useNativeListener: true,
        preventDefault: true,
    
        updates: {
    
            globalAlpha: ['globalAlpha', 'float'],
            globalCompositeOperation: ['globalCompositeOperation', 'raw'],
        },
    });
  • §

    Setup form

    const globalAlpha = document.querySelector('#globalAlpha');
  • §

    @ts-expect-error

    globalAlpha.value = 1;
  • §

    @ts-expect-error

    document.querySelector('#filter').options.selectedIndex = 0;
  • §

    Drag-and-Drop image loading functionality

    addImageDragAndDrop(canvas, '#my-image-store', piccy);
  • §

    Development and testing

    console.log(scrawl.library);