mirror of
https://github.com/2234839/web-font.git
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a0c2b4aafc
- webfont-sdk: 新增 Node 模式（node-registry），GlobalFonts 注册 + 每 chunk 唯一 family + 逗号链回退 - leafer-x-webfont: fontFamily 链写回（Node 端），scan 链归一化防套娃、rewriteFamily 跳过链形态防抹回 - 修复 pnpm 双实例 bug: @napi-rs/canvas 版本对齐 1.0.6（根与 SDK 同版本共享 .pnpm 条目） - 基准测试重构: 用例表抽取为 基准测试用例.ts 共享，SSIM 计算收敛到 scripts/ssim.ts - 新增 基准测试_leafer.test.ts: @leafer-ui/node + Skia 渲染验证（无浏览器），ttf 输出用例 SSIM=1.0000；woff2 用例仅计时（Skia 不吃 woff2，容器验证由 puppeteer 版守护） - Node 端集成测试 scripts/test-leafer-node.mts（插件链路 SSIM=1.0000）
93 lines
3.3 KiB
TypeScript
93 lines
3.3 KiB
TypeScript
/**
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* SSIM（结构相似性）计算 —— Wang 2004 实现
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*
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* 基准测试（浏览器渲染 vs 裁剪字体渲染）与 leafer Node 端生图验证共用。
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* 使用 11x11 均匀滑动窗口 + 积分图加速，返回 0~1。
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*
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* 约定：输入为 RGBA 像素数据，width/height 必须与数据长度匹配
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*（width * height * 4 === data.length），否则返回 0。
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*/
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export function calculateSSIM(a: Uint8Array, b: Uint8Array, width: number, height: number): number {
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if (a.length !== b.length) return 0;
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if (width * height * 4 !== a.length) return 0;
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if (width === 0 || height === 0) return 0;
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/** 转灰度并提取到独立数组 */
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const N = width * height;
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const grayA = new Float64Array(N);
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const grayB = new Float64Array(N);
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for (let i = 0; i < N; i++) {
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const idx = i * 4;
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grayA[i] = 0.299 * a[idx]! + 0.587 * a[idx + 1]! + 0.114 * a[idx + 2]!;
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grayB[i] = 0.299 * b[idx]! + 0.587 * b[idx + 1]! + 0.114 * b[idx + 2]!;
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}
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/** 构建积分图: S(x,y) = sum of gray[0..x-1, 0..y-1] */
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const w1 = width + 1;
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const intA = new Float64Array(w1 * (height + 1));
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const intA2 = new Float64Array(w1 * (height + 1));
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const intB = new Float64Array(w1 * (height + 1));
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const intB2 = new Float64Array(w1 * (height + 1));
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const intAB = new Float64Array(w1 * (height + 1));
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for (let y = 0; y < height; y++) {
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const rowOff = y * width;
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const irowOff = (y + 1) * w1;
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for (let x = 0; x < width; x++) {
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const va = grayA[rowOff + x]!;
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const vb = grayB[rowOff + x]!;
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const ip = irowOff + x + 1;
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intA[ip] = va + intA[ip - 1]! + intA[ip - w1]! - intA[ip - w1 - 1]!;
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intA2[ip] = va * va + intA2[ip - 1]! + intA2[ip - w1]! - intA2[ip - w1 - 1]!;
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intB[ip] = vb + intB[ip - 1]! + intB[ip - w1]! - intB[ip - w1 - 1]!;
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intB2[ip] = vb * vb + intB2[ip - 1]! + intB2[ip - w1]! - intB2[ip - w1 - 1]!;
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intAB[ip] = va * vb + intAB[ip - 1]! + intAB[ip - w1]! - intAB[ip - w1 - 1]!;
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}
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}
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/**
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* 从积分图计算矩形区域 [x1, x2) x [y1, y2) 的和
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* 矩形包含 (x2-x1) * (y2-y1) 个像素
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*/
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const rectSum = (img: Float64Array, x1: number, y1: number, x2: number, y2: number) =>
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img[y2 * w1 + x2]! - img[y1 * w1 + x2]! - img[y2 * w1 + x1]! + img[y1 * w1 + x1]!;
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/** 11x11 窗口, 半径=5 */
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const R = 5;
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/** (0.01 * 255)^2 */
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const C1 = 6.5025;
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/** (0.03 * 255)^2 */
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const C2 = 58.5225;
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let ssimSum = 0;
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let windowCount = 0;
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for (let y = R; y < height - R; y++) {
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for (let x = R; x < width - R; x++) {
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const x1 = x - R, x2 = x + R + 1;
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const y1 = y - R, y2 = y + R + 1;
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const n = (2 * R + 1) * (2 * R + 1);
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const sA = rectSum(intA, x1, y1, x2, y2);
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const sA2 = rectSum(intA2, x1, y1, x2, y2);
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const sB = rectSum(intB, x1, y1, x2, y2);
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const sB2 = rectSum(intB2, x1, y1, x2, y2);
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const sAB = rectSum(intAB, x1, y1, x2, y2);
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const muA = sA / n;
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const muB = sB / n;
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const sigmaA2 = sA2 / n - muA * muA;
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const sigmaB2 = sB2 / n - muB * muB;
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const sigmaAB = sAB / n - muA * muB;
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const num = (2 * muA * muB + C1) * (2 * sigmaAB + C2);
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const den = (muA * muA + muB * muB + C1) * (sigmaA2 + sigmaB2 + C2);
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ssimSum += num / den;
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windowCount++;
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}
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}
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return windowCount > 0 ? ssimSum / windowCount : 0;
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}
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