JCM:Scripting/PIDS

Concept

Global Environment

A script is evaluated & executed when a PIDS Preset is loaded during the resource-pack loading phase.

Therefore, the same type of PIDS Preset will use the same working environment (global variables and etc).

Code written in top-level space outside of functions will run when a resource package is loaded, and can be used to load resources such as models and textures. It is recommended to store resources (such as models, fonts and textures) in global variables, which do not need to be different for each PIDS block, to avoid excessive memory usage caused by loading a copy of the same content for each PIDS.

Draw/Rendering

JCM PIDS Scripting allows you to draw either a Text/Texture onto the Minecraft World.

Note that the text/textures are just regular polygons rendered onto the Minecraft World rather than being a 2D plane with a texture. Therefore it is possible for elements to overflow beyond the PIDS screen, and it is the