First shot at support for the Hexen 4-level Demo

With these changes it is possible to run the game using the HEXEN.WAD
IWAD from the 4-level Demo and start a new game as one of the three
player classes.

Known missing bits:
 - The game does not yet identify itself as the demo version
 - The cheat codes are still unchanged
 - Bug compatibility, see e.g.
   http://dengine.net/dew/index.php?title=Libhexen

1 files changed, 7 insertions, 0 deletions

diff --git a/src/hexen/p_switch.c b/src/hexen/p_switch.c
index 9d86f92a..92bd0be4 100644
--- a/src/hexen/p_switch.c
+++ b/src/hexen/p_switch.c
@@ -66,6 +66,13 @@ void P_InitSwitchList(void)
             switchlist[index] = -1;
             break;
         }
+
+        if (R_CheckTextureNumForName(alphSwitchList[i].name1) == -1 &&
+            gamemode == shareware)
+        {
+            continue;
+        }
+
         switchlist[index++] = R_TextureNumForName(alphSwitchList[i].name1);
         switchlist[index++] = R_TextureNumForName(alphSwitchList[i].name2);
     }