Project OverviewProject Overview

Team: Ben Smith, Avrum Tilman, Josh Weinberg, Ron Weiss

Mapwad: A Maze Generation language

Overview and SummaryOverview 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

MotivationMotivation

MotivationMotivation

Designing mazes by hand is tedious and error prone

Build large, complex mazes algorithmically

GoalsGoals

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 DesignLanguage 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 syntaxMapwad 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 WordsReserved Words

Control Flow– if, else, for, while, break, continue,

returnPrimitive Data Types– int, float, boolean, string

Values– true, false, null

Object Data TypesObject Data Types

Room– Walls - Super Data Structure

Wall Location Thing

Built inBuilt 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 <Location>– MapHeight <float>– CeilingTexture <string>– FloorTexture <string>

SemanticsSemantics 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 ComponentsCompiler 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 DiagramBlock Diagram

MWMap qbsp

MWGui

Sample CodeSample Code//creates a regular polygon shaped roomRoom 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 OutputCompiler Output

"sounds" "1" "classname" "worldspawn" "wad" "quake101.wad" "worldtype" "0" { ( 0 0 0 ) ( 100 0 0 ) ( 0 0 1 ) BRICKA2_4 0 0 0 1.0 1.0 ( 0 -1 0 ) ( 0 -1 1 ) ( 100 -1 0 ) BRICKA2_4 0 0 0 1.0 1.0 ( 0 0 0 ) ( 0 0 1 ) ( 0 -1 0 ) BRICKA2_4 0 0 0 1.0 1.0 ( 100 0 0 ) ( 100 -1 0 ) ( 100 0 1 ) BRICKA2_4 0 0 0 1.0 1.0 ( 0 0 0 ) ( 1 0 0 ) ( 0 1 0 ) BRICKA2_4 0 0 0 1.0 1.0 ( 0 0 100 ) ( 0 1 100 ) ( 1 0 100 ) BRICKA2_4 0 0 0 1.0 1.0 } { ( 100 0 0 ) ( 181 59 0 ) ( 100 0 1 ) BRICKA2_4 0 0 0 1.0 1.0 ( 101 -1 0 ) ( 101 -1 1 ) ( 181 58 0 ) BRICKA2_4 0 0 0 1.0 1.0

…

What does it look like?What does it look like?

Error CheckingError 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

TestingTesting

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 LearnedLessons 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 WorkFuture Work

Support more generalized 3D structures

More sophisticated error checkingSupport for more interactive objects– Doors, Elevators, Moving platforms

Integrate into a graphical level editor