* Adds pkg/savegame to store user progress thru Level Packs.
* The savegame.json is mildly tamper resistant by including a checksum
along with the JSON body.
* The checksum combines the JSON string + an app secret (in savegame.go)
+ user specific entropy (stored in their settings.json). If the user
modifies their save file and the checksum becomes invalid the game
will not load the save file, acting like it didn't exist, resetting
all their high scores.
Updates to the Story Mode window:
* On the LevelPacks list: shows e.g. "[completed 0 of 3 levels]" showing
a user's progress thru the level pack.
* Below the levels on the Detail screen:
* Shows an indicator whether the level is completed or not.
* Shows high scores (fastest times beating the level)
* Shows a padlock icon if levels are locked and the player hasn't
reached them yet. Pops up an Alert modal if a locked level is
clicked on.
Scoring is based around your fastest time elapsed to finish the level.
* Perfect Time (gold coin): player has not died during the level.
* Best Time (silver coin): player has continued from a checkpoint.
In-game an elapsed timer is shown in the top left corner along with the
gold or silver coin indicating if your run has been Perfect.
If the user enters any Cheat Codes during gameplay they are not eligible
to win a high score, but the level will still be marked as completed.
The icon next to the in-game timer disappears when a cheat code has been
entered.
* The loading screen for Edit and Play modes is stable and the risk of
game crash is removed. The root cause was the setupAsync() functions
running on a background goroutine, and running SDL2 draw functions
while NOT on the main thread, which causes problems.
* The fix is all SDL2 Texture draws become lazy loaded: when the main
thread is presenting, any Wallpaper or ui.Image that has no texture
yet gets one created at that time from the cached image.Image.
* All internal game logic then uses image.Image types, to cache bitmaps
of Level Chunks, Wallpaper images, Sprite icons, etc. and the game is
free to prepare these asynchronously; only the main thread ever
Presents and the SDL2 textures initialize on first appearance.
* Several functions had arguments cleaned up: Canvas.LoadLevel() does
not need the render.Engine as (e.g. wallpaper) textures don't render
at that stage.
* Migrate off go-bindata to embed built-in fonts, levels and doodads in
favor of Go 1.16 native embed functionality.
* `make bindata` prints a deprecation warning to not break older build
scripts
* Removes all references of bindata from the program
Add new doodads:
* Start Flag: place this in a level to set the spawn point of the player
character. If no flag is found, the player spawns at 0,0 in the top
corner of the map. Only use one Start Flag per level, otherwise the
player will randomly spawn at one of them.
* Crumbly Floor: a solid floor that begins to shake and then fall apart
after a moment when a mobile character steps on it. The floor respawns
after 5 seconds.
* State Blocks: blue and orange blocks that toggle between solid and
pass-thru whenever a State Button is activated.
* State Button: a solid "ON/OFF" block that toggles State Blocks back
and forth when touched. Only activates if touched on the side or bottom;
acts as a solid floor when walked on from the top.
New features for doodad scripts:
* Actor scripts: call SetMobile(true) to mark an actor as a mobile mob
(i.e. player character or enemy). Other doodads can check if the actor
colliding with them IsMobile so they don't activate if placed too close
to other (non-mobile) doodads in a level. The Blue and Red Azulians
are the only mobile characters so far.
* Message.Broadcast allows sending a pub/sub message out to ALL doodads
in the level, instead of only to linked doodads as Message.Publish does.
This is used for the State Blocks to globally communicate on/off status
without needing to link them all together manually.
* Toolbar has icon buttons for the Pencil Tool, Line Tool, Rect Tool,
Actor Tool and Link Tool.
* Remove the tab buttons from the top of the Palette window. The palette
tab is now toggled between Swatches and Doodads by the tool selected
on the tool bar, instead of the tab buttons setting the tool.
* Remove the "Link Doodads" button from the Doodad Palette. The Link
Tool has its own dedicated toolbar button with the others.
