added new sanity checks and compile-time assertions to prevent errors

fixed stair-building issue
new test-cases
added elevator support
fixed/improved some walker modules

data/RingBuffer.h

@@ -21,14 +21,18 @@ public:
 		;
 	}
 
-	/** add a new element */
-	void add(const Element& element) {
+	/** add a new element WITH overflow check! */
+	void addSafe(const Element& element) {
 		Assert::isTrue(available != (int)data.size(), "buffer overflow");
+		add(element);
+	}
+
+	/** add a new element WIUTHOUT checking for overflows */
+	void add(const Element& element) {
 		data[iWrite] = element;
 		++iWrite;
 		iWrite %= data.size();
 		++available;
-		//if (available > (int)data.size()) {available = data.size();}
 	}
 
 	/** get the next element */
@@ -42,6 +46,25 @@ public:
 		return tmp;
 	}
 
+	/** peek into the given element without removing it */
+	const Element& peek(const int idx) const {
+		const Element& tmp = data[(iRead + idx) % data.size()];
+		return tmp;
+	}
+
+	/** peek into the given element without removing it */
+	const Element& operator [] (const int idx) const {
+		return peek(idx);
+	}
+
+	/** does the buffer contain the given element? */
+	bool contains(const Element& e) const {
+		for (int i = 0; i < available; ++i) {
+			if (peek(i) == e) {return true;}
+		}
+		return false;
+	}
+
 	/** reset the ringbuffer */
 	void reset() {
 		iWrite = 0;