Backport the Blockmap library I made two years ago

SRB2.cbp

@@ -1549,6 +1549,9 @@ HW3SOUND for 3D hardware sound  support
 		<Unit filename="src/lua_baselib.c">
 			<Option compilerVar="CC" />
 		</Unit>
+		<Unit filename="src/lua_blockmaplib.c">
+			<Option compilerVar="CC" />
+		</Unit>
 		<Unit filename="src/lua_consolelib.c">
 			<Option compilerVar="CC" />
 		</Unit>

src/CMakeLists.txt

@@ -237,6 +237,7 @@ if(${SRB2_CONFIG_HAVE_BLUA})
 	add_definitions(-DHAVE_BLUA)
 	set(SRB2_LUA_SOURCES
 		lua_baselib.c
+		lua_blockmaplib.c
 		lua_consolelib.c
 		lua_hooklib.c
 		lua_hudlib.c

src/blua/Makefile.cfg

@@ -39,6 +39,7 @@ OBJS:=$(OBJS) \
 	$(OBJDIR)/lvm.o \
 	$(OBJDIR)/lua_script.o \
 	$(OBJDIR)/lua_baselib.o \
+	$(OBJDIR)/lua_blockmaplib.o \
 	$(OBJDIR)/lua_mathlib.o \
 	$(OBJDIR)/lua_hooklib.o \
 	$(OBJDIR)/lua_consolelib.o \

