From cc375bba4e944b534b2c519930eee64b7b0226d9 Mon Sep 17 00:00:00 2001
From: Linus Probert <linus.probert@gmail.com>
Date: Fri, 22 Feb 2019 00:09:31 +0100
Subject: [PATCH] Implements control over lua random numbers

---
 bh_random/src/bh_random.cpp | 14 ++++++++++++++
 bh_random/src/bh_random.h   |  6 ++++++
 data/chestgen.lua           |  2 +-
 data/mapgen.lua             |  4 ++--
 data/maproombuilder.lua     |  4 ++--
 data/monstergen.lua         |  2 +-
 data/trapgen.lua            |  2 +-
 src/map_lua.c               | 23 +++++++++++++++++++++++
 8 files changed, 50 insertions(+), 7 deletions(-)

diff --git a/bh_random/src/bh_random.cpp b/bh_random/src/bh_random.cpp
index 88742ec..4934584 100644
--- a/bh_random/src/bh_random.cpp
+++ b/bh_random/src/bh_random.cpp
@@ -23,6 +23,7 @@ extern "C" {
 }
 
 static std::mt19937 generator;
+static std::mt19937 map_generator;
 static std::uniform_int_distribution<int> distribution(0, INT_MAX);
 
 extern "C" void
@@ -37,3 +38,16 @@ bh_rand(void)
 {
 	return distribution(generator);
 }
+
+extern "C" void
+bh_map_srand(unsigned int seed)
+{
+	map_generator.seed(seed);
+}
+
+
+extern "C" unsigned int
+bh_map_rand(void)
+{
+	return distribution(map_generator);
+}
diff --git a/bh_random/src/bh_random.h b/bh_random/src/bh_random.h
index d967631..c6a0de9 100644
--- a/bh_random/src/bh_random.h
+++ b/bh_random/src/bh_random.h
@@ -23,3 +23,9 @@ bh_srand(unsigned int);
 
 unsigned int
 bh_rand(void);
+
+void
+bh_map_srand(unsigned int);
+
+unsigned int
+bh_map_rand(void);
diff --git a/data/chestgen.lua b/data/chestgen.lua
index 6f53c2c..bc22d7a 100644
--- a/data/chestgen.lua
+++ b/data/chestgen.lua
@@ -1,6 +1,6 @@
 local room_builder = require "maproombuilder"
 local module = {}
-local random = math.random
+local random = map_random
 
 local textures = {
 	"Items/Chest0.png",
diff --git a/data/mapgen.lua b/data/mapgen.lua
index 5b03d5c..ff7f3c8 100644
--- a/data/mapgen.lua
+++ b/data/mapgen.lua
@@ -5,8 +5,8 @@ local chest_gen = require "chestgen"
 
 -- Setting up some functions
 local time = os.time
-local random = math.random
-local randomseed = math.randomseed
+local random = map_random
+local randomseed = map_randomseed
 
 -- CONSTANTS
 local UP	= 1
diff --git a/data/maproombuilder.lua b/data/maproombuilder.lua
index 1ac3b1a..4ad53dc 100644
--- a/data/maproombuilder.lua
+++ b/data/maproombuilder.lua
@@ -1,5 +1,5 @@
 -- FUNCTIONS
-local random = math.random
+local random = map_random
 
 -- CONSTANTS
 local UP	= 1
@@ -536,7 +536,7 @@ function module.load_textures(map)
 
 	local seed = get_random_seed(CURRENT_LEVEL);
 	info("Map room random seed: " .. seed)
-	math.randomseed(seed)
+	map_randomseed(seed)
 	local xo = (random(3) - 1) * 112
 	local yo = (random(8)) * 48
 
diff --git a/data/monstergen.lua b/data/monstergen.lua
index a7ea9dd..3faba59 100644
--- a/data/monstergen.lua
+++ b/data/monstergen.lua
@@ -1,6 +1,6 @@
 local room_builder = require "maproombuilder"
 local module = {}
-local random = math.random
+local random = map_random
 
 local texturePaths = {
 	aquatic0 = "Characters/Aquatic0.png",
diff --git a/data/trapgen.lua b/data/trapgen.lua
index 8e47892..9abdfc9 100644
--- a/data/trapgen.lua
+++ b/data/trapgen.lua
@@ -1,6 +1,6 @@
 local room_builder = require "maproombuilder"
 local module = {}
-local random = math.random
+local random = map_random
 
 local textures = {
 	"Objects/Trap1.png",
diff --git a/src/map_lua.c b/src/map_lua.c
index 688cbd5..e2bd492 100644
--- a/src/map_lua.c
+++ b/src/map_lua.c
@@ -36,6 +36,7 @@
 #include "item.h"
 #include "item_builder.h"
 #include "random.h"
+#include "bh_random.h"
 
 static
 lua_State* load_lua_state(void)
@@ -475,6 +476,22 @@ l_get_random_seed(lua_State *L)
 	return 1;
 }
 
+static int
+l_set_random_seed(lua_State *L)
+{
+	unsigned int seed = (unsigned int) luaL_checkinteger(L, 1);
+	bh_map_srand(seed);
+	return 0;
+}
+
+static int
+l_get_random(lua_State *L)
+{
+	unsigned int max = (unsigned int) luaL_checkinteger(L, 1);
+	lua_pushnumber(L, (bh_map_rand() % max) + 1);
+	return 1;
+}
+
 static Map*
 generate_map(unsigned int level, const char *file, GameMode gameMode, SDL_Renderer *renderer)
 {
@@ -534,6 +551,12 @@ generate_map(unsigned int level, const char *file, GameMode gameMode, SDL_Render
 	lua_pushcfunction(L, l_get_random_seed);
 	lua_setglobal(L, "get_random_seed");
 
+	lua_pushcfunction(L, l_set_random_seed);
+	lua_setglobal(L, "map_randomseed");
+
+	lua_pushcfunction(L, l_get_random);
+	lua_setglobal(L, "map_random");
+
 	lua_pushinteger(L, level);
 	lua_setglobal(L, "CURRENT_LEVEL");