High-Performance Graphics

Goals

• To educate on improvements to the internal architecture of graphics for the Java™ platform and new API that enables access to platform-dependent graphics acceleration

Learning Objectives

• After this presentation, you should be able to understand:

  • Key improvements in the software architecture of the Java 2D™ API that enable higher performance graphics in the JDK™ 1.4 release
  • Full-Screen Mode usage and capabilities
  • VolatileImage API usage and capabilities

Agenda

• Java 2D™ API-based Software Performance

• Full-Screen Mode

• Accelerated Offscreen Images

• Java™ Technology on Apple

Java 2D™ API-based Software Performance

Jim Graham

Staff Engineer
Sun Microsystems, Inc.

Speaker’s Qualifications

• Technical lead of Java 2D API team

• Responsible for internal rendering architecture and overall software rendering performance

• Working on imaging for the Java platform since the JDK™ 1.0 release

Software Performance Overview

• Less validation overhead

• Faster blit dispatching

• Support for accelerated images

• Better code sharing

• More reliable rendering

Java™ Foundation Classes (JFC/Swing) API Benefits

• Less overhead for common operations

  • Graphics.setColor()
  • Scrolling
  • Graphics.create() / dispose()

• Using accelerated back buffer

Remote X11 Benefits

• Server side offscreen images

• Better logic to choose X11 pipelines

• JFC/Swing API now usable in the remote case

• TBD: Improve advanced rendering

  • Antialiasing
  • Alpha blending

More Reliable Rendering

• Glyph cache used more consistently

• Fixed hangs when using large scale factors

• Overlapping copyareas

More Efficient Implementation

• Better graphics primitive management

  • Better sharing of setup/cleanup code
  • Modular inheritance of pixel formats

• Added new alpha blending modes w/ no code(!)

• More intelligent caches

  • Pipeline configurations
  • Graphics loops

Demos

• CopyArea

• FadeText

• ImageRotation

Full-Screen Mode

Michael Martak

Software Engineer
Sun Microsystems, Inc.

Speaker’s Qualifications

• Member of AWT team

• Responsible for implementing Full-Screen and related APIs

• Background in gaming technologies prior to work on AWT

Full-Screen Mode Overview

• Games

• Slide shows

• Exclusive rendering

• Double buffering

• Changing display mode

Full-Screen and Exclusive Mode

• Exclusive means:

  • Suspend windowing system
  • Direct rendering to hardware

• Knowing whether exclusive mode supported

  • GraphicsDevices.isFullScreenSupported()

• Entering full-screen mode

  • GraphicsDevice.setFullScreenWindow()

Setting Display Modes

• Control over application presentation

  • Resolution could be governed by frame rate
  • Media sizes (images) may work best in some display modes

• A display mode is:

  • Width, height, bit depth, refresh rate
  • Set on GraphicsDevice

• May not be supported on device

• Must be in Fullscreen/Exclusive mode

Passive vs. Active Rendering

• Important for Fullscreen/exclusive mode

  • Don’t want erroneous window events

• Passive: typical windowed GUI application

  • Rendering code in paint() method

• Active: high-frame-rate animation application

  • Rendering usually on own thread

Double-Buffering

• Bit-blit

  • Copy bits between buffers

• Flip

  • Move a pointer

Blt

Double Buffering

Flip

Page Flipping

Buffering

• BufferStrategy

  • Number of buffers
  • Buffering technique (Blt vs. Flip)
  • Common rendering loop

• BufferCapabilities

  • Blt vs. Flip
  • Fullscreen requirements
  • Multibuffer (> 2) availability
  • Back buffer contents post-flip

Demos

• DisplayModeTest

  • Setting display modes
  • Using the JFC/Swing API for full-screen GUI

Accelerated Offscreen Images

Chet Haase

President
Warewolf Technologies

Speaker’s Qualifications

• Member of Java 2D API team for the JDK 1.4 implementation

• Responsible for implementation of hardware acceleration for offscreen images, especially for win32

• Experience implementing 2D and 3D graphics systems at the driver, API, and application level for over 10 years

History Lesson

• JDK 1.1 release would sometimes put images in VRAM for you

  • Driver- and situation-dependent, unpredictable
  • When in VRAM, rendering was accelerated

• JDK 1.2–1.3 releases put images in system memory

  • New API needed pixel access; 1.1-style storage not possible

• JDK 1.4 release puts images in accelerated memory whenever possible

  • Upon user request (new API)
  • For user (existing API)

Problem: Win32 Surface Loss

• (VRAM + HW Accel + pixel-access) == Ddraw

• BUT: DirectDraw surfaces can be “lost”

  • Screen saver
  • Task manager (NT)
  • Other app running fullscreen

• Can’t just insert feature under existing API

Answer: VolatileImage API

• New subclass of Image

• API to handle content loss

  • int validate(GraphicsConfiguration)
  • boolean contentsLost()

• Acceleration and control

  • ImageCapabilities getCapabilities()
  • Image lives in accelerated memory when possible (VRAM on win32, pixmap on the Solaris™ platform)

But Wait, There’s More!

• Component.createImage(), Toolkit.getImage(), etc.

• Created BufferedImage in jdk1.2/1.3

• Now also creates accelerated image copy

• Great for images rendered to infrequently, copied from often

  • Sprites vs. back buffers

• We handle surface loss for you

The Java 2D™ API vs. Native API Performance

• VolatileDuke demo: Basic fill/sprite-copy/buffer-copy operations

Demos

• VolatileDuke

  • Advantages of acceleration for fills and copies

• DukeRoids

  • Gaming technology demo

• Blastian2

  • Better gaming technology demo. From FriendlyGiants, ported from the JDK 1.1 to JDK 1.4 release

Demos (Cont.) Blastian2 Porting Case Study

• Basic port to JDK 1.4 API and features took about one full day

• Minor tweaks to take advantage of new acceleration (image types, rendering primitives)

  • Example: fillOval(2,2) changed to 2 drawLine() commands

• Performance hint: Render as image copies and rectangular fills as much as possible

Conclusions

• Graphics performance overall much better in the JDK 1.4 release

• Use VolatileImage API for hardware- accelerated back buffers

• Use Full-Screen and BufferStrategy APIs for fullscreen display and hardware-accelerated buffer flipping

Java™ Technology on Apple

John Burkey

Software Engineer
Apple Computer

Speaker’s Qualifications

• Technical lead of UI classes team at Apple

• Responsible for porting Java 2D™ technology onto Apple’s internal APIs

Java™ Technology Ships With Mac OS X

• JDK™ 1.3 release with first Mac OS X Release

• JDK™ 1.3.1 release ships this summer

• Apple and Sun working together to provide high-performance platform

High-Performance Java™ Technology on Mac OS X

• Way faster than Mac OS 7/8/9

• Hardware acceleration for the JDK™ 1.3.1 release

  • BufferedImage, JFC/Swing API (accelerated double-buffering), alpha blending, affine transforms, text

Results

Demos

More Information

• Java 2D API website:

  • http://java.sun.com/products/java-media/2D/index.html

• Full-Screen tutorial

  • http://java.sun.com/docs/books/tutorial/extra/fullscreen

• Game Developers

  • http://www.javagaming.org

• Apple site, for Java technology

  • http://developer.apple.com/java

• FriendlyGiants

  • http://www.friendlygiants.com