TweetFollow Us on Twitter

Game Sprocket Intro

Volume Number: 13 (1997)
Issue Number: 2
Column Tag: Game Development

Sprockets are Forever

By Jeremy Vineyard, Viperware

Macs Were Made to Play Games

The Beginning...

When I was a child, I used to beg my parents for quarters to play in the local arcade. Wasting thousands of hours with this activity, I developed a passion for creating games. The desire to create my own games magnified with every quarter I spent.

Reality is often harsh, especially for the would-be game developer. I discovered that games can be very difficult to write. A good game developer must have extensive knowledge of animation techniques, music composition, sound recording, graphics synchronization, algorithm design, data structures, and more. Game developers lose sleep over the slowdown caused by CD-quality sound and full-screen scrolling graphics, and the complexities of an arcade game type environment. Until fairly recently, there wasn't much documentation explaining how to write games, if you wanted to learn, you did so by trial and error.

Not long ago, Apple officially announced something that Mac lovers have known for years: the Mac is a game machine. In fact, the Mac is a great game machine, featuring built-in support for high-resolution graphics and CD-quality sound. Along with this announcement, Apple resolved to help Mac game developers write even cooler games for the Mac. The result - Apple's Game Sprockets.

What is a Sprocket?

A sprocket is a component of Apple's new game development architecture. Each sprocket adds extra features to the MacOS that specifically benefit those who are writing games. There are six sprockets currently under development by Apple: DrawSprocket, SoundSprocket, InputSprocket, NetSprocket, SpeechSprocket, and QuickDraw 3D Rave. SpeechSprocket is just a repackaged version of Apple's Speech Recognition Manager. Game Sprockets will run only on PowerMacs, but certain sprockets may be ported to 68k in the future. Game Sprockets require the newest system software including OpenTransport 1.1, Display Manager 2.0, and Sound Manager 3.2.1.

DrawSprocket

Prepare for battle! Flames rupture your view; sirens wail. You have the enemy in your sights. Fire! The screen jerks and the action grinds to a halt. Unexpectedly, you find yourself waiting for the screen to refresh. As the computer calculates the next frame of animation, your senses are brought to terms with reality. You lose interest, quit, and go to your living room to read a book. Full-screen, high-resolution graphics are quite possibly the bane of all computer games.

The Macs make great game machines, but they lack certain characteristics that make the primeval PCs more suitable for playing games. One noticeable shortcoming is that unlike PC's, most Macs don't have page-flipping. Page-flipping is the ability to almost instantly switch frames of animation by simply telling the display device (the monitor) to look somewhere else in memory for the display data (the graphics). DrawSprocket provides transparent support for page-flipping on the Macs that support it, and falls back on more compatible methods for those that don't. When page-flipping is not available, DrawSprocket reverts to using CopyBits, which is much slower than page-flipping because QuickDraw must copy the entire contents of each frame of animation onto the screen.

DrawSprocket also supports multi-buffering, with which the next frame of animation can be drawn even while the current frame is being copied to the screen. Multi-buffering can decrease the animation bottleneck that occurs when the processor overtakes the speed of the display device.

Figure 1. Select a Display with DrawSprocket.

DrawSprocket offers common game-related tasks such as a user interface for selecting monitors and providing an easy way for games to take control of the entire screen, which includes hiding the menu bar and blanking all unused monitors. DrawSprocket takes care of fading the screen to any color by altering a monitor's gamma tables. This is good for making a cool fade, setting up the screen for the next scene, and fading back into the game.

DrawSprocket makes it easy for you to include an underlay in your game. An underlay is an image that is always behind all other graphical elements. For example, you might have a scrolling picture of a mountain that is always in the background. In the future, DrawSprocket will support overlays allowing game developers to easily implement foreground images.

DrawSprocket's routines can provide your game with a consistent frame rate so that the animations don't change speed when they are becoming more or less processor-intensive. For the animated elements, Apple provides a sprite manager within QuickTime.

InputSprocket

Have you been frustrated while trying to use a Mac joystick? Until the introduction of InputSprocket, the Mac had no built-in support for game input devices, resulting in emulated performance by the Mac joysticks, flight sticks, and game pads.

InputSprocket is an API for the Mac joystick developers that provides a consistent user experience when using joysticks and other game-related input devices on the Mac. Joystick manufacturers write drivers for their devices that communicate with games about the elements of the joystick. Some examples of elements are buttons, controllers, directional pads, and others that are common to game-related input devices. Games that use InputSprocket can interact directly with these elements, eliminating the need for the elements to be emulated through the mouse or keyboard.

