AuroraMiddleware/qt5base-lts
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Direct2D QPA: Match raster engine line output

Browse Source 
For whatever reason direct2d and the raster engine disagree by one pixel
about the positioning of positively sloping aliased lines. To get the same
output, we shift such lines by one pixel.

Change-Id: I4b20319770c02e3fdd212b3535ccae3c27ca9f2f
Reviewed-by: Risto Avila <risto.avila@digia.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
This commit is contained in:
Louai Al-Khanji 2014-05-23 14:53:03 +03:00 committed by The Qt Project
parent 1b19f66037
commit 8701c20f0d
1 changed files with 27 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
src/plugins/platforms/direct2d/qwindowsdirect2dpaintengine.cpp
View File

@ -1160,6 +1160,25 @@ void QWindowsDirect2DPaintEngine::drawRects(const QRectF *rects, int rectCount)
}
}
static bool isLinePositivelySloped(const QPointF &p1, const QPointF &p2)
{
if (p2.x() > p1.x())
return p2.y() < p1.y();
if (p1.x() > p2.x())
return p1.y() < p2.y();
return false;
}
static void adjustLine(QPointF *p1, QPointF *p2)
{
if (isLinePositivelySloped(*p1, *p2)) {
p1->ry() -= qreal(1.0);
p2->ry() -= qreal(1.0);
}
}
void QWindowsDirect2DPaintEngine::drawLines(const QLine *lines, int lineCount)
{
Q_D(QWindowsDirect2DPaintEngine);
@ -1181,6 +1200,10 @@ void QWindowsDirect2DPaintEngine::drawLines(const QLine *lines, int lineCount)
continue;
}
// Match raster engine output
if (!antiAliasingEnabled())
adjustLine(&p1, &p2);
adjustForAliasing(&p1);
adjustForAliasing(&p2);
@ -1213,6 +1236,10 @@ void QWindowsDirect2DPaintEngine::drawLines(const QLineF *lines, int lineCount)
continue;
}
// Match raster engine output
if (!antiAliasingEnabled())
adjustLine(&p1, &p2);
adjustForAliasing(&p1);
adjustForAliasing(&p2);