diff options
| author | Allan Sandfeld Jensen <allan.jensen@qt.io> | 2017-12-12 12:07:38 +0100 |
|---|---|---|
| committer | Allan Sandfeld Jensen <allan.jensen@qt.io> | 2018-03-12 11:16:09 +0000 |
| commit | 5473535344e7abe12c9a02559020b37480d30d21 (patch) | |
| tree | 6a26e15971cd8acea994c7221306426ea2dea897 /src/gui | |
| parent | 951e204b29bf42459e8cfdf42eadec5fa250226b (diff) | |
Fix scaling precision with large zooms
Avoid using the two fast-scaling paths, while they might not overflow
in this case, they do not have enough precision in their fixed point
math to render accurately.
Task-number: QTBUG-53582
Change-Id: I2e063ee90defbecd79a12a6ce02a74c60d1805df
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>
Diffstat (limited to 'src/gui')
| -rw-r--r-- | src/gui/painting/qpaintengine_raster.cpp | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/src/gui/painting/qpaintengine_raster.cpp b/src/gui/painting/qpaintengine_raster.cpp index f7578a3c57..33fde8c61a 100644 --- a/src/gui/painting/qpaintengine_raster.cpp +++ b/src/gui/painting/qpaintengine_raster.cpp @@ -2341,8 +2341,12 @@ void QRasterPaintEngine::drawImage(const QRectF &r, const QImage &img, const QRe if (s->matrix.type() > QTransform::TxTranslate || stretch_sr) { QRectF targetBounds = s->matrix.mapRect(r); - bool exceedsPrecision = targetBounds.width() > 0x7fff - || targetBounds.height() > 0x7fff; + bool exceedsPrecision = r.width() > 0x7fff + || r.height() > 0x7fff + || targetBounds.width() > 0x7fff + || targetBounds.height() > 0x7fff + || s->matrix.m11() >= 512 + || s->matrix.m22() >= 512; if (!exceedsPrecision && d->canUseFastImageBlending(d->rasterBuffer->compositionMode, img)) { if (s->matrix.type() > QTransform::TxScale) { @@ -4639,9 +4643,13 @@ void QSpanData::setupMatrix(const QTransform &matrix, int bilin) bilinear = bilin; const bool affine = inv.isAffine(); + const qreal f1 = m11 * m11 + m21 * m21; + const qreal f2 = m12 * m12 + m22 * m22; fast_matrix = affine - && m11 * m11 + m21 * m21 < 1e4 - && m12 * m12 + m22 * m22 < 1e4 + && f1 < 1e4 + && f2 < 1e4 + && f1 > (1.0 / 65536) + && f2 > (1.0 / 65536) && qAbs(dx) < 1e4 && qAbs(dy) < 1e4; |