Size and location of text

[Jacob]

When rendering text I am concerned about its exact
pixel location. Apparently java.awt.font.TextLayout
is the class to use.

Following the example from the javadoc of the class
(the first example in the overview), I still get the
location off a pixel or two in some cases compared to
the expected result. Code:

Graphics2D g = ...;
int x = ...;
int y = ...;

// Render text
g.setColor (Color.BLACK);
Font font = new Font ("Dialog", Font.BOLD, 56);
TextLayout layout = new TextLayout ("d", font,
g.getFontRenderContext());
layout.draw (g, (float) x, (float) y);

// Render glyph box
g.setColor (new Color (1.0f, 0.0f, 0.0f, 0.3f));
Rectangle2D r = layout.getBounds();
r.setRect (r.getX() + x,
r.getY() + y,
r.getWidth(),
r.getHeight());
g.draw (r);


Playing with font size, the glyph is outside the box in
different ways, normally just a single pixel.

What am I doing wrong?

Thanks!

 

[Larry Barowski]

When rendering text I am concerned about its exact
pixel location. Apparently java.awt.font.TextLayout
is the class to use.

Following the example from the javadoc of the class
(the first example in the overview), I still get the
location off a pixel or two in some cases compared to
the expected result.

See http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=5012037 .
Apparently an exact bound is not guaranteed. This
is currently undocumented.

 

[Thomas G. Marshall]

Larry Barowski coughed up:

See http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=5012037 .
Apparently an exact bound is not guaranteed. This
is currently undocumented.

I've had to write my own bounding box checker in the past. No big deal.
Essentially render the glyph or string in question someplace, and check it
pixel for pixel for the real graphic extents.