You can create your own interface for choosing the active game device and assigning functions to game controls, but InputSprocket provides a standard user interface for you.

Figure 2. InputSprocket Interface.

For a game input device to work with InputSprocket, a driver must be written for that device. As of the writing of this article, no joystick manufacturers shipped InputSprocket drivers for their products, but companies such as Gravis and Thrustmaster have demonstrated prototype InputSprocket drivers. InputSprocket has problems working with some third-party input devices such as Kensington mice, but Apple developers are working to fix this problem.

QuickDraw 3D RAVE

QuickDraw 3D RAVE (Rendering Acceleration Virtual Engine) is a Hardware Abstraction Layer (HAL) that allows game developers who write their own 3D rendering engines (as does Bungie for Marathon) to take advantage of the features offered by 3D accelerator cards when they are present. QuickDraw 3D Rave is a stripped-down version of QuickDraw 3D, and it is highly optimized, making it ideal for game developers who need every amount of speed they can get.

Games communicate with QuickDraw 3D RAVE by converting their rendered images into triangles, which RAVE then sends to the accelerator card if present, or otherwise emulates in software. In addition to supporting 3D accelerator cards, RAVE will soon be cross-platform, allowing game developers to easily port their low-level 3D rendering code.

SoundSprocket

3D games are the rage nowadays. This is evident by the huge sales of games like Doom and Marathon. Along with freedom of movement comes the responsibility to make the user experience as realistic as possible. Players are expecting to be drawn into their games more and more as computer processing power increases. 3D sound adds an extra dimension of reality and helps the game developer write really cool games.

Figure 3. Configuring a Sound Device for 3D Sound.

SoundSprocket adds the capability of making sounds appear to come from positions relative to the game player. This allows realistic feedback such as: "The aliens are to my left!" and can make game play much more enjoyable. Like all the other sprockets, SoundSprocket provides a standard user interface for configuring sound output devices to take maximum advantage of their 3D sound capabilities.

Future versions of SoundSprocket promise to add effects such as altering sound as it travels through the environment. Sound will be heard differently based on the humidity of the environment, and will even be able to travel through dense fog or water. Sound will also reverberate by bouncing off walls.

You don't have to have a 3D game to benefit from 3D sound. Most games that use sound effects can benefit from more realistic sound and a more in-depth user experience.

NetSprocket

As adrenaline pulses through your veins, your finger slips from sweat as you pull at the trigger. The force from the rocket blast kicks you back. Splat! A direct hit. You drool in ecstasy as your opponent's corpse splatters to the ground. Are you competing in Bloodsport? No- you have just finished off the last of your assailants in a networked game of Marathon. Unlike competing against a personality-less computer, going head-to-head with your best friends (or even your enemies) can be a heck of a good time.

Macs have been one of the easiest platforms to network together since their introduction. Setting up a local area network is as simple as connecting a cable between two Macs. This ease of use takes most of the pain out of adding networking to Mac games. However, because there are many different protocols that a network might support (IP, IPX, AppleTalk, Serial, etc.), a game developer probably won't have time to implement all of these protocols in addition to testing the reliability of their network code.

NetSprocket provides a set of high-level routines designed specifically to help developers add networking code to their games. NetSprocket hides the low-level details of the network from the programmer and takes care of many tasks that the developer would otherwise be forced to implement.

Figure 4. Hosting a Network Game.

Figure 5. Joining a Network Game.

NetSprocket is based on a client/server architecture in that one player acting as a server hosts a game session, and other players join as clients to the network game. In the future, NetSprocket will provide more models other than the client/server model for interacting between networked players. NetSprocket hides the implementation details of supporting various protocols, saving the developer time needed to re-write the networking code for each protocol. NetSprocket is fast and fault tolerant - when one computer in the networked game crashes, it doesn't bring down everyone else. Since the low-level network code is already written, NetSprocket can save a game developer hundreds of hours of work.

NetSprocket assigns each player a player ID and a player type. Player types might include referees, observers, and participants. Players can belong to groups (red team, black team, etc.).

A networked game works like a conversation - players pass messages back and forth. This communication activity is known as a protocol. A network protocol is very much like a conversation - players ask questions and wait for responses. Although NetSprocket makes it very easy to pass messages between networked players, knowledge of designing protocols is important. Fortunately, designing protocols is not a difficult topic to learn, and can end up being somewhat addicting. (Or maybe it's just me?)