src/lua_blockmaplib.c

@@ -0,0 +1,266 @@
+// SONIC ROBO BLAST 2
+//-----------------------------------------------------------------------------
+// Copyright (C) 2016 by Iestyn "Monster Iestyn" Jealous.
+// Copyright (C) 2016 by Sonic Team Junior.
+//
+// This program is free software distributed under the
+// terms of the GNU General Public License, version 2.
+// See the 'LICENSE' file for more details.
+//-----------------------------------------------------------------------------
+/// \file  lua_blockmaplib.c
+/// \brief blockmap library for Lua scripting
+
+#include "doomdef.h"
+#ifdef HAVE_BLUA
+#include "p_local.h"
+#include "r_main.h" // validcount
+#include "lua_script.h"
+#include "lua_libs.h"
+//#include "lua_hud.h" // hud_running errors
+
+static const char *const search_opt[] = {
+	"objects",
+	"lines",
+	NULL};
+
+// a quickly-made function pointer typedef used by lib_searchBlockmap...
+// return values:
+// 0 - normal, no interruptions
+// 1 - stop search through current block
+// 2 - stop search completely
+typedef UINT8 (*blockmap_func)(lua_State *, INT32, INT32, mobj_t *);
+
+static boolean blockfuncerror = false; // errors should only print once per search blockmap call
+
+// Helper function for "objects" search
+static UINT8 lib_searchBlockmap_Objects(lua_State *L, INT32 x, INT32 y, mobj_t *thing)
+{
+	mobj_t *mobj, *bnext = NULL;
+
+	if (x < 0 || y < 0 || x >= bmapwidth || y >= bmapheight)
+		return 0;
+
+	// Check interaction with the objects in the blockmap.
+	for (mobj = blocklinks[y*bmapwidth + x]; mobj; mobj = bnext)
+	{
+		P_SetTarget(&bnext, mobj->bnext); // We want to note our reference to bnext here incase it is MF_NOTHINK and gets removed!
+		if (mobj == thing)
+			continue; // our thing just found itself, so move on
+		lua_pushvalue(L, 1); // push function
+		LUA_PushUserdata(L, thing, META_MOBJ);
+		LUA_PushUserdata(L, mobj, META_MOBJ);
+		if (lua_pcall(gL, 2, 1, 0)) {
+			if (!blockfuncerror || cv_debug & DBG_LUA)
+				CONS_Alert(CONS_WARNING,"%s\n",lua_tostring(gL, -1));
+			lua_pop(gL, 1);
+			blockfuncerror = true;
+			return 0; // *shrugs*
+		}
+		if (!lua_isnil(gL, -1))
+		{ // if nil, continue
+			if (lua_toboolean(gL, -1))
+				return 2; // stop whole search
+			else
+				return 1; // stop block search
+		}
+		lua_pop(gL, 1);
+		if (P_MobjWasRemoved(thing) // func just popped our thing, cannot continue.
+		|| (bnext && P_MobjWasRemoved(bnext))) // func just broke blockmap chain, cannot continue.
+		{
+			P_SetTarget(&bnext, NULL);
+			return (P_MobjWasRemoved(thing)) ? 2 : 1;
+		}
+	}
+	return 0;
+}
+
+// Helper function for "lines" search
+static UINT8 lib_searchBlockmap_Lines(lua_State *L, INT32 x, INT32 y, mobj_t *thing)
+{
+	INT32 offset;
+	const INT32 *list; // Big blockmap
+#ifdef POLYOBJECTS
+	polymaplink_t *plink; // haleyjd 02/22/06
+#endif
+	line_t *ld;
+
+	if (x < 0 || y < 0 || x >= bmapwidth || y >= bmapheight)
+		return 0;
+
+	offset = y*bmapwidth + x;
+
+#ifdef POLYOBJECTS
+	// haleyjd 02/22/06: consider polyobject lines
+	plink = polyblocklinks[offset];
+
+	while (plink)
+	{
+		polyobj_t *po = plink->po;
+
+		if (po->validcount != validcount) // if polyobj hasn't been checked
+		{
+			size_t i;
+			po->validcount = validcount;
+
+			for (i = 0; i < po->numLines; ++i)
+			{
+				if (po->lines[i]->validcount == validcount) // line has been checked
+					continue;
+				po->lines[i]->validcount = validcount;
+
+				lua_pushvalue(L, 1);
+				LUA_PushUserdata(L, thing, META_MOBJ);
+				LUA_PushUserdata(L, po->lines[i], META_LINE);
+				if (lua_pcall(gL, 2, 1, 0)) {
+					if (!blockfuncerror || cv_debug & DBG_LUA)
+						CONS_Alert(CONS_WARNING,"%s\n",lua_tostring(gL, -1));
+					lua_pop(gL, 1);
+					blockfuncerror = true;
+					return 0; // *shrugs*
+				}
+				if (!lua_isnil(gL, -1))
+				{ // if nil, continue
+					if (lua_toboolean(gL, -1))
+						return 2; // stop whole search
+					else
+						return 1; // stop block search
+				}
+				lua_pop(gL, 1);
+				if (P_MobjWasRemoved(thing))
+					return 2;
+			}
+		}
+		plink = (polymaplink_t *)(plink->link.next);
+	}
+#endif
+
+	offset = *(blockmap + offset); // offset = blockmap[y*bmapwidth+x];
+
+	// First index is really empty, so +1 it.
+	for (list = blockmaplump + offset + 1; *list != -1; list++)
+	{
+		ld = &lines[*list];
+
+		if (ld->validcount == validcount)
+			continue; // Line has already been checked.
+
+		ld->validcount = validcount;
+
+		lua_pushvalue(L, 1);
+		LUA_PushUserdata(L, thing, META_MOBJ);
+		LUA_PushUserdata(L, ld, META_LINE);
+		if (lua_pcall(gL, 2, 1, 0)) {
+			if (!blockfuncerror || cv_debug & DBG_LUA)
+				CONS_Alert(CONS_WARNING,"%s\n",lua_tostring(gL, -1));
+			lua_pop(gL, 1);
+			blockfuncerror = true;
+			return 0; // *shrugs*
+		}
+		if (!lua_isnil(gL, -1))
+		{ // if nil, continue
+			if (lua_toboolean(gL, -1))
+				return 2; // stop whole search
+			else
+				return 1; // stop block search
+		}
+		lua_pop(gL, 1);
+		if (P_MobjWasRemoved(thing))
+			return 2;
+	}
+	return 0; // Everything was checked.
+}
+
+// The searchBlockmap function
+// arguments: searchBlockmap(searchtype, function, mobj, [x1, x2, y1, y2])
+// return value:
+//   true = search completely uninteruppted,
+//   false = searching of at least one block stopped mid-way (including if the whole search was stopped)
+static int lib_searchBlockmap(lua_State *L)
+{
+	int searchtype = luaL_checkoption(L, 1, "objects", search_opt);
+	int n;
+	mobj_t *mobj;
+	INT32 xl, xh, yl, yh, bx, by;
+	fixed_t x1, x2, y1, y2;
+	boolean retval = true;
+	UINT8 funcret = 0;
+	blockmap_func searchFunc;
+
+	lua_remove(L, 1); // remove searchtype, stack is now function, mobj, [x1, x2, y1, y2]
+	luaL_checktype(L, 1, LUA_TFUNCTION);
+
+	switch (searchtype)
+	{
+		case 0: // "objects"
+		default:
+			searchFunc = lib_searchBlockmap_Objects;
+			break;
+		case 1: // "lines"
+			searchFunc = lib_searchBlockmap_Lines;
+			break;
+	}
+
+	// the mobj we are searching around, the "calling" mobj we could say
+	mobj = *((mobj_t **)luaL_checkudata(L, 2, META_MOBJ));
+	if (!mobj)
+		return LUA_ErrInvalid(L, "mobj_t");
+
+	n = lua_gettop(L);
+
+	if (n > 2) // specific x/y ranges have been supplied
+	{
+		if (n < 6)
+			return luaL_error(L, "arguments 4 to 6 not all given (expected 4 fixed-point integers)");
+
+		x1 = luaL_checkfixed(L, 3);
+		x2 = luaL_checkfixed(L, 4);
+		y1 = luaL_checkfixed(L, 5);
+		y2 = luaL_checkfixed(L, 6);
+	}
+	else // mobj and function only - search around mobj's radius by default
+	{
+		fixed_t radius = mobj->radius + MAXRADIUS;
+		x1 = mobj->x - radius;
+		x2 = mobj->x + radius;
+		y1 = mobj->y - radius;
+		y2 = mobj->y + radius;
+	}
+	lua_settop(L, 2); // pop everything except function, mobj
+
+	xl = (unsigned)(x1 - bmaporgx)>>MAPBLOCKSHIFT;
+	xh = (unsigned)(x2 - bmaporgx)>>MAPBLOCKSHIFT;
+	yl = (unsigned)(y1 - bmaporgy)>>MAPBLOCKSHIFT;
+	yh = (unsigned)(y2 - bmaporgy)>>MAPBLOCKSHIFT;
+
+	BMBOUNDFIX(xl, xh, yl, yh);
+
+	blockfuncerror = false; // reset
+	validcount++;
+	for (bx = xl; bx <= xh; bx++)
+		for (by = yl; by <= yh; by++)
+		{
+			funcret = searchFunc(L, bx, by, mobj);
+			// return value of searchFunc determines searchFunc's return value and/or when to stop
+			if (funcret == 2){ // stop whole search
+				lua_pushboolean(L, false); // return false
+				return 1;
+			}
+			else if (funcret == 1) // search was interrupted for this block
+				retval = false; // this changes the return value, but doesn't stop the whole search
+			// else don't do anything, continue as normal
+			if (P_MobjWasRemoved(mobj)){ // ...unless the original object was removed
+				lua_pushboolean(L, false); // in which case we have to stop now regardless
+				return 1;
+			}
+		}
+	lua_pushboolean(L, retval);
+	return 1;
+}
+
+int LUA_BlockmapLib(lua_State *L)
+{
+	lua_register(L, "searchBlockmap", lib_searchBlockmap);
+	return 0;
+}
+
+#endif

