Optimize initialization of QStaticText

Since QStaticText would be created once and used often, not much thought
was put into optimizing its initialization. For simplicity, the code
would do two drawText() passes. Since this was an unnecessary overhead,
the extra pass has been removed and replaced by memmoves instead.
Initialization is now twice as fast.

Reviewed-by: Samuel

1 files changed, 15 insertions, 4 deletions

diff --git a/src/gui/text/qstatictext_p.h b/src/gui/text/qstatictext_p.h
index f017ed1..2ab5579 100644
--- a/src/gui/text/qstatictext_p.h
+++ b/src/gui/text/qstatictext_p.h
@@ -88,9 +88,18 @@ public:
         userData = newUserData;
     }
 
-    QFixedPoint *glyphPositions;                 // 8 bytes per glyph
-    glyph_t *glyphs;                             // 4 bytes per glyph
-    const QChar *chars;                          // 2 bytes per glyph
+    union {
+        QFixedPoint *glyphPositions;             // 8 bytes per glyph
+        int positionOffset;
+    };
+    union {
+        glyph_t *glyphs;                         // 4 bytes per glyph
+        int glyphOffset;
+    };
+    union {
+        QChar *chars;                            // 2 bytes per glyph
+        int charOffset;
+    };
                                                  // =================
                                                  // 14 bytes per glyph
 
@@ -134,14 +143,16 @@ public:
     QTransform matrix;                   // 80 bytes per text
     QStaticTextItem *items;              // 4 bytes per text
     int itemCount;                       // 4 bytes per text
+
     glyph_t *glyphPool;                  // 4 bytes per text
     QFixedPoint *positionPool;           // 4 bytes per text
+    QChar *charPool;                     // 4 bytes per text
 
     unsigned char needsRelayout : 1;
     unsigned char useBackendOptimizations : 1; // 1 byte per text
     unsigned char textFormat              : 2;
                                          // ================
-                                         // 163 bytes per text
+                                         // 167 bytes per text
 
     static QStaticTextPrivate *get(const QStaticText *q);
 };