Make Noto Color Emoji font work on Linux

Noto Color Emoji is a bitmap color font, Cairo knows how to scale such
fonts and FontConfig will identify them as scalable but not outline
fonts, so change the FontConfig checks to checks for scalability.

Make sft.cxx:doOpenTTFont() accept non-outline fonts, the text will not
show in PDF but that is not worse than the status quo.

Change-Id: I756c718296d2c43e3165cd2f07b11bbb981318d3
Reviewed-on: https://gerrit.libreoffice.org/78218
Tested-by: Jenkins
Reviewed-by: Khaled Hosny <khaledhosny@eglug.org>

4 files changed, 34 insertions, 32 deletions

diff --git a/vcl/source/font/fontmetric.cxx b/vcl/source/font/fontmetric.cxx
index 72a5a77cc6fe..4da3575d7597 100644
--- a/vcl/source/font/fontmetric.cxx
+++ b/vcl/source/font/fontmetric.cxx
@@ -381,8 +381,8 @@ void ImplFontMetricData::ImplCalcLineSpacing(LogicalFontInstance *pFontInstance)
     if (mnAscent || mnDescent)
         mnIntLeading = mnAscent + mnDescent - mnHeight;
 
-    SAL_INFO("vcl.gdi.fontmetric",
-                  "fsSelection: "   << rInfo.fsSelection
+    SAL_INFO("vcl.gdi.fontmetric", GetFamilyName()
+             << ": fsSelection: "   << rInfo.fsSelection
              << ", typoAscender: "  << rInfo.typoAscender
              << ", typoDescender: " << rInfo.typoDescender
              << ", typoLineGap: "   << rInfo.typoLineGap
diff --git a/vcl/source/fontsubset/sft.cxx b/vcl/source/fontsubset/sft.cxx
index 47e4f7a8d7f4..52b2e0360b50 100644
--- a/vcl/source/fontsubset/sft.cxx
+++ b/vcl/source/fontsubset/sft.cxx
@@ -1669,7 +1669,10 @@ static SFErrCodes doOpenTTFont( sal_uInt32 facenum, TrueTypeFont* t )
         /* TODO: implement to get subsetting */
         assert(t->goffsets != nullptr);
     } else {
-        return SFErrCodes::TtFormat;
+        // Bitmap font, accept for now.
+        t->goffsets = static_cast<sal_uInt32 *>(calloc(1+t->nglyphs, sizeof(sal_uInt32)));
+        /* TODO: implement to get subsetting */
+        assert(t->goffsets != nullptr);
     }
 
     table = getTable(t, O_hhea);
diff --git a/vcl/unx/generic/fontmanager/fontconfig.cxx b/vcl/unx/generic/fontmanager/fontconfig.cxx
index 3f0a2aa4418b..9fd6b380b73a 100644
--- a/vcl/unx/generic/fontmanager/fontconfig.cxx
+++ b/vcl/unx/generic/fontmanager/fontconfig.cxx
@@ -67,7 +67,7 @@ namespace
 
 class FontCfgWrapper
 {
-    FcFontSet* m_pOutlineSet;
+    FcFontSet* m_pFontSet;
 
     void addFontSet( FcSetName );
 
@@ -95,17 +95,14 @@ private:
 };
 
 FontCfgWrapper::FontCfgWrapper()
-    : m_pOutlineSet( nullptr )
+    : m_pFontSet( nullptr )
 {
     FcInit();
 }
 
 void FontCfgWrapper::addFontSet( FcSetName eSetName )
 {
-    /*
-      add only acceptable outlined fonts to our config,
-      for future fontconfig use
-    */
+    // Add only acceptable fonts to our config, for future fontconfig use.
     FcFontSet* pOrig = FcConfigGetFonts( FcConfigGetCurrent(), eSetName );
     if( !pOrig )
         return;
@@ -114,10 +111,12 @@ void FontCfgWrapper::addFontSet( FcSetName eSetName )
     for( int i = 0; i < pOrig->nfont; ++i )
     {
         FcPattern* pPattern = pOrig->fonts[i];
-        // #i115131# ignore non-outline fonts
-        FcBool bOutline = FcFalse;
-        FcResult eOutRes = FcPatternGetBool( pPattern, FC_OUTLINE, 0, &bOutline );
-        if( (eOutRes != FcResultMatch) || (bOutline == FcFalse) )
+        // #i115131# ignore non-scalable fonts
+        // Scalable fonts are usually outline fonts, but some bitmaps fonts
+        // (like Noto Color Emoji) are also scalable.
+        FcBool bScalable = FcFalse;
+        FcResult eScalableRes = FcPatternGetBool(pPattern, FC_SCALABLE, 0, &bScalable);
+        if ((eScalableRes != FcResultMatch) || (bScalable == FcFalse))
             continue;
 
         // Ignore Type 1 fonts, too.
@@ -127,7 +126,7 @@ void FontCfgWrapper::addFontSet( FcSetName eSetName )
             continue;
 
         FcPatternReference( pPattern );
-        FcFontSetAdd( m_pOutlineSet, pPattern );
+        FcFontSetAdd( m_pFontSet, pPattern );
     }
 
     // TODO?: FcFontSetDestroy( pOrig );
@@ -218,16 +217,16 @@ namespace
 
 FcFontSet* FontCfgWrapper::getFontSet()
 {
-    if( !m_pOutlineSet )
+    if( !m_pFontSet )
     {
-        m_pOutlineSet = FcFontSetCreate();
+        m_pFontSet = FcFontSetCreate();
         addFontSet( FcSetSystem );
         addFontSet( FcSetApplication );
 
