Variable friction, max-speed, and grabbability!

tl;dr: I added support for configurable frictions, dynamic max speeds, and collinear neighbor surfaces.

What happened last week?

Highlights

These are parameters like friction, max-speed, grabbability, fall-through-ability.
These can be configured on a given tile in a tile-set.

My old approach didn’t support making it difficult to get up-to-speed when the floor is slippery.
It previously only added a force against the direction of motion, which is what causes the character to slow down when not pressing sideways controls.

Update stopping-distance calculations to account for new friction logic.
Update intra-surface edge and calculator to include counter-acceleration friction.

I originally added this very quickly during my last game jam.
My original implementation was consequently pretty broken.
Now it scales the intra-surface acceleration/velocity (walk, climb, crawl) as well as the max-horizontal-velocity while attached to surfaces.

Fix default velocity-cap to account for intra_surface_edge_speed_multiplier.
Add a separate max-speed multiplier for in-air.
Add more utilities for accessing the current on-surface and in-air max-horizontal-speed values.
Start adding support for a speed_multiplier in individual surface properties.
Update walk_acceleration to use speed_multiplier.
Include surface speed_multiplier in velocity, acceleration, and max-speed calculations.
Replace clamp_horizontal_velocity_to_max_default with more specific logic using new distinct-surface and multiplier logic.
Fix some bugs from the recent speed-multiplier logic.

Add support for not merging collinear neighbor surfaces.
Update WaypointUtils to account for collinear neighbor surfaces.
Update climb-to-adjacent-surface edge and calculator logic for collinear neighbors.
Add a separate edge weight for collinear neighbor surfaces.
Fix a bug with PositionAlongSurface instances referencing a collinear neighbor.
Fix surface-annotation drawing for collinear neighbors.
Update navigation-state-update logic to account for collinear-neighbor surfaces.
Add logic to nudge a contact point along an axially-aligned segment toward the shape center.

This is important because Godot will determine that the contact-point is the corner of the character’s collision boundary.
This is technically correct (since two collinear and overlapping segments have infinitely many points of intersection), but a centered contact-point is more intuitive and useful.
Before fixing this, I was seeing problems with collisions being detected on the wrong collinear neighbor surface.

Similarly, add logic to correct which axially-aligned collinear-neighbor surface is used when Godot collision detection returns contact points based on collider corners rather than mid-segment.

That is, this corrects which surface is used, and before we were just correcting the point that was used.

Update SurfaceParser to remove any single-vertex collinear-neighbor surfaces.
Fix an issue with move-to-adjacent-collinear-surface-edges never colliding with the end surface.

Update intra-surface-edge start-velocities to match previous-edge end-velocities.
Fix a bug with check_just_landed_on_expected_surface.
Fix a coordinate-typo bug in nudge_point_along_axially_aligned_segment_toward_shape_center.
Create a surface_enablement editor icon.
Update SurfaceStore filtering to omit surfaces with `can_grab=false` in their properties.
Add some new tiles for testing other surface properties.
Finish adding support for slow, fast, and disabled tiles.

A very short week!
If I have time, I'll try adding support for referring to categories of characters, rather than individual characters, throughout my frameworks.

🎉 Cheers!