From 3cae115d6d6e8a1d4d0385e3cde16f59b25acad0 Mon Sep 17 00:00:00 2001 From: Allan Sandfeld Jensen Date: Wed, 27 Apr 2016 11:53:16 +0200 Subject: Correct compositionMode documentation Most composition modes require an alpha-channel to be meaningful, but not all, and there is no requirements of specific formats. Change-Id: I11e930ccc07e9ff5df06dbda6745e4afb79f5e08 Reviewed-by: Leena Miettinen Reviewed-by: Gunnar Sletta --- src/gui/painting/qpainter.cpp | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'src/gui/painting/qpainter.cpp') diff --git a/src/gui/painting/qpainter.cpp b/src/gui/painting/qpainter.cpp index 1acd84754a..51c0f3e22a 100644 --- a/src/gui/painting/qpainter.cpp +++ b/src/gui/painting/qpainter.cpp @@ -2182,11 +2182,10 @@ void QPainter::setBrushOrigin(const QPointF &p) destination pixel in such a way that the alpha component of the source defines the translucency of the pixel. - When the paint device is a QImage, the image format must be set to - \l {QImage::Format}{Format_ARGB32_Premultiplied} or - \l {QImage::Format}{Format_ARGB32} for the composition modes to have - any effect. For performance the premultiplied version is the preferred - format. + Several composition modes require an alpha channel in the source or + target images to have an effect. For optimal performance the + image format \l {QImage::Format}{Format_ARGB32_Premultiplied} is + preferred. When a composition mode is set it applies to all painting operator, pens, brushes, gradients and pixmap/image drawing. -- cgit v1.2.3