Introduce QFontEngine::glyphIndex(uint)

...an optimized drop-in replacement for the code like this:
`stringToCMap(&uc, 1, &g, &numGlyphs, QFontEngine::GlyphIndicesOnly)`
(aka "get the glyph index for exactly one Unicode character").

Change-Id: I22babf49f7cf28892d27533a5ac51ad449779f75
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

12 files changed, 142 insertions, 0 deletions

diff --git a/src/gui/text/qfontengine.cpp b/src/gui/text/qfontengine.cpp
index 6f62d24f1e..61816c83fb 100644
--- a/src/gui/text/qfontengine.cpp
+++ b/src/gui/text/qfontengine.cpp
@@ -1408,6 +1408,12 @@ QFontEngineBox::~QFontEngineBox()
 {
 }
 
+glyph_t QFontEngineBox::glyphIndex(uint ucs4) const
+{
+    Q_UNUSED(ucs4)
+    return 0;
+}
+
 bool QFontEngineBox::stringToCMap(const QChar *str, int len, QGlyphLayout *glyphs, int *nglyphs, QFontEngine::ShaperFlags flags) const
 {
     Q_ASSERT(glyphs->numGlyphs >= *nglyphs);
@@ -1582,6 +1588,35 @@ QFontEngineMulti::~QFontEngineMulti()
     }
 }
 
+glyph_t QFontEngineMulti::glyphIndex(uint ucs4) const
+{
+    glyph_t glyph = engine(0)->glyphIndex(ucs4);
+    if (glyph == 0 && ucs4 != QChar::LineSeparator) {
+        const_cast<QFontEngineMulti *>(this)->ensureFallbackFamiliesQueried();
+        for (int x = 1, n = qMin(engines.size(), 256); x < n; ++x) {
+            QFontEngine *engine = engines.at(x);
+            if (!engine) {
+                if (!shouldLoadFontEngineForCharacter(x, ucs4))
+                    continue;
+                const_cast<QFontEngineMulti *>(this)->loadEngine(x);
+                engine = engines.at(x);
+            }
+            Q_ASSERT(engine != 0);
+            if (engine->type() == Box)
+                continue;
+
+            glyph = engine->glyphIndex(ucs4);
+            if (glyph != 0) {
+                // set the high byte to indicate which engine the glyph came from
+                glyph |= (x << 24);
+                break;
+            }
+        }
+    }
+
+    return glyph;
+}
+
 bool QFontEngineMulti::stringToCMap(const QChar *str, int len,
                                     QGlyphLayout *glyphs, int *nglyphs,
                                     QFontEngine::ShaperFlags flags) const
diff --git a/src/gui/text/qfontengine_ft.cpp b/src/gui/text/qfontengine_ft.cpp
index 140bf16394..b50c8fd95a 100644
--- a/src/gui/text/qfontengine_ft.cpp
+++ b/src/gui/text/qfontengine_ft.cpp
@@ -1525,6 +1525,36 @@ void QFontEngineFT::addGlyphsToPath(glyph_t *glyphs, QFixedPoint *positions, int
     unlockFace();
 }
 
