[gl4java-usergroup] display and reshape. Possible bug.

[Jacob M. <ja...@ma...>]

Hi,

My first gl4java application was written using the old
model where you derive from GLAnimCanvas. I have
just ported it to the new model where I just implement
GLEventListener. It all works fine with one exception:

For the very first frame display() is called
before reshape(). Reshape is then called for the second
frame and all is good. However it is custom in all 
the OpenGL implementations I have seen to call the
equivalent of reshape() before any calls to display().
So I think this is a bug.

A workaround is simply to call reshape() as the last
instruction in init().

------

And then a little tip:

I have noted that many demos do this or something similar:

Dimension ps = applet.getPreferredSize();
  f.setBounds(-100,-100,99,99);
  f.setVisible(true);
  f.setVisible(false);
  f.setVisible(true);
  Insets i = f.getInsets();
  f.setBounds(0,0,
       ps.width+i.left+i.right, 
              ps.height+i.top+i.bottom);
  f.setVisible(true);

Showing the frame seems to be needed to make the insets
be correct. However, I have found that  it can be done simpler
and faster as (I have only tested it with applications not applets):

Dimension ps = applet.getPreferredSize();
f.pack();
Insets i = f.getInsets();
f.setBounds(0,0,
       ps.width+i.left+i.right, 
              ps.height+i.top+i.bottom);
f.setVisible(true);

---------------------

PS: Thanks Kenneth for answering my newbie question
a few days ago. I have since then learned much I feel
that I am quite capable of writing gl4java apps.

Sincerely,
Jacob Marner