Project Overview Team: Ben Smith, Avrum Tilman, Josh Weinberg, Ron Weiss Mapwad: A Maze Generation language

Overview and Summary A high level language for creating mazes rendered in 3 dimensions using Quake. Built in data structures and functions to naturally express a map. Ability to define custom functions to ease implementation of maps Java/C style syntax and semantics

Motivation

Motivation Designing mazes by hand is tedious and error prone Build large, complex mazes algorithmically

Goals Easy to use - intuitive syntax, simple language constructs Flexible - few constraints on maze - walls can be at any angle to each other, etc. Concise - able to generate complex maze with few lines of code

Language Design The language is designed around high- level data types that offer an intuitive description of a map Instead of dealing with planes you deal with rooms Mapwad eliminates the need to specify coordinates –All objects are positioned relative to each other

Mapwad syntax Java/C –Whitespace ignored –Comments /**/ and // –Blocks enclosed in {} –Function default parameters: MyFunc(int a,int b=3,int c=4) {…} MyFunc(1,,10); MyFunc(1,2); –“dot” operator (built-in types only): myRoom.Walls[0].Length = 10;

Reserved Words Control Flow –if, else, for, while, break, continue, return Primitive Data Types –int, float, boolean, string Values –true, false, null

Object Data Types Room –Walls - Super Data Structure Wall Location Thing

Built in Functions –boolean Add(Room r, Wall newWall) –boolean AddAfter(Wall w, Wall newWall) –Remove(Wall w) –boolean Attach(Wall a, Wall b, string connectpoint) –boolean Close(Room r) –boolean IsClosed(Room r) –Math Functions Variables –MapStart –MapHeight –CeilingTexture –FloorTexture

Semantics Scoping rules –Global scope –{} blocks have own scope –Rooms and Things automatically added to map Primitive Types –Passed by value –Instantiated when variable is created int x; //creates a variable and instantiates an int Object types – Passed by reference –Object-typed variables are references –Must be explicitly instantiated Room r;//creates a reference to a Room r = Room(); //instantiates a Room object

Compiler Components Lexer/Parser Tree Walker –Walks the AST generated by the parser –Checks types, resolves symbols, etc. –Executes the code Internal package –Contains code called by the tree walker to manipulate Mapwad structures Code generator –Creates Quake.map file - text file containing information about contents of map. QBSP –Compiles.map file into Quake.bsp map file that the game understands.

MapwadParser MapwadLexer MapwadWalker Mapwad Builtin Functions Block Diagram MWMap qbspMWGui

Sample Code //creates a regular polygon shaped room Room regularRoom(int walls, float length, string texture="BRICKA2_2") { Room newRoom = Room(); float angle = 180*(walls-2)/walls; int i; for(i=0;i < walls;i++) { Wall w = Wall(length,angle,"",texture); Add(newRoom, w); } Close(newRoom); return newRoom; } Map() { Room r = regularRoom(10, 15, "BRICKA2_4"); Room start = regularRoom(4, 5); Attach(r.Walls[0], start.Walls[0]); Thing t = Thing("monster_army", Location(r.Walls[5], "center", 10)); MapStart = Location(start.Walls[3], "center", 2); CeilingTexture = "sky1"; }

Compiler Output "sounds" "1" "classname" "worldspawn" "wad" "quake101.wad" "worldtype" "0" { ( ) ( ) ( ) BRICKA2_ ( ) ( ) ( ) BRICKA2_ ( ) ( ) ( ) BRICKA2_ ( ) ( ) ( ) BRICKA2_ ( ) ( ) ( ) BRICKA2_ ( ) ( ) ( ) BRICKA2_ } { ( ) ( ) ( ) BRICKA2_ ( ) ( ) ( ) BRICKA2_ …

What does it look like?

Error Checking There are three types of error checking in Mapwad Syntax Error –Caught by the lexer/parser Semantic Error –Caught by the tree walker Incorrect types, wrong arguments, etc… Runtime Error/Warning –Caught during code generation Invalid Geometry Locations outside of map

Testing Modular Testing –Each module was tested independently Regression Testing –Basic test cases were reused as code evolved Integration Testing –Modules were combined slowly and tested at every stage

Lessons Learned Don’t overextend yourself –Our initial design was too ambitious for a one semester project Fully define interfaces early –We had to modify all our methods late in development Generalize your code –When we found problems we they were resolved without major code revisions

Future Work Support more generalized 3D structures More sophisticated error checking Support for more interactive objects –Doors, Elevators, Moving platforms Integrate into a graphical level editor