+glyph_t QFontEngineFT::glyphIndex(uint ucs4) const
+{
+    glyph_t glyph = ucs4 < QFreetypeFace::cmapCacheSize ? freetype->cmapCache[ucs4] : 0;
+    if (glyph == 0) {
+        FT_Face face = freetype->face;
+        glyph = FT_Get_Char_Index(face, ucs4);
+        if (glyph == 0) {
+            // Certain fonts don't have no-break space and tab,
+            // while we usually want to render them as space
+            if (ucs4 == QChar::Nbsp || ucs4 == QChar::Tabulation) {
+                glyph = FT_Get_Char_Index(face, QChar::Space);
+            } else if (freetype->symbol_map) {
+                // Symbol fonts can have more than one CMAPs, FreeType should take the
+                // correct one for us by default, so we always try FT_Get_Char_Index
+                // first. If it didn't work (returns 0), we will explicitly set the
+                // CMAP to symbol font one and try again. symbol_map is not always the
+                // correct one because in certain fonts like Wingdings symbol_map only
+                // contains PUA codepoints instead of the common ones.
+                FT_Set_Charmap(face, freetype->symbol_map);
+                glyph = FT_Get_Char_Index(face, ucs4);
+                FT_Set_Charmap(face, freetype->unicode_map);
+            }
+        }
+        if (ucs4 < QFreetypeFace::cmapCacheSize)
+            freetype->cmapCache[ucs4] = glyph;
+    }
+
+    return glyph;
+}
+
 bool QFontEngineFT::stringToCMap(const QChar *str, int len, QGlyphLayout *glyphs, int *nglyphs,
                                  QFontEngine::ShaperFlags flags) const
 {
diff --git a/src/gui/text/qfontengine_ft_p.h b/src/gui/text/qfontengine_ft_p.h
index ad1598ba6d..7fc73c816d 100644
--- a/src/gui/text/qfontengine_ft_p.h
+++ b/src/gui/text/qfontengine_ft_p.h
@@ -225,6 +225,7 @@ private:
     virtual QFixed lineThickness() const;
     virtual QFixed underlinePosition() const;
 
+    virtual glyph_t glyphIndex(uint ucs4) const;
     void doKerning(QGlyphLayout *, ShaperFlags) const;
 
     inline virtual Type type() const
diff --git a/src/gui/text/qfontengine_p.h b/src/gui/text/qfontengine_p.h
index 72f5c092dd..f497085ce2 100644
--- a/src/gui/text/qfontengine_p.h
+++ b/src/gui/text/qfontengine_p.h
@@ -167,6 +167,7 @@ public:
     virtual QFixed emSquareSize() const { return ascent(); }
 
     /* returns 0 as glyph index for non existent glyphs */
+    virtual glyph_t glyphIndex(uint ucs4) const = 0;
     virtual bool stringToCMap(const QChar *str, int len, QGlyphLayout *glyphs, int *nglyphs, ShaperFlags flags) const = 0;
     virtual void recalcAdvances(QGlyphLayout *, ShaperFlags) const {}
     virtual void doKerning(QGlyphLayout *, ShaperFlags) const;
@@ -352,6 +353,7 @@ public:
     QFontEngineBox(int size);
     ~QFontEngineBox();
 
+    virtual glyph_t glyphIndex(uint ucs4) const;
     virtual bool stringToCMap(const QChar *str, int len, QGlyphLayout *glyphs, int *nglyphs, ShaperFlags flags) const;
     virtual void recalcAdvances(QGlyphLayout *, ShaperFlags) const;
 
@@ -388,6 +390,7 @@ public:
     explicit QFontEngineMulti(int engineCount);
     ~QFontEngineMulti();
 
+    virtual glyph_t glyphIndex(uint ucs4) const;
     virtual bool stringToCMap(const QChar *str, int len, QGlyphLayout *glyphs, int *nglyphs, ShaperFlags flags) const;
 
     virtual glyph_metrics_t boundingBox(const QGlyphLayout &glyphs);
diff --git a/src/gui/text/qfontengine_qpa.cpp b/src/gui/text/qfontengine_qpa.cpp
index c12cb37edf..f48b44374e 100644
--- a/src/gui/text/qfontengine_qpa.cpp
+++ b/src/gui/text/qfontengine_qpa.cpp
@@ -340,6 +340,19 @@ bool QFontEngineQPA::getSfntTableData(uint tag, uchar *buffer, uint *length) con
     return false;
 }
 
