From 776b5254e689e362276c815c7daad5d11f979c5c Mon Sep 17 00:00:00 2001
From: RedEnchilada <redenchilada@derpymail.com>
Date: Wed, 29 Apr 2015 00:29:51 -0500
Subject: [PATCH] Slope collision fixes

---
 src/p_local.h  |  2 ++
 src/p_map.c    | 22 ++++++++++++++++------
 src/p_maputl.c |  8 ++++----
 src/p_mobj.c   | 26 ++++++++++++++++++++++++--
 4 files changed, 46 insertions(+), 12 deletions(-)

diff --git a/src/p_local.h b/src/p_local.h
index 53e5b18b4..c3e21dbe9 100644
--- a/src/p_local.h
+++ b/src/p_local.h
@@ -296,6 +296,8 @@ extern fixed_t tmfloorz;
 extern fixed_t tmceilingz;
 extern mobj_t *tmfloorthing, *tmthing;
 extern camera_t *mapcampointer;
+extern fixed_t tmx;
+extern fixed_t tmy;
 
 /* cphipps 2004/08/30 */
 extern void P_MapStart(void);
diff --git a/src/p_map.c b/src/p_map.c
index 50f172798..31f0acc62 100644
--- a/src/p_map.c
+++ b/src/p_map.c
@@ -38,8 +38,8 @@
 fixed_t tmbbox[4];
 mobj_t *tmthing;
 static INT32 tmflags;
-static fixed_t tmx;
-static fixed_t tmy;
+fixed_t tmx;
+fixed_t tmy;
 
 static precipmobj_t *tmprecipthing;
 static fixed_t preciptmbbox[4];
@@ -1208,8 +1208,8 @@ boolean P_CheckPosition(mobj_t *thing, fixed_t x, fixed_t y)
 	// that contains the point.
 	// Any contacted lines the step closer together
 	// will adjust them.
-	tmfloorz = tmdropoffz = P_GetFloorZ(thing, newsubsec->sector, thing->x, thing->y, NULL); //newsubsec->sector->floorheight;
-	tmceilingz = P_GetCeilingZ(thing, newsubsec->sector, thing->x, thing->y, NULL); //newsubsec->sector->ceilingheight;
+	tmfloorz = tmdropoffz = P_GetFloorZ(thing, newsubsec->sector, x, y, NULL); //newsubsec->sector->floorheight;
+	tmceilingz = P_GetCeilingZ(thing, newsubsec->sector, x, y, NULL); //newsubsec->sector->ceilingheight;
 
 	// Check list of fake floors and see if tmfloorz/tmceilingz need to be altered.
 	if (newsubsec->sector->ffloors)
@@ -1945,13 +1945,23 @@ boolean P_TryMove(mobj_t *thing, fixed_t x, fixed_t y, boolean allowdropoff)
 				{
 					if (thingtop == thing->ceilingz && tmceilingz > thingtop && tmceilingz - thingtop <= maxstep)
 					{
-						thing->z = tmceilingz - thing->height;
+						thing->z = (thing->ceilingz = thingtop = tmceilingz) - thing->height;
+						thing->eflags |= MFE_JUSTSTEPPEDDOWN;
+					}
+					else if (thingtop == thing->ceilingz && tmceilingz , thingtop && thingtop - tmceilingz <= maxstep)
+					{
+						thing->z = (thing->ceilingz = thingtop = tmceilingz) - thing->height;
 						thing->eflags |= MFE_JUSTSTEPPEDDOWN;
 					}
 				}
 				else if (thing->z == thing->floorz && tmfloorz < thing->z && thing->z - tmfloorz <= maxstep)
 				{
-					thing->z = tmfloorz;
+					thing->z = thing->floorz = tmfloorz;
+					thing->eflags |= MFE_JUSTSTEPPEDDOWN;
+				}
+				else if (thing->z == thing->floorz && tmfloorz > thing->z && tmfloorz - thing->z <= maxstep)
+				{
+					thing->z = thing->floorz = tmfloorz;
 					thing->eflags |= MFE_JUSTSTEPPEDDOWN;
 				}
 			}
diff --git a/src/p_maputl.c b/src/p_maputl.c
index 7641dd1eb..e9e0bb776 100644
--- a/src/p_maputl.c
+++ b/src/p_maputl.c
@@ -560,8 +560,8 @@ void P_LineOpening(line_t *linedef)
 	{ // Set open and high/low values here
 		fixed_t frontheight, backheight;
 
