QRect top is smaller than bottom why ?

Qt Enthusiast

I am makign a QRect with following

QRectF rect = QRectF(left, top, width, height);
int left = rect.left();
int bottom = rect.bottom();
int right = rect.right();
int top = rect.top();

In this top is < bottom . Why such behavior ?

joeQ

@Qt-Enthusiast Hi, friend, did you check the value of left, top, width, height before QRectF(left,top,width,height) ?

joeQ

@Qt-Enthusiast and, You used QRectF means float value. but,

qreal left = rect.left();  ///< return qreal
/** ... */

joeQ

@Qt-Enthusiast

QRectF(qreal x, qreal y, qreal width, qreal height)
qreal	bottom() const

/** ... */
qreal x,y,w,h;
x = y = 0.0;
w = h = 10.0;
QRectF fRect = QRectF(x,y,w,h);
qDebug() << fRect;
/** ... */

Try it to see the value;

jsulm

@Qt-Enthusiast "Why such behavior ?" - because the coordinate system works this way. The top left corner is (0, 0), the bottom right corner is (max width - 1, max height - 1).
See http://doc.qt.io/qt-5.9/coordsys.html