OpenGL ES Game Development (Game Development Series)

319 Pages·2004·6.48 MB·English

by  Dave Astle

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For my family and all my best friends.
Dave Durnil
For Lissa, whom I ignored when she told me to stop
writing these damn books.
Dave Astle
Foreword
Y
ou say you want a revolution? Well,sometimes the smallest things can create the
biggest changes.OpenGL ES originated that way—in a modest 3Dlabs project in
2001 that sought to define a standardized subset ofOpenGL for a range ofembed-
ded systems.It soon became clear that there was a widespread industry desire for a small
footprint,cross platform API with excellent 2D and 3D functionality,particularly as 3D
silicon was rapidly becoming both more capable and significantly cheaper, but such an
API simply didn’t exist in 2001.
Asinterest quickly grew around 3Dlabs’idea,the search began for a standards body able
tocreate a 3D graphics API for embedded systems that leveraged the proven strengths of
OpenGL—an API that has been used by a huge range ofapplications from games to CAD
systems on a wide variety of workstations and PCs. With the support of the OpenGL
Architecture Board, the industry body responsible for evolving OpenGL for 10 years,
3Dlabs took the idea of defining a subset of OpenGL to the Khronos Group—an open
standards consortium working on OpenGL-related standards. Khronos recognized the
opportunity and began to organize to undertake this new project.
Then things started getting really interesting.
At that time,the cell phone industry was also searching for a graphics API to enable the
market for 3D gaming on handsets.An early indication of how fast things were about to
start developing occurred when Symbian arranged an industry-wide meeting in April
2002,and in a single day,the decision was made to adopt the embryonic OpenGL ES as
that standard.
So a small physical platform,the cell phone,began to provide a large commercial momen-
tum that propelled the nascent OpenGL ES into the fast track.In just twelve months the
industry’s foremost experts in 3D graphics,OpenGL,and embedded systems worked to
vi
Foreword vii
create the OpenGL ES 1.0 and EGL 1.0 specifications that were publicly released,royalty
free,to the industry at Siggraph in July 2003.Six months later Khronos released confor-
mance tests for OpenGL ES—ensuring that products that use the OpenGL ES logo pro-
vide consistent levels of quality and functionality that application developers can truly
rely on.
OpenGL ES 1.0 immediately gathered strong industry momentum and pushed Khronos
membership to over 50 companies.This tremendous success is a testament to what can be
achieved when committed companies,some fierce competitors,lay down arms and work
together to create a standard to benefit the industry as a whole.The OpenGL ES standard
has already spawned a range of software implementations,some that fit within a minute
75 Kbytes,and an array of powerful,but low-power accelerators that are small and cheap
enough to fit within cell-phone handsets.
The widespread appeal ofOpenGL ES is a result offollowing the same design principles as
the original OpenGL.OpenGL ES is a low-level API that provides just enough abstraction
tocreate cross-platform portability and fosterimplementation innovation in software and
silicon.By staying at a low level,OpenGL ES is able to form the foundation for an unlim-
ited range of applications,games engines,middleware,and higher-level 3D software.
The remarkable thing,even for those working in the midst ofthe standardization process,
is how quickly the cell phone industry is establishing the industry infrastructure for hand-
held 3D gaming.In one year we have achieved the same level ofwidespread acceptance for
a single 3D API that took almost four years on the PC. Things are likely to continue to
develop in “cell phone time,”and I believe we are witnessing the beginning of the trans-
formation ofcell phones from communication devices into ubiquitous personal comput-
ing tools that most ofus will eventually use for the bulk ofour computing needs.Bringing
richmedia capabilities,including 3D graphics,onto these devices is one important step in
this industry-changing process.
Looking forward,one thing is certain:that innovation will accelerate,and we will soon see
OpenGL ES being used in all manner of devices and platforms,including game consoles
and set-top boxes, to communicate and entertain. The Khronos Group will continue to
develop OpenGL ES to enable the evolving 3D capabilities of embedded platforms,and
they have recently delivered the OpenGL ES 1.1 specification at Siggraph 2004 to provide
developers access to the increasing capabilities of phones with full 3D acceleration.
The next version ofOpenGL ES,OpenGL ES 2.0,is currently being developed by Khronos
members for release in 2005 and will bring the power of programmable shaders and the
OpenGL Shading Language to embedded platforms—remarkably just one year after
OpenGL 2.0 was ratified for desktop machines. By innovating the unique solutions
