From be83c229e027ef08c451824c04803fa947333ad9 Mon Sep 17 00:00:00 2001
From: Denis Pauk <pauk.denis@gmail.com>
Date: Sat, 2 Nov 2024 17:54:27 +0200
Subject: [PATCH] game: fix position of dropped objects

---
 Makefile           |  4 ++--
 src/game/g_items.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index d26b013f..612a789e 100644
--- a/Makefile
+++ b/Makefile
@@ -150,7 +150,7 @@ endif
 # Highest supported optimizations are -O2, higher levels
 # will likely break this crappy code.
 ifdef DEBUG
-CFLAGS ?= -O0 -g -Wall -pipe -DDEBUG
+CFLAGS ?= -O0 -g -Wall -Wpointer-arith -pipe -DDEBUG
 ifdef ASAN
 override CFLAGS += -fsanitize=address -DUSE_SANITIZER
 endif
@@ -158,7 +158,7 @@ ifdef UBSAN
 override CFLAGS += -fsanitize=undefined -DUSE_SANITIZER
 endif
 else
-CFLAGS ?= -O2 -Wall -pipe -fomit-frame-pointer
+CFLAGS ?= -O2 -Wall -Wpointer-arith -pipe -fomit-frame-pointer
 endif
 
 # Always needed are:
diff --git a/src/game/g_items.c b/src/game/g_items.c
index a20e5138..6ccf8f21 100644
--- a/src/game/g_items.c
+++ b/src/game/g_items.c
@@ -1931,6 +1931,57 @@ Use_Item(edict_t *ent, edict_t *other /* unused */, edict_t *activator /* unused
 
 /* ====================================================================== */
 
+static void
+FixObjectPosition(edict_t *ent)
+{
+	int i;
+
+	for (i = 0; i < 3; i++)
+	{
+		int j;
+
+		for (j = 0; j < 3; j++)
+		{
+			vec3_t pos;
+			trace_t tr_pos;
+			int k;
+
+			VectorCopy(ent->s.origin, pos);
+
+			/* move by min */
+			for (k = 0; k < i + 1; k++)
+			{
+				int v;
+
+				v = (j + k) % 3;
+				pos[v] = ent->s.origin[v] - ent->mins[v];
+			}
+
+			tr_pos = gi.trace(pos, ent->mins, ent->maxs, ent->s.origin, ent, MASK_SOLID);
+			if (!tr_pos.startsolid)
+			{
+				VectorCopy(tr_pos.endpos, ent->s.origin);
+				return;
+			}
+
+			/* move by max */
+			for (k = 0; k < i + 1; k++)
+			{
+				int v;
+
+				v = (j + k) % 3;
+				pos[v] = ent->s.origin[v] - ent->maxs[v];
+			}
+			tr_pos = gi.trace(pos, ent->mins, ent->maxs, ent->s.origin, ent, MASK_SOLID);
+			if (!tr_pos.startsolid)
+			{
+				VectorCopy(tr_pos.endpos, ent->s.origin);
+				return;
+			}
+		}
+	}
+}
+
 void
 droptofloor(edict_t *ent)
 {
@@ -1966,6 +2017,13 @@ droptofloor(edict_t *ent)
 
 	tr = gi.trace(ent->s.origin, ent->mins, ent->maxs, dest, ent, MASK_SOLID);
 
+	if (tr.startsolid)
+	{
+		FixObjectPosition(ent);
+
+		tr = gi.trace(ent->s.origin, ent->mins, ent->maxs, dest, ent, MASK_SOLID);
+	}
+
 	if (tr.startsolid)
 	{
 		if (strcmp(ent->classname, "foodcube") == 0)