To Infinity and Beyond

Apple is not supporting 68k machines with its Game Sprockets architecture. Until Apple develops 68k versions of Game Sprockets, Game Sprocket developers must limit their audience to PowerMac users.

Apple has a tarnished reputation for settling for complacency when it releases new technologies to developers (see QuickDraw GX, AOCE). In order for Game Sprockets to thrive, Apple must provide game developers with an abundance of tools, source code, and updates to the existing API. Thankfully, Apple has been doing a good job with Game Sprockets, keeping updates coming steadily and keeping in touch with the developers who use the technologies.

Apple's Game Sprockets are definitely a step in the right direction if they want to remain a competitive OS solution into the future. I look forward to seeing games released that take advantage of the features that are offered. Thank you to those people within Apple who are working hard to bring more cool games to the Mac!

Footnote

The Internet is a great place to find information on Apple's Game Sprocket architecture. Here are some URL's that can help you get started.

Apple's Game Sprocket Page

http://dev.info.apple.com/evangelism/games/games.html

Developer University Course- Game Development with Sprockets

http://devworld.apple.com/dev/du/Using_Game_Sprockets/Using_Sprockets.html

Licorice Web Page for Game Sprocket Developers

http://www.viperware.com/licorice

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

ScreenFlow 7.1.1 - Create screen recordi...
ScreenFlow is powerful, easy-to-use screencasting software for the Mac. With ScreenFlow you can record the contents of your entire monitor while also capturing your video camera, microphone and your... Read more
Xcode 9.0.1 - Integrated development env...
Xcode includes everything developers need to create great applications for Mac, iPhone, iPad, and Apple Watch. Xcode provides developers a unified workflow for user interface design, coding, testing... Read more
TotalFinder 1.10.2 - Adds tabs, hotkeys,...
TotalFinder is a universally acclaimed navigational companion for your Mac. Enhance your Mac's Finder with features so smart and convenient, you won't believe you ever lived without them. Features... Read more
Adobe Flash Player 27.0.0.170 - Plug-in...
Adobe Flash Player is a cross-platform, browser-based application runtime that provides uncompromised viewing of expressive applications, content, and videos across browsers and operating systems.... Read more
VirtualBox 5.1.30 - x86 virtualization s...
VirtualBox is a family of powerful x86 virtualization products for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers... Read more
VirtualBox 5.1.30 - x86 virtualization s...
VirtualBox is a family of powerful x86 virtualization products for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers... Read more
ScreenFlow 7.1.1 - Create screen recordi...
ScreenFlow is powerful, easy-to-use screencasting software for the Mac. With ScreenFlow you can record the contents of your entire monitor while also capturing your video camera, microphone and your... Read more
Adobe Flash Player 27.0.0.170 - Plug-in...
Adobe Flash Player is a cross-platform, browser-based application runtime that provides uncompromised viewing of expressive applications, content, and videos across browsers and operating systems.... Read more
Xcode 9.0.1 - Integrated development env...
Xcode includes everything developers need to create great applications for Mac, iPhone, iPad, and Apple Watch. Xcode provides developers a unified workflow for user interface design, coding, testing... Read more
TotalFinder 1.10.2 - Adds tabs, hotkeys,...
TotalFinder is a universally acclaimed navigational companion for your Mac. Enhance your Mac's Finder with features so smart and convenient, you won't believe you ever lived without them. Features... Read more

