diff options
| author | Eirik Aavitsland <eirik.aavitsland@qt.io> | 2024-02-20 08:07:38 +0100 |
|---|---|---|
| committer | Eirik Aavitsland <eirik.aavitsland@qt.io> | 2024-02-20 16:27:20 +0100 |
| commit | a43d86fe1c0bc9d352f67c134a9ee5f754aea5e6 (patch) | |
| tree | a66ebd2dde0bc7bd7f15d65aab9f2a017e65d58d /src | |
| parent | 9362e4f3fa7c42b9d76fd5b4dd504e749b3bcaab (diff) | |
QPainter: fix assert when drawing bitmaps at very near to .5 coord
The code assumed that the rounding of a floating point value, and the
rounding of the sum of that value and an integer, would always snap in
the same direction. But because of accuracy limits (independently
of the rounding function employed), that is not always the case for
fractions very near to .5.
Fixes: QTBUG-122451
Pick-to: 6.7 6.6 6.5 6.2 5.15
Change-Id: I0825d42e6be7f6e3397760a5e9be5dddca42dcdc
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Diffstat (limited to 'src')
| -rw-r--r-- | src/gui/painting/qpaintengine_raster.cpp | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/src/gui/painting/qpaintengine_raster.cpp b/src/gui/painting/qpaintengine_raster.cpp index 0ff52a87303..582ad500f8d 100644 --- a/src/gui/painting/qpaintengine_raster.cpp +++ b/src/gui/painting/qpaintengine_raster.cpp @@ -3397,16 +3397,18 @@ void QRasterPaintEngine::drawBitmap(const QPointF &pos, const QImage &image, QSp // Boundaries int w = image.width(); int h = image.height(); - int ymax = qMin(qRound(pos.y() + h), d->rasterBuffer->height()); - int ymin = qMax(qRound(pos.y()), 0); - int xmax = qMin(qRound(pos.x() + w), d->rasterBuffer->width()); - int xmin = qMax(qRound(pos.x()), 0); + int px = qRound(pos.x()); + int py = qRound(pos.y()); + int ymax = qMin(py + h, d->rasterBuffer->height()); + int ymin = qMax(py, 0); + int xmax = qMin(px + w, d->rasterBuffer->width()); + int xmin = qMax(px, 0); - int x_offset = xmin - qRound(pos.x()); + int x_offset = xmin - px; QImage::Format format = image.format(); for (int y = ymin; y < ymax; ++y) { - const uchar *src = image.scanLine(y - qRound(pos.y())); + const uchar *src = image.scanLine(y - py); if (format == QImage::Format_MonoLSB) { for (int x = 0; x < xmax - xmin; ++x) { int src_x = x + x_offset; |