From 74f09c794d5fdcb8f4b547b1c55bcd512ef07b95 Mon Sep 17 00:00:00 2001 From: Jason Barron Date: Wed, 22 Sep 2010 15:41:40 +0200 Subject: Avoid OpenVG rendering errors when stroking an aliased path. Stroking a path can sometimes result in inconsistent rendering especially when combined with a clip. For example, if the logical edge of a clip rect coincides with the logical edge of a path then it can happen that the edge is not painted correctly because the stroke lies outside the bounds of the clip rect. To workaround this problem, we add the 'aliasedCoordinateDelta' such that the rounding will err on the side of caution. This improves the correctness when using the raster engine as a reference. Task-number: QTBUG-13165 Reviewed-by: Samuel --- src/openvg/qpaintengine_vg.cpp | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/src/openvg/qpaintengine_vg.cpp b/src/openvg/qpaintengine_vg.cpp index 3c2fd3d..74395a2 100644 --- a/src/openvg/qpaintengine_vg.cpp +++ b/src/openvg/qpaintengine_vg.cpp @@ -248,7 +248,11 @@ public: inline void ensurePathTransform() { if (!pathTransformSet) { - setTransform(VG_MATRIX_PATH_USER_TO_SURFACE, pathTransform); + QTransform aliasedTransform = pathTransform; + if (renderingQuality == VG_RENDERING_QUALITY_NONANTIALIASED && currentPen != Qt::NoPen) + aliasedTransform = aliasedTransform + * QTransform::fromTranslate(aliasedCoordinateDelta, -aliasedCoordinateDelta); + setTransform(VG_MATRIX_PATH_USER_TO_SURFACE, aliasedTransform); pathTransformSet = true; } } @@ -306,6 +310,7 @@ inline void QVGPaintEnginePrivate::setRenderingQuality(VGRenderingQuality mode) if (renderingQuality != mode) { vgSeti(VG_RENDERING_QUALITY, mode); renderingQuality = mode; + pathTransformSet = false; // need to tweak transform for aliased stroking } } -- cgit v0.12