src/lua_libs.h

@@ -69,6 +69,7 @@ int LUA_PlayerLib(lua_State *L);
 int LUA_SkinLib(lua_State *L);
 int LUA_ThinkerLib(lua_State *L);
 int LUA_MapLib(lua_State *L);
+int LUA_BlockmapLib(lua_State *L);
 int LUA_HudLib(lua_State *L);
 
 #endif

src/lua_script.c

@@ -51,6 +51,7 @@ static lua_CFunction liblist[] = {
 	LUA_SkinLib, // skin_t, skins[]
 	LUA_ThinkerLib, // thinker_t
 	LUA_MapLib, // line_t, side_t, sector_t, subsector_t
+	LUA_BlockmapLib, // blockmap stuff
 	LUA_HudLib, // HUD stuff
 	NULL
 };

src/sdl/Srb2SDL-vc10.vcxproj

@@ -297,6 +297,7 @@
     </ClCompile>
     <ClCompile Include="..\i_tcp.c" />
     <ClCompile Include="..\lua_baselib.c" />
+	<ClCompile Include="..\lua_blockmaplib.c" />
     <ClCompile Include="..\lua_consolelib.c" />
     <ClCompile Include="..\lua_hooklib.c" />
     <ClCompile Include="..\lua_hudlib.c" />

src/sdl/Srb2SDL-vc10.vcxproj.filters

@@ -639,6 +639,9 @@
     <ClCompile Include="..\lua_baselib.c">
       <Filter>LUA</Filter>
     </ClCompile>
+    <ClCompile Include="..\lua_blockmaplib.c">
+      <Filter>LUA</Filter>
+    </ClCompile>
     <ClCompile Include="..\lua_consolelib.c">
       <Filter>LUA</Filter>
     </ClCompile>

src/win32/Srb2win-vc10.vcxproj

@@ -132,6 +132,7 @@
     </ClCompile>
     <ClCompile Include="..\i_tcp.c" />
     <ClCompile Include="..\lua_baselib.c" />
+	<ClCompile Include="..\lua_blockmaplib.c" />
     <ClCompile Include="..\lua_consolelib.c" />
     <ClCompile Include="..\lua_hooklib.c" />
     <ClCompile Include="..\lua_hudlib.c" />

src/win32/Srb2win-vc10.vcxproj.filters

@@ -228,6 +228,9 @@
     <ClCompile Include="..\lua_baselib.c">
       <Filter>LUA</Filter>
     </ClCompile>
+    <ClCompile Include="..\lua_blockmaplib.c">
+      <Filter>LUA</Filter>
+    </ClCompile>
     <ClCompile Include="..\lua_consolelib.c">
       <Filter>LUA</Filter>
     </ClCompile>