Move RNG functions to their own header/source files

CMakeLists.txt

@@ -397,6 +397,7 @@ set(libdevilutionx_SRCS
   Source/engine/animationinfo.cpp
   Source/engine/load_cel.cpp
   Source/engine/load_file.cpp
+  Source/engine/random.cpp
   Source/engine/render/automap_render.cpp
   Source/engine/render/cel_render.cpp
   Source/engine/render/cl2_render.cpp

Source/diablo.cpp

@@ -29,6 +29,7 @@
 #include "engine/cel_sprite.hpp"
 #include "engine/load_cel.hpp"
 #include "engine/load_file.hpp"
+#include "engine/random.hpp"
 #include "error.h"
 #include "gamemenu.h"
 #include "gmenu.h"

Source/drlg_l1.cpp

@@ -7,6 +7,7 @@
 
 #include "engine/load_file.hpp"
 #include "engine/point.hpp"
+#include "engine/random.hpp"
 #include "gendung.h"
 #include "lighting.h"
 #include "player.h"

Source/drlg_l2.cpp

@@ -11,6 +11,7 @@
 #include "diablo.h"
 #include "drlg_l1.h"
 #include "engine/load_file.hpp"
+#include "engine/random.hpp"
 #include "objects.h"
 #include "player.h"
 #include "quests.h"

Source/drlg_l3.cpp

@@ -8,6 +8,7 @@
 
 #include "drlg_l1.h"
 #include "engine/load_file.hpp"
+#include "engine/random.hpp"
 #include "lighting.h"
 #include "monster.h"
 #include "objdat.h"

Source/drlg_l4.cpp

@@ -7,6 +7,7 @@
 
 #include "drlg_l1.h"
 #include "engine/load_file.hpp"
+#include "engine/random.hpp"
 #include "monster.h"
 #include "multi.h"
 #include "objdat.h"

Source/effects.cpp

@@ -5,6 +5,7 @@
  */
 #include "effects.h"
 
+#include "engine/random.hpp"
 #include "init.h"
 #include "player.h"
 #include "sound.h"

Source/engine.cpp

@@ -20,19 +20,6 @@
 
 namespace devilution {
 
-/** Current game seed */
-uint32_t sglGameSeed;
-
-/**
- * Specifies the increment used in the Borland C/C++ pseudo-random.
- */
-const uint32_t RndInc = 1;
-
-/**
- * Specifies the multiplier used in the Borland C/C++ pseudo-random number generator algorithm.
- */
-const uint32_t RndMult = 0x015A4E35;
-
 namespace {
 
 template <bool SkipColorIndexZero>
@@ -238,53 +225,6 @@ int CalculateWidth2(int width)
 	return (width - 64) / 2;
 }
 
-/**
- * @brief Set the RNG seed
- * @param s RNG seed
- */
-void SetRndSeed(uint32_t s)
-{
-	sglGameSeed = s;
-}
-
-/**
- * @brief Advance the internal RNG seed and return the new value
- * @return RNG seed
- */
-int32_t AdvanceRndSeed()
-{
-	sglGameSeed = (RndMult * sglGameSeed) + RndInc;
-	return GetRndSeed();
-}
-
-/**
- * @brief Get the current RNG seed
- * @return RNG seed
- */
-int32_t GetRndSeed()
-{
-	return abs(static_cast<int32_t>(sglGameSeed));
-}
-
-uint32_t GetLCGEngineState()
-{
-	return sglGameSeed;
-}
-
-/**
- * @brief Main RNG function
- * @param v The upper limit for the return value
- * @return A random number from 0 to (v-1)
- */
-int32_t GenerateRnd(int32_t v)
-{
-	if (v <= 0)
-		return 0;
-	if (v < 0xFFFF)
-		return (AdvanceRndSeed() >> 16) % v;
-	return AdvanceRndSeed() % v;
-}
-
 /**
  * @brief Fade to black and play a video
  * @param pszMovie file path of movie

