From f3904724d7e6901a881911b1fd49565ec3eb1fdb Mon Sep 17 00:00:00 2001
From: ac-stef <ac_stef@users.sf.net>
Date: Mon, 18 May 2015 14:06:42 +0200
Subject: [PATCH] limit the range of certain entity attributes

For example, direction angle values can be reduced to +- 360 degree.
(0..360 would be sufficient, but some people like their angles negative)

This is not a reduction of functionality or a security measure - it's for
convenience only: values now wrap around at the borders of their useful
ranges.
---
 source/src/entities.cpp | 19 +++++++++++++++++++
 source/src/protos.h     |  1 +
 source/src/server.h     |  4 ++--
 source/src/world.cpp    |  3 +++
 source/src/worldio.cpp  |  3 ++-
 5 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/source/src/entities.cpp b/source/src/entities.cpp
index 424c26fc..7a9c212a 100644
--- a/source/src/entities.cpp
+++ b/source/src/entities.cpp
@@ -662,3 +662,22 @@ void syncentchanges(bool force)
     changedents.setsize(0);
     lastentsync = lastmillis;
 }
+
+void clampentityattributes(persistent_entity &e)
+{
+    if(e.type < MAXENTTYPES)
+    {
+        int c;
+        #define CLAMPATTR(x) \
+            c = entwraparound[e.type][x - 1]; \
+            if(c > 0) e.attr##x = (e.attr##x % c + c) % c;  /* fold value into range 0..c */ \
+            else if(c < 0) e.attr##x = e.attr##x % (-c)     /* fold value into range -c..c */
+        CLAMPATTR(1);
+        CLAMPATTR(2);
+        CLAMPATTR(3);
+        CLAMPATTR(4);
+        CLAMPATTR(5);
+        CLAMPATTR(6);
+        CLAMPATTR(7);
+    }
+}
diff --git a/source/src/protos.h b/source/src/protos.h
index cadcb7c0..0121450b 100644
--- a/source/src/protos.h
+++ b/source/src/protos.h
@@ -788,6 +788,7 @@ extern void setspawn(int i, bool on);
 extern void checkitems(playerent *d);
 extern vector<int> changedents;
 extern void syncentchanges(bool force = false);
+extern void clampentityattributes(persistent_entity &e);
 
 // rndmap
 extern void perlinarea(block &b, int scale, int seed, int psize);
diff --git a/source/src/server.h b/source/src/server.h
index e2683466..5dd8dc40 100644
--- a/source/src/server.h
+++ b/source/src/server.h
@@ -464,10 +464,10 @@ short entwraparound[MAXENTTYPES][7] =
     {    0,    0,    0,    0,    0,    0,    0 },  // helmet
     {    0,    0,    0,    0,    0,    0,    0 },  // armour
     {    0,    0,    0,    0,    0,    0,    0 },  // akimbo
-    { 3600,    0,    0,    0, 3600,    0,    0 },  // mapmodel
+    { -3600,   0,    0,    0, -3600,   0,    0 },  // mapmodel
     {    0,    0,    0,    0,    0,    0,    0 },  // trigger
     {    0,    0,    0,    0,    0,    0,    0 },  // ladder
-    { 3600,    0,    0,    0,    0,    0,    0 },  // ctf-flag
+    { -3600,   0,    0,    0,    0,    0,    0 },  // ctf-flag
     {  256,    0,    0,    0,    0,    0,    0 },  // sound
     {    0,    0,    0,    0,    0,    0,    0 },  // clip
     {    0,    0,    0,    0,    0,    0,    0 }   // plclip
diff --git a/source/src/world.cpp b/source/src/world.cpp
index 3cd432b4..6bc09a8b 100644
--- a/source/src/world.cpp
+++ b/source/src/world.cpp
@@ -185,6 +185,7 @@ void entproperty(int prop, int amount)
         case 12: e.y += amount; break;
         case 13: e.z += amount; break;
     }
+    clampentityattributes(e);
     switch(e.type)
     {
         case LIGHT: calclight(); break;
@@ -301,6 +302,7 @@ entity *newentity(int index, int x, int y, int z, char *what, int v1, int v2, in
             if(type != PLAYERSTART) e.attr1 = e.attr1 + 70 - (e.attr1 + 70) % 150;
             break;
     }
+    clampentityattributes(e);
     syncentchanges(true);
     addmsg(SV_EDITENT, "ri9i3", index<0 ? ents.length() : index, type, e.x, e.y, e.z, e.attr1, e.attr2, e.attr3, e.attr4, e.attr5, e.attr6, e.attr7);
     e.spawned = true;
@@ -404,6 +406,7 @@ void editentity(char **args, int numargs) // index x y z a1 a2 a3 a4 ...
                     case 7: e.attr4 = v; break;
                 }
             }
+            clampentityattributes(e);
             switch(e.type)
             {
                 case LIGHT: calclight(); break;
diff --git a/source/src/worldio.cpp b/source/src/worldio.cpp
index 12f4943f..775c9d96 100644
--- a/source/src/worldio.cpp
+++ b/source/src/worldio.cpp
@@ -568,6 +568,7 @@ void save_world(char *mname, bool skipoptimise, bool addcomfort)
         {
             if(!ne--) break;
             persistent_entity tmp = ents[i];
+            clampentityattributes(tmp);
             lilswap((short *)&tmp, 4);
             lilswap(&tmp.attr5, 1);
             f->write(&tmp, sizeof(persistent_entity));
@@ -716,7 +717,7 @@ bool load_world(char *mname)        // still supports all map formats that have
             if(e.type == LIGHT && e.attr1 < 0) e.attr1 = 0; // negative lights had no meaning before version 10
             int ov, ss;
             #define SCALEATTR(x) \
-            if((ss = entwraparound[e.type][x - 1] / entscale[e.type][x - 1])) e.attr##x = (int(e.attr##x) % ss + ss) % ss; \
+            if((ss = abs(entwraparound[e.type][x - 1] / entscale[e.type][x - 1]))) e.attr##x = (int(e.attr##x) % ss + ss) % ss; \
             e.attr##x = ov = e.attr##x * entscale[e.type][x - 1]; \
             if(ov != e.attr##x) conoutf("overflow during conversion of attr%d of entity #%d (%s) - pls check before saving the map", x, i, entnames[e.type]);
             SCALEATTR(1);