diff options
author | Eirik Aavitsland <eirik.aavitsland@qt.io> | 2021-07-30 13:03:49 +0200 |
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committer | Eirik Aavitsland <eirik.aavitsland@qt.io> | 2021-08-10 12:00:13 +0200 |
commit | 84aba80944a2e1c3058d7a1372e0e66676411884 (patch) | |
tree | 3f4b0815cf3a7f9df07678142ec242bd9a68b0c3 | |
parent | aa25e8d87e1392459fc5de511798356cb5b5f7cb (diff) |
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>
-rw-r--r-- | src/gui/painting/qpaintengineex.cpp | 8 | ||||
-rw-r--r-- | tests/auto/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 22e9a621c3..d85c2a951c 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 QList<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 1679d5b8df..f0cc06a2e4 100644 --- a/tests/auto/gui/painting/qpainter/tst_qpainter.cpp +++ b/tests/auto/gui/painting/qpainter/tst_qpainter.cpp @@ -300,6 +300,7 @@ private slots: void fillPolygon(); void drawImageAtPointF(); + void scaledDashes(); private: void fillData(); @@ -5362,6 +5363,36 @@ 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" |