+glyph_t QFontEngineQPA::glyphIndex(uint ucs4) const
+{
+    const uchar *cmap = externalCMap ? externalCMap : (fontData + cmapOffset);
+
+    glyph_t glyph = getTrueTypeGlyphIndex(cmap, ucs4);
+    if (glyph == 0 && symbol && ucs4 < 0x100)
+        glyph = getTrueTypeGlyphIndex(cmap, ucs4 + 0xf000);
+    if (!findGlyph(glyph))
+        glyph = 0;
+
+    return glyph;
+}
+
 bool QFontEngineQPA::stringToCMap(const QChar *str, int len, QGlyphLayout *glyphs, int *nglyphs, QFontEngine::ShaperFlags flags) const
 {
     Q_ASSERT(glyphs->numGlyphs >= *nglyphs);
diff --git a/src/gui/text/qfontengine_qpa_p.h b/src/gui/text/qfontengine_qpa_p.h
index c8b40abd7f..bcd48ca690 100644
--- a/src/gui/text/qfontengine_qpa_p.h
+++ b/src/gui/text/qfontengine_qpa_p.h
@@ -163,6 +163,7 @@ public:
     FaceId faceId() const { return face_id; }
     bool getSfntTableData(uint tag, uchar *buffer, uint *length) const;
 
+    virtual glyph_t glyphIndex(uint ucs4) const;
     bool stringToCMap(const QChar *str, int len, QGlyphLayout *glyphs, int *nglyphs, ShaperFlags flags) const;
     void recalcAdvances(QGlyphLayout *, ShaperFlags) const;
 
diff --git a/src/platformsupport/fontdatabases/mac/qfontengine_coretext.mm b/src/platformsupport/fontdatabases/mac/qfontengine_coretext.mm
index 4e50d6c53f..2ea7e6f00d 100644
--- a/src/platformsupport/fontdatabases/mac/qfontengine_coretext.mm
+++ b/src/platformsupport/fontdatabases/mac/qfontengine_coretext.mm
@@ -192,6 +192,25 @@ void QCoreTextFontEngine::init()
     setUserData(QVariant::fromValue((void *)cgFont));
 }
 
+glyph_t QCoreTextFontEngine::glyphIndex(uint ucs4) const
+{
+    int len = 0;
+
+    QChar str[2];
+    if (Q_UNLIKELY(QChar::requiresSurrogates(ucs4))) {
+        str[len++] = QChar(QChar::highSurrogate(ucs4));
+        str[len++] = QChar(QChar::lowSurrogate(ucs4));
+    } else {
+        str[len++] = QChar(ucs4);
+    }
+
+    CGGlyph glyphIndices[2];
+
+    CTFontGetGlyphsForCharacters(ctfont, (const UniChar *)str, glyphIndices, len);
+
+    return glyphIndices[0];
+}
+
 bool QCoreTextFontEngine::stringToCMap(const QChar *str, int len, QGlyphLayout *glyphs,
                                        int *nglyphs, QFontEngine::ShaperFlags flags) const
 {
diff --git a/src/platformsupport/fontdatabases/mac/qfontengine_coretext_p.h b/src/platformsupport/fontdatabases/mac/qfontengine_coretext_p.h
index 1cdac820b6..0070aede24 100644
--- a/src/platformsupport/fontdatabases/mac/qfontengine_coretext_p.h
+++ b/src/platformsupport/fontdatabases/mac/qfontengine_coretext_p.h
@@ -62,6 +62,7 @@ public:
     QCoreTextFontEngine(CGFontRef font, const QFontDef &def);
     ~QCoreTextFontEngine();
 
+    virtual glyph_t glyphIndex(uint ucs4) const;
     virtual bool stringToCMap(const QChar *str, int len, QGlyphLayout *glyphs, int *nglyphs, ShaperFlags flags) const;
     virtual void recalcAdvances(QGlyphLayout *, ShaperFlags) const;
 
diff --git a/src/plugins/platforms/windows/qwindowsfontengine.cpp b/src/plugins/platforms/windows/qwindowsfontengine.cpp
index 87eca98e44..a2f65c766d 100644
--- a/src/plugins/platforms/windows/qwindowsfontengine.cpp
+++ b/src/plugins/platforms/windows/qwindowsfontengine.cpp
@@ -340,6 +340,30 @@ QWindowsFontEngine::~QWindowsFontEngine()
     }
 }
 