needed to bring programmability to small and diverse platforms, Khronos will unleash
enormous computing power in the palm ofyour hand.The embedded 3D revolution has
truly just begun.
viii Foreword
And now,by reading this book,you too have become a part of this revolution! The best-
designed API is just an academic exercise until it is used by developers to create com-
pelling content. Khronos hopes that you will find using OpenGL ES to be an enjoyable
and rewarding experience.It is a growing,evolving API—and so please tell us something
of your experiences on the Khronos public forums at www.khronos.org so that we may
collectively moveforward together.
Finally,I would like to take this opportunity to thank everyone who has brought us here,
especially all the members of the OpenGL ES Working Group—it is a genuine pleasure
and privilege to work with you all.I would also make special mention ofKurt Akeley and
the OpenGL ARB that created OpenGL,the solid and trusted foundation for everything
we do;Randi Rost at 3Dlabs,who undertook the first design for an OpenGL subset that
was the catalyst for OpenGL ES;Shawn Underwood,Jon Leech,and Thomas Tannert of
SGI for their support and expert guidance in expanding the reach of OpenGL into new
territories; David Blythe of Hi Corporation and Aaftab Munshi of ATI Technologies for
their wisdom and efforts as specification editors; Ed Plowman of ARM, Kari Pulli of
Nokia,and Bill Pinnell of Symbian,who had the vision to bring OpenGL ES into the cell
phone industry;and Elizabeth Riegel at Gold Standard Group for her tireless organization
and promotion of Khronos.
But most importantly—thank you to Dave Astle and Dave Durnil.You have created an
outstanding book that will play a vital role in educating developers how this API can be
effectively used and the opportunities it creates. You have also done it in “cell-phone”
time—making this,the first OpenGL ES book,amazingly up-to-the-minute!
I strongly recommend this book to anyone who wishes to be part ofthe handheld 3D rev-
olution.
Neil Trevett
Senior Vice President Market Development,3Dlabs
President,Khronos Group;Chairman,OpenGL ES Working Group
[email protected]
August 2004
Acknowledgments
W
ith any major project, it is the ongoing encouragement of colleagues and
loved ones that keeps you motivated. So we both would like to personally
thank our friends and family for their continued support and understanding.
Wehope everyone will enjoy this book.We couldn’t have provided this information with-
out the help of some very talented people. So a special thanks to our contributing
authors—Mike Street, Devin Maxwell, and Anders Granlund—for taking their time in
adding to the overall quality ofthis book.Their efforts are greatly appreciated.In the same
vein,we’d like to thank our co-worker Brian Ellis for his contributions to the EGL chapter.
Overall,we would like to thank everyone at Course Technology for their efforts in pub-
lishing this book. As always, they are an outstanding group of people to work with—
though they seem to have forgotten how to party.
Wewould also like to thank QUALCOMM for allowing us to pursue our passion for writ-
ing. Thanks to John Boackle, Vice President of Engineering, and David Ligon, Senior
Product Manger for 3D Graphics,for their continued support of projects like this.
Wewould also like to thank Fathammer,Superscape,and Hi Corporation for allowing us
to provide information on their 3D mobile gaming engines. Thank you to Arto Astala,
CTO,and Ville Vaten,Project Manager,of Fathammer for their very responsive e-mails,
detailed information, and screenshots of the Fathammer X-Forge engine. Thanks to
Brendan Roberts, Vice President of North American business development for Super-
scape.We also appreciate the great efforts of Stephane Groud of Superscape for helping
us collect information on the Swerve engine.Finally,thank you to Carl Korobkin,Presi-
dent and CEO of Mascot Capsule,Inc.(a division of Hi Corporation),for his efforts in
providing details on the V3 and V4 Mascot Capsule engine.
ix
x Acknowledgments
Wewould like to thank the QUALCOMM QIS Business and Marketing Unit for BREW™,
who provided a general overview of the mobile gaming market. Thanks to Mike Yuen,
Director of Product Management,for providing the core explanations of how the mobile
gaming market works, and Aaron Bernstein, Product Manager, Game Developer Rela-
tions,for helping pull this information together.A very special thanks goes to Bella Ala-
banza, Manager of Marketing Communications, for her tireless efforts in pulling the
mobile business chapter together for us.
The Khronos Group richly deserves credit for their support of this book,and of course,
for developing and promoting OpenGL ES in the first place. Neil Trevett and Elizabeth
Riegel were particularly helpful in promoting and supporting this book.
Last, but certainly not least, we would personally like to thank ATI and our technical
editor,Aaftab Munshi.Thanks,Affie,for helping edit the book,for providing information
on the ATI 2300 series hardware,and for keeping us up-to-date with the evolving OpenGL
ES 1.1 specification.