From 081d835c040a90f8ee76807354355062ac521dfb Mon Sep 17 00:00:00 2001
From: Eirik Aavitsland <eirik.aavitsland@qt.io>
Date: Tue, 13 Apr 2021 14:23:45 +0200
Subject: [PATCH] Avoid processing-intensive painting of high number of tiny
dashes
When stroking a dashed path, an unnecessary amount of processing would
be spent if there is a huge number of dashes visible, e.g. because of
scaling. Since the dashes are too small to be indivdually visible
anyway, just replace with a semi-transparent solid line for such
cases.
Pick-to: 6.1 6.0 5.15
Change-Id: I9e9f7861257ad5bce46a0cf113d1a9d7824911e6
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
(cherry picked from commit f4d791b330d02777fcaf02938732892eb3167e9b)
* asturmlechner 2021-08-21:
Conflict from preceding 94dd2ceb in dev branch:
src/gui/painting/qpaintengineex.cpp
Resolved via:
if (pen.style() > Qt::SolidLine) {
QRectF cpRect = path.controlPointRect();
const QTransform &xf = state()->matrix;
- if (pen.isCosmetic()) {
+ if (qt_pen_is_cosmetic(pen, state()->renderHints)){
clipRect = d->exDeviceRect;
cpRect.translate(xf.dx(), xf.dy());
} else {
FTBFS from preceding 471e4fcb in dev branch changing QVector to QList:
Resolved via:
QRectF extentRect = cpRect.adjusted(-pw, -pw, pw, pw) & clipRect;
qreal extent = qMax(extentRect.width(), extentRect.height());
qreal patternLength = 0;
- const QList<qreal> pattern = pen.dashPattern();
+ const QVector<qreal> pattern = pen.dashPattern();
const int patternSize = qMin(pattern.size(), 32);
for (int i = 0; i < patternSize; i++)
patternLength += qMax(pattern.at(i), qreal(0));
---
src/gui/painting/qpaintengineex.cpp | 44 +++++++++++++++----
.../other/lancelot/scripts/tinydashes.qps | 34 ++++++++++++++
2 files changed, 69 insertions(+), 9 deletions(-)
create mode 100644 tests/auto/other/lancelot/scripts/tinydashes.qps
diff --git a/src/gui/painting/qpaintengineex.cpp b/src/gui/painting/qpaintengineex.cpp
index 5d8f89eadd..55fdb0c2a0 100644
--- a/src/gui/painting/qpaintengineex.cpp
+++ b/src/gui/painting/qpaintengineex.cpp
@@ -385,7 +385,7 @@ QPainterState *QPaintEngineEx::createState(QPainterState *orig) const
Q_GUI_EXPORT extern bool qt_scaleForTransform(const QTransform &transform, qreal *scale); // qtransform.cpp
-void QPaintEngineEx::stroke(const QVectorPath &path, const QPen &pen)
+void QPaintEngineEx::stroke(const QVectorPath &path, const QPen &inPen)
{
#ifdef QT_DEBUG_DRAW
qDebug() << "QPaintEngineEx::stroke()" << pen;
@@ -403,6 +403,38 @@ void QPaintEngineEx::stroke(const QVectorPath &path, const QPen &pen)
d->stroker.setCubicToHook(qpaintengineex_cubicTo);
}
+ QRectF clipRect;
+ QPen pen = inPen;
+ if (pen.style() > Qt::SolidLine) {
+ QRectF cpRect = path.controlPointRect();
+ const QTransform &xf = state()->matrix;
+ if (qt_pen_is_cosmetic(pen, state()->renderHints)){
+ clipRect = d->exDeviceRect;
+ cpRect.translate(xf.dx(), xf.dy());
+ } else {
+ clipRect = xf.inverted().mapRect(QRectF(d->exDeviceRect));
+ }
+ // Check to avoid generating unwieldy amount of dashes that will not be visible anyway
+ QRectF extentRect = cpRect & clipRect;
+ qreal extent = qMax(extentRect.width(), extentRect.height());
+ qreal patternLength = 0;
+ const QVector<qreal> pattern = pen.dashPattern();
+ const int patternSize = qMin(pattern.size(), 32);
+ for (int i = 0; i < patternSize; i++)
+ patternLength += qMax(pattern.at(i), qreal(0));
+ if (pen.widthF())
+ patternLength *= pen.widthF();
