Alternative code for slipping (#6256)

* Alternative code for slipping

- does not depend on frame rate
- controllable via environment variables for now

* Adjust slipping speed for item entities too.

* Final version of framerate-independent slippery code

* Remove dead code and fix formatting

* getStandingNodePos should only look 0.05 nodes downwards

This ensures that, even if the player is standing on a partially
filled node, this node is used as the standing node and not the
node below it.

Specific use: enables slippery slabs

* Exchange global getStandingPosNode change for local inline change

Reverts previous commit

* Revert the item movement changes

* Slippery nodes now slip over cliffs and edges

Players no longer suddenly stop before falling off.
Also refactored slippery code into getSlipFactor method.

* Slipping over an edge gated by player's is_slipping state

A new flag for just this case, to reduce costly node lookups in
the normal case of leaning over a non-slippery edge.
Public access for consistency and potential future uses.

* Minor code tweaks / cosmetics

* Add temp variable to improve readability and fix indentation issues

1 files changed, 3 insertions, 3 deletions

diff --git a/src/localplayer.h b/src/localplayer.h
index c64e0042a..3521512af 100644
--- a/src/localplayer.h
+++ b/src/localplayer.h
@@ -60,6 +60,7 @@ 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;
@@ -143,11 +144,10 @@ public:
 	void setCollisionbox(const aabb3f &box) { m_collisionbox = box; }
 
 private:
-	// clang-format off
-	void accelerateHorizontal(const v3f &target_speed, f32 max_increase, bool slippery);
-	// clang-format on
+	void accelerateHorizontal(const v3f &target_speed, const f32 max_increase);
 	void accelerateVertical(const v3f &target_speed, const f32 max_increase);
 	bool updateSneakNode(Map *map, const v3f &position, const v3f &sneak_max);
+	float getSlipFactor(Environment *env, const v3f &speedH);
 
 	v3f m_position;