Use premultiplied alpha pixel format in Symbian

Gives better performance in the raster paint engine.
For Symbian 9.3 onwards, this can also be used as the native pixmap
format. For 9.2, conversion is required.

Reviewed-by: Sami Merila
Reviewed-by: Jani Hautakangas

4 files changed, 28 insertions, 15 deletions

diff --git a/src/gui/image/qpixmap_s60.cpp b/src/gui/image/qpixmap_s60.cpp
index 9ae8d72..666d608 100644
--- a/src/gui/image/qpixmap_s60.cpp
+++ b/src/gui/image/qpixmap_s60.cpp
@@ -496,11 +496,12 @@ void QS60PixmapData::fromImage(const QImage &img, Qt::ImageConversionFlags flags
         mode = EColor16MU;
         break;
     case QImage::Format_ARGB32_Premultiplied:
-#if !defined(__SERIES60_31__) && !defined(__S60_32__)
-        mode = EColor16MAP;
-        break;
-#endif
-        destFormat = QImage::Format_ARGB32;
+        if (S60->supportsPremultipliedAlpha) {
+            mode = Q_SYMBIAN_ECOLOR16MAP;
+            break;
+        } else {
+            destFormat = QImage::Format_ARGB32;
+        }
         // Fall through intended
     case QImage::Format_ARGB32:
         mode = EColor16MA;
@@ -690,6 +691,10 @@ void QS60PixmapData::beginDataAccess()
     bytes = newBytes;
     TDisplayMode mode = cfbsBitmap->DisplayMode();
     QImage::Format format = qt_TDisplayMode2Format(mode);
+    //on S60 3.1, premultiplied alpha pixels are stored in a bitmap with 16MA type
+    if (format == QImage::Format_ARGB32)
+        format = QImage::Format_ARGB32_Premultiplied; // pixel data is actually in premultiplied format
+
     TSize size = cfbsBitmap->SizeInPixels();
 
     QVector<QRgb> savedColorTable;
@@ -794,8 +799,8 @@ void* QS60PixmapData::toNativeType(NativeType type)
         bool needsCopy = false;
 
         QSysInfo::SymbianVersion symbianVersion = QSysInfo::symbianVersion();
-        if (symbianVersion == QSysInfo::SV_9_2 || symbianVersion == QSysInfo::SV_9_3) {
-            // Convert argb32_premultiplied to argb32 since Symbian 9.2 and Symbian 9.3 do
+        if (!(S60->supportsPremultipliedAlpha)) {
+            // Convert argb32_premultiplied to argb32 since Symbian 9.2 does
             // not support premultipied format.
 
             if (image.format() == QImage::Format_ARGB32_Premultiplied) {
diff --git a/src/gui/kernel/qapplication_s60.cpp b/src/gui/kernel/qapplication_s60.cpp
index cb9dda4..656bbc9 100644
--- a/src/gui/kernel/qapplication_s60.cpp
+++ b/src/gui/kernel/qapplication_s60.cpp
@@ -1056,6 +1056,13 @@ void qt_init(QApplicationPrivate * /* priv */, int)
     TDisplayMode mode = S60->screenDevice()->DisplayMode();
     S60->screenDepth = TDisplayModeUtils::NumDisplayModeBitsPerPixel(mode);
 
+    //NB: RWsSession::GetColorModeList tells you what window modes are supported,
+    //not what bitmap formats.
+    if(QSysInfo::symbianVersion() == QSysInfo::SV_9_2)
+        S60->supportsPremultipliedAlpha = 0;
+    else
+        S60->supportsPremultipliedAlpha = 1;
+
     RProcess me;
     TSecureId securId = me.SecureId();
     S60->uid = securId.operator TUid();
diff --git a/src/gui/kernel/qt_s60_p.h b/src/gui/kernel/qt_s60_p.h
index d33791b..e25bc81 100644
--- a/src/gui/kernel/qt_s60_p.h
+++ b/src/gui/kernel/qt_s60_p.h
@@ -81,6 +81,9 @@ QT_BEGIN_NAMESPACE
 // system events seems to start with 0x10
 const TInt KInternalStatusPaneChange = 0x50000000;
 
