Chapter 3 Study Guide May 20, 2015

Today’s Objective: Review chapter 3 for MTA Gaming Certification test. Certification Test next week Wednesday and Thursday!

We will review the following: DirectX® Video and audio compression Resolution (Full Screen, Windowed) VSync

REVIEW What is DirectX and how do you use it? DirectX is a collection of application programming interfaces (APIs) from Microsoft® for handling tasks related to multimedia, especially programming games and high- performance multimedia applications, including 2-D and 3-D graphics. How can audio and video be compressed? Audio and video can be compressed with codecs, which are software programs used to compress audio and video. Windows Media Player®, which copies a song from a CD and makes it playable on your computer, is an example of a codec. When is VSync used? VSync stands for vertical synchronization and is used to synchronize the frames per second with the monitor’s refresh rate to prevent tearing.

DirectX Enhances the multimedia capabilities of computers. Provides access to the capabilities of display and audio cards, enabling programs to provide realistic 3-D graphics and immersive music and audio effects. A set of low-level application programming interfaces (APIs) that provide Microsoft Windows® programs with high-performance hardware-accelerated multimedia support. Provides a set of APIs that you can use to create games and other high-performance multimedia applications. application programming interface (API): a set of rules and specifications that software programs can follow to communicate with each other.

Resolution Full Screen mode The game is the only thing on the display screen. Typically the default game mode. Windowed mode Only uses a portion of the display. If the resolution is set too high, some of the game will be off the display. VSync Short for “vertical synchronization”; used to synchronize the graphics card with the output on the monitor. Tearing Occurs when the VSync is disabled and the graphics card and monitor rates have different refresh rates. A line appears to be separating the display.

Video compression Refers to reducing the amount of data used to represent digital video images. Combines spatial image compression and temporal motion compensation. Lossy compression compresses data by discarding (losing) some of it. The procedure aims to minimize the amount of data that needs to be held, handled, and/or transmitted by a computer. Used to compress multimedia data (audio, video, and still images), especially in applications such as streaming media. Lossless compression allows the exact original data to recovered from the compressed data. Methods for lossy compression: Reducing the color space to the most common colors in the image is one method. The selected colors are specified in the color palette in the header of the compressed image. This method can be combined with dithering. Chroma subsampling takes advantage of the fact that the human eye perceives spatial changes of brightness more sharply than those of color, by dropping some of the color information in the image. Transform coding is the most commonly used method. Some image file formats, like PNG or GIF, use only lossless compression, while others, like TIFF and MNG, may use either lossless or lossy methods.

Audio Compression Lossy compression in which the amount of data in a recorded waveform is reduced with some loss of quality. Typically used in CD and MP3® encoding, Internet radio, and video games. XACT is used to add .wav files that can be built and interpreted by an XNA Game Studio game. Compress WAVE (*.wav) files using XACT. This is an example of a codec used to compress .wav files, which could be used for an XNA game

Answers to worksheet questions #1-7, Fill IN, Multiple choice, and Your Scenario’s.

What are the different audio and video compression techniques? Audio and video can be compressed with codecs, which are software programs used to compress audio and video. Windows Media Player®, which copies a song from a CD and makes it playable on your computer, is an example of a codec.

What is a suitable UI concept for a sports game in the mobile platform? When selecting a UI concept you need to keep it simple. Too many options can confuse the player, resulting in a frustrating gaming experience. The UI f your game should contain only necessary UI elements. Your game player should be able to navigate the game with ease. Maybe you might want a basketball court, player, net, ball, etc.

What is DirectX? DirectX is a collection of application programming interfaces (APIs) from Microsoft® for handling tasks related to multimedia, especially programming games and high-performance multimedia applications, including 2-D and 3-D graphics.

What are the different APIS included in DirectX and for what purpose? Direct3D – is a set of 3D graphics that you can use to develop games for Windows operating systems 95 and above and Xbox360 console. Direct2D- Contains the 2D graphics API that provides high performance and high quality rendering of 2D images. DirectSound3D – is a set of APIs that provides communication between multimedia applications, including your game applications and sound card driver. DirectPlay – provides a set of APIs that provides an interface between your game applications and communication services, such as the Internet or local networks. DirectInput – is a set of APIs that helps your game application collect input from the players through the input devices. and so forth. The “X” in DirectX refers to the respective API names.

