From a1cf8a127c57719d18fa0ccbe4a3fa3ac5504ef2 Mon Sep 17 00:00:00 2001
From: SmallJoker <SmallJoker@users.noreply.github.com>
Date: Sat, 3 Mar 2018 10:59:14 +0100
Subject: [PATCH] Slippery: Simplify, make more efficient (#7086)

Use already existing collision results for the nearest colliding node
Fix slippery effect in free_move mode
---
 src/localplayer.cpp | 44 +++++++++-----------------------------------
 src/localplayer.h   |  1 -
 2 files changed, 9 insertions(+), 36 deletions(-)

diff --git a/src/localplayer.cpp b/src/localplayer.cpp
index 3133c2652..a8bd21839 100644
--- a/src/localplayer.cpp
+++ b/src/localplayer.cpp
@@ -681,7 +681,10 @@ void LocalPlayer::applyControl(float dtime, Environment *env)
 	else
 		incH = incV = movement_acceleration_default * BS * dtime;
 
-	float slip_factor = getSlipFactor(env, speedH);
+	float slip_factor = 1.0f;
+	if (!free_move)
+		slip_factor = getSlipFactor(env, speedH);
+
 	// Accelerate to target speed with maximum increment
 	accelerateHorizontal(speedH * physics_override_speed,
 			incH * physics_override_speed * slip_factor);
@@ -1057,49 +1060,20 @@ void LocalPlayer::old_move(f32 dtime, Environment *env, f32 pos_max_d,
 
 float LocalPlayer::getSlipFactor(Environment *env, const v3f &speedH)
 {
-
-	if (!touching_ground)
-		return 1.0f;
-
-	float slip_factor = 1.0f;
 	// Slip on slippery nodes
 	const NodeDefManager *nodemgr = env->getGameDef()->ndef();
 	Map *map = &env->getMap();
 	const ContentFeatures &f = nodemgr->get(map->getNodeNoEx(
-			floatToInt(getPosition() - v3f(0, 0.05f * BS, 0), BS)));
+			getStandingNodePos()));
 	int slippery = 0;
-	if (f.walkable) {
+	if (f.walkable)
 		slippery = itemgroup_get(f.groups, "slippery");
-	} else if (is_slipping) {
-		// slipping over an edge? Check surroundings for slippery nodes
-		slippery = 2 << 16; // guard value, bigger than all realistic ones
-		for (int z = 0; z <= 1; z++) {
-			for (int x = 0; x <= 1; x++) {
-				// this should cover all nodes surrounding player position
-				v3f offset((x - 0.5f) * BS, 0.05f * BS, (z - 0.5f) * BS);
-				const ContentFeatures &f2 = nodemgr->get(map->getNodeNoEx(
-						floatToInt(getPosition() - offset, BS)));
-				if (f2.walkable) {
-					// find least slippery node we might be standing on
-					int s = itemgroup_get(f2.groups, "slippery");
-					if (s < slippery)
-						slippery = s;
-				}
-			}
-		}
-		// without any hits, ignore slippery
-		if (slippery >= (2 << 16))
-			slippery = 0;
-	}
+
 	if (slippery >= 1) {
 		if (speedH == v3f(0.0f)) {
 			slippery = slippery * 2;
 		}
-		slip_factor = core::clamp(1.0f / (slippery + 1), 0.001f, 1.0f);
-		is_slipping = true;
-	} else {
-		// remember this to avoid checking the edge case above too often
-		is_slipping = false;
+		return core::clamp(1.0f / (slippery + 1), 0.001f, 1.0f);
 	}
-	return slip_factor;
+	return 1.0f;
 }
diff --git a/src/localplayer.h b/src/localplayer.h
index 77d79e472..dc59c4179 100644
--- a/src/localplayer.h
+++ b/src/localplayer.h
@@ -61,7 +61,6 @@ public:
 	u8 liquid_viscosity = 0;
 	bool is_climbing = false;
 	bool swimming_vertical = false;
-	bool is_slipping = false;
 
 	float physics_override_speed = 1.0f;
 	float physics_override_jump = 1.0f;
-- 
2.25.1