+//this macro exists because EColor16MAP enum value doesn't exist in Symbian OS 9.2
+#define Q_SYMBIAN_ECOLOR16MAP TDisplayMode(13)
+
 class QS60Data
 {
 public:
@@ -108,6 +111,7 @@ public:
     int mouseInteractionEnabled : 1;
     int virtualMouseRequired : 1;
     int qtOwnsS60Environment : 1;
+    int supportsPremultipliedAlpha : 1;
     QApplication::QS60MainApplicationFactory s60ApplicationFactory; // typedef'ed pointer type
     static inline void updateScreenSize();
 	static inline RWsSession& wsSession();
@@ -199,7 +203,7 @@ inline void QS60Data::updateScreenSize()
     S60->screenHeightInPixels = params.iPixelSize.iHeight;
     S60->screenWidthInTwips = params.iTwipsSize.iWidth;
     S60->screenHeightInTwips = params.iTwipsSize.iHeight;
-    
+
     S60->virtualMouseMaxAccel = qMax(S60->screenHeightInPixels, S60->screenWidthInPixels) / 20;
 
     TReal inches = S60->screenHeightInTwips / (TReal)KTwipsPerInch;
@@ -302,11 +306,9 @@ static inline QImage::Format qt_TDisplayMode2Format(TDisplayMode mode)
     case EColor16MA:
         format = QImage::Format_ARGB32;
         break;
-#if !defined(__SERIES60_31__) && !defined(__S60_32__)
-    case EColor16MAP:
+    case Q_SYMBIAN_ECOLOR16MAP:
         format = QImage::Format_ARGB32_Premultiplied;
         break;
-#endif
     default:
         format = QImage::Format_Invalid;
         break;
diff --git a/src/gui/styles/qs60style_s60.cpp b/src/gui/styles/qs60style_s60.cpp
index cde48d8..d760016 100644
--- a/src/gui/styles/qs60style_s60.cpp
+++ b/src/gui/styles/qs60style_s60.cpp
@@ -747,9 +747,8 @@ QPixmap QS60StyleModeSpecifics::createSkinnedGraphicsLX(QS60StylePrivate::SkinFr
     QPixmap result;
 
 //        QS60WindowSurface::unlockBitmapHeap();
-    static const bool canDoEColor16MAP = !(QSysInfo::s60Version() == QSysInfo::SV_S60_3_1 || QSysInfo::s60Version() == QSysInfo::SV_S60_3_2);
-    static const TDisplayMode displayMode = canDoEColor16MAP ? TDisplayMode(13) : EColor16MA; // 13 = EColor16MAP
-    static const TInt drawParam = canDoEColor16MAP ? KAknsDrawParamDefault : KAknsDrawParamNoClearUnderImage|KAknsDrawParamRGBOnly;
+    static const TDisplayMode displayMode = S60->supportsPremultipliedAlpha ? Q_SYMBIAN_ECOLOR16MAP : EColor16MA;
+    static const TInt drawParam = S60->supportsPremultipliedAlpha ? KAknsDrawParamDefault : KAknsDrawParamNoClearUnderImage|KAknsDrawParamRGBOnly;
 
     CFbsBitmap *frame = new (ELeave) CFbsBitmap(); //offscreen
     CleanupStack::PushL(frame);
@@ -776,7 +775,7 @@ QPixmap QS60StyleModeSpecifics::createSkinnedGraphicsLX(QS60StylePrivate::SkinFr
                            frameSkinID, centerSkinID,
                            drawParam );
 
-    if (canDoEColor16MAP) {
+    if (S60->supportsPremultipliedAlpha) {
         if (drawn)
             result = fromFbsBitmap(frame, NULL, flags, QImage::Format_ARGB32_Premultiplied);
     } else {