generator: generation utilities

src/generator.h

@@ -5,6 +5,8 @@
 #include "settings.h"
 using namespace libnum;
 
+//======= Generation utilities =======//
+
 /* A utility structure holding data for path carver - a generator tool that
    produces a random traversable path. */
 struct path_carver
@@ -14,8 +16,9 @@ struct path_carver
 	/* Advance by one platform of the specified length and generate the
 	   associated platform data. A platform might not be generated if the path
 	   decides to skip for a jump! Returns true if a platform was generated in
-	   *p, false otherwise (in that case don't use *p). */
-	bool next(num length, struct platform *p);
+	   *p, false otherwise (in that case don't use *p). If force is set, always
+	   generates a platform. */
+	bool next(num length, struct platform *p, bool force=false);
 
 private:
 	/* Face where the next platform will be generated */
@@ -26,8 +29,27 @@ private:
 	bool m_last_skipped;
 };
 
+static inline int add_to_face(int face, int how_much)
+{
+	int f = (face + how_much) % PLATFORM_COUNT;
+	return (f < 0) ? f + PLATFORM_COUNT : f;
+}
+
+static inline int next_face(int face)
+{
+	return add_to_face(face, 1);
+}
+
+static inline int prev_face(int face)
+{
+	return add_to_face(face, -1);
+}
+
+//======= Level generator API =======//
+
 struct generator
 {
+	/* Generate more stuff. */
 	virtual void generate(struct level *) = 0;
 	virtual ~generator() = default;
 };

src/generator/path.cpp

@@ -8,9 +8,9 @@ path_carver::path_carver(int initial_face)
     m_z = num(0);
 }
 
-bool path_carver::next(num length, struct platform *p)
+bool path_carver::next(num length, struct platform *p, bool force)
 {
-    int skip = !m_last_skipped && (rand() % 4 == 0);
+    int skip = !force && !m_last_skipped && (rand() % 4 == 0);
 
     if(skip) {
         m_last_skipped = true;