splitscreen: tweak view drawing: use player's cursectnum and simulate z clamping.

Using the players's cursectnum instead of "updating" the sectnum means that it
won't glitch on SoS.  The z clamping (basically a port of some code from
G_DrawRooms) is so that the view won't be drawn from under the floor when shrunk.

git-svn-id: https://svn.eduke32.com/eduke32@2939 1a8010ca-5511-0410-912e-c29ae57300e0

polymer/eduke32/samples/splitscr.con

@@ -40,6 +40,7 @@ gamevar pid 1 0 // This hold player 2 id
 gamevar pnum 0 0 // This is set to player 2 sprite number
 
 // Temp variables
+gamevar tmp 0 0
 gamevar px 0 0 // Player (both 1 and 2) X coordinate
 gamevar py 0 0 // Player Y coordinate
 gamevar pz 0 0 // Player Z coordinate
@@ -269,37 +270,55 @@ define ORIENT 1032  // 26
 define P1X 4
 define P2X 164
 
+gamevar arg_player_id 0 0
+
+state show_player_view
+  getplayer[arg_player_id].posx px
+  getplayer[arg_player_id].posy py
+  getplayer[arg_player_id].posz pz
+  getplayer[arg_player_id].ang pang
+  getplayer[arg_player_id].horiz phoriz
+  getplayer[arg_player_id].horizoff phorizoff
+  addvarvar phoriz phorizoff
+
+  // simulate corresponding part in G_DrawRooms (almost)
+  ifvarvare player[arg_player_id].spritebridge 0
+  {
+    setvarvar tmp player[arg_player_id].truecz
+    addvar tmp 1024
+    ifvarvarl pz tmp
+      setvarvar pz tmp
+    else
+    {
+      setvarvar tmp player[arg_player_id].truefz
+      subvar tmp 1024
+      ifvarvarg pz tmp
+        setvarvar pz tmp
+    }
+  }
+
+  getplayer[arg_player_id].cursectnum psect
+
+  ifvarg psect -1
+  {
+    ifvare arg_player_id 0
+      showviewunbiased px py pz pang phoriz psect 0 0 160 199
+    else
+      showviewunbiased px py pz pang phoriz psect 160 0 319 199
+  }
+ends
+
 onevent EVENT_DISPLAYROOMS
     setvar RETURN 1  // don't draw them
 
     // an EDuke32 hack now:
 //    setplayer[THISACTOR].rotscrnang 0 // (almost) Prevent the screen rotation when player 1 die
 
-// Took this code from the wiki
-// It show player 1 view
-  getplayer[THISACTOR].posx px
-  getplayer[THISACTOR].posy py
-  getplayer[THISACTOR].posz pz
-  getplayer[THISACTOR].ang pang
-  getplayer[THISACTOR].horiz phoriz
-  getplayer[THISACTOR].horizoff phorizoff
-  addvarvar phoriz phorizoff
-  updatesector px py psect
-  ifvarg psect -1
-    showviewunbiased px py pz pang phoriz psect 0 0 160 199
-// -------------------------------------
-// Player 2 view
-  getplayer[pid].posx px
-  getplayer[pid].posy py
-  getplayer[pid].posz pz
-  getplayer[pid].ang pang
-  getplayer[pid].horiz phoriz
-  getplayer[pid].horizoff phorizoff
-  addvarvar phoriz phorizoff
-  updatesector px py psect
-  ifvarg psect -1
-    showviewunbiased px py pz pang phoriz psect 160 0 319 199
-// -------------------------------------
+  // DRAW THE PLAYER VIEWS!
+  setvar arg_player_id 0
+  state show_player_view
+  setvar arg_player_id 1
+  state show_player_view
 
 // Draw crosshairs if they are enabled
   getuserdef[THISACTOR].crosshair pcrosshair

polymer/eduke32/source/game.c

@@ -3574,6 +3574,9 @@ void G_DrawRooms(int32_t snum, int32_t smoothratio)
             ud.camerahoriz = 100+sprite[p->newowner].shade;
         else if (p->spritebridge == 0)
         {
+            // NOTE: when shrunk, p->pos.z can be below the floor.  This puts the
+            // camera into the sector again then.
+
             if (ud.camera.z < (p->truecz + (4<<8)))
                 ud.camera.z = cz + (4<<8);
             else if (ud.camera.z > (p->truefz - (4<<8)))

polymer/eduke32/source/player.c

@@ -5022,7 +5022,6 @@ void P_ProcessInput(int32_t snum)
                     }
             }
         }
-
         else
         {
             p->falling_counter = 0;
@@ -5308,6 +5307,8 @@ HORIZONLY:
             P_CheckTouchDamage(p, j);
     }
 
+    // This makes the player view lower when shrunk.  NOTE that it can get the
+    // view below the sector floor (and does, when on the ground).
     if (p->jetpack_on == 0 && psectlotag != 2 && psectlotag != 1 && shrunk)
         p->pos.z += 32<<8;