Mobile game development review 1, background introduction
The current mobile phone is a small computer, its processing power is very limited compared to desktop standard processing capabilities, but enough to run a small game.
One feature of the current mobile phone is whether they are still a network computer, which is able to express and receive digital data at high speed. In addition to speech data, they can also send and receive other types of data. So online games like "Legend", "Millennium" can also be implemented on mobile phones.
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Of course, in terms of processing capabilities and performance, the current stage of support Java is very close to the second generation console game console, home computer and early hand holding game machine in the mid-1980s. Memory is usually limited - general 128kb to 500kb - Although some smartphones are like NOKIA 3650 with 4 MB of memory. Compared to the PC, their input and display functions are also limited; small screens (many still black and white screens), small keyboards optimized for phone, are not for text input, and limited sound processing capabilities.
Second, how mobile game is implemented
The technology currently implementing games in mobile phones has the following:
1, embedded game
Some games are cured in the chip before leaving, and like NOKIA's greedy snake is the most famous example. But because users cannot install new games themselves, they gradually become less popular.
2, short message service game
Short message service (SMS) is used to send short text information from one mobile phone to another. Users generally pay 1 cent information fee for each information. The short message service gameplay typically sends a message to a number, this number corresponds to the game vendor server, the server receives this message, performs some operations and then returns a message with the result to the player's phone. Short message service is not a particularly good technology for implementing mobile games because it relysses the user into text, so it is a command line environment. And it is still very expensive, even if you only exchange 10 messages with the server, you have to spend 1 money or more money. Although the introduction of multimedia message service (MMS) technology makes messages more attractive, it is still not an important game environment, so we will not discuss it in a deep exploration.
3, browser game
Each mobile phone that is existing in 1999 has a wireless application protocol (WAP) browser. WAP is essentially a static browsing vector, very like a simplified web, which is specifically optimized for mobile phone small features and low bandwidth. To play WAP games, you can enter the game vendor's URL (usually by a link to the mobile operator portal), download and browse one or more pages, select a menu or enter text, submit data to the server, then browse Multi-page. WAP (1.x) version uses a unique tag language WML, allowing users to download multiple pages, i.e., card groups. The new version of WAP (2.x) uses a subset of XHTML, pass a page at a time and allows for a better control display format. Both version of WAP provide a more friendly interface than SMS, and more cheap, as long as the payment is paid according to usage time, not based on the number of information. But it is a static browsing carrier; the phone itself does not need to do any processing, and all games must pass through the network, all operations are executed on the remote server. The mobile phone will continue to have a WAP browser, and developers may find that WAP is conducive to greater more detailed help information or rules than the game application, because most of the games are still limited by limited memory. However, WAP has not reached the goal of high usage (in Europe and North America, only 6% of mobile phones use WAP), and mobile operators and game developers are staying away from WAP technology. We will not explore any details of any WAP here.
4, J2ME and other interpreted languages
Java 2 Micro Edition (J2ME) is a Java language for small devices such as mobile phones and PDAs. Most mobile phone manufacturers are urgently hoping that JAVA mobile phone can be promoted. Tens million Java phones have reached the consumer's hand. J2ME has a great restriction compared to Java in the desktop, but it has greatly improved the ability of mobile phones to support games. It has a better-controlled interface than SMS or WAP, allowing the use of sub-graphics animation, and can be connected to the remote server via a wireless network. Supporting the popularity of Java's mobile phones, so it becomes the best mobile game development environment, we will study the development of J2ME games here. J2ME is not the only interpretation language configured on your phone, but it is a business standard supported by many manufacturers. Some dedicated interpretations have good performance in some areas, such as North American Qualcomm Brew (Binary Runtime Environment for Wireless, binary operating environment for wireless applications) and some Korean mobile operators supported by GVM Standard. In this series of articles, we will focus on discussing using J2ME to develop mobile games and will introduce a method of developing mobile games on the NOKIA platform. 5, C app or other compile language
Another development method is to develop mobile games using C , compile the program into local machine code. Compile language programs generally tell to provide a better control user interface, and faster than interpreting languages. C developers can be positioned in Series 60 platform devices. In addition, Microsoft's .NET CF can also develop games on mobile devices in a compiled form. In the later articles, I will introduce the way to develop game development on the Pocket PC platform. Third, the difference between mobile game development and traditional game development
Mobile game development is different from traditional game development in many aspects:
1. The size of the development team
Traditional PCs and console games generally require 12 to 30 development teams. Because most of the mobile game size is small than the console game, only the team developed by 3 to 5 people, sometimes the designer and programmer are the same person.
2, budget
The traditional game budget is between $ 10 million to $ 5 million. Most of the mobile game budget is usually less than one million dollars. In fact, mobile phones have limited display capabilities and limits for application size make it impossible to put a lot of financial resources like traditional games. In a sense, this is also an advantage.
