Noah Petherbridge
08e65c32b5
* 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.
5.3 KiB
Doodad Scripts
Each Doodad can have a JavaScript file attached to give them some logic and code to run in-game when a level is being played. Buttons, trap doors, and other dynamic doodads have JavaScript code that tells them how to behave.
This game uses otto for its JavaScript engine, so it only works with ES5 syntax and has a few weird quirks. You get used to them.
Example
Provide a script file with a main function:
function main() {
console.log("%s initialized!", Self.Doodad().Title);
var timer = 0;
Events.OnCollide( function() {
if (timer > 0) {
clearTimeout(timer);
}
Self.ShowLayer(1);
timer = setTimeout(function() {
Self.ShowLayer(0);
timer = 0;
}, 200);
})
}
JavaScript API
Functions
Global functions available to your script:
RGBA(uint8 red, uint8 green, uint8 blue, uint8 alpha)
Get a render.Color object from the given color code. Each number must be between 0 and 255. For example, RGBA(255, 0, 255, 255) creates an opaque magenta color equivalent to #FF00FF.
The render.Color type may be needed in certain API calls that require the game's native color type.
Point(x int, y int)
Get a render.Point object that refers to a position in the game world.
Common JavaScript Functions
The following common JavaScript APIs seen in web browsers work in the doodad scripts:
-
int setTimeout(function, int milliseconds)
Set a timeout to run your function after a delay in milliseconds. Returns a timer ID to be used with clearTimeout() if you want to cancel the timeout.
-
int setInterval(function, int milliseconds)
Like setTimeout, but repeatedly re-runs the function after the delay in milliseconds. Returns a timer ID to be used with clearInterval() if you want to cancel the interval.
-
clearTimeout(int timerID), clearInterval(int timerID)
Cancel a timeout or interval by passing its timer ID, which was returned when the timer or interval was first created.
-
console.log(str message, v...)
Write to the game's log console. There are also
console.warn,console.errorandconsole.logvariants.
Self
The global variable Self holds an API for the current doodad. The full
surface area of this API is subject to change, but some useful examples you
can do with this are as follows.
Self.Doodad()
Self.Doodad() is a pointer into the doodad's metadata file. Not all properties in there can be written to or read from the JavaScript engine, but some useful attributes are:
str Self.Doodad().Title: the title of the doodad.str Self.Doodad().Author: the author name of the doodad.str Self.Doodad().Script: your own source code. Note that editing this won't have any effect in-game, as your doodad's source has already been loaded into the interpreter.str Self.Doodad().GameVersion: the game version that created the doodad.
Self.ShowLayer(int index)
Set the doodad's visible layer to the index.
A layer is a drawing created in the in-game format. Only one layer is visible on-screen during Edit Mode or Play Mode. Layers can be used to store alternate versions of your doodad to show different states or as animation frames.
The first and default layer is always zero. Use CountLayers()
to query how many layers are in the doodad.
int Self.CountLayers()
Returns the number of layers, or frames, available in your doodad's drawing data. Usually these layers are for alternate drawings or animation frames.
The number is the len() of the array, and layers are
zero-indexed, so the first and default layer is always layer 0
and the final layer is like so:
// set the final frame as the active one
Self.ShowLayer( Self.CountLayers() - 1 );
Animations
Self.AddAnimation(string name, int interval, [layers...]) error
Add a new animation using some of the layers in your doodad's drawing.
The interval is counted in milliseconds, with 1000 meaning one second between frames of the animation.
The layers are an array of strings or integers. If strings, use the layer names from the drawing. With integers, these are the layer index numbers where 0 is the first (default) layer.
Self.PlayAnimation(string name, function callback)
Play the named animation. When the animation is finished, the callback function
will be called. Set the callback to null if you don't want a callback function.
Self.StopAnimation()
Stop and cancel any current animations. Their callback functions will not be called.
Self.IsAnimating() bool
Returns true if an animation is currently playing.
Events
Use the Events object to register event handlers from your doodad. Usually you'll configure these in your main() function.
Example configuring event handlers:
function main() {
Events.OnCollide(function(e) {
console.log("I've been collided with!");
})
}
OnCollide
Triggers when another doodad has collided with your doodad's box space on the level. Arguments TBD.
OnEnter
Triggers when another doodad has fully intersected your doodad's box.
OnLeave
Triggers when a doodad who was intersecting your box has left your box.
KeypressEvent
Triggers when the player character has pressed a key.
This only triggers when your doodad is the focus of the camera in-game, i.e. for the player character doodad.