Fix compiling issue for FreeType version earlier than 2.1.10

FT_GlyphSlot_Embolden was introduced since FreeType 2.1.10 and we
started using it since 4.7. Some systems (including RHEL/CentOS 4) only
provide earlier versions will get a compiling error if they use
-system-freetype to build Qt. This patch fix it by providing a graceful
degradation when the function is not available.

Task-number: QTBUG-13274
Reviewed-by: Eskil

1 files changed, 9 insertions, 2 deletions

diff --git a/src/gui/text/qfontengine_ft.cpp b/src/gui/text/qfontengine_ft.cpp
index 2c4fbab..60db8b6 100644
--- a/src/gui/text/qfontengine_ft.cpp
+++ b/src/gui/text/qfontengine_ft.cpp
@@ -94,6 +94,13 @@ QT_BEGIN_NAMESPACE
 #define Y_SIZE(face,i) ((face)->available_sizes[i].height << 6)
 #endif
 
+/* FreeType 2.1.10 starts to provide FT_GlyphSlot_Embolden */
+#if (FREETYPE_MAJOR*10000+FREETYPE_MINOR*100+FREETYPE_PATCH) >= 20110
+#define Q_FT_GLYPHSLOT_EMBOLDEN(slot)   FT_GlyphSlot_Embolden(slot)
+#else
+#define Q_FT_GLYPHSLOT_EMBOLDEN(slot)
+#endif
+
 #define FLOOR(x)    ((x) & -64)
 #define CEIL(x)	    (((x)+63) & -64)
 #define TRUNC(x)    ((x) >> 6)
@@ -794,7 +801,7 @@ QFontEngineFT::Glyph *QFontEngineFT::loadGlyphMetrics(QGlyphSet *set, uint glyph
     }
 
     FT_GlyphSlot slot = face->glyph;
-    if (embolden) FT_GlyphSlot_Embolden(slot);
+    if (embolden) Q_FT_GLYPHSLOT_EMBOLDEN(slot);
     int left  = slot->metrics.horiBearingX;
     int right = slot->metrics.horiBearingX + slot->metrics.width;
     int top    = slot->metrics.horiBearingY;
@@ -940,7 +947,7 @@ QFontEngineFT::Glyph *QFontEngineFT::loadGlyph(QGlyphSet *set, uint glyph, Glyph
         return 0;
 
     FT_GlyphSlot slot = face->glyph;
-    if (embolden) FT_GlyphSlot_Embolden(slot);
+    if (embolden) Q_FT_GLYPHSLOT_EMBOLDEN(slot);
     FT_Library library = qt_getFreetype();
 
     info.xOff = TRUNC(ROUND(slot->advance.x));