commit f388d888518486676931e0fc3bd915fbb8b338e3
Author: alexey.lysiuk <alexey.lysiuk@gmail.com>
AuthorDate: Sat May 10 15:50:44 2014 +0300
Commit: alexey.lysiuk <alexey.lysiuk@gmail.com>
CommitDate: Sat May 10 15:50:44 2014 +0300
hexen: Fix desync of demo1 on some platforms/compilers
Official release of Hexen's source code relies on unspecified behavior the in order of function's argument evaluation, see ISO-IEC 9899-1999, [6.5.2.2.10]
P_Random() are called in different parameters of P_SpawnMobj() within A_LeafSpawn()
---
src/hexen/a_action.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/src/hexen/a_action.c b/src/hexen/a_action.c
index 3100a074..e25b4f84 100644
--- a/src/hexen/a_action.c
+++ b/src/hexen/a_action.c
@@ -295,10 +295,15 @@ void A_LeafSpawn(mobj_t * actor)
for (i = (P_Random() & 3) + 1; i; i--)
{
- mo = P_SpawnMobj(actor->x + ((P_Random() - P_Random()) << 14),
- actor->y + ((P_Random() - P_Random()) << 14),
- actor->z + (P_Random() << 14),
- MT_LEAF1 + (P_Random() & 1));
+ // Official release of Hexen's source code relies on unspecified behavior
+ // the in order of function's argument evaluation,
+ // see ISO-IEC 9899-1999, [6.5.2.2.10]
+ mobjtype_t type = MT_LEAF1 + (P_Random() & 1);
+ fixed_t z = actor->z + (P_Random() << 14);
+ fixed_t y = actor->y + ((P_Random() - P_Random()) << 14);
+ fixed_t x = actor->x + ((P_Random() - P_Random()) << 14);
+
+ mo = P_SpawnMobj(x, y, z, type);
if (mo)
{
P_ThrustMobj(mo, actor->angle, (P_Random() << 9) + 3 * FRACUNIT);