From b670f97ed1512655c7bd0463fc54b9f06106e40d Mon Sep 17 00:00:00 2001
From: Lactozilla <jp6781615@gmail.com>
Date: Fri, 4 Aug 2023 00:36:11 -0300
Subject: [PATCH] Add lighttable_t support

---
 src/lua_baselib.c  |  1 +
 src/lua_colorlib.c | 33 ++++++++++++++++++++++++++++++++-
 src/lua_libs.h     |  3 ++-
 src/r_defs.h       |  3 +++
 src/r_draw.c       |  2 --
 5 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/src/lua_baselib.c b/src/lua_baselib.c
index ecebae4ac..cdda48e8f 100644
--- a/src/lua_baselib.c
+++ b/src/lua_baselib.c
@@ -214,6 +214,7 @@ static const struct {
 	{META_PATCH,        "patch_t"},
 	{META_COLORMAP,     "colormap"},
 	{META_EXTRACOLORMAP,"extracolormap_t"},
+	{META_LIGHTTABLE,   "lighttable_t"},
 	{META_CAMERA,       "camera_t"},
 
 	{META_ACTION,       "action"},
diff --git a/src/lua_colorlib.c b/src/lua_colorlib.c
index ee7074e84..a963a6a6b 100644
--- a/src/lua_colorlib.c
+++ b/src/lua_colorlib.c
@@ -209,7 +209,7 @@ static int extracolormap_get(lua_State *L)
 		lua_pushinteger(L, exc->fadeend);
 		break;
 	case extracolormap_colormap:
-		LUA_PushUserdata(L, exc->colormap, META_COLORMAP);
+		LUA_PushUserdata(L, exc->colormap, META_LIGHTTABLE);
 		break;
 	}
 	return 1;
@@ -321,6 +321,29 @@ static int extracolormap_set(lua_State *L)
 	return 0;
 }
 
+static int lighttable_get(lua_State *L)
+{
+	void **userdata;
+
+	lighttable_t *table = *((lighttable_t **)luaL_checkudata(L, 1, META_LIGHTTABLE));
+	UINT32 row = luaL_checkinteger(L, 2);
+	if (row < 1 || row > 34)
+		return luaL_error(L, "lighttable row %d out of range (1 - %d)", row, 34);
+
+	userdata = lua_newuserdata(L, sizeof(void *));
+	*userdata = &table[256 * (row - 1)];
+	luaL_getmetatable(L, META_COLORMAP);
+	lua_setmetatable(L, -2);
+
+	return 1;
+}
+
+static int lighttable_len(lua_State *L)
+{
+	lua_pushinteger(L, NUM_PALETTE_ENTRIES);
+	return 1;
+}
+
 int LUA_ColorLib(lua_State *L)
 {
 	luaL_newmetatable(L, META_EXTRACOLORMAP);
@@ -331,5 +354,13 @@ int LUA_ColorLib(lua_State *L)
 		lua_setfield(L, -2, "__newindex");
 	lua_pop(L, 1);
 
+	luaL_newmetatable(L, META_LIGHTTABLE);
+		lua_pushcfunction(L, lighttable_get);
+		lua_setfield(L, -2, "__index");
+
+		lua_pushcfunction(L, lighttable_len);
+		lua_setfield(L, -2, "__len");
+	lua_pop(L, 1);
+
 	return 0;
 }
diff --git a/src/lua_libs.h b/src/lua_libs.h
index b520bb983..65d5acb1b 100644
--- a/src/lua_libs.h
+++ b/src/lua_libs.h
@@ -84,7 +84,8 @@ extern boolean mousegrabbedbylua;
 #define META_HUDINFO "HUDINFO_T*"
 #define META_PATCH "PATCH_T*"
 #define META_COLORMAP "COLORMAP"
-#define META_EXTRACOLORMAP "EXTRACOLORMAP_T"
+#define META_EXTRACOLORMAP "EXTRACOLORMAP_T*"
+#define META_LIGHTTABLE "LIGHTTABLE_T*"
 #define META_CAMERA "CAMERA_T*"
 
 #define META_ACTION "ACTIONF_T*"
diff --git a/src/r_defs.h b/src/r_defs.h
index a9b9a4a08..1edbba473 100644
--- a/src/r_defs.h
+++ b/src/r_defs.h
@@ -53,6 +53,9 @@ typedef struct
 // Could even use more than 32 levels.
 typedef UINT8 lighttable_t;
 
+#define NUM_PALETTE_ENTRIES 256
+#define DEFAULT_STARTTRANSCOLOR 96
+
 #define CMF_FADEFULLBRIGHTSPRITES  1
 #define CMF_FOG 4
 
diff --git a/src/r_draw.c b/src/r_draw.c
index df9e1a460..671767b21 100644
--- a/src/r_draw.c
+++ b/src/r_draw.c
@@ -132,8 +132,6 @@ UINT32 nflatxshift, nflatyshift, nflatshiftup, nflatmask;
 #define RAINBOW_TT_CACHE_INDEX (MAXSKINS + 4)
 #define BLINK_TT_CACHE_INDEX (MAXSKINS + 5)
 #define DASHMODE_TT_CACHE_INDEX (MAXSKINS + 6)
-#define DEFAULT_STARTTRANSCOLOR 96
-#define NUM_PALETTE_ENTRIES 256
 
 static UINT8 **translationtablecache[MAXSKINS + 7] = {NULL};
 UINT8 skincolor_modified[MAXSKINCOLORS];