whytofly
/
qt6-bb10
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Limit Bezier curve subdivision to maximum 512 line segments. 

Avoid running out of time and memory for extreme cases.

Task-number: QTBUG-23443
Change-Id: Iac7799097d61295bb7395a2efe48b3e7d9257919
Reviewed-by: Gunnar Sletta <gunnar.sletta@nokia.com>
bb10
Kim Motoyoshi Kalland 2012-01-06 14:11:55 +01:00 committed by Qt by Nokia
parent ce5c8743e9
commit fc6c050b40
1 changed files with 16 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

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

@ -190,9 +190,12 @@ static inline bool findInflections(qreal a, qreal b, qreal c,
void QBezier::addToPolygon(QPolygonF *polygon, qreal bezier_flattening_threshold) const
{
QBezier beziers[32];
QBezier beziers[10];
int levels[10];
beziers[0] = *this;
levels[0] = 9;
QBezier *b = beziers;
int *lvl = levels;
while (b >= beziers) {
// check if we can pop the top bezier curve from the stack
@ -208,23 +211,29 @@ void QBezier::addToPolygon(QPolygonF *polygon, qreal bezier_flattening_threshold
qAbs(b->x1 - b->x3) + qAbs(b->y1 - b->y3);
l = 1.;
}
if (d < bezier_flattening_threshold*l || b == beziers + 31) {
if (d < bezier_flattening_threshold*l || *lvl == 0) {
// good enough, we pop it off and add the endpoint
polygon->append(QPointF(b->x4, b->y4));
--b;
--lvl;
} else {
// split, second half of the polygon goes lower into the stack
b->split(b+1, b);
lvl[1] = --lvl[0];
++b;
++lvl;
}
}
}
void QBezier::addToPolygon(QDataBuffer<QPointF> &polygon, qreal bezier_flattening_threshold) const
{
QBezier beziers[32];
QBezier beziers[10];
int levels[10];
beziers[0] = *this;
levels[0] = 9;
QBezier *b = beziers;
int *lvl = levels;
while (b >= beziers) {
// check if we can pop the top bezier curve from the stack
@ -240,14 +249,17 @@ void QBezier::addToPolygon(QDataBuffer<QPointF> &polygon, qreal bezier_flattenin
qAbs(b->x1 - b->x3) + qAbs(b->y1 - b->y3);
l = 1.;
}
if (d < bezier_flattening_threshold*l || b == beziers + 31) {
if (d < bezier_flattening_threshold*l || *lvl == 0) {
// good enough, we pop it off and add the endpoint
polygon.add(QPointF(b->x4, b->y4));
--b;
--lvl;
} else {
// split, second half of the polygon goes lower into the stack
b->split(b+1, b);
lvl[1] = --lvl[0];
++b;
++lvl;
}
}
}