Project Overview
Mapwad: A Maze Generation language
Team: Ben Smith, Avrum Tilman,
Josh Weinberg, Ron Weiss
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 highlevel 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 <Location>
MapHeight <float>
CeilingTexture <string>
FloorTexture <string>
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.
Block Diagram
Mapwad
MapwadLexer
MapwadParser
MapwadWalker
Builtin Functions
MWMap
qbsp
MWGui
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"
{
( 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?
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