+ if (qFuzzyIsNull(patternLength)) {
+ pen.setStyle(Qt::NoPen);
+ } else if (extent / patternLength > 10000) {
+ // approximate stream of tiny dashes with semi-transparent solid line
+ pen.setStyle(Qt::SolidLine);
+ QColor color(pen.color());
+ color.setAlpha(color.alpha() / 2);
+ pen.setColor(color);
+ }
+ }
+
if (!qpen_fast_equals(pen, d->strokerPen)) {
d->strokerPen = pen;
d->stroker.setJoinStyle(pen.joinStyle());
@@ -430,14 +462,8 @@ void QPaintEngineEx::stroke(const QVectorPath &path, const QPen &pen)
return;
}
- if (pen.style() > Qt::SolidLine) {
- if (qt_pen_is_cosmetic(pen, state()->renderHints)){
- d->activeStroker->setClipRect(d->exDeviceRect);
- } else {
- QRectF clipRect = state()->matrix.inverted().mapRect(QRectF(d->exDeviceRect));
- d->activeStroker->setClipRect(clipRect);
- }
- }
+ if (!clipRect.isNull())
+ d->activeStroker->setClipRect(clipRect);
if (d->activeStroker == &d->stroker)
d->stroker.setForceOpen(path.hasExplicitOpen());
diff --git a/tests/auto/other/lancelot/scripts/tinydashes.qps b/tests/auto/other/lancelot/scripts/tinydashes.qps
new file mode 100644
index 0000000000..d41ced7f5f
--- /dev/null
+++ b/tests/auto/other/lancelot/scripts/tinydashes.qps
@@ -0,0 +1,34 @@
+# Version: 1
+# CheckVsReference: 5%
+
+path_addEllipse mypath 20.0 20.0 200.0 200.0
+
+save
+setPen blue 20 SolidLine FlatCap
+pen_setCosmetic true
+pen_setDashPattern [ 0.0004 0.0004 ]
+setBrush yellow
+
+drawPath mypath
+translate 300 0
+setRenderHint Antialiasing true
+drawPath mypath
+restore
+
+path_addEllipse bigpath 200000.0 200000.0 2000000.0 2000000.0
+
+setPen blue 20 DotLine FlatCap
+setBrush yellow
+
+save
+translate 0 300
+scale 0.0001 0.00011
+drawPath bigpath
+restore
+
+save
+translate 300 300
+setRenderHint Antialiasing true
+scale 0.0001 0.00011
+drawPath bigpath
+restore
--
GitLab
From 6b400e3147dcfd8cc3a393ace1bd118c93762e0c Mon Sep 17 00:00:00 2001
From: Eirik Aavitsland <eirik.aavitsland@qt.io>
Date: Fri, 23 Jul 2021 15:53:56 +0200
Subject: [PATCH] Improve fix for avoiding huge number of tiny dashes
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Some pathological cases were not caught by the previous fix.
Fixes: QTBUG-95239
Pick-to: 6.2 6.1 5.15
Change-Id: I0337ee3923ff93ccb36c4d7b810a9c0667354cc5
Reviewed-by: Robert Löhning <robert.loehning@qt.io>
---
src/gui/painting/qpaintengineex.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/gui/painting/qpaintengineex.cpp b/src/gui/painting/qpaintengineex.cpp
index 2997d533107..22e9a621c3c 100644
--- a/src/gui/painting/qpaintengineex.cpp
+++ b/src/gui/painting/qpaintengineex.cpp
@@ -426,7 +426,7 @@ void QPaintEngineEx::stroke(const QVectorPath &path, const QPen &inPen)
patternLength *= pen.widthF();
if (qFuzzyIsNull(patternLength)) {
pen.setStyle(Qt::NoPen);
- } else if (extent / patternLength > 10000) {
+ } else if (qFuzzyIsNull(extent) || extent / patternLength > 10000) {
// approximate stream of tiny dashes with semi-transparent solid line
pen.setStyle(Qt::SolidLine);
QColor color(pen.color());
From 427df34efdcb56582a9ae9f7d2d1f39eeff70328 Mon Sep 17 00:00:00 2001
From: Eirik Aavitsland <eirik.aavitsland@qt.io>
Date: Fri, 30 Jul 2021 13:03:49 +0200
Subject: [PATCH] Refix for avoiding huge number of tiny dashes
Previous fix hit too widely so some valid horizontal and vertical
lines were affected; the root problem being that such lines have an
empty control point rect (width or height is 0). Fix by caculating in
the pen width.
