* The "Giant Screenshot" feature takes a very long time, so it is made
asynchronous. If you try and run a second one while the first is busy,
you get an error flash. You can continue editing the level, even
playtest it, or load a different level, and it will continue crunching
on the Giant Screenshot and flash when it's finished.
* Updated the player physics to use proper Velocity to jump off the
ground rather than the hacky timer-based fixed speed approach.
* FlashError() function to flash "error level" messages to the screen.
They appear in orange text instead of the usual blue, and most error
messages in the game use this now. The dev console "error <msg>"
command can simulate an error message.
* Flashed message fonts are updated. The blue font now uses softer
stroke and shadow colors and the same algorithm applies to the orange
error flashes.
Some other changes to player physics:
* Max velocity, acceleration speed, and gravity have been tweaked.
* Fast turn-around if you are moving right and then need to go left.
Your velocity resets to zero at the transition so you quickly get
going the way you want to go.
Some levels that need a bit of love for the new platforming physics:
* Tutorial 3.level
* The crumbly floor doodad was made 50% larger.
* New doodad: Small Key and Small Key Door. These work like the colored
doors and locks except each Small Key is consumed when it unlocks a
door. The door's appearance is of iron bars.
* The inventory HUD displays a small quantity label in the lower-right
corner of items that have a quantity, such as the Small Key. This is
done as a Canvas.CornerLabel string attribute on uix.Canvas.
* The "give all keys" cheat adds 99 Small Keys to your inventory.
* Player character now experiences acceleration and friction when
walking around the map!
* Actor position and movement had to be converted from int's
(render.Point) to float64's to support fine-grained acceleration
steps.
* Added "physics" package and physics.Vector to be a float64 counterpart
for render.Point. Vector is used for uix.Actor.Position() for the sake
of movement math. Vector is flattened back to a render.Point for
collision purposes, since the levels and hitboxes are pixel-bound.
* Refactor the uix.Actor to no longer extend the doodads.Drawing (so it
can have a Position that's a Vector instead of a Point). This broke
some code that expected `.Doodad` to directly reference the
Drawing.Doodad: now you had to refer to it as `a.Drawing.Doodad` which
was ugly. Added convenience method .Doodad() for a shortcut.
* Moved functions like GetBoundingRect() from doodads package to
collision, where it uses its own slimmer Actor interface for just the
relevant methods it needs.
* Added an inventory system for actors as a replacement to the arbitrary
key/value data store. Colored keys now add themselves to the player's
inventory, and colored doors check the inventory.
* Inventory is a map[string]int between doodad filenames
(red-key.doodad) and quantity (0 for key items/unlimited qty).
* API methods to add and remove inventory.
* Items HUD appears in Play Mode in lower-left corner showing doodad
sprites of all the items in the Player's inventory.