Source/engine.h

@@ -5,7 +5,6 @@
  * - Sprite blitting
  * - Drawing
  * - Angle calculation
- * - RNG
  * - Memory allocation
  * - File loading
  * - Video playback
@@ -264,12 +263,6 @@ Direction GetDirection(Point start, Point destination);
  */
 int CalculateWidth2(int width);
 
-void SetRndSeed(uint32_t s);
-int32_t AdvanceRndSeed();
-int32_t GetRndSeed();
-uint32_t GetLCGEngineState();
-int32_t GenerateRnd(int32_t v);
-
 void PlayInGameMovie(const char *pszMovie);
 
 } // namespace devilution

Source/engine/random.cpp

@@ -0,0 +1,67 @@
+#include "engine/random.hpp"
+
+#include "utils/stdcompat/abs.hpp"
+
+namespace devilution {
+
+/** Current game seed */
+uint32_t sglGameSeed;
+
+/**
+ * Specifies the increment used in the Borland C/C++ pseudo-random.
+ */
+const uint32_t RndInc = 1;
+
+/**
+ * Specifies the multiplier used in the Borland C/C++ pseudo-random number generator algorithm.
+ */
+const uint32_t RndMult = 0x015A4E35;
+
+/**
+ * @brief Set the RNG seed
+ * @param s RNG seed
+ */
+void SetRndSeed(uint32_t s)
+{
+	sglGameSeed = s;
+}
+
+/**
+ * @brief Advance the internal RNG seed and return the new value
+ * @return RNG seed
+ */
+int32_t AdvanceRndSeed()
+{
+	sglGameSeed = (RndMult * sglGameSeed) + RndInc;
+	return GetRndSeed();
+}
+
+/**
+ * @brief Get the current RNG seed
+ * @return RNG seed
+ */
+int32_t GetRndSeed()
+{
+	return abs(static_cast<int32_t>(sglGameSeed));
+}
+
+uint32_t GetLCGEngineState()
+{
+	return sglGameSeed;
+}
+
+/**
+ * @brief Main RNG function
+ * @param v The upper limit for the return value
+ * @return A random number from 0 to (v-1)
+ */
+int32_t GenerateRnd(int32_t v)
+{
+	if (v <= 0)
+		return 0;
+	if (v < 0xFFFF)
+		return (AdvanceRndSeed() >> 16) % v;
+	return AdvanceRndSeed() % v;
+}
+
+}

Source/engine/random.hpp

@@ -0,0 +1,21 @@
+/**
+ * @file random.hpp
+ *
+ * Contains convenience functions for random number generation
+ *
+ * This includes specific engine/distribution functions for logic that needs to be compatible with the base game.
+ */
+#pragma once
+
+#include <cstdint>
+
+namespace devilution
+{
+
+void SetRndSeed(uint32_t s);
+int32_t AdvanceRndSeed();
+int32_t GetRndSeed();
+uint32_t GetLCGEngineState();
+int32_t GenerateRnd(int32_t v);
+
+} // namespace devilution

Source/gendung.cpp

@@ -6,6 +6,7 @@
 #include "gendung.h"
 
 #include "engine/load_file.hpp"
+#include "engine/random.hpp"
 #include "init.h"
 #include "options.h"
 

Source/items.cpp

@@ -17,6 +17,7 @@
 #include "dx.h"
 #include "engine/cel_sprite.hpp"
 #include "engine/load_cel.hpp"
+#include "engine/random.hpp"
 #include "engine/render/cel_render.hpp"
 #include "engine/render/text_render.hpp"
 #include "init.h"

Source/loadsave.cpp

@@ -16,6 +16,7 @@
 #include "doom.h"
 #include "engine.h"
 #include "engine/point.hpp"
+#include "engine/random.hpp"
 #include "init.h"
 #include "inv.h"
 #include "lighting.h"

