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GLCanvas rendering differs among JVM version

Posted by Martin on Oct 19, 2015; 12:26pm
URL: https://forum.jogamp.org/GLCanvas-rendering-differs-among-JVM-version-tp4035514.html

Hi,

I noticed rendering differs among different JVM with JOGL 2.3.2 : in these two examples, left window is 1.6 and right window is 1.8 (details below).

* text size of axis box differ (it uses GLUT.glutBitmapString)
* aliasing settings are not the same (1.8 version is cleaner than 1.6)
* alpha values are handled differently (1.8 appears lighter than 1.6)
* colorbar is not rendered properly on its translucent part (where text stand) : it is initially a Java2d image rendered by gl.getGL2().glPixelZoom, glRasterPos3f and then glDrawPixels)

And I just change JVM not JOGL or JZY3d versions.

Important : all pictures are based on GLCanvas for AWT.

Are these known issues?

http://download.jzy3d.org/jogldiscuss/jzy1.0-jogl2.3.2-surface.png
http://download.jzy3d.org/jogldiscuss/jzy1.0-jogl2.3.2-scatter.png

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Now if I use NewtCanvasAWT on jogl 2.3.2 I can see both version (6/8) rendering the same way : as GLCanvas renders on 1.8 (better aliasing, smaller text) without bug (no pb rendering alpha off Java2d images).

Should we throw away GLCanvas? 

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I then tried to do the same comparison using jzy-0.9 and jogl 2.0-rc1 (or earlier, sorry for lack of precision) with GLCanvas. There is no difference in rendering quality, but only a canvas position bug occuring for 1.8

http://download.jzy3d.org/jogldiscuss/jzy0.9.0-jogl2.0rc11-or-earlier-scatter.png
http://download.jzy3d.org/jogldiscuss/jzy0.9.0-jogl2.0rc11-or-earlier-surf.png

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I am comparing :

java version "1.6.0_65"
Java(TM) SE Runtime Environment (build 1.6.0_65-b14-462-11M4609)
Java HotSpot(TM) 64-Bit Server VM (build 20.65-b04-462, mixed mode)

and

java version "1.8.0_40-ea"
Java(TM) SE Runtime Environment (build 1.8.0_40-ea-b22)
Java HotSpot(TM) 64-Bit Server VM (build 25.40-b25, mixed mode)

on MacOSX 10.8.5