arm platform qt4.8 qpainterpath.arcTo drawed incorrect with wide qpen.setwidth,but in windows10 draw the correct

xiaokai_mao

QPen pen = painter->pen();
    pen.setWidthF(31.2112);
    painter->setPen(pen);
// first. incorrect , in this values, qpainterpath.elementCount() == 11
    double rx = 29.8467; 
    double ry = 29.8198;
    double startAngle = -0.00192632;
    double spanAngle = 90.0711;

//second. correct, in this values, qpainterpath.elementCount() == 4
//    double rx = 29.8477;
//    double ry = 29.8208;
//    double startAngle = 3.29033e-05;
//    double spanAngle = 90;

    QPointF topleft(1331.62, 393.798);
    QRectF rect(topleft.x(), topleft.y(), 2*rx, 2*ry);
    QPainterPath path;
    path.arcMoveTo(rect,startAngle);
    path.arcTo(rect,startAngle, spanAngle);

    painter->drawPath(path);

on arm draw :

on window draw:

how to resolve this problem on arm qt4.8? thinks.

SGaist

Hi and welcome to devnet,

What kind of ARM processor are you using ?
By the way, Qt 4.8 has reached end of life a long time ago, you should really consider moving to a more recent version like 6.2 which is the current LTS.

xiaokai_mao

thanks for your attention. It is A133 ARM in my company.
Using other implement method, I had replaced qpainterpath.arcTo with two qpainter.drawpie and setted clipping region.