* Fix collision detection to allow actors to walk up slopes smoothly, without
losing any horizontal velocity.
* Fix scrolling a level canvas so that chunks near the right or bottom edge
of the viewpoint were getting culled prematurely.
* Centralize JavaScript exception catching logic to attach Go and JS stack
traces where possible to be more useful for debugging.
* Performance: flush all SDL2 textures from memory between scene transitions
in the app. Also add a `flush-textures` dev console command to flush the
textures at any time - they all should regenerate if still needed based on
underlying go.Images which can be garbage collected.
* Rework the Story Mode UI to display level thumbnails.
* Responsive UI: defaults to wide screen mode and shows 3 levels horizontally
but on narrow/mobile display, shows 2 levels per page in portrait.
* Add "Tiny" screenshot size (224x126) to fit the Story Mode UI.
* Make the pager buttons bigger and more touchable.
* Maximize the game window on startup unless the -w option with a specific
window resolution is provided.
* Add an exception catcher that pops open a UI window showing errors that
occur in doodad scripts during gameplay.
* Shows a preview of the header of the error (character wrapped) with a
Copy button to copy the full raw text to clipboard for inspection.
* Buttons to dismiss the modal once or stop any further errors from
opening during this gameplay session (until next restart).
* Add developer shell commands to test the exception catcher:
- 'throw <message>' to throw a custom message.
- 'throw2' to stress test a "long" message.
- 'throw3' to throw a realistic message copied from an actual error.
* Scripting engine: console.log() and friends will now insert the script
VM's name in front of its messages (the filename + actor ID).
Added a new level property: Difficulty
* An enum ranging from -1, 0, 1 (Peaceful, Normal, Hard)
* Default difficulty is Normal; pre-existing levels are Normal by
default per the zero value.
Doodad scripts can read the difficulty via the new global variable
`Level.Difficulty` and some doodads have been updated:
* Azulians: on Peaceful they ignore all player characters, and on Hard
they are in "hunt mode": infinite aggro radius and they're aggressive
to all characters.
* Bird: on Peaceful they will not dive and attack any player character.
Other spit and polish:
* New Level/Level Properties UI reworked into a magicform.
* New "PromptPre(question, answer, func)" function for prompting the
user with the developer shell, but pre-filling in an answer for them
to either post or edit.
* magicform has a PromptUser field option for simple Text/Int fields
which present as buttons, so magicform can prompt and update the
variable itself.
* Don't show the _autosave.doodad in the Doodad Dropper window.
Two new tools added to the Level Editor:
* Pan Tool: left-click to scroll the level around safely.
* Text Tool: write text onto your level.
Features of the Text Tool:
* Can choose from the game's built-in fonts, size and enter the message
you want to write.
* The mouse cursor previews the text when hovered over the level.
* Click to "stamp" the text onto your level. The currently selected
color swatch will be used to color the text in.
* Adds two new fonts: Azulian.ttf and Rive.ttf that can be selected in
the Text Tool.
Some implementation notes:
* Added package native/engine_sdl.go that handles the lower-level
SDL2_TTF logic to rasterize the text into a black&white image.
* WASM not supported yet (if the game even still built for WASM);
native/engine_wasm.go stubs out the TextToImage() call with a "not
supported" error just in case.
Other changes:
* New Toolbar icons: they are 24x24 instead of 32x32 to make more room
for more tools.
* The toolbar now shows two buttons per row for a more densely packed
layout. For very narrow screen widths (< 600px) the default Vertical
Toolbar layout will use one-button-per-row to not eat too much screen
real estate.
* In the Horizontal Toolbars layout there are 2 buttons per column.
