Spec-Zone .ru
спецификации, руководства, описания, API
Java

New Java 2DTM Features
in J2SE 5.0

2D Contents

Caching All BufferedImages

As of J2SE 5.0, all images created with a BufferedImage constructor are now managed images and can be cached in video memory or, in the case of a remote X server, on the X server side. Previously, the Sun implementation managed only compatible images — those created with the Component createImage(int, int) method or with the GraphicsConfiguration createCompatibleImage methods. Managed images generally perform better than unmanaged images.

Methods for Controlling Hardware Acceleration of Images

The bug report that corresponds to this change is: 4881082

The Image class has three new methods related to hardware acceleration. The getCapabilities method, formerly defined only in VolatileImage, allows you to determine whether the image is currently accelerated. Two other methods let you set or get a hint about how important acceleration is for the image: setAccelerationPriority and getAccelerationPriority.

The GraphicsConfiguration class has two new methods, createCompatibleVolatileImage(int, int, int) and createCompatibleVolatileImage(int, int, ImageCapabilities, int), that allow you to create transparent VolatileImages.

Note: In J2SE 5.0, these methods are not fully operational. The value set by setAccelerationPriority is ignored, and images created with the createCompatibleVolatileImage methods are not always hardware accelerated. On Linux and Solaris systems, only OPAQUE VolatileImages are hardware accelerated. On Microsoft Windows systems, images created with createCompatibleVolatileImage in J2SE 5.0 are hardware accelerated only if the hardware supports acceleration and one of the following is true: We expect to fully implement these methods on all platforms in future releases.

Support for Hardware-Accelerated Rendering Using OpenGL

The bug reports that correspond to this change are: 4607536 and 5008045.

J2SE 5.0 includes a new OpenGL-based pipeline for Java 2D. This pipeline provides hardware acceleration for simple rendering operations (text, images, lines, and filled primitives) as well as those that involve complex transforms, paints, composites, and clips. This pipeline is available on all platforms (Solaris, Linux, and Microsoft Windows) and is currently disabled by default.

To silently enable the OpenGL-based pipeline, specify the following system property on the command line: 

    -Dsun.java2d.opengl=true

To receive verbose console output about whether the OpenGL-based pipeline is initialized successfully for a particular screen, specify "True" (note the uppercase T): 

    -Dsun.java2d.opengl=True

Minimum requirements for Solaris/Linux:

Minimum requirements for Microsoft Windows:

Solaris OpenGL Notes

Accelerated OpenGL libraries for the Solaris SPARC platform are available directly from Sun:

http://wwws.sun.com/software/graphics/opengl/index.html
The following Sun framebuffers are known to work with the OpenGL-based Java 2D pipeline:

Accelerated OpenGL libraries for the Solaris x86 platform are not available from Sun. However, third-parties such as Xi Graphics are known to support OpenGL libraries for Solaris x86.

Linux OpenGL Notes

Most Linux distributions include the Mesa 3D graphics library, which is a software implementation of the OpenGL specification. Since Mesa does not take advantage of hardware acceleration, it is likely that the OpenGL-based Java 2D pipeline will run much more slowly than the default (X11-based) pipeline. Therefore, to achieve optimal performance with the OpenGL-based pipeline, it is recommended that you install accelerated OpenGL drivers provided by your graphics hardware manufacturer.

The following web sites may have accelerated OpenGL drivers you can download.

Microsoft Windows OpenGL Notes

To achieve optimal performance with the OpenGL-based pipeline, install accelerated OpenGL drivers provided by your graphics hardware manufacturer. The following websites have accelerated OpenGL drivers available for download that are known to be compatible with the OpenGL-based Java 2D pipeline:

Note: The latest drivers from both Nvidia and ATI have known issues on Microsoft Windows that might cause rendering artifacts in your application. We are actively investigating these driver bugs and are working with the manufacturers to have them resolved in future driver updates.

Solaris and Linux Support for CUPS Printers

The bug reports that correspond to this change are: 4641868 and 4683270

Solaris and Linux systems can now use printers configured as CUPS (Common UNIX Printing System) printers. This expands the printers the Java platform can use to all those supported by CUPS — including most PostScript and raster printers — making it much easier to use low-cost printers with Linux. CUPS is based on IPP (Internet Printing Protocol).

See http://www.cups.org for more information.

Bicubic Interpolation

The bug report that corresponds to this change is: 4200154

The 2D implementation now supports bicubic interpolation and uses it whenever requested. Previously, the VALUE_INTERPOLATION_BICUBIC hint defined by the RenderingHints class wasn't honored, and bilinear interpolation was used instead. Now the bicubic rendering hint is honored, and a new constant TYPE_BICUBIC has been added to AffineTransformOp.

Creating Fonts from Files and Streams

The bug reports that correspond to this change are: 4390880 and 4468862

It is now possible to create Font objects from Type 1 fonts and to create Font objects directly from files containing either Type 1 or TrueType font data.

To support the new functionality, the Font class has a new createFont method that creates Font objects from files. The pre-existing createFont method creates Font objects from streams. A new constant, Font.TYPE1_FONT, specifies Type 1 fonts to either createFont method.

Improved Text Rendering Performance and Reliability

The bug report that corresponds to this change is: 4641861

A number of internal changes to text rendering code greatly improve its robustness, performance, and scalability.

Multilingual Text Rendering

The bug report that corresponds to this change is: 4097028

2D text rendering using logical fonts now takes advantage of installed host OS fonts for all supported writing systems to render multilingual text. For example, if you run in a Thai locale environment but have Korean fonts installed, both Thai and Korean are rendered.

Copyright © 1995-2004 Sun Microsystems, Inc. All Rights Reserved.

Please send comments using the Java 2D Feedback page. 		Sun Microsystems, Inc
Java Software