Generate seeds from the core seed so that levels will look different.

data/mapgen.lua

@@ -43,7 +43,7 @@ local function generate_path ()
 	end
 
 	local cx, cy = 1, 1
-	local seed = get_random_seed()
+	local seed = get_random_seed(CURRENT_LEVEL)
 	info("Map generation seed: " .. seed)
 	randomseed(seed)
 	local direction = 0

data/maproombuilder.lua

@@ -534,7 +534,7 @@ function module.load_textures(map)
 	t_pit0 = add_texture(map, "Objects/Pit0.png")
 	t_pit1 = add_texture(map, "Objects/Pit1.png")
 
-	local seed = get_random_seed();
+	local seed = get_random_seed(CURRENT_LEVEL);
 	info("Map room random seed: " .. seed)
 	math.randomseed(seed)
 	local xo = (random(3) - 1) * 112

src/map_lua.c

@@ -470,7 +470,8 @@ l_read_file(lua_State *L)
 static int
 l_get_random_seed(lua_State *L)
 {
-	lua_pushnumber(L, get_random_seed());
+	unsigned int level = (unsigned int) luaL_checkinteger(L, 1);
+	lua_pushnumber(L, get_random_map_seed(level));
 	return 1;
 }
 

src/random.c

@@ -23,14 +23,31 @@
 #include "util.h"
 
 static unsigned int seed = 0;
+static unsigned int map_seeds[20];
+static unsigned int runtime_seed = 0;
+
+static void
+generate_random_seeds(void)
+{
+	// Use seed for generating map seeds
+	srand(seed);
+	info("Core random seed: %d", seed);
+	for (int i = 0; i < 20; ++i) {
+		map_seeds[i] = rand();
+	}
+
+	// Set a more random seed for runtime random
+	runtime_seed = (unsigned int) time(NULL);
+	srand(runtime_seed);
+	info("Runtime random seed: %d", runtime_seed);
+}
 
 static void
 init_seed(void)
 {
 	if (seed == 0) {
 		seed = (unsigned int) time(NULL);
-		srand(seed);
+		generate_random_seeds();
-		info("Core random seed: %d", seed);
 	}
 }
 
@@ -38,7 +55,7 @@ void
 set_random_seed(unsigned int s)
 {
 	seed = s;
-	info("Core random seed: %d", seed);
+	generate_random_seeds();
 }
 
 unsigned int
@@ -48,6 +65,12 @@ get_random_seed(void)
 	return seed;
 }
 
+unsigned int
+get_random_map_seed(unsigned int level)
+{
+	return map_seeds[level-1];
+}
+
 unsigned int
 get_random(unsigned int max)
 {

src/random.h

@@ -19,6 +19,9 @@
 #ifndef RANDOM_H_
 #define	RANDOM_H_
 
+unsigned int
+get_random_map_seed(unsigned int level);
+
 unsigned int
 get_random_seed(void);