-        ::std::sort(m_pOutlineSet->fonts,m_pOutlineSet->fonts+m_pOutlineSet->nfont,SortFont());
+        ::std::sort(m_pFontSet->fonts,m_pFontSet->fonts+m_pFontSet->nfont,SortFont());
     }
 
-    return m_pOutlineSet;
+    return m_pFontSet;
 }
 
 FontCfgWrapper::~FontCfgWrapper()
@@ -372,10 +371,10 @@ void FontCfgWrapper::clear()
 {
     m_aFontNameToLocalized.clear();
     m_aLocalizedToCanonical.clear();
-    if( m_pOutlineSet )
+    if( m_pFontSet )
     {
-        FcFontSetDestroy( m_pOutlineSet );
-        m_pOutlineSet = nullptr;
+        FcFontSetDestroy( m_pFontSet );
+        m_pFontSet = nullptr;
     }
     m_pLanguageTag.reset();
 }
@@ -506,7 +505,7 @@ void PrintFontManager::countFontconfigFonts( std::unordered_map<OString, int>& o
             int width = 0;
             int spacing = 0;
             int nEntryId = -1;
-            FcBool outline = false;
+            FcBool scalable = false;
 
             FcResult eFileRes         = FcPatternGetString(pFSet->fonts[i], FC_FILE, 0, &file);
             FcResult eFamilyRes       = rWrapper.LocalizedElementFromPattern( pFSet->fonts[i], &family, FC_FAMILY, FC_FAMILYLANG );
@@ -517,11 +516,11 @@ void PrintFontManager::countFontconfigFonts( std::unordered_map<OString, int>& o
             FcResult eWeightRes       = FcPatternGetInteger(pFSet->fonts[i], FC_WEIGHT, 0, &weight);
             FcResult eWidthRes        = FcPatternGetInteger(pFSet->fonts[i], FC_WIDTH, 0, &width);
             FcResult eSpacRes         = FcPatternGetInteger(pFSet->fonts[i], FC_SPACING, 0, &spacing);
-            FcResult eOutRes          = FcPatternGetBool(pFSet->fonts[i], FC_OUTLINE, 0, &outline);
+            FcResult eScalableRes     = FcPatternGetBool(pFSet->fonts[i], FC_SCALABLE, 0, &scalable);
             FcResult eIndexRes        = FcPatternGetInteger(pFSet->fonts[i], FC_INDEX, 0, &nEntryId);
             FcResult eFormatRes       = FcPatternGetString(pFSet->fonts[i], FC_FONTFORMAT, 0, &format);
 
-            if( eFileRes != FcResultMatch || eFamilyRes != FcResultMatch || eOutRes != FcResultMatch )
+            if( eFileRes != FcResultMatch || eFamilyRes != FcResultMatch || eScalableRes != FcResultMatch )
                 continue;
 
             SAL_INFO(
@@ -531,15 +530,15 @@ void PrintFontManager::countFontconfigFonts( std::unordered_map<OString, int>& o
                 << (eSpacRes == FcResultMatch ? slant : -1) << ", style = \""
                 << (eStyleRes == FcResultMatch ? reinterpret_cast<const char*>(style) : "<nil>")
                 << "\",  width = " << (eWeightRes == FcResultMatch ? width : -1) << ", spacing = "
-                << (eSpacRes == FcResultMatch ? spacing : -1) << ", outline = "
-                << (eOutRes == FcResultMatch ? outline : -1) << ", format "
+                << (eSpacRes == FcResultMatch ? spacing : -1) << ", scalable = "
+                << (eScalableRes == FcResultMatch ? scalable : -1) << ", format "
                 << (eFormatRes == FcResultMatch
                     ? reinterpret_cast<const char*>(format) : "<unknown>"));
 
-//            OSL_ASSERT(eOutRes != FcResultMatch || outline);
+//            OSL_ASSERT(eScalableRes != FcResultMatch || scalable);
 
-            // only outline fonts are usable to psprint anyway
-            if( eOutRes == FcResultMatch && ! outline )
+            // only scalable fonts are usable to psprint anyway
+            if( eScalableRes == FcResultMatch && ! scalable )
                 continue;
 
             if (isPreviouslyDuplicateOrObsoleted(pFSet, i))
diff --git a/vcl/unx/generic/glyphs/freetype_glyphcache.cxx b/vcl/unx/generic/glyphs/freetype_glyphcache.cxx
index 9c0773e6a340..1b3532ceee1b 100644
--- a/vcl/unx/generic/glyphs/freetype_glyphcache.cxx
+++ b/vcl/unx/generic/glyphs/freetype_glyphcache.cxx
@@ -436,9 +436,9 @@ FreetypeFont::FreetypeFont(LogicalFontInstance* pFontInstance, FreetypeFontInfo*
 
     FT_New_Size( maFaceFT, &maSizeFT );
     FT_Activate_Size( maSizeFT );
-    FT_Error rc = FT_Set_Pixel_Sizes( maFaceFT, mnWidth, rFSD.mnHeight );
-    if( rc != FT_Err_Ok )
-        return;
+    /* This might fail for color bitmap fonts, but that is fine since we will
+     * not need any glyph data from FreeType in this case */
+    /*FT_Error rc = */ FT_Set_Pixel_Sizes( maFaceFT, mnWidth, rFSD.mnHeight );
 
     FT_Select_Charmap(maFaceFT, FT_ENCODING_UNICODE);