3, development cycle
Traditional games generally have to develop two to three years. Most of the mobile games can be opened within a few months. In other words, as long as there is a small development team and a small budget, you can develop and promote a professional mobile game. Therefore, for many developers who have appeared in the traditional game field, mobile game development has strong attractions.
4, network equipment
Mobile games may differ from any game we have seen before: it is limited by carrier factors, but supports networks and multiplayers. The modem for the PC is only 8 years ago; the console game is only available now. The characteristics of the mobile phone determine it is a network device. Even though their processing power makes people think of previous vintage computer technology, their network performance is even more prosperous.
5, open standard
Console game development needs to be authorized and supported from console gaming vendors, and it is necessary to pay for them "platform usage". In the World Wireless Applications (like in PC game development), you can develop any styles for free without paying a penny for NOKIA, Sun or other platform providers. In addition, these mobile game development platform standards can be released to developers, open and free.
6, deployment
Traditional games are mainly purchased on the software market. The mobile game is mainly downloaded and installed by the user from the mobile portal. In some cases, they are downloaded through the wireless network. Some mobile phones allow you to download an application to your computer and then transfer to your phone via the data line.
Therefore, the sales channel of mobile games is very different. Users typically find mobile games on the game menu or wireless application portal in your mobile phone by mobile operators. Fourth, the advantages of the carrier
1, huge potential user group
It is now being used in more than one billion mobile phone worldwide, and this number is gradually increased. In each developed country other than the United States, the number of people with mobile phones is more than the number of people with a computer. Although only a small part of the mobile phone is a mobile phone that supports Java, this number is rapidly increased and the Java mobile phone will become industry standards in a few years. Mobile game potential markets are larger than any other platform, such as PlayStation and GameBoy.
2, portability
GameBoy sells more reasons than any other console game is: portability. People can play their choices anytime, anywhere. Compared with the current game console or personal computer, the phone may not be a good game device, but people basically take them around them. When they leave home or want to play, give developers should provide them with fun games.
3, support network
Because the mobile phone is a network device, you can implement multiplayer games, although there are certain restrictions. Five, the shortcomings of the carrier
1, small screen
You face a small screen. Although the screen resolution continues to increase, and the color screen is about to be standard, but the screen size is still small, because no one is happy to take a brick phone.
There is also a related problem: the screen size of different phones is different. For example, the NOKIA Series 60 platform device provides different screen sizes for Series 40 devices such as NOKIA 5100. Although individual vendors have standardized their product's screen size to avoid segmentation, developers still need to optimize their games for different calls - you'll know all available screen space on a specific mobile phone.
2, limited color and sound support
Most of the mobile phones in the hands of the users are still black and white, although most of the support of Java's mobile phone now is a color screen phone. The 12bit color is very popular in these phones.
Even if the phone has a sound device, the ability of the application playing sound is very limited. The J2ME specification does not require hardware vendors to support sound, although the basic Java mobile phone allows you to use some sounds and MIDI support is becoming standard. Typically, there is only one voice or a channel available in the phone.
3, application size limit
Most of the Java phones have only very few memory spaces for running the MIDlet. In addition, there is always a limit to the size of the MIDlet. The actual restriction depends on the rules of mobile devices and mobile operators.
It is very difficult to design and develop mobile games under such restriction conditions, but we have to know that only 64 kB of memory is only 64 kB, but it is still passionate about developing game software. There are fewer restrictions on some smartphones, such as NOKIA 3650, can even run a few megabytes of applications.
4, high-class time
Waiting time ---- The machine issues a request and receives the time spent between the response ---- is calculated in microseconds on the computer; in the wired Internet calculation; and in seconds of the wireless network .
Waiting time is a problem that has always been in online games, and developers always work hard to eliminate the problems it bring. Wireless network waiting time is very long, which is impossible to develop multi-person fast motion mobile games. However, the turn-based multiplayer game is quite possible, and we will discuss how to use various methods to handle this problem in later articles.
Although mobile operators are always working to increase the bandwidth available to mobile phones, they do not have the problem of lowering waiting time as a primary resolution, as it is not important for other applications.
There is also a special case: mobile phones that use Bluetooth technology or other wireless local area network technology can use the Internet waiting time (general 200-400 milliseconds) communication using the nearby Bluetooth device. In this way, using smartphones like Nokia 3650, you can play multiplayer with a nearby mobile user.
5, can be interrupted is the key
When the user answers the phone, the mobile phone will interrupt the game. The game program must be able to suspend and continue, and will not cause the game problem (for example, the player is still moving when the phone is called, killing the player's role, causing the game) and does not cause memory overflow. This requires more attention when programming, NOKIA provides technical documentation Help J2ME and Symbian C developers understand and resolve this issue. 6. Technology is developing
Techniques for developing mobile games are not for game design, so there is often a specific limit condition. For example, the J2ME specification does not need to support transparency, which makes the sub-graphics in addition to the blank background, it will be ugly on any background.
