fix: font-size in Firefox

weizhenye · Aug 4, 2024 · c2c0ed5 · c2c0ed5
1 parent aba114a
commit c2c0ed5
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Showing 2 changed files with 6 additions and 4 deletions.
diff --git a/src/global.css b/src/global.css
@@ -124,7 +124,6 @@
   transform-origin: var(--ass-align-h) var(--ass-align-v);
 }
 .ASS-fix-font-size {
-  font-size: 2048px;
   font-family: Arial;
   line-height: normal;
   width: 0;

diff --git a/src/renderer/font-size.js b/src/renderer/font-size.js
@@ -1,14 +1,17 @@
 // https://github.com/weizhenye/ASS/wiki/Font-Size-in-ASS
 
+// It seems max line-height is 1200px in Firefox.
+const isFirefox = navigator.userAgent.toLowerCase().includes('firefox');
+const unitsPerEm = isFirefox ? 512 : 2048;
+const lineSpacing = Object.create(null);
+
 export const $fixFontSize = document.createElement('div');
 $fixFontSize.className = 'ASS-fix-font-size';
+$fixFontSize.style.fontSize = `${unitsPerEm}px`;
 const $span = document.createElement('span');
 $span.textContent = '0';
 $fixFontSize.append($span);
 
-const unitsPerEm = 2048;
-const lineSpacing = Object.create(null);
-
 export function getRealFontSize(fn, fs) {
   if (!lineSpacing[fn]) {
     $span.style.fontFamily = fn;