Changeset 769 for trunk/doc/src/howtos/openvg.qdoc

Timestamp:

Aug 2, 2010, 9:27:30 PM (15 years ago)

Author:

Dmitry A. Kuminov

Message:

trunk: Merged in qt 4.6.3 sources from branches/vendor/nokia/qt.

Location:

trunk

Files:

• . (modified) (1 prop)
• doc/src/howtos/openvg.qdoc (modified) (2 diffs)

trunk/doc/src/howtos/openvg.qdoc

@@ -173 +173 @@
 
     The other members of QPainter::CompositionMode are not supported
-    because OpenVG 1.1 does not have an equivalent in its \c VGBlendMode
-    enumeration.  Any attempt to set an unsupported mode will result in
+    unless the \c{VG_KHR_advanced_blending} extension is present,
+    in which case the following additional modes are supported:
+
+    \list
+    \o QPainter::CompositionMode_Overlay
+    \o QPainter::CompositionMode_ColorDodge
+    \o QPainter::CompositionMode_ColorBurn
+    \o QPainter::CompositionMode_HardLight
+    \o QPainter::CompositionMode_SoftLight
+    \o QPainter::CompositionMode_Difference
+    \o QPainter::CompositionMode_Exclusion
+    \o QPainter::CompositionMode_SourceOut
+    \o QPainter::CompositionMode_DestinationOut
+    \o QPainter::CompositionMode_SourceAtop
+    \o QPainter::CompositionMode_DestinationAtop
+    \o QPainter::CompositionMode_Xor
+    \endlist
+
+    Any attempt to set an unsupported mode will result in
     the actual mode being set to QPainter::CompositionMode_SourceOver.
     Client applications should avoid using unsupported modes.
@@ -296 +313 @@
     using OpenVG operations.
 
+    \section2 Scrolling
+
+    By default, accelerated scrolling is not enabled because the impact on
+    performance is very much tied to the hardware platform. To enable
+    accelerated scrolling, you should ensure that QVG_BUFFER_SCROLLING is
+    defined when compiling the QtOpenVG module.
+
+    You should only enable this feature if vgCopyPixels() is known to be
+    efficient on your hardware platform.
+
     \section1 Known issues