feat: 实现 Chromium PDF 导出与精确预览

2026-07-26 13:21:17 +08:00
parent d62552384f
commit d1b5880a5b
26 changed files with 3328 additions and 316 deletions
@@ -0,0 +1,29 @@
+export const PDF_POINTS_PER_INCH = 72;
+export const CSS_PIXELS_PER_INCH = 96;
+export const PDF_PAGE_CSS_SCALE =
+  CSS_PIXELS_PER_INCH / PDF_POINTS_PER_INCH;
+
+export function getPdfPageCssDimensions(
+  widthPoints: number,
+  heightPoints: number
+) {
+  return {
+    width: widthPoints * PDF_PAGE_CSS_SCALE,
+    height: heightPoints * PDF_PAGE_CSS_SCALE
+  };
+}
+
+export function getPdfCanvasRenderScale(
+  widthPoints: number,
+  displayWidthCssPixels: number,
+  devicePixelRatio: number
+) {
+  if (
+    widthPoints <= 0 ||
+    displayWidthCssPixels <= 0 ||
+    devicePixelRatio <= 0
+  ) {
+    return 0;
+  }
+  return (displayWidthCssPixels / widthPoints) * devicePixelRatio;
+}