From 7a5a19a87493c4e62534182c940f5c9c88fa7a4b Mon Sep 17 00:00:00 2001
From: helixhorned <helixhorned@1a8010ca-5511-0410-912e-c29ae57300e0>
Date: Thu, 12 Jan 2012 20:48:00 +0000
Subject: [PATCH] Fix actor[].dispicnum becoming negative.

Since the original source code release of Duke3D, there was a potentially
dangerous hack where actor[].dispicnum was set to -4 to signal "this actor
should not have a floor shadow for this moment" (it doesn't really work,
if you ask me).
Now, use another bit of actor[].flags for that purpose because setting
any picnum members to negative values asks for trouble.

git-svn-id: https://svn.eduke32.com/eduke32@2249 1a8010ca-5511-0410-912e-c29ae57300e0
---
 polymer/eduke32/source/actors.h   | 1 +
 polymer/eduke32/source/game.c     | 9 ++++++++-
 polymer/eduke32/source/gameexec.c | 5 ++++-
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/polymer/eduke32/source/actors.h b/polymer/eduke32/source/actors.h
index 0363907f1..874101fa5 100644
--- a/polymer/eduke32/source/actors.h
+++ b/polymer/eduke32/source/actors.h
@@ -149,6 +149,7 @@ enum sflags_t {
     SPRITE_USEACTIVATOR = 0x00000200,
     SPRITE_NULL         = 0x00000400, // null sprite in multiplayer
     SPRITE_NOCLIP       = 0x00000800, // clipmove it with cliptype 0
+    SPRITE_NOFLOORSHADOW= 0x00001000, // for temp. internal use, per-tile flag not checked
 };
 
 // custom projectiles
diff --git a/polymer/eduke32/source/game.c b/polymer/eduke32/source/game.c
index e9ffadfa3..a3c30d5ff 100644
--- a/polymer/eduke32/source/game.c
+++ b/polymer/eduke32/source/game.c
@@ -6513,10 +6513,17 @@ skip:
             {
                 if (actor[i].dispicnum < 0)
                 {
+                    // a negative actor[i].dispicnum used to mean 'no floor shadow please' but
+                    // that was a bad hack since the value could propagate to sprite[].picnum
+                    OSD_Printf(OSD_ERROR "actor[%d].dispicnum = %d\n", i, actor[i].dispicnum);
                     actor[i].dispicnum++;
                     continue;
                 }
-                else if (ud.shadows && spritesortcnt < (MAXSPRITESONSCREEN-2) && getrendermode() != 4)
+
+                if (actor[i].flags & SPRITE_NOFLOORSHADOW)
+                    continue;
+
+                if (ud.shadows && spritesortcnt < (MAXSPRITESONSCREEN-2) && getrendermode() != 4)
                 {
                     int32_t daz,xrep,yrep;
 
diff --git a/polymer/eduke32/source/gameexec.c b/polymer/eduke32/source/gameexec.c
index 2458c3c95..83a18aed2 100644
--- a/polymer/eduke32/source/gameexec.c
+++ b/polymer/eduke32/source/gameexec.c
@@ -302,6 +302,8 @@ void A_GetZLimits(int32_t iActor)
 
         s->cstat = cstat;
 
+        actor[iActor].flags &= ~SPRITE_NOFLOORSHADOW;
+
         if ((lz&49152) == 49152 && (sprite[lz&(MAXSPRITES-1)].cstat&48) == 0)
         {
             const spritetype *hitspr = &sprite[lz&(MAXSPRITES-1)];
@@ -311,7 +313,8 @@ void A_GetZLimits(int32_t iActor)
             if ((A_CheckEnemySprite(hitspr) && hitspr->pal != 1 && s->statnum != STAT_PROJECTILE)
                     || (hitspr->picnum == APLAYER && A_CheckEnemySprite(s)))
             {
-                actor[iActor].dispicnum = -4; // No shadows on actors
+                actor[iActor].flags |= SPRITE_NOFLOORSHADOW;  // No shadows on actors
+//                actor[iActor].dispicnum = -4; // No shadows on actors
                 s->xvel = -256;
                 A_SetSprite(iActor,CLIPMASK0);
             }