ANU comp2110 Software Design lecture 5 COMP2110 Software Design in 2003 lecture 5 Requirements Specifications lecture 3 of 3 The Encounter game case study 1. introduction to the Problem – the Encounter Game 2. examples from the specification document

ANU comp2110 Software Design lecture 5 The Software Requirements Specification SRS The product of the Analysis phase is a well defined information model: a set of labelled, organised requirements statements: functional consumer and developer requirements system requirements performance requirements a set of use cases or scenarios that capture and express the relationships between the model and the real world of the problem other explanatory models: interfaces, states, decisions

ANU comp2110 Software Design lecture 5 A Case Study of Encounter: Overview (1) An overview of the Specification of the Encounter video game Specification document comes in 2 parts: Encounter-SRS/EncounterSRS-1.html and... EncounterSRS-1.html you need to study this to prepare for tutorial in week 3

ANU comp2110 Software Design lecture 5 A Case Study of Encounter: Overview (2) The Encounter game is a computer based role playing game which simulates all or part of the lifetime of the player’s character includes characters not under player’s control, called foreign chacters game characters have a number of qualities: strength, speed, patience etc each quality has a numerical values the game is played over a map of areas (rooms) characters engage each other when in the same area the result of an engagement depends on the area and the values of the qualities of the two characters success is measured by living as long as possible with accumulated points

ANU comp2110 Software Design lecture 5 Sample Encounter Screen dressing room kitchen living room COURTYARD Set qualitiesEnd gameGet status Graphics reproduced with permission from Corel. Adapted from Software Engineering: An Object-Oriented Perspective by Eric J. Braude (Wiley 2001), with permission.

ANU comp2110 Software Design lecture 5

User Interface for Setting Quality Values Shawn Choose the quality you wish to set 16.3 Current life points: Choose the value of the quality selected image Adapted from Software Engineering: An Object-Oriented Perspective by Eric J. Braude (Wiley 2001), with permission.

ANU comp2110 Software Design lecture 5 User Interface for Setting Quality Values The values of the qualities not specifically chosen remain in the same proportion to each other. Values less than 1.0 are counted as zero. E.g., before: strength = 10.0, endurance = 60.0, intelligence = 30.0, patience = 0.0 (current life points = 100.0) change: strength from 10.0 to 20.0 after: strength = 20, endurance = 53.33, intelligence = Current life points: Image Choose the quality you wish to set Choose the value of the quality selected Explanation Shawn OK Graphics reproduced with permission from Corel. Adapted from Software Engineering: An Object-Oriented Perspective by Eric J. Braude (Wiley 2001), with permission.

ANU comp2110 Software Design lecture 5 2. Player requests a window for setting his character’s qualities.

ANU comp2110 Software Design lecture 5 Engage Foreign Character Use Case Encounter player 1. System displays the foreign character in the same area as the player’s. 2. System exchanges data between the two characters. 3. System displays the results of the engagement in a message window. 4. Player dismisses window. Initialize.. Engage foreign character Name of use case Details of use case Actor (agency external to the application) Adapted from Software Engineering: An Object-Oriented Perspective by Eric J. Braude (Wiley 2001), with permission.

ANU comp2110 Software Design lecture 5 A use case expressed in text "Engage Foreign character" use case Actor: player of Encounter 1. System displays the foreign character into the same area as the player 2. System exchanges data between the two characters 3. System displays the results of the engagement in a message window. 4. Player dismisses window.

ANU comp2110 Software Design lecture 5 A use case expressed in text "Engage Encounter Foreign character" use case Actor: player of Encounter 1. System displays the moves a foreign character into the same area as area occupied by the player or Player moves into the area containing a foreign character. 2. System exchanges data between the two characters causes the two characters to engage. 3. System displays the results of the engagement in a message window. 4. Player dismisses window. 4. If either the player's character or the foreign character has no points, the game terminates; or 5. System moves the player's character to a random area different from that in which the encounter took place, and displays it there.

ANU comp2110 Software Design lecture 5 A use case expressed in text - and refined "Encounter Foreign character" use case Actor: player of Encounter 1. System moves a foreign character into the area occupied by the player or Player moves into the area containing a foreign character. 2. System causes the two characters to engage. 3. System displays the results of the engagement 4. If either the player's character or the foreign character has no points, the game terminates; or 5. System moves the player's character to a random area different from that in which the encounter took place, and displays it there.

ANU comp2110 Software Design lecture create; display Sequence Diagram for Engage Foreign Character Use Case 2.1 execute 3 create and show :Engagement Display :Engagement 2.2 change quality values 1.2 create :Player Character :Encounter Game freddie: Foreign Character Adapted from Software Engineering: An Object-Oriented Perspective by Eric J. Braude (Wiley 2001), with permission.

ANU comp2110 Software Design lecture 5 From Sequence diagrams to Domain classes (1) these sequence diagrams are figures 13.22, 13.23, in Braude SD (with some changes) use cases are a beginning point for requirements and analysis alternatives include scenarios, event-action cases no prescribed format: but writing the use cases drags needs from the client drives the analysis of the information model to identify the “ingredients” - domain classes and some of the actions drives refinement, organisation, improvement of specification

ANU comp2110 Software Design lecture 5 From Sequence diagrams to Domain classes (2) Classes in the Encounter game classobject from Initialize sequence diagram: EncounterGame(a single object) PlayerCharactermainPlayerCharacter AreadressingRoom PlayerQualityWindow (a GUI class for the use case only) from Encounter foreign character: ForeignCharacterfreddie Engagement(a single object) Other domain classes can come from brainstorming & paring down.

ANU comp2110 Software Design lecture 5 Other sources of Domain classes? The use cases do not provide all of the useful classes for writing and organising the specifications EncounterGame PlayerCharacter Area PlayerQualityWindow ForeignCharacter Engagement EngagementDisplay GameCharacter AreaConnection ConnectionHyperlink Other domain classes can come from brainstorming & paring down door exit combat passageway result score rule quality... and more see fig 13.41

ANU comp2110 Software Design lecture 5 Other sources of Domain classes? (2)... brainstorming & paring down Game: not a domain class, too general GameCharacter : too general – replace by PlayerCharacter ForeignCharacter : OK to keep, acts a bit differently from PlayerCharacter – so introduce EncounterCharacter as common parent Quality : omit, try to handle as an attribute of EncounterCharacter Room : we already have Area which covers this concept, no need to distinguish any difference

ANU comp2110 Software Design lecture 5 Why look for the domain classes? the domain classes are the key concepts (nouns) that should appear in most of our functional requirements statements we want to easily match requirements with classes in the design: keeping the domain classes (and adding more classes) is a good starting point for design

ANU comp2110 Software Design lecture 5 Information models – finite state model