From f8e64a13af7ab0a90accbf0869600bb134139a14 Mon Sep 17 00:00:00 2001
From: Randy Heit <rheit@zdoom.fake>
Date: Thu, 26 Apr 2012 03:50:11 +0000
Subject: [PATCH] - On second thought, using FloorBounceMissile() for bouncing
 off the top of an actor might not   be the best idea.

SVN r3598 (trunk)
---
 src/p_local.h  |  4 ++--
 src/p_map.cpp  | 64 ++++++++++++++++++++++++++++++++++++++++----------
 src/p_mobj.cpp |  9 ++++---
 3 files changed, 58 insertions(+), 19 deletions(-)

diff --git a/src/p_local.h b/src/p_local.h
index 97b5e5fa38..e71fba1241 100644
--- a/src/p_local.h
+++ b/src/p_local.h
@@ -417,8 +417,8 @@ bool	P_TeleportMove (AActor* thing, fixed_t x, fixed_t y, fixed_t z, bool telefr
 void	P_PlayerStartStomp (AActor *actor);		// [RH] Stomp on things for a newly spawned player
 void	P_SlideMove (AActor* mo, fixed_t tryx, fixed_t tryy, int numsteps);
 bool	P_BounceWall (AActor *mo);
-bool	P_BounceActor (AActor *mo, AActor * BlockingMobj);
-bool	P_CheckSight (const AActor* t1, const AActor* t2, int flags=0);
+bool	P_BounceActor (AActor *mo, AActor *BlockingMobj, bool ontop);
+bool	P_CheckSight (const AActor *t1, const AActor *t2, int flags=0);
 
 enum ESightFlags
 {
diff --git a/src/p_map.cpp b/src/p_map.cpp
index 9b5c2101ac..b221736cf8 100644
--- a/src/p_map.cpp
+++ b/src/p_map.cpp
@@ -2854,7 +2854,7 @@ bool P_BounceWall (AActor *mo)
 //==========================================================================
 
 extern FRandom pr_bounce;
-bool P_BounceActor (AActor *mo, AActor * BlockingMobj)
+bool P_BounceActor (AActor *mo, AActor *BlockingMobj, bool ontop)
 {
 	if (mo && BlockingMobj && ((mo->BounceFlags & BOUNCE_AllActors)
 		|| ((mo->flags & MF_MISSILE) && (BlockingMobj->flags2 & MF2_REFLECTIVE))
@@ -2862,17 +2862,57 @@ bool P_BounceActor (AActor *mo, AActor * BlockingMobj)
 		))
 	{
 		if (mo->bouncecount > 0 && --mo->bouncecount == 0) return false;
-		
-		fixed_t speed;
-		angle_t angle = R_PointToAngle2 (BlockingMobj->x,
-		BlockingMobj->y, mo->x, mo->y) + ANGLE_1*((pr_bounce()%16)-8);
-		speed = P_AproxDistance (mo->velx, mo->vely);
-		speed = FixedMul (speed, mo->wallbouncefactor); // [GZ] was 0.75, using wallbouncefactor seems more consistent
-		mo->angle = angle;
-		angle >>= ANGLETOFINESHIFT;
-		mo->velx = FixedMul (speed, finecosine[angle]);
-		mo->vely = FixedMul (speed, finesine[angle]);
-		mo->PlayBounceSound(true);
+
+		if (!ontop)
+		{
+			fixed_t speed;
+			angle_t angle = R_PointToAngle2 (BlockingMobj->x,
+				BlockingMobj->y, mo->x, mo->y) + ANGLE_1*((pr_bounce()%16)-8);
+			speed = P_AproxDistance (mo->velx, mo->vely);
+			speed = FixedMul (speed, mo->wallbouncefactor); // [GZ] was 0.75, using wallbouncefactor seems more consistent
+			mo->angle = angle;
+			angle >>= ANGLETOFINESHIFT;
+			mo->velx = FixedMul (speed, finecosine[angle]);
+			mo->vely = FixedMul (speed, finesine[angle]);
+			mo->PlayBounceSound(true);
+		}
+		else
+		{
+			fixed_t dot = mo->velz;
+
+			if (mo->BounceFlags & (BOUNCE_HereticType | BOUNCE_MBF))
+			{
+				mo->velz -= MulScale15 (FRACUNIT, dot);
+				if (!(mo->BounceFlags & BOUNCE_MBF)) // Heretic projectiles die, MBF projectiles don't.
+				{
+					mo->flags |= MF_INBOUNCE;
+					mo->SetState(mo->FindState(NAME_Death));
+					mo->flags &= ~MF_INBOUNCE;
+					return false;
+				}
+				else
+				{
+					mo->velz = FixedMul(mo->velz, mo->bouncefactor);
+				}
+			}
+			else // Don't run through this for MBF-style bounces
+			{
+				// The reflected velocity keeps only about 70% of its original speed
+				mo->velz = FixedMul(mo->velz - MulScale15(FRACUNIT, dot), mo->bouncefactor);
+			}
+
+			mo->PlayBounceSound(true);
+			if (mo->BounceFlags & BOUNCE_MBF) // Bring it to rest below a certain speed
+			{
+				if (abs(mo->velz) < (fixed_t)(mo->Mass * mo->GetGravity() / 64))
+					mo->velz = 0;
+			}
+			else if (mo->BounceFlags & BOUNCE_AutoOff)
+			{
+				if (!(mo->flags & MF_NOGRAVITY) && (mo->velz < 3*FRACUNIT))
+					mo->BounceFlags &= ~BOUNCE_TypeMask;
+			}
+		}
 		return true;
 	}
 	return false;
diff --git a/src/p_mobj.cpp b/src/p_mobj.cpp
index a0784dbf0f..8df97f1db7 100644
--- a/src/p_mobj.cpp
+++ b/src/p_mobj.cpp
@@ -1763,7 +1763,7 @@ fixed_t P_XYMovement (AActor *mo, fixed_t scrollx, fixed_t scrolly)
 			line_t *BlockingLine = mo->BlockingLine;
 
 			if (!(mo->flags & MF_MISSILE) && (mo->BounceFlags & BOUNCE_MBF) 
-				&& (BlockingMobj != NULL ? P_BounceActor(mo, BlockingMobj) : P_BounceWall(mo)))
+				&& (BlockingMobj != NULL ? P_BounceActor(mo, BlockingMobj, false) : P_BounceWall(mo)))
 			{
 				// Do nothing, relevant actions already done in the condition.
 				// This allows to avoid setting velocities to 0 in the final else of this series.
@@ -1858,7 +1858,7 @@ fixed_t P_XYMovement (AActor *mo, fixed_t scrollx, fixed_t scrolly)
 					if (mo->BounceFlags & BOUNCE_Actors)
 					{
 						// Bounce test and code moved to P_BounceActor
-						if (!P_BounceActor(mo, BlockingMobj))
+						if (!P_BounceActor(mo, BlockingMobj, false))
 						{	// Struck a player/creature
 							P_ExplodeMissile (mo, NULL, BlockingMobj);
 						}
@@ -3305,10 +3305,9 @@ void AActor::Tick ()
 						} 
 						z = onmo->z + onmo->height;
 					}
-					if (velz != 0 && (flags & MF_MISSILE) && (BounceFlags & BOUNCE_Actors))
+					if (velz != 0 && (BounceFlags & BOUNCE_Actors))
 					{
-						secplane_t plane = { 0, 0, FRACUNIT, -z, FRACUNIT };
-						FloorBounceMissile(plane);
+						P_BounceActor(this, onmo, true);
 					}
 					else
 					{