>
> PERFORMANCE VS. ACCURACY
> In simple cases (basic geometric shapes and Beziers), utilizing hardware
> accelerated OpenGL rendering calls boosted Java 2D performance
> somewhat. However, in many cases the shapes and lines which were drawn
> to the screen differed visibly from those rendered using the current
> Java 2D implementation. For example, antialiased lines may look
> noticably different when drawn by OpenGL rather than Java 2D.
> Furthermore, these differences in rendering accuracy may vary in OpenGL
> from implementation to implementation.
>
> INCONSISTENCIES BETWEEN APIs
> A majority of Java 2D rendering methods can be re-implemented using
> OpenGL without much hassle. Unfortunately, a one-to-one mapping between
> the two APIs simply does not exist in many cases. For example:
> - the two APIs interpret compositing (aka blending in OpenGL) rules in
> slightly different ways
> - implementing special Java 2D rendering objects such as GradientPaint
> is difficult in OpenGL (although workarounds do exist)
> - the full-featured and highly configurable image support in Java 2D
> is not matched by OpenGL (especially, for example, when dealing with
> image formats associated with lookup tables)
> - the Java 2D API does not have any notion of "display lists" in the
> OpenGL sense (there is no way to take advantage of "precompiled"
> rendering data in the Java 2D architecture for use in repetitive drawing
> calls; therefore, OpenGL wouldn't be of much help in this area)
>
> CONCLUSION
> In conclusion, a considerable amount of time has been spent exploring
> the ways in which Java 2D could benefit from a lift from OpenGL. At
> this point in time, we believe that in order to integrate the OpenGL API
> with Java 2D, we would be "shoving" code in here and there to get any
> favorable results. The new architecture mentioned above eliminates much
> software overhead and is pluggable enough such that it allows hardware
> manufacturers to devise the best optimizations for many operations at a
> fine-grained level. In this case, utilizing OpenGL acceleration is not
> an "all or nothing" endeavour; we can accelerate very specific
> operations as long as we can find an adequate resolution to the "mixing
> calls" issue.
>
As a CAD developper, I need the performance of rendering in Java 2D
especially draw and fill of the Shapes.
It is vital becuase current Java2D's draw and fill are much slower than AWT's.
The fully compatibility with openGL is not needed.
The mixing support of the both APIs is not needed.
We should not sacrifice the substance for the form.
OpenGL is not a purpose but an expedient.
Is it possible to exploit OpenGL only inside of Java2D APIs ?
This use of OpenGL is optional case.
This purpose is just utilizing hardware accelerated OpenGL rendering calls.
--
Tadashi Ohmura
E-mail : [EMAIL PROTECTED]
5-3-4 kaijin Funabashi City Chiba Pref. 273 JAPAN
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