From 97b0c99e29a60e858f7328094de7e59e5ad02278 Mon Sep 17 00:00:00 2001
From: Andrey Kleshchev <117672381+akleshchev@users.noreply.github.com>
Date: Thu, 9 Jul 2026 21:08:09 +0300
Subject: #5966 Fixed width font's numbers

Dejavu used fixed width numbers by default, tweaked fonts to do the same
for inter (when weight > 0).
---
 indra/llrender/llfontfreetype.cpp | 48 ++++++++++++++++++++++++++++++++++++---
 1 file changed, 45 insertions(+), 3 deletions(-)

(limited to 'indra/llrender/llfontfreetype.cpp')

diff --git a/indra/llrender/llfontfreetype.cpp b/indra/llrender/llfontfreetype.cpp
index 3c5682dfc9..bc4020a06b 100644
--- a/indra/llrender/llfontfreetype.cpp
+++ b/indra/llrender/llfontfreetype.cpp
@@ -109,6 +109,7 @@ LLFontManager::~LLFontManager()
 LLFontGlyphInfo::LLFontGlyphInfo(U32 index, EFontGlyphType glyph_type)
 :   mGlyphIndex(index),
     mGlyphType(glyph_type),
+    mChar(0),
     mWidth(0),          // In pixels
     mHeight(0),         // In pixels
     mXAdvance(0.f),     // In pixels
@@ -126,6 +127,7 @@ LLFontGlyphInfo::LLFontGlyphInfo(U32 index, EFontGlyphType glyph_type)
 LLFontGlyphInfo::LLFontGlyphInfo(const LLFontGlyphInfo& fgi)
     : mGlyphIndex(fgi.mGlyphIndex)
     , mGlyphType(fgi.mGlyphType)
+    , mChar(fgi.mChar)
     , mWidth(fgi.mWidth)
     , mHeight(fgi.mHeight)
     , mXAdvance(fgi.mXAdvance)
@@ -150,7 +152,8 @@ LLFontFreetype::LLFontFreetype()
     mFTFace(nullptr),
     mRenderGlyphCount(0),
     mStyle(0),
-    mPointSize(0)
+    mPointSize(0),
+    mMaxDigitWidth(0.0f)
 {
 }
 
@@ -343,6 +346,10 @@ F32 LLFontFreetype::getXAdvance(llwchar wch) const
     LLFontGlyphInfo* gi = getGlyphInfo(wch, EFontGlyphType::Unspecified);
     if (gi)
     {
+        if (wch >= '0' && wch <= '9' && mMaxDigitWidth > 0.0f)
+        {
+            return mMaxDigitWidth;
+        }
         return gi->mXAdvance;
     }
     else
@@ -363,6 +370,12 @@ F32 LLFontFreetype::getXAdvance(const LLFontGlyphInfo* glyph) const
     if (mFTFace == nullptr)
         return 0.0;
 
+    // Use max digit width for tabular numbers
+    if (mWeight > 0 && glyph->mChar >= '0' && glyph->mChar <= '9' && mMaxDigitWidth > 0.0f)
+    {
+        return mMaxDigitWidth;
+    }
+
     return glyph->mXAdvance;
 }
 
@@ -384,8 +397,27 @@ F32 LLFontFreetype::getXKerning(const LLFontGlyphInfo* left_glyph_info, const LL
     if (mFTFace == nullptr)
         return 0.0;
 
-    U32 left_glyph = left_glyph_info ? left_glyph_info->mGlyphIndex : 0;
-    U32 right_glyph = right_glyph_info ? right_glyph_info->mGlyphIndex : 0;
+    U32 left_glyph = 0;
+    U32 right_glyph = 0;
+
+    if (left_glyph_info)
+    {
+        if (mWeight > 0 && left_glyph_info->mChar >= '0' && left_glyph_info->mChar <= '9')
+        {
+            // Disable kerning for digits when using tabular numbers
+            return 0.0;
+        }
+        left_glyph = left_glyph_info->mGlyphIndex;
+    }
+    if (right_glyph_info)
+    {
+        if (mWeight > 0 && right_glyph_info->mChar >= '0' && right_glyph_info->mChar <= '9')
+        {
+            // Disable kerning for digits when using tabular numbers
+            return 0.0;
+        }
+        right_glyph = right_glyph_info->mGlyphIndex;
+    }
 
     FT_Vector  delta;
 
@@ -548,6 +580,7 @@ LLFontGlyphInfo* LLFontFreetype::addGlyphFromFont(const LLFontFreetype *fontp, l
     mFontBitmapCachep->nextOpenPos(width, pos_x, pos_y, bitmap_glyph_type, bitmap_num);
 
     LLFontGlyphInfo* gi = new LLFontGlyphInfo(glyph_index, requested_glyph_type);
+    gi->mChar = wch;
     gi->mXBitmapOffset = pos_x;
     gi->mYBitmapOffset = pos_y;
     gi->mBitmapEntry = std::make_pair(bitmap_glyph_type, bitmap_num);
@@ -564,6 +597,14 @@ LLFontGlyphInfo* LLFontFreetype::addGlyphFromFont(const LLFontFreetype *fontp, l
     gi->mXAdvance = fontp->mFTFace->glyph->advance.x / 64.f;
     gi->mYAdvance = fontp->mFTFace->glyph->advance.y / 64.f;
 
+    if (mWeight > 0 && wch >= '0' && wch <= '9')
+    {
+        // Digits are supposed to be preloaded, and buffers
+        // refresh when new chars get added, so this lazy load
+        // should not cause any issues.
+        mMaxDigitWidth = llmax(mMaxDigitWidth, gi->mXAdvance);
+    }
+
     insertGlyphInfo(wch, gi);
 
     if (requested_glyph_type != bitmap_glyph_type)
@@ -799,6 +840,7 @@ void LLFontFreetype::resetBitmapCache()
     }
     mCharGlyphInfoMap.clear();
     mFontBitmapCachep->reset();
+    mMaxDigitWidth = 0.0f;
 
     // Adding default glyph is skipped for fallback fonts here as well as in loadFace().
     // This if was added as fix for EXT-4971.
-- 
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