Fix GetEngineBuildNumber and entity property stuff

I still haven't bothered to flesh out all the possible indices for
GetEngineBuildNumber but we're back to being able to use it to detect
The Last Stand (as a result of some old version testing Aciidz did -
thanks again!). This means we can do away with the terrible map file-
based hotfix. Also, turns out sst_l4d_testwarp doesn't work if the
plugin gets loaded early via VDF because certain SendTable offsets start
out negated, so we work around that too now.

4 files changed, 27 insertions, 12 deletions

diff --git a/gamedata/engine.kv b/gamedata/engine.kv
index 39fa1df..80caa74 100644
--- a/gamedata/engine.kv
+++ b/gamedata/engine.kv
@@ -26,16 +26,19 @@ vtidx_GetGameDirectory {
 		2013 35
 	}
 	Client013 {
-		L4Dx 36 // AND THEN THEY CHANGED IT BACK LATER!
+		L4Dx 36 // AND THEN THEY CHANGED IT BACK LATER! (on 2.0.4.1)
 		default 35 // <- most things have this!
 	}
 	Client012 37 // dmomm, ep1, ...
 }
-// TODO(compat): apparently this changed, in early versions it's NOT 99!
-// Come up with some way to detect it properly!?
 vtidx_GetEngineBuildNumber {
-	//L4D2 99
+	L4D2 {
+		Client013 99
+		//Client014 ??? // TODO(compat): find out what this (maybe 136?)
+	}
 }
+
+// VEngineServer
 vtidx_PEntityOfEntIndex { OrangeBox 19 } // probably OE too but???
 
 sz_edict {
diff --git a/src/build/mkentprops.c b/src/build/mkentprops.c
index 5dd2fea..e99873b 100644
--- a/src/build/mkentprops.c
+++ b/src/build/mkentprops.c
@@ -144,11 +144,11 @@ _( "static void initentprops(struct ServerClass *class) {")
 F( "	for (int needclasses = %d; class; class = class->next) {", nclasses)
 	char *else1 = "";
 	for (struct class *c = classes.x[0]; c; c = c->hdr.x[0]) {
-		// TODO(opt): some sort of PHF instead of chained strcmp, if we ever
-		// have more than a few classes/properties?
+		// TODO(opt): some sort of PHF or trie instead of chained strcmp, if we
+		// ever have more than a few classes/properties?
 F( "		%sif (!strcmp(class->name, \"%s\")) {", else1, c->name)
 _( "			struct SendTable *st = class->table;")
-				// christ this is awful :(
+				// XXX: christ this is all awful :(
 F( "			int needprops = %d;", c->props.sz)
 _( "			for (struct SendProp *p = st->props; (char *)p -")
 _( "					(char *)st->props < st->nprops * sz_SendProp;")
@@ -159,7 +159,12 @@ _( "					p = mem_offset(p, sz_SendProp)) {")
 F( "				%sif (!strcmp(*(const char **)mem_offset(p, off_SP_varname), \"%s\")) {",
 		else2, (*pp)->propname) // ugh
 F( "					has_%s = true;", (*pp)->varname)
-F( "					%s = *(int *)mem_offset(p, off_SP_offset);", (*pp)->varname)
+			// from AM L4D2 SDK headers:
+			// > SENDPROP_VECTORELEM makes [offset] negative to start with so we
+			// > can detect that and set the SPROP_IS_VECTOR_ELEM flag.
+			// apparently if we're loaded via VDF, it hasn't been flipped back
+			// yet. just calling abs() on it as an easy solution.
+F( "					%s = abs(*(int *)mem_offset(p, off_SP_offset));", (*pp)->varname)
 _( "					if (!--needprops) break;")
 _( "				}")
 			else2 = "else ";
diff --git a/src/engineapi.c b/src/engineapi.c
index 369bebd..ec3d857 100644
--- a/src/engineapi.c
+++ b/src/engineapi.c
@@ -15,6 +15,7 @@
  */
 
 #include <stdbool.h> // used in generated code
+#include <stdlib.h> // "
 #include <string.h> // "
 
 #include "con_.h"
@@ -43,6 +44,8 @@ void *globalvars;
 DECL_VFUNC_DYN(void *, GetAllServerClasses)
 DECL_VFUNC_DYN(int, GetEngineBuildNumber)
 
+DECL_VFUNC(int, GetEngineBuildNumber_newl4d2, 99) // duping gamedata entry, yuck
+
 #include <entpropsinit.gen.h>
 
 bool engineapi_init(int pluginver) {
@@ -84,9 +87,13 @@ bool engineapi_init(int pluginver) {
 		_gametype_tag |= _gametype_tag_Portal1;
 	}
 
-	// TERRIBLE HACK: TODO(compat): come up with a better method later
-	if (GAMETYPE_MATCHES(L4D2) && os_access(OS_LIT(
-			"update/maps/c14m1_junkyard.bsp"), R_OK) != -1) {
+	// Ugly HACK: we want to call GetEngineBuildNumber to find out if we're on a
+	// Last Stand version (because they changed entity vtables for some reason),
+	// but that function also got moved in 2.0.4.1 which means we can't call it
+	// till gamedata is set up, so we have to have a bit of redundant logic here
+	// to bootstrap things.
+	if (GAMETYPE_MATCHES(L4D2) && GAMETYPE_MATCHES(Client013) &&
+			VCALL(engclient, GetEngineBuildNumber_newl4d2) >= 2200) {
 		_gametype_tag |= _gametype_tag_TheLastStand;
 	}
 
@@ -100,7 +107,6 @@ bool engineapi_init(int pluginver) {
 			has_off_SP_varname && has_off_SP_offset) {
 		initentprops(VCALL(srvdll, GetAllServerClasses));
 	}
-
 	return true;
 }
 
diff --git a/src/gametype.h b/src/gametype.h
index c825ee6..2464000 100644
--- a/src/gametype.h
+++ b/src/gametype.h
@@ -59,6 +59,7 @@ extern u64 _gametype_tag;
 #define _gametype_tag_L4Dbased	(_gametype_tag_L4Dx | _gametype_tag_Portal2)
 #define _gametype_tag_OrangeBoxbased \
 	(_gametype_tag_OrangeBox | _gametype_tag_2013)
+#define _gametype_tag_Portal (_gametype_tag_Portal1 | _gametype_tag_Portal2)
 
 #define GAMETYPE_MATCHES(x) !!(_gametype_tag & (_gametype_tag_##x))