GRIMM GRIMM Choose- -Your Your- -Own Own- -Story Language - PowerPoint PPT Presentation

GRIMM GRIMM Choose- -Your Your- -Own Own- -Story Language Story Language Choose Mike Lenner Mike Lenner Billy Liu Billy Liu Mariya Nomanbhoy Nomanbhoy Mariya Becky Plummer Becky Plummer

What is GRIMM What is GRIMM ! Named for famous storytellers Named for famous storytellers – – Grimm Grimm ! Brothers Brothers ! Designed to make creating an interactive, Designed to make creating an interactive, ! first- -person role playing game easy and person role playing game easy and first intuitive intuitive ! No programming experience required No programming experience required – – ! language based on free- -form English form English language based on free ! Reallocates the majority of effort where it Reallocates the majority of effort where it ! belongs – – the story writing the story writing belongs

Language Outline Language Outline ! First section of GRIMM programs are declarations First section of GRIMM programs are declarations ! ! Developer declares scenes within a story. Each scene Developer declares scenes within a story. Each scene ! contains standard set of properties contains standard set of properties – Name (“The Living Room”) Name (“The Living Room”) – – – Description (“You are standing in a room with green walls”) Description (“You are standing in a room with green walls”) – Picture (“ Picture (“room.jpg room.jpg”) ”) – – Items (couch, notebook) Items (couch, notebook) – – – Exits (hallway, kitchen) Exits (hallway, kitchen) ! Developer may also declare items and characters Developer may also declare items and characters !

GRIMM Example - - Declarations Declarations GRIMM Example scene castleGate scene castleGate scene scene courtYard courtYard castleGate name “The Castle Gate” castleGate name “The Castle Gate” castleGate description “You are standing in front of a large castleGate description “You are standing in front of a large wooden gate. The gate is locked and there are two soldiers wooden gate. The gate is locked and there are two soldiers preventing your passage.” preventing your passage.” castleGate exit courtYard castleGate exit courtYard courtYard name “Castle Court Yard” courtYard name “Castle Court Yard” courtYard description “You have entered the castle court yard. courtYard description “You have entered the castle court yard. You see that a joust tournament is about to begin.” You see that a joust tournament is about to begin.” courtYard contains item lance courtYard contains item lance courtYard contains item helmet courtYard contains item helmet character Merlin character Merlin Merlin holds item staff Merlin holds item staff

Language Outline Language Outline ! Second part of GRIMM program is the Second part of GRIMM program is the ! actual story using these declared scenes, actual story using these declared scenes, characters and items. characters and items. ! Control flow constructs guide user through Control flow constructs guide user through ! declared scenes based on user input. declared scenes based on user input. ! Conditionals test the state of the user Conditionals test the state of the user ! (what scene is occupied, what items are (what scene is occupied, what items are owned). owned).

GRIMM Example – – Control Flow Control Flow GRIMM Example while user inside dungeon while user inside dungeon read user input read user input if user says “unlock cage door” and not user has key then if user says “unlock cage door” and not user has key then say “You cannot unlock the door without the key.” say “You cannot unlock the door without the key.” otherwiseif user says “unlock cage door” and user has key then otherwiseif user says “unlock cage door” and user has key then say “The door is unlocked and you slip through the cage say “The door is unlocked and you slip through the cage unnoticed. You move quickly to the treasure room unnoticed. You move quickly to the treasure room next door.” next door.” goto treasureRoom goto treasureRoom otherwiseif user says “open treasure chest” then otherwiseif user says “open treasure chest” then say “You open the chest and you see a silver key.” say “You open the chest and you see a silver key.” read user input read user input if user says “take key” then if user says “take key” then user pickup key user pickup key say “You took the key” say “You took the key” otherwise otherwise say “The chest has closed shut on its own.” say “The chest has closed shut on its own.” endif endif endif endif endwhile endwhile

Game Play Game Play ! Story is played out by displaying current Story is played out by displaying current ! scene to the user, then waiting for input. scene to the user, then waiting for input. ! Many such games are text based Many such games are text based – – GRIMM GRIMM ! creates graphical based applications. creates graphical based applications. ! User interacts with a GUI console User interacts with a GUI console ! – shows the current state of the game as well shows the current state of the game as well – as allows for user interaction. as allows for user interaction.

GUI Components GUI Components Scene title scene castle scene name “Castle Path” scene description “You are standing on a Scene image dirt path. Ahead of you in the distance you see the Castle of the North Kingdom. You think you hear something that sounds like trumpets blaring way off in the distance. To your left is a small dagger.” scene image “castle.jpg” scene castle contains item dagger scene exit gate Scene description if user says “pick up dagger” Non-hidden pickup dagger scene exits endif User items User – Game interaction Non-hidden scene items

Scene Update Scene Update slay dragon

GRIMM Implementation GRIMM Implementation ! Lexer Lexer – – separate text into token stream separate text into token stream ! ! Parser Parser – – builds syntactically correct AST builds syntactically correct AST ! ! Walker Walker – – builds symbol table while builds symbol table while ! checking for semantic errors checking for semantic errors ! Translator Translator – – walks AST generating Java walks AST generating Java ! code based on each node code based on each node ! Runtime Environment Runtime Environment – – Java classes used Java classes used ! by Translator in creating application code by Translator in creating application code

GRIMM Implementation GRIMM Implementation

Runtime Environment Runtime Environment

Lessons Learned Lessons Learned ! Understand big picture before coding Understand big picture before coding ! begins begins ! Split up responsibilities earlier in the Split up responsibilities earlier in the ! project project ! Know the scope of your language from the Know the scope of your language from the ! beginning and try not to deviate beginning and try not to deviate ! Difficult to maintain free Difficult to maintain free- -from English from English ! syntax when building the compiler syntax when building the compiler

Summary Summary ! GRIMM is a useful tool for the storywriter GRIMM is a useful tool for the storywriter ! – Less time spent on coding, more on Less time spent on coding, more on – developing storylines. developing storylines. – A lot can be accomplished without a lot of A lot can be accomplished without a lot of – code. code. ! Maintained somewhat intuitive syntax Maintained somewhat intuitive syntax ! ! Extremely successful team collaboration Extremely successful team collaboration !