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Move SVG renderer logic back into SVGSkin
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This will allow for fancier stuff to be done with the SVG viewbox in the
future to avoid subpixel jitter.
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adroitwhiz committed Mar 4, 2021
1 parent 9560de4 commit 801b0da
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Showing 2 changed files with 50 additions and 22 deletions.
68 changes: 48 additions & 20 deletions src/SVGSkin.js
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
const twgl = require('twgl.js');

const Skin = require('./Skin');
const SvgRenderer = require('scratch-svg-renderer').SVGRenderer;
const {loadSvgString, serializeSvgToString} = require('scratch-svg-renderer');
const ShaderManager = require('./ShaderManager');

const MAX_TEXTURE_DIMENSION = 2048;
Expand All @@ -28,8 +28,17 @@ class SVGSkin extends Skin {
/** @type {RenderWebGL} */
this._renderer = renderer;

/** @type {SvgRenderer} */
this._svgRenderer = new SvgRenderer();
/** @type {HTMLImageElement} */
this._svgImage = null;

/** @type {Array<number>} */
this._size = [0, 0];

/** @type {HTMLCanvasElement} */
this._canvas = document.createElement('canvas');

/** @type {CanvasRenderingContext2D} */
this._context = this._canvas.getContext('2d');

/** @type {Array<WebGLTexture>} */
this._scaledMIPs = [];
Expand All @@ -56,7 +65,7 @@ class SVGSkin extends Skin {
* @return {Array<number>} the natural size, in Scratch units, of this skin.
*/
get size () {
return this._svgRenderer.size;
return [this._size[0], this._size[1]];
}

useNearest (scale, drawable) {
Expand Down Expand Up @@ -94,18 +103,27 @@ class SVGSkin extends Skin {
* @return {SVGMIP} An object that handles creating and updating SVG textures.
*/
createMIP (scale) {
this._svgRenderer.draw(scale);
const [width, height] = this._size;
this._canvas.width = width * scale;
this._canvas.height = height * scale;
if (
this._canvas.width <= 0 ||
this._canvas.height <= 0 ||
// Even if the canvas at the current scale has a nonzero size, the image's dimensions are floored
// pre-scaling; e.g. if an image has a width of 0.4 and is being rendered at 3x scale, the canvas will have
// a width of 1, but the image's width will be rounded down to 0 on some browsers (Firefox) prior to being
// drawn at that scale, resulting in an IndexSizeError if we attempt to draw it.
this._svgImage.naturalWidth <= 0 ||
this._svgImage.naturalHeight <= 0
) return super.getTexture();
this._context.clearRect(0, 0, this._canvas.width, this._canvas.height);
this._context.setTransform(scale, 0, 0, scale, 0, 0);
this._context.drawImage(this._svgImage, 0, 0);

// Pull out the ImageData from the canvas. ImageData speeds up
// updating Silhouette and is better handled by more browsers in
// regards to memory.
const canvas = this._svgRenderer.canvas;
// If one of the canvas dimensions is 0, set this MIP to an empty image texture.
// This avoids an IndexSizeError from attempting to getImageData when one of the dimensions is 0.
if (canvas.width === 0 || canvas.height === 0) return super.getTexture();

const context = canvas.getContext('2d');
const textureData = context.getImageData(0, 0, canvas.width, canvas.height);
const textureData = this._context.getImageData(0, 0, this._canvas.width, this._canvas.height);

const textureOptions = {
auto: false,
Expand Down Expand Up @@ -147,7 +165,7 @@ class SVGSkin extends Skin {
// Can't use bitwise stuff here because we need to handle negative exponents
const mipScale = Math.pow(2, mipLevel - INDEX_OFFSET);

if (this._svgRenderer.loaded && !this._scaledMIPs[mipLevel]) {
if (this._svgImage.complete && !this._scaledMIPs[mipLevel]) {
this._scaledMIPs[mipLevel] = this.createMIP(mipScale);
}

Expand All @@ -172,14 +190,21 @@ class SVGSkin extends Skin {
* @param {Array<number>} [rotationCenter] - Optional rotation center for the SVG.
*/
setSVG (svgData, rotationCenter) {
this._svgRenderer.loadSVG(svgData, false, () => {
const svgSize = this._svgRenderer.size;
if (svgSize[0] === 0 || svgSize[1] === 0) {
const svgTag = loadSvgString(svgData);
this._svgImage = document.createElement('img');
const svgText = serializeSvgToString(svgTag, true /* shouldInjectFonts */);

this._svgImage.addEventListener('load', () => {
const {x, y, width, height} = svgTag.viewBox.baseVal;
this._size[0] = width;
this._size[1] = height;

if (width === 0 || height === 0) {
super.setEmptyImageData();
return;
}

const maxDimension = Math.ceil(Math.max(this.size[0], this.size[1]));
const maxDimension = Math.ceil(Math.max(width, height));
let testScale = 2;
for (testScale; maxDimension * testScale <= MAX_TEXTURE_DIMENSION; testScale *= 2) {
this._maxTextureScale = testScale;
Expand All @@ -188,12 +213,15 @@ class SVGSkin extends Skin {
this.resetMIPs();

if (typeof rotationCenter === 'undefined') rotationCenter = this.calculateRotationCenter();
const viewOffset = this._svgRenderer.viewOffset;
this._rotationCenter[0] = rotationCenter[0] - viewOffset[0];
this._rotationCenter[1] = rotationCenter[1] - viewOffset[1];
// Compensate for viewbox offset.
// See https://github.com/LLK/scratch-render/pull/90.
this._rotationCenter[0] = rotationCenter[0] - x;
this._rotationCenter[1] = rotationCenter[1] - y;

this.emit(Skin.Events.WasAltered);
});

this._svgImage.src = `data:image/svg+xml;utf8,${encodeURIComponent(svgText)}`;
}

}
Expand Down
4 changes: 2 additions & 2 deletions test/helper/page-util.js
Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,7 @@ window.waitForSVGSkinLoad = renderer => new Promise(resolve => {
for (const skin of renderer._allSkins) {
if (skin.constructor.name !== 'SVGSkin') continue;
numSVGSkins++;
if (skin._svgRenderer.loaded) numLoadedSVGSkins++;
if (skin._svgImage.complete) numLoadedSVGSkins++;
}

if (numSVGSkins === numLoadedSVGSkins) {
Expand Down Expand Up @@ -47,7 +47,7 @@ window.initVM = render => {

vm.attachStorage(storage);
vm.attachRenderer(render);
vm.attachV2SVGAdapter(new ScratchSVGRenderer.SVGRenderer());
vm.attachV2SVGAdapter(ScratchSVGRenderer.V2SVGAdapter);
vm.attachV2BitmapAdapter(new ScratchSVGRenderer.BitmapAdapter());

return vm;
Expand Down

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