Late night commit!

* Seriously reworked a lot of stuff behind the scenes, thanks to Red's comments.
* More consistent behaviour.
* Launching power is now scaled to the slope's angle relative to the wall you hit, so no massive launches when you hit the side of a steep slope.
* The code is a lot messier and the function name doesn't make any sense any more, so I need to clean that up in the morning.
* Need to figure out how to prevent tiny launches that uncurl you when spindashing up against walls.
* Spindashing trails now takes into account vertical momentum as well as horizontal - it was stupid not seeing your spintrail just because you weren't moving very fast horizontally!

No exe uploaded because it's almost 2am.

src/p_mobj.c

@@ -2121,14 +2121,19 @@ void P_XYMovement(mobj_t *mo)
 
 	if (!P_TryMove(mo, mo->x + xmove, mo->y + ymove, true) && !(mo->eflags & MFE_SPRUNG))
 	{
+#ifdef ESLOPE
+		pslope_t *transferslope = NULL;
+		fixed_t transfermomz = 0;
+		if (oldslope && (P_MobjFlip(mo)*(predictedz - mo->z) > 0)) // Only for moving up (relative to gravity), otherwise there's a failed launch when going down slopes and hitting walls
+		{
+			transferslope = ((mo->standingslope) ? mo->standingslope : oldslope);
+			transfermomz = P_PrepareSlopeToWallTransfer(mo, transferslope); // This isn't the end of it; momz will be scaled based upon the angle of movement after collision, and then it'll be applied.
+		}
+#endif
+
 		// blocked move
 		moved = false;
 
-#ifdef ESLOPE
-		if (oldslope && predictedz > mo->z) // Only for moving up, otherwise there's a failed launch when going down slopes and hitting walls
-			P_SlopeToWallTransfer(mo);
-#endif
-
 		if (player) {
 			if (player->bot)
 				B_MoveBlocked(player);
@@ -2185,6 +2190,19 @@ void P_XYMovement(mobj_t *mo)
 		{ // try to slide along it
 			P_SlideMove(mo);
 			xmove = ymove = 0;
+#ifdef ESLOPE
+			if (transfermomz && transferslope) // Scale transfer momentum based on how head-on it is to the slope.
+			{
+				angle_t relation = (transferslope->xydirection - R_PointToAngle2(0, 0, mo->momx, mo->momy));
+				fixed_t scalefactor = abs(FINESINE((relation >> ANGLETOFINESHIFT) & FINEMASK));
+				transfermomz = FixedMul(transfermomz, scalefactor);
+				if ((P_MobjFlip(mo)*(transfermomz - mo->momz)) > 2*FRACUNIT) // Do the actual launch!
+				{
+					mo->standingslope = NULL;
+					mo->momz = transfermomz;
+				}
+			}
+#endif
 		}
 		else if (mo->type == MT_SPINFIRE)
 		{

src/p_slopes.c

@@ -808,24 +808,31 @@ void P_SlopeLaunch(mobj_t *mo)
 // P_SlopeToWallTransfer
 //
 // Handles slope-to-wall transfer for objects.
-void P_SlopeToWallTransfer(mobj_t *mo)
+fixed_t P_PrepareSlopeToWallTransfer(mobj_t *mo, pslope_t *slope)
 {
-	if (!(mo->standingslope->flags & SL_NOPHYSICS)) // If there's physics, time for launching.
-	{
-		// Doesn't kill the vertical momentum as much as P_SlopeLaunch does.
-		vector3_t slopemom;
-		slopemom.x = mo->momx;
-		slopemom.y = mo->momy;
-		slopemom.z = 3*(mo->momz/2);
-		P_QuantizeMomentumToSlope(&slopemom, mo->standingslope);
+	vector3_t slopemom, axis;
+	angle_t ang;
 
-		mo->momx = slopemom.x;
-		mo->momy = slopemom.y;
-		mo->momz = 2*(slopemom.z/3);
-	}
+	if (mo->standingslope->flags & SL_NOPHYSICS)
+		return 0;
 
-	//CONS_Printf("Transferred off of slope.\n");
-	mo->standingslope = NULL;
+	// If there's physics, time for launching.
+	// Doesn't kill the vertical momentum as much as P_SlopeLaunch does.
+	ang = slope->zangle + ANG15*((slope->zangle > 0) ? 1 : -1);
+	if (ang > ANGLE_90 && ang < ANGLE_180)
+		ang = ((slope->zangle > 0) ? ANGLE_90 : InvAngle(ANGLE_90)); // hard cap of directly upwards
+
+	slopemom.x = mo->momx;
+	slopemom.y = mo->momy;
+	slopemom.z = 3*(mo->momz/2);
+
+	axis.x = -slope->d.y;
+	axis.y = slope->d.x;
+	axis.z = 0;
+
+	FV3_Rotate(&slopemom, &axis, ang >> ANGLETOFINESHIFT);
+
+	return 2*(slopemom.z/3);
 }
 
 // Function to help handle landing on slopes

src/p_slopes.h

@@ -37,7 +37,7 @@ fixed_t P_GetZAt(pslope_t *slope, fixed_t x, fixed_t y);
 void P_QuantizeMomentumToSlope(vector3_t *momentum, pslope_t *slope);
 void P_ReverseQuantizeMomentumToSlope(vector3_t *momentum, pslope_t *slope);
 void P_SlopeLaunch(mobj_t *mo);
-void P_SlopeToWallTransfer(mobj_t *mo);
+fixed_t P_PrepareSlopeToWallTransfer(mobj_t *mo, pslope_t *slope);
 void P_HandleSlopeLanding(mobj_t *thing, pslope_t *slope);
 void P_ButteredSlope(mobj_t *mo);
 

src/p_user.c

@@ -6895,7 +6895,7 @@ static void P_MovePlayer(player_t *player)
 		P_ResetScore(player);
 
 	// Show the "THOK!" graphic when spinning quickly across the ground. (even applies to non-spinners, in the case of zoom tubes)
-	if (player->pflags & PF_SPINNING && player->speed > FixedMul(15<<FRACBITS, player->mo->scale) && !(player->pflags & PF_JUMPED))
+	if (player->pflags & PF_SPINNING && P_AproxDistance(player->speed, player->mo->momz) > FixedMul(15<<FRACBITS, player->mo->scale) && !(player->pflags & PF_JUMPED))
 	{
 		P_SpawnSpinMobj(player, player->spinitem);
 		if (demorecording)