+glyph_t QWindowsFontEngine::glyphIndex(uint ucs4) const
+{
+    glyph_t glyph;
+
+#if !defined(Q_OS_WINCE)
+    if (symbol) {
+        glyph = getTrueTypeGlyphIndex(cmap, ucs4);
+        if (glyph == 0 && ucs4 < 0x100)
+            glyph = getTrueTypeGlyphIndex(cmap, ucs4 + 0xf000);
+    } else if (ttf) {
+        glyph = getTrueTypeGlyphIndex(cmap, ucs4);
+#else
+    if (tm.tmFirstChar > 60000) {
+        glyph = ucs4;
+#endif
+    } else if (ucs4 >= tm.tmFirstChar && ucs4 <= tm.tmLastChar) {
+        glyph = ucs4;
+    } else {
+        glyph = 0;
+    }
+
+    return glyph;
+}
+
 HGDIOBJ QWindowsFontEngine::selectDesignFont() const
 {
     LOGFONT f = m_logfont;
diff --git a/src/plugins/platforms/windows/qwindowsfontengine.h b/src/plugins/platforms/windows/qwindowsfontengine.h
index e3fb3281a3..390de1d16e 100644
--- a/src/plugins/platforms/windows/qwindowsfontengine.h
+++ b/src/plugins/platforms/windows/qwindowsfontengine.h
@@ -86,6 +86,7 @@ public:
     virtual int synthesized() const;
     virtual QFixed emSquareSize() const;
 
+    virtual glyph_t glyphIndex(uint ucs4) const;
     virtual bool stringToCMap(const QChar *str, int len, QGlyphLayout *glyphs, int *nglyphs, ShaperFlags flags) const;
     virtual void recalcAdvances(QGlyphLayout *glyphs, ShaperFlags) const;
 
diff --git a/src/plugins/platforms/windows/qwindowsfontenginedirectwrite.cpp b/src/plugins/platforms/windows/qwindowsfontenginedirectwrite.cpp
index a4e4dd38d4..cd5defdfea 100644
--- a/src/plugins/platforms/windows/qwindowsfontenginedirectwrite.cpp
+++ b/src/plugins/platforms/windows/qwindowsfontenginedirectwrite.cpp
@@ -301,6 +301,19 @@ QFixed QWindowsFontEngineDirectWrite::emSquareSize() const
         return QFontEngine::emSquareSize();
 }
 
+glyph_t QWindowsFontEngineDirectWrite::glyphIndex(uint ucs4) const
+{
+    UINT16 glyphIndex;
+
+    HRESULT hr = m_directWriteFontFace->GetGlyphIndicesW(&ucs4, 1, &glyphIndex);
+    if (FAILED(hr)) {
+        qErrnoWarning("%s: glyphIndex failed", __FUNCTION__);
+        glyphIndex = 0;
+    }
+
+    return glyphIndex;
+}
+
 // ### Qt 5.1: replace with QStringIterator
 inline unsigned int getChar(const QChar *str, int &i, const int len)
 {
diff --git a/src/plugins/platforms/windows/qwindowsfontenginedirectwrite.h b/src/plugins/platforms/windows/qwindowsfontenginedirectwrite.h
index 399bb5f5ad..aacdcd5a89 100644
--- a/src/plugins/platforms/windows/qwindowsfontenginedirectwrite.h
+++ b/src/plugins/platforms/windows/qwindowsfontenginedirectwrite.h
@@ -74,6 +74,7 @@ public:
     bool getSfntTableData(uint tag, uchar *buffer, uint *length) const;
     QFixed emSquareSize() const;
 
+    virtual glyph_t glyphIndex(uint ucs4) const;
     bool stringToCMap(const QChar *str, int len, QGlyphLayout *glyphs, int *nglyphs, ShaperFlags flags) const;
     void recalcAdvances(QGlyphLayout *glyphs, ShaperFlags) const;