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

Fixed inconsistent rounding of square cap pens.

Browse Source 
A horizontal line should round up at the same time as a vertical line
with square cap, when rendering at subpixel coordinates. Thus, the
special casing in the cosmetic stroker of offsetting by half a pixel
should be for flat caps instead of for square caps.

Task-number: QTBUG-26013
Change-Id: Ic09249337f814c7de95a17976ec9e651561a744b
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
This commit is contained in:
Samuel Rødal 2012-09-20 15:30:24 +02:00 committed by The Qt Project
parent 562d6ff90f
commit 72aaba336c
2 changed files with 39 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
src/gui/painting/qcosmeticstroker.cpp
View File

@ -409,7 +409,7 @@ void QCosmeticStroker::calculateLastPoint(qreal rx1, qreal ry1, qreal rx2, qreal
if (clipLine(rx1, ry1, rx2, ry2))
return;
const int half = 32;
const int half = 31;
int x1 = toF26Dot6(rx1) + half;
int y1 = toF26Dot6(ry1) + half;
int x2 = toF26Dot6(rx2) + half;
@ -429,8 +429,8 @@ void QCosmeticStroker::calculateLastPoint(qreal rx1, qreal ry1, qreal rx2, qreal
int xinc = F16Dot16FixedDiv(x2 - x1, y2 - y1);
int x = x1 << 10;
int y = y1 >> 6;
int ys = y2 >> 6;
int y = (y1 + 32) >> 6;
int ys = (y2 + 32) >> 6;
if (y != ys) {
x += ( ((((y << 6) + 32 - y1))) * xinc ) >> 6;
@ -460,8 +460,8 @@ void QCosmeticStroker::calculateLastPoint(qreal rx1, qreal ry1, qreal rx2, qreal
int yinc = F16Dot16FixedDiv(y2 - y1, x2 - x1);
int y = y1 << 10;
int x = x1 >> 6;
int xs = x2 >> 6;
int x = (x1 + 32) >> 6;
int xs = (x2 + 32) >> 6;
if (x != xs) {
y += ( ((((x << 6) + 32 - x1))) * yinc ) >> 6;
@ -702,7 +702,7 @@ static void drawLine(QCosmeticStroker *stroker, qreal rx1, qreal ry1, qreal rx2,
if (stroker->clipLine(rx1, ry1, rx2, ry2))
return;
static const int half = 32;
static const int half = 31;
int x1 = toF26Dot6(rx1) + half;
int y1 = toF26Dot6(ry1) + half;
int x2 = toF26Dot6(rx2) + half;
@ -735,8 +735,8 @@ static void drawLine(QCosmeticStroker *stroker, qreal rx1, qreal ry1, qreal rx2,
capAdjust(caps, y1, y2, x, xinc);
int y = y1 >> 6;
int ys = y2 >> 6;
int y = (y1 + 32) >> 6;
int ys = (y2 + 32) >> 6;
if (y != ys) {
x += ( ((((y << 6) + 32 - y1))) * xinc ) >> 6;
@ -810,8 +810,8 @@ static void drawLine(QCosmeticStroker *stroker, qreal rx1, qreal ry1, qreal rx2,
capAdjust(caps, x1, x2, y, yinc);
int x = x1 >> 6;
int xs = x2 >> 6;
int x = (x1 + 32) >> 6;
int xs = (x2 + 32) >> 6;
if (x != xs) {
y += ( ((((x << 6) + 32 - x1))) * yinc ) >> 6;

29
tests/auto/gui/painting/qpainter/tst_qpainter.cpp
View File

@ -278,6 +278,7 @@ private slots:
void drawTextOutsideGuiThread();
void drawTextWithComplexBrush();
void QTBUG26013_squareCapStroke();
private:
void fillData();
@ -4361,6 +4362,34 @@ void tst_QPainter::drawTextWithComplexBrush()
QVERIFY(paintedPixels > 0);
}
void tst_QPainter::QTBUG26013_squareCapStroke()
{
QImage image(4, 4, QImage::Format_RGB32);
QPainter p(&image);
p.setPen(QPen(Qt::black, 0, Qt::SolidLine, Qt::SquareCap));
for (int i = 0; i < 3; ++i) {
qreal d = i / 3.0;
image.fill(0xffffffff);
p.drawLine(QLineF(0, d, 0, d + 2));
p.drawLine(QLineF(1, d, 3, d));
// ensure that a horizontal line and a vertical line with square cap round up (downwards) at the same time
QCOMPARE(image.pixel(0, 0), image.pixel(1, 0));
image.fill(0xffffffff);
p.drawLine(QLineF(d, 0, d + 2, 0));
p.drawLine(QLineF(d, 1, d, 3));
// ensure that a vertical line and a horizontal line with square cap round up (to the right) at the same time
QCOMPARE(image.pixel(0, 0), image.pixel(0, 1));
}
}
QTEST_MAIN(tst_QPainter)
#include "tst_qpainter.moc"