Pick-to: 6.2 6.1 5.15
Change-Id: I7a436e873f6d485028f6759d0e2c6456f07eebdc
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
(cherry picked from commit 84aba80944a2e1c3058d7a1372e0e66676411884)
---
src/gui/painting/qpaintengineex.cpp | 8 ++---
.../gui/painting/qpainter/tst_qpainter.cpp | 31 +++++++++++++++++++
2 files changed, 35 insertions(+), 4 deletions(-)
diff --git a/src/gui/painting/qpaintengineex.cpp b/src/gui/painting/qpaintengineex.cpp
index 19e4b23423..9fe510827a 100644
--- a/src/gui/painting/qpaintengineex.cpp
+++ b/src/gui/painting/qpaintengineex.cpp
@@ -415,18 +415,18 @@ void QPaintEngineEx::stroke(const QVectorPath &path, const QPen &inPen)
clipRect = xf.inverted().mapRect(QRectF(d->exDeviceRect));
}
// Check to avoid generating unwieldy amount of dashes that will not be visible anyway
- QRectF extentRect = cpRect & clipRect;
+ qreal pw = pen.widthF() ? pen.widthF() : 1;
+ QRectF extentRect = cpRect.adjusted(-pw, -pw, pw, pw) & clipRect;
qreal extent = qMax(extentRect.width(), extentRect.height());
qreal patternLength = 0;
const QVector<qreal> pattern = pen.dashPattern();
const int patternSize = qMin(pattern.size(), 32);
for (int i = 0; i < patternSize; i++)
patternLength += qMax(pattern.at(i), qreal(0));
- if (pen.widthF())
- patternLength *= pen.widthF();
+ patternLength *= pw;
if (qFuzzyIsNull(patternLength)) {
pen.setStyle(Qt::NoPen);
- } else if (qFuzzyIsNull(extent) || extent / patternLength > 10000) {
+ } else if (extent / patternLength > 10000) {
// approximate stream of tiny dashes with semi-transparent solid line
pen.setStyle(Qt::SolidLine);
QColor color(pen.color());
diff --git a/tests/auto/gui/painting/qpainter/tst_qpainter.cpp b/tests/auto/gui/painting/qpainter/tst_qpainter.cpp
index 42e98ce363..d7c3f95f1d 100644
--- a/tests/auto/gui/painting/qpainter/tst_qpainter.cpp
+++ b/tests/auto/gui/painting/qpainter/tst_qpainter.cpp
@@ -308,6 +308,7 @@ private slots:
void fillPolygon();
void drawImageAtPointF();
+ void scaledDashes();
private:
void fillData();
@@ -5468,6 +5469,36 @@ void tst_QPainter::drawImageAtPointF()
paint.end();
}
+void tst_QPainter::scaledDashes()
+{
+ // Test that we do not hit the limit-huge-number-of-dashes path
+ QRgb fore = qRgb(0, 0, 0xff);
+ QRgb back = qRgb(0xff, 0xff, 0);
+ QImage image(5, 32, QImage::Format_RGB32);
+ image.fill(back);
+ QPainter p(&image);
+ QPen pen(QColor(fore), 3, Qt::DotLine);
+ p.setPen(pen);
+ p.scale(1, 2);
+ p.drawLine(2, 0, 2, 16);
+ p.end();
+
+ bool foreFound = false;
+ bool backFound = false;
+ int i = 0;
+ while (i < 32 && (!foreFound || !backFound)) {
+ QRgb pix = image.pixel(3, i);
+ if (pix == fore)
+ foreFound = true;
+ else if (pix == back)
+ backFound = true;
+ i++;
+ }
+
+ QVERIFY(foreFound);
+ QVERIFY(backFound);
+}
+
QTEST_MAIN(tst_QPainter)
#include "tst_qpainter.moc"
--
GitLab