On 16/10/2017 02:50, Prasanta Sadhukhan wrote:
Probably this is a root cause of the bug?
Does not seem like. If we only use floating point API
getTabbedTextWidth() in GlyphPainter1.getSpan() to get floating point
width, it calls SwingUtilities2.getFontStringWidth() which calls
getStringBounds() with default FRC.
When getStringBounds() calls fm.getFontRenderContext(), it returns
DEFAULT_FRC which has a null AffineTransform so when we try to get the
transform for that through getTransform(), it creates a new
AffineTransform with scale 1
public AffineTransform getTransform() {
return (tx == null) ? new AffineTransform() : new
AffineTransform(tx);
}
So this is a problem why default FRC is used. We should find a way to
create a correct one instead.
It will apply the screens scale to the FRC even if the component is
located on some other screen.
I was of the opinion that this
GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice().getDefaultConfiguration().getDefaultTransform().getScaleX()
will give the scale factor as passed to sun.java2d.uiScale which should
be applicable for all screen(s), which is what I leveraged in my fix.
The "sun.java2d.uiScale" is a debug option which applies the scale on
all screens, but in case of the common configuration it is possible to
have different scales(example: hidpi laptop + lowdpi external screen).
GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice().getDefaultConfiguration().getDefaultTransform().getScaleX()
Will returns default transform for default configuration of the
main/default screen.
--
Best regards, Sergey.
