Files
cs8803p4/src/dk/itu/mario/level/grammar/LevelGrammar.java
2012-03-18 10:56:25 -04:00

123 lines
3.2 KiB
Java

package dk.itu.mario.level.grammar;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Random;
import java.util.Set;
import java.util.TreeSet;
import dk.itu.mario.level.LevelComponent;
import dk.itu.mario.level.LevelComponent.TYPE;
public class LevelGrammar {
private Variable start;
private Map<Variable, ProductionRule> ruleMap = new HashMap<Variable, ProductionRule>();
private Set<Variable> variables = new TreeSet<Variable>();
public void addVariable(Variable var) {
if (variables.contains(var)) {
throw new IllegalArgumentException(
"Grammar already contains variable: " + var);
}
variables.add(var);
}
public void addProductionRule(ProductionRule rule) {
if (ruleMap.containsKey(rule.getLHS())) {
throw new IllegalArgumentException(
"Grammar already contains rule with LHS: " + rule.getLHS());
}
ruleMap.put(rule.getLHS(), rule);
}
public LevelParseTree generateRandomTree(long randomSeed, int width) {
System.out.println("Generating random level parameters using seed: "
+ randomSeed);
Variable startRuleLHS = getStart();
ParseNode rootNode = new ParseNode(startRuleLHS.getType(), 1.0);
generateRecursive(rootNode, getRule(startRuleLHS).getRHS(), 1.0);
LevelParseTree parseTree = new LevelParseTree(rootNode, 0, width);
return parseTree;
}
private ParseNode generateRecursive(ParseNode parseNode, Clause clause,
double relativeWidth) {
if (clause.isVariable()) {
if (clause.isTerminal()) {
parseNode.addChild(new ParseNode(((Variable) clause).getType(),
relativeWidth));
} else {
generateRecursive(parseNode, getRule((Variable) clause)
.getRHS(), relativeWidth);
}
} else {
if (clause.isChoice()) {
generateRecursive(parseNode, clause.makeRandomChoice(),
relativeWidth);
} else {
int numSubClauses = clause.getNumSubClauses();
for (int i = 0; i < numSubClauses; i++) {
generateRecursive(parseNode, clause.getSubClause(i),
relativeWidth / numSubClauses);
}
}
}
return parseNode;
}
public Variable getVariable(String varName) {
for (Variable var : variables) {
if (varName.equals(var.getValue())) {
return var;
}
}
return null;
}
public ProductionRule getRule(Variable var) {
return ruleMap.get(var);
}
public Variable getStart() {
return start;
}
public void setStart(String startVar) {
for (Variable var : variables) {
if (startVar.equals(var.getValue())) {
start = var;
return;
}
}
}
public void setStart(Variable start) {
this.start = start;
}
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append("Variables:\n");
for (Variable var : variables) {
sb.append("VAR ");
sb.append(var.getValue());
sb.append(" = ");
sb.append(var.getType());
sb.append("\n");
}
sb.append("\n");
for (Entry<Variable,ProductionRule> entry : ruleMap.entrySet()) {
//could as easily have used LHS instead of getKey().getValue()
sb.append("RULE " + entry.getKey().getValue() + " -> " + entry.getValue().getRHS());
sb.append("\n");
}
sb.append("\n");
sb.append("START = " + start.getValue());
return sb.toString();
}
}