QPainter的QImage的到

Question

我試圖呈現一個QGraphicsScene使用下面的代碼使用Qt5圖像：

QImage image(outputWidth, outputHeight, QImage::Format_ARGB32_Premultiplied); 
QPainter painter(&image); 
scene->render(&painter); 
painter.setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform); 
image.mirrored().save("output.png"); 

的問題是，過於接近圖像邊界點不渲染。有沒有辦法強制填充/保證金？

Answer 1

您可以通過渲染到較大的圖像然後剪切到較小的圖像來實現墊。

int pad_width = 4; 
QImage image; 
QImage padded_image(outputWidth + 2 * pad_width, outputHeight + 2 * pad_width, QImage::Format_ARGB32_Premultiplied); 
QPainter painter(&padded_image); 
scene->render(&painter); 
painter.setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform); 
image = padded_image.copy(pad_width, pad_width, outputWidth, outputHeight); 
image.mirrored().save("output.png");