-		frontheight = P_GetCeilingZ(tmthing, front, tmthing->x, tmthing->y, linedef);
-		backheight = P_GetCeilingZ(tmthing, back, tmthing->x, tmthing->y, linedef);
+		frontheight = P_GetCeilingZ(tmthing, front, tmx, tmy, linedef);
+		backheight = P_GetCeilingZ(tmthing, back, tmx, tmy, linedef);
 
 		if (frontheight < backheight)
 		{
@@ -574,8 +574,8 @@ void P_LineOpening(line_t *linedef)
 			highceiling = frontheight;
 		}
 
-		frontheight = P_GetFloorZ(tmthing, front, tmthing->x, tmthing->y, linedef);
-		backheight = P_GetFloorZ(tmthing, back, tmthing->x, tmthing->y, linedef);
+		frontheight = P_GetFloorZ(tmthing, front, tmx, tmy, linedef);
+		backheight = P_GetFloorZ(tmthing, back, tmx, tmy, linedef);
 
 		if (frontheight > backheight)
 		{
diff --git a/src/p_mobj.c b/src/p_mobj.c
index 1be713bf4..d57e398ec 100644
--- a/src/p_mobj.c
+++ b/src/p_mobj.c
@@ -747,7 +747,7 @@ fixed_t P_GetFloorZ(mobj_t *mobj, sector_t *sector, fixed_t x, fixed_t y, line_t
 
 		if (slope->zdelta > 0) {
 			testx = -testx;
-			testx = -testy;
+			testy = -testy;
 		}
 
 		testx += x;
@@ -775,6 +775,17 @@ fixed_t P_GetFloorZ(mobj_t *mobj, sector_t *sector, fixed_t x, fixed_t y, line_t
 			v2.x = line->v2->x;
 			v2.y = line->v2->y;
 
+			/*CONS_Printf("BEFORE: v1 = %f %f %f\n",
+						FIXED_TO_FLOAT(v1.x),
+						FIXED_TO_FLOAT(v1.y),
+						FIXED_TO_FLOAT(P_GetZAt(slope, v1.x, v1.y))
+						);
+			CONS_Printf("        v2 = %f %f %f\n",
+						FIXED_TO_FLOAT(v2.x),
+						FIXED_TO_FLOAT(v2.y),
+						FIXED_TO_FLOAT(P_GetZAt(slope, v2.x, v2.y))
+						);*/
+
 			if (abs(v1.x-x) > mobj->radius) {
 				// v1's x is out of range, so rein it in
 				fixed_t diff = abs(v1.x-x) - mobj->radius;
@@ -827,6 +838,17 @@ fixed_t P_GetFloorZ(mobj_t *mobj, sector_t *sector, fixed_t x, fixed_t y, line_t
 				}
 			}
 
+			/*CONS_Printf("AFTER:  v1 = %f %f %f\n",
+						FIXED_TO_FLOAT(v1.x),
+						FIXED_TO_FLOAT(v1.y),
+						FIXED_TO_FLOAT(P_GetZAt(slope, v1.x, v1.y))
+						);
+			CONS_Printf("        v2 = %f %f %f\n",
+						FIXED_TO_FLOAT(v2.x),
+						FIXED_TO_FLOAT(v2.y),
+						FIXED_TO_FLOAT(P_GetZAt(slope, v2.x, v2.y))
+						);*/
+
 			// Return the higher of the two points
 			return max(
 				P_GetZAt(slope, v1.x, v1.y),
@@ -860,7 +882,7 @@ fixed_t P_GetCeilingZ(mobj_t *mobj, sector_t *sector, fixed_t x, fixed_t y, line
 
 		if (slope->zdelta < 0) {
 			testx = -testx;
-			testx = -testy;
+			testy = -testy;
 		}
 
 		testx += x;