Fortunately, most equipment manufacturers' Java mobile phones have complement J2ME and support transparency. To make full use of J2ME performance, you need to support mobile phone-specific API; in order to get the best results, you need to write several versions for a game. Recently Incebted MIDP 2.0 specification solves some such problems, but mobile phones that are not compatible with MIDP 2.0 are invalid. Sixth, avoid the short place
The game has amazing plasticity; they can be implemented using each technology from the stone age to modern high technology. Whenever you use the technology you have never used before, you need to understand its performance and limitations, and strive to bring its performance to the limit while avoiding or resolving its limitations.
What conclusions can we get in the performance and limitations of our mobile games?
1, short game time
People will call or answer the phone sooner or later, and they don't want to use all the power to play games. The ideal case is that each round of games should remain within five minutes or less. This doesn't mean that a complete game must end within five minutes - but you should allow the player to interrupt, save, and continue the game.
2, players have their own timetable, not to follow your timetable
Let people play when they want to play games, don't force them to wait (if you can avoid), don't ask them to be in the game at any time.
3, avoid waiting time
This is easy to implement for single games. In multiplayer games, you need to solve the problem of waiting time. (We will discuss this problem later.)
4, use the network
The network is not necessarily necessary for each mobile game, but the feeling of competition with people, even if there is only one leaderboard, you can attract more players. To remember that mobile phones are actually a social equipment, adding some social factors to your game to make it more popular.
5, keep the game small as possible
Remember, people still heat in the 80s excellent game. In some respects, the limitations of technology forced you to put more attention in the basic game.
When we explore development in subsequent articles, we will discuss some technical issues.
6, do a good job in supporting a variety of mobile phones
At least, you need to support different screen sizes, which is easy to do for the Nokia series. Develop a version for Series 40 to develop another version for SERIES 60. In most cases, you have to use a specific mobile phone performance and API, such as NOKIA interface and SMS API, you have to develop different versions for mobile phones that do not have the same feature.
7, prepare for internationalization
The whole world is using mobile phones, and every language has its own market. You have to do a good job when you develop it, in order to make more localization.
Seven, handling waiting time
How do mobile games solve the high-class time for wireless networks?
1, single game
The game does not need to use the network unless you send the high score to the list, or allow the player to browse the list. This network communication has little effect on the game, and the delay in a few seconds will not cause the user's dislike.
In essence, there is no such problem in most single games.
2, "more players" single game
In a "multi-player" single game, the player feels that they are playing with a multiplayer game, but in fact, everyone is only facing the same game, comparing the score at the end of the game or round. When a player joins the game, he tells other players his ID number and then start playing a single game. The server either sends a game status file containing the same message to each player, or send a code from the client software from the constructor. Each player plays games, try the highest score. When a player ends the game, his client program submits his score to the server. When all players complete the game (or after a certain time), the server tells each player who has achieved the highest score, and the score obtained by each player.
This style of game is quite successful in the Internet; AOL's most popular game SLINGO is a good example.
Because only the exchange message is only required when the server starts or ends the game, the waiting time is only a problem when it is.
3, round-based game
In a round-based game, the player enters their turn and needs to wait for a while before receiving the results. A few seconds of delay can be tolerated.
There are two round-based games:
3.1, turning game
In a turnt game, each player enters the round in order. Classic games like chess, red heart war are very good examples. The disadvantage of this game is that the player can do anything before re-enter the round. Although the classic game has many players in the Internet, there are fewer bones, but have a little borus.
Therefore, the number of games that limit the turntable game is a very good idea, so that the delay will not become very long. Two to four players are more ideal.
3.2, simultaneous action game
In a simultaneous action game, each player is independent of other players planning his own actions. When a player is ready, he sends an instruction to the server. The server waits until all the players have received the instructions, then decompose the round, and then send the results to all the players there.
4, "Instant Action" game
In a "instant action" game, the game may last for a long time (a few days, a few weeks, a few months or even forever). The player can enter the game at any time and perform the action in the game. In some games, they may only interact with other users who enter the game; in other games, they may be able to interact with any other players, even if these players have offline.
6, distribute the waiting time to the game
Another simple way to let the player accept high-class time is to distribute the waiting time into the game itself. For example, most of the interstellar ship combat games make people feel like a fellow war, the warship whistling, and fires you. However, it seems difficult to achieve this hot scene on the phone. We can change a kind of thinking, we can make the interstellar warship game into a game similar to the first World War, the interstellar spacecraft slowly moves, and the fire cannon bomb, the missile is slow, and the missile is slow. To their goals. You can use this method to hide the waiting time for a few seconds. There is also more ways to solve long wait time. This is a problem worth speaking to solve the problem.
In subsequent articles, we will explore the technology of mobile game development.