Home Street guide - how to make friends...
From the creators of Food Street comes Home Street, a new simulation game that tasks you with building a social network and designing a beautiful home. It's a bit like The Sims, but you won't have to worry about the daily chores involved (feeding,... | Read more »
Color Ballz guide - how to bounce to the...
Color Ballz is an addictive new arcade title from Ketchapp Studios. It takes old school mechanics from games like Brickles and puts a fun twist on it. Your job? To catch balls with a paddle and send them back into a chute to be carried back to... | Read more »
Q&A: A-33 Studio explains why Combat...
When it comes to mobile FPS, it’s often tricky to get the fundamentals right on a platform lacking a physical controller, large display and hefty RAM. With Combat Squad: Project Wednesday, A-33 Studio bravely took on the challenge of making a... | Read more »
Taichi Panda 3: Dragon Hunter guide - ti...
Taichi Panda 3: Dragon Hunter launched this week to players all over the world. It's a beautiful mobile MMORPG that blends elements of Eastern and Western fantasy. It reminds us of a mix between World of Warcraft and Jade Empire. MMO's can have a... | Read more »
The best new games we played this week -...
Phew. It has been a week, but now it's time to relax, put your feet up, and enjoy some brand new mobile games. It was a bit of slow week, but there's still plenty of new titles to add to your collection. Here are four of our favorites. [Read... | Read more »
Yoink - Improved Drag and Drop (Product...
Yoink - Improved Drag and Drop 1.0 Device: iOS Universal Category: Productivity Price: $2.99, Version: 1.0 (iTunes) Description: Yoink for iPad and iPhone lets you easily and quickly store items you drag, copy or share, for later use... | Read more »
Cottage Garden (Games)
Cottage Garden 1.11 Device: iOS Universal Category: Games Price: $4.99, Version: 1.11 (iTunes) Description: | Read more »
Into the Dead 2 guide - how to survive t...
Into the Dead 2 is an endless gunner, of sorts, with a lot of grit and satisfying gunplay behind it. The game looks amazing, and tells an effective story to boot. Plus, it has some quality voice acting behind it to really bring the story to life... | Read more »
Smash Up - The Card Game (Games)
Smash Up - The Card Game 1.0.7 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.7 (iTunes) Description: ***“It’s a goofy theme with fun art and high replayability, but beneath that veneer of casual play is a great... | Read more »
Dive in to Combat Squad if you’re lookin...
Earlier this year, A-33 Studio made the leap from developing Counter Strike Online to launching its very own FPS for the mobile. Combat Squad: Project Wednesday pits your team of mercs against the world in multiplayer death matches, so if you’re on... | Read more »

Price Scanner via MacPrices.net

Sale! 10″ Apple WiFi iPad Pros for up to $100...
B&H Photo has 10.5″ WiFi iPad Pros in stock today and on sale for $50-$100 off MSRP. Each iPad includes free shipping, and B&H charges sales tax in NY & NJ only: – 10.5″ 64GB iPad Pro: $... Read more
Apple iMacs on sale for up to $130 off MSRP w...
B&H Photo has 21-inch and 27-inch iMacs in stock and on sale for up to $130 off MSRP including free shipping. B&H charges sales tax in NY & NJ only: – 27″ 3.8GHz iMac (MNED2LL/A): $2179 $... Read more
2017 3.5GHz 6-Core Mac Pro on sale for $2799,...
B&H Photo has the 2017 3.5GHz 6-Core Mac Pro (MD878LL/A) on sale today for $2799 including free shipping plus NY & NJ sales tax only . Their price is $200 off MSRP. Read more
12″ 1.2GHz Space Gray MacBook on sale for $11...
Amazon has the 2017 12″ 1.2GHz Space Gray Retina MacBook on sale for $100 off MSRP. Shipping is free: 12″ 1.2GHz Space Gray MacBook: $1199.99 $100 off MSRP Read more
Bare Bones Software Releases macOS High Sierr...
Bare Bones Software has announced the release and immediate availability of BBEdit 12.0, a significant upgrade to its professional strength text and code editor. BBEdit 12 introduces a new foundation... Read more
Yale Announces Availability of Apple HomeKit-...
Yale Locks & Hardware has announced that Apple HomeKit support for its Assure Lock family is available this month. The new Yale iM1 Network Module, which provides support for the Apple Home app... Read more
Clearance 2016 13″ MacBook Pros, refurbished,...
Apple has Certified Refurbished 2016 13″ MacBook Pros available starting at $1189. An Apple one-year warranty is included with each model, and shipping is free: – 13″ 2.9GHz/512GB Touch Bar Gray... Read more
12-inch 64GB iPad Pro on sale for $749, save...
Adorama has 12″ 64GB iPad Pros on sale today for $749 including free shipping plus NY & NJ sales tax only. Their price is $50 off MSRP. Read more
13″ 3.1GHz/256GB Silver MacBook Pro on sale f...
Amazon has the Silver 13″ 3.1GHz/256GB MacBook Pro (MPXX2LL/A) on sale for $1699 including free shipping. Their price is $100 off MSRP. Read more
12″ MacBook available for $1099 with Apple re...
Apple has Certified Refurbished 2017 12″ Retina MacBooks available for $200-$240 off the cost of new models. Apple will include a standard one-year warranty with each MacBook, and shipping is free.... Read more

Jobs Board

*Apple* Retail - Multiple Positions - Apple,...
Job Description:SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions - Farmin...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions - Apple...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions - Apple...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.