Retractable "3D" sprites for walls etc.

[mlange-42]

Summary

Interface "Retractable '3D' sprites for walls etc."

Purpose of change

Upcoming isometric tilesets offer the opportunity for a more 3-dimensional look. For a consistent perspective across terrain, furniture and monsters, walls need to have a certain height. Orthogonal tilesets could also profit from higher walls for a more consistent perspective.

3D walls, however, will obstruct other terrain, etc.:

Courtesy tileset: UlticaISO by @vetall812

This PR tries to resolve this conflict and adds the ability to change/toggle wall height using a mapped key (see GIFs below).

Describe the solution

• In addition to the normal offset per spritesheet, add an optional offset for the retracted state
• Add an option (cached) to toggle retracted walls, under debug
• Add an action to make a key bind for the toggle possible
• Adapt gfx tools Python scripts for the new properties

Things to note:

• Retract/toggle hight seems to be a good solution, as it works well for most wall-like tiles and requires very few work by artists
• The retracted offset is optional, and defaults to the normal offset. Existing tilesets should simply do nothing when toggled.
• Artists can specify retracted offset on a per-sheet basis. This allows for great control over how much sprites retract.
• Added the toggle as an option to the debug tab. Move it? Remove it from the options?
• Did not add a default key binding

Describe alternatives you've considered

• Use a true/false property for tilesheets and switch between normal and zero offset (less flexible)
• Add the possibility to switch between two tilesets (normal/retracted, a lot of redundency)
• Add the possibility for individual alternative, lowered sprites (increases tileset size)
• Use and alpha threshold to mark sprite regions that should disappear (retracted often looks better, as it shows the top)

Testing

• Tested the toggle ingame, with and without key binding
• Tested compose.py with UlticaISO (thanks @vetall812)

Additional context

GIFs showing the toggle using a key binding.

Courtesy tileset: UlticaISO by @vetall812

[github-actions]

Spell checker encountered unrecognized words in the in-game text added in this pull request. See below for details.

Click to expand

• Draw walls retracted in ISO tilesets

This alert is automatically generated. You can simply disregard if this is inaccurate, or (optionally) you can also add the new words to tools/spell_checker/dictionary.txt so they will not trigger an alert next time.

[mlange-42]

Rebased to resolve conflicts after #60283