Recently, I had a problem in my application (So I provided a mini example of the problem) that I faced when creating large-scale images, and when I looked at the output image, it was not fully drawn! I don't know why, so I created a mini-example of that.
#include <QGuiApplication>#include <QPainter>#include <QPixmap>static QPixmap imageTest(int width, int height, QColor const &color) { static constexpr auto VERTICAL_PADDING = 2; QPixmap pixmap(width, height); pixmap.fill(Qt::transparent); QPainter painter(&pixmap); painter.setRenderHint(QPainter::Antialiasing); QPen pen(color); double const widthF = 1.0; pen.setWidthF(widthF); painter.setPen(pen); for (int i = 0; i < width; ++i) { QPointF p1(i, 94.9445); // mini example assume fixed height QPointF p2(i, 167.055); // mini example consider fixed height painter.drawLine(p1, p2); } painter.end(); return pixmap;}int main(int argc, char *argv[]) { QGuiApplication app(argc, argv); auto image = imageTest(211'459, 262, Qt::GlobalColor::green); image.save("testFile.png", "PNG"); app.quit(); return 0;}the result of image , is something like this:
Image may be NSFW.
Clik here to view.
I also tested that with other approaches, like drawLines and fillRect, but it didn't help me. What's the problem?