Source/missiles.cpp

@@ -12,6 +12,7 @@
 #include "dead.h"
 #include "engine/cel_header.hpp"
 #include "engine/load_file.hpp"
+#include "engine/random.hpp"
 #include "init.h"
 #include "inv.h"
 #include "lighting.h"

Source/monster.cpp

@@ -18,6 +18,7 @@
 #include "drlg_l4.h"
 #include "engine/cel_header.hpp"
 #include "engine/load_file.hpp"
+#include "engine/random.hpp"
 #include "engine/render/cl2_render.hpp"
 #include "init.h"
 #include "lighting.h"

Source/msg.cpp

@@ -15,6 +15,7 @@
 #include "drlg_l1.h"
 #include "dthread.h"
 #include "encrypt.h"
+#include "engine/random.hpp"
 #include "gamemenu.h"
 #include "lighting.h"
 #include "missiles.h"

Source/multi.cpp

@@ -13,6 +13,7 @@
 #include "diablo.h"
 #include "dthread.h"
 #include "engine/point.hpp"
+#include "engine/random.hpp"
 #include "mainmenu.h"
 #include "nthread.h"
 #include "options.h"

Source/objects.cpp

@@ -13,6 +13,7 @@
 #include "drlg_l1.h"
 #include "drlg_l4.h"
 #include "engine/load_file.hpp"
+#include "engine/random.hpp"
 #include "error.h"
 #include "init.h"
 #include "lighting.h"

Source/pack.cpp

@@ -5,6 +5,7 @@
  */
 #include "pack.h"
 
+#include "engine/random.hpp"
 #include "init.h"
 #include "loadsave.h"
 #include "stores.h"

Source/palette.cpp

@@ -6,6 +6,7 @@
 
 #include "dx.h"
 #include "engine/load_file.hpp"
+#include "engine/random.hpp"
 #include "hwcursor.hpp"
 #include "options.h"
 #include "utils/display.h"

Source/player.cpp

@@ -11,6 +11,7 @@
 #include "dead.h"
 #include "engine/cel_header.hpp"
 #include "engine/load_file.hpp"
+#include "engine/random.hpp"
 #include "gamemenu.h"
 #include "init.h"
 #include "lighting.h"

Source/quests.cpp

@@ -10,6 +10,7 @@
 #include "control.h"
 #include "cursor.h"
 #include "engine/load_file.hpp"
+#include "engine/random.hpp"
 #include "engine/render/cel_render.hpp"
 #include "engine/render/text_render.hpp"
 #include "gendung.h"

Source/spells.cpp

@@ -8,6 +8,7 @@
 #include "control.h"
 #include "cursor.h"
 #include "engine/point.hpp"
+#include "engine/random.hpp"
 #include "gamemenu.h"
 #include "inv.h"
 #include "missiles.h"

Source/stores.cpp

@@ -11,6 +11,7 @@
 
 #include "cursor.h"
 #include "engine/load_cel.hpp"
+#include "engine/random.hpp"
 #include "engine/render/cel_render.hpp"
 #include "engine/render/text_render.hpp"
 #include "init.h"

Source/themes.cpp

@@ -5,6 +5,7 @@
  */
 #include "themes.h"
 
+#include "engine/random.hpp"
 #include "items.h"
 #include "monster.h"
 #include "objects.h"

Source/town.cpp

@@ -7,6 +7,7 @@
 
 #include "drlg_l1.h"
 #include "engine/load_file.hpp"
+#include "engine/random.hpp"
 #include "init.h"
 #include "player.h"
 #include "quests.h"

Source/towners.cpp

@@ -3,6 +3,7 @@
 #include "cursor.h"
 #include "engine/cel_header.hpp"
 #include "engine/load_file.hpp"
+#include "engine/random.hpp"
 #include "inv.h"
 #include "minitext.h"
 #include "stores.h"

test/random_test.cpp

@@ -1,6 +1,6 @@
 #include <gtest/gtest.h>
 
-#include "engine.h"
+#include "engine/random.hpp"
 
 namespace devilution {