- added a new 'playeruseback' linedef trigger type that allows using lines from the bxck side.

SVN r2302 (trunk)

specs/udmf_zdoom.txt

@@ -1,5 +1,5 @@
 ===============================================================================
-Universal Doom Map Format ZDoom extensions v1.9 - 17.04.2010
+Universal Doom Map Format ZDoom extensions v1.10 - 25.04.2010
 
 
     Copyright (c) 2008 Christoph Oelckers.
@@ -89,6 +89,7 @@ Note: All <bool> fields default to false unless mentioned otherwise.
       alpha = <float>;          // Translucency of this line, default is 1.0
       renderstyle = <string>;   // Render style, can be "translucent" or "add",
                                 // default is "translucent".
+      playeruseback = <bool>;   // New SPAC flag, true = player can use from back side.
       anycross = <bool>;        // New SPAC flag, true = any non-projectile 
                                 // crossing will trigger this line
       monsteractivate = <bool>; // Monsters can trigger this line.
@@ -259,6 +260,9 @@ Fixed conversion specifications for TranslucentLine special.
 1.9 17.04.2010
 Changed node specifications to deprecate compression of node lump.
 
+1.10 25.04.2010
+Added 'playeruseback' line trigger flag.
+
 ===============================================================================
 EOF
 ===============================================================================

src/doomdata.h

@@ -169,8 +169,9 @@ enum SPAC
 	SPAC_AnyCross = 1<<7,	// when anything without the MF2_TELEPORT flag crosses the line
 	SPAC_MUse = 1<<8,		// monsters can use
 	SPAC_MPush = 1<<9,		// monsters can push
+	SPAC_UseBack = 1<<10,	// Can be used from the backside
 
-	SPAC_PlayerActivate = (SPAC_Cross|SPAC_Use|SPAC_Impact|SPAC_Push|SPAC_AnyCross|SPAC_UseThrough),
+	SPAC_PlayerActivate = (SPAC_Cross|SPAC_Use|SPAC_Impact|SPAC_Push|SPAC_AnyCross|SPAC_UseThrough|SPAC_UseBack),
 };
 
 enum EMapLineFlags	// These are flags that use different values internally

src/namedef.h

@@ -386,6 +386,7 @@ xx(Repeatspecial)
 
 xx(Playercross)
 xx(Playeruse)
+xx(Playeruseback)
 xx(Monstercross)
 xx(Impact)
 xx(Playerpush)

src/p_map.cpp

@@ -3983,7 +3983,7 @@ bool P_UseTraverse(AActor *usething, fixed_t endx, fixed_t endy, bool &foundline
 		}
 
 		FLineOpening open;
-		if (in->d.line->special == 0 || !(in->d.line->activation & (SPAC_Use|SPAC_UseThrough)))
+		if (in->d.line->special == 0 || !(in->d.line->activation & (SPAC_Use|SPAC_UseThrough|SPAC_UseBack)))
 		{
 	blocked:
 			if (in->d.line->flags & (ML_BLOCKEVERYTHING|ML_BLOCKUSE))
@@ -4029,9 +4029,25 @@ bool P_UseTraverse(AActor *usething, fixed_t endx, fixed_t endy, bool &foundline
 		}
 			
 		if (P_PointOnLineSide (usething->x, usething->y, in->d.line) == 1)
+		{
+			if (!(in->d.line->activation & SPAC_UseBack))
+			{
 				// [RH] continue traversal for two-sided lines
 				//return in->d.line->backsector != NULL;		// don't use back side
 				goto blocked;	// do a proper check for back sides of triggers
+			}
+			else
+			{
+				P_ActivateLine (in->d.line, usething, 1, SPAC_UseBack);
+				return true;
+			}
+		}
+		else 
+		{
+			if ((in->d.line->activation & (SPAC_Use|SPAC_UseThrough|SPAC_UseBack)) == SPAC_UseBack)
+			{
+				goto blocked; // Line cannot be used from front side so treat it as a non-trigger line
+			}
 
 			P_ActivateLine (in->d.line, usething, 0, SPAC_Use);
 
@@ -4050,6 +4066,9 @@ bool P_UseTraverse(AActor *usething, fixed_t endx, fixed_t endy, bool &foundline
 				if (!(in->d.line->activation & SPAC_Use)) continue;
 				else return true;
 			}
+
+		}
+
 	}
 	return false;
 }

src/p_spec.cpp

@@ -294,7 +294,7 @@ bool P_TestActivateLine (line_t *line, AActor *mo, int side, int activationType)
 	{
 		lineActivation |= SPAC_Cross|SPAC_MCross;
 	}
-	if (activationType == SPAC_Use)
+	if (activationType ==SPAC_Use || activationType == SPAC_UseBack)
 	{
 		if (!P_CheckSwitchRange(mo, line, side))
 		{

src/p_udmf.cpp

@@ -721,6 +721,10 @@ struct UDMFParser
 				Flag(ld->activation, SPAC_Use, key); 
 				continue;
 
+			case NAME_Playeruseback:
+				Flag(ld->activation, SPAC_UseBack, key); 
+				continue;
+
 			case NAME_Monstercross:
 				Flag(ld->activation, SPAC_MCross, key); 
 				continue;