Full screen mode for mobile devices and consoles. What are the possible display modes that you can select for an MMORPg game? Full screen mode for mobile devices and consoles. Windowed mode for PC’s Where do you play your MMORPG game? On a PC its windowed. Mobile its full screen.

What is the role of VSYNC in a game display? VSync controls the refresh rates of your display. It restricts the video card from producing frame rates higher than the refresh rate of the monitor. In other words, Vsync makes the computer wait until the monitor has drawn the image completely. Therefore, the number of times the image is drawn cannot be greater than the monitor refresh rate. This reduces the load on the graphics card because Vsync sets a limitation on the number of times the image is drawn.

Fill-in the blanks 1. Parallax mapping is a 3D technique that helps the game objects look three-dimensional with depth that is more apparent. 2. Sprite Font helps to draw text in your game visuals. 3. Bitmap image is represented in pixels. 4. Multi-user Dungeons is an example of a multiplayer online text game. 5. Direct3D API exposes the advanced features of 3D graphics card. 6. XInput provides a set of APIs that help your game application to collect input from the players through the Xbox console. 7. VSync technology helps prevent tearing of the image by restricting the video card from producing frame rates higher than the refresh rate of the monitor. 8. Lossy and Lossless are the two types of compression techniques. 9. Audio Video Interleaved compression provides a larger file size even after compression. 10. Silence compression type compresses the periods of silence in speech samples.

Multiple choice In your action game, you create a scene where the player character assaults the villain character on his hand. Which of the following design elements can be used to create the effect of broken fingers of the villain character? a. Sprite b. Parallax mapping c. Vector graphics d. Textures Answer: A A sprite helps to include small unrelated images into a single image on the screen.

You develop an adventure game You develop an adventure game. You are required to mimic a cell built with brick walls for a particular scene. Which of the following technique would you choose to provide an illusion of depth on the surface of the wall? a. Sprite b. Parallax mapping c. Lighting d. 3D geometry Answer: b Using parallel mapping techniques, you can make the game objects such as a stone wall look three-dimensional with more apparent depth.

In your sports game, which of the following design elements would you choose to display the scores of the players? a. Sprite font b. Parallax mapping c. Sprite d. 3D geometry Answer: a Sprite font helps to display the scores of the players.

You develop an action game You develop an action game. You want to provide options for the players to choose a suitable weapon before an attack. Which of the following UI component would you choose? (Choose all that apply.) a. Sprite b. Diegetic component c. Nondiegetic component d. Menu Answer: c Both nondiegetic and menu can be used in a game to provide the player with a list of options.

In an action game, you decide to show the balance amount of ammunition in the player character's gun. Which of the following UI components would best display the information? a. HUD b. Nondiegetic component c. Spatial component d. 3D geometry Answer: a A HUD provides game- specific information such as the balance amount of ammunition in a player character's gun through visual representations.

You would like to provide the users of your game with game sessions You would like to provide the users of your game with game sessions. Which of the following API do you think would facilitate game sessions? a. DirectInput b. DirectPlay c. DirectSound d. XInput Answer: b DirectPlay provides your game players with game sessions and manages the flow of information between hosts and players.

You are creating a game for PC users You are creating a game for PC users. Which of the following display modes would you choose for your game? (Choose all that apply.) a. Full screen b. Windowed c. VSync d. Adaptive VSync Answer: a A PC supports full screen and windowed display mode. Moreover, you can also choose the Vsync display option that allows the players to turn on or turn off the VSync for the game.

You decide to use M- JPEG compression in your game You decide to use M- JPEG compression in your game. Which of the following data redundancy type does M-JPEG compression eliminates? a. Spatial b. Spectral c. Temporal d. Psycho-visual Answer: a M-JPEG involves intraframe coding for eliminating the spatial redundant data.

You use compression tools to compress your game You use compression tools to compress your game. Which of the following are compression tools? (Choose all that apply.) a. Zencoder b. Bink Video c. DivX compression d. Code Excited Linear Predictor (CELP) Answer: a Zencoder and Bink Video from Rad Game Tools are the tools for compression of games. Option c and d are video and audio compression types.

In your game, you decide to choose video and audio formats that are available by default in all the computer systems. Which of the following formats should you choose? a. AVI and WAV b. MPEG and WMA c. H.261 and Real Audio d. H.261 and WMA Answer: a By default, all the computer systems support the AVI and WAV formats.

Scenario 3-2: Using DirectX You develop a console game. Explain with reason the different DirectX components your game might use. Solution: In general, all console devices have a good GPU acceleration support. Therefore, you can use almost all the DirectX components in your game. The following lists the possible DirectX components that your game can use: Direct3D: You can use Direct3D because it provides a set of 3D graphics API for developing games for console devices such as Xbox 360. DirectSound: DirectSound places the sound using a three-dimensional coordinate system instead of a simple left and right pan. This allows the game players to experience multichannel surround sound of your game at a high resolution. DirectPlay: DirectPlay provides a set of APIs that provides an interface between your game applications and communication services such as the Internet or local networks. This allows you to provide your game players with game sessions and manage the flow of information between host and players. DirectInput: DirectInput is a set of APIs that helps your game application to collect input from the players through the input devices such as a keyboard, mouse, or any other game controllers. Moreover, this API also helps you to assign game-specific actions to the buttons and axes of the respective input device.

Scenario 3-3: Developing Visual Theme and UI Concept You are developing a fantasy game for the mobile platform. Develop the visual theme and the UI concept for your game. Solution: Game Genre: Fantasy Game Name: Forbidden Caves Game Concept: The game involves around a mine with unexplored wealth. Four explorers endeavor in this and find a century old hidden world below. Visual Theme: As this game involves a hidden world of the past, the visual theme of this game will involve Rocky Mountains, trees, and plants with the look of the gone era and even the look of both creatures and humans in this virtual world will be of the past era. UI Concept: The UI concept will be in line with the game concept. Because the game concept involves a virtual world from the gone era, the UI should reflect the feel of darkness. Moreover, as the game involves four explorers undertaking mission underground, the UI will also involve equipment that normally miners would use for mining. In general, the UI concept should reflect the visual theme of the game.

Scenario 3-4: Selecting Rendering Engines and Design Components You are developing a mobile game. Your game concept is similar to Angry Bird. Select the suitable rendering engine and decide on the required game design components for your game. Solution: The rendering engine that the game can use is Microsoft XNA Game Engine. As the game is developed for a mobile platform, the game can probably use 2D graphics medium to cater to all the game players irrespective of whether they possess the latest technology mobile or not. Based on this, you can use the following design components that impose 2D features for your game. Vector images Sprites Sprite font Textures Normal mapping

Key Terms bitmap - A file format that is used to store images, made up of pixels or dots that contain rows and columns of little squares.   codec - A device or a program that encodes or decodes a digital data. compression - A technique that reduces the data to lesser bits. DirectX - A collection of APIs from Microsoft that handles high performance multimedia applications including games. display initialization - A set of minimum requirements that should be available for your game to run smoothly on the chosen platform.   display mode - The characteristics of a computer display that can have different image resolutions. graphics type - A medium of graphics that a game designer uses to create the game design elements. lossless compression - A compression technique that accounts for data reduction without any data loss after compression. The original data can be reconstructed from the compressed data, without losing any information.

Key Terms   lossy compression - A compression technique that accounts for data reduction. The original information cannot be reconstructed when the file is decompressed. parallax mapping - A 3D technique that is an enhancement of the “normal mapping” technique applied to textures. rendering engine - An engine that abstracts the communication between the graphics hardware such as the graphics processing unit (GPU) or video card and the respective device drivers through a set of application programming interface (API). resolution - A term that describes the number of pixels that can be displayed on a display device such as a monitor or a television. UI components - The constituents that encompass the interactive and non-interactive UI elements of a game.   UI concept - A visual theme that describes the idea of a game. UI layout - An arrangement of the user interface elements in the game.

Key Terms visual design - An expression of thought or the idea of the game through graphical representation.   visual design elements - The components that are used for creating the visual design of your game characters and game objects. Vertical Synchronization (VSync) - A display option that allows the players to synchronize the frame rate of the game display with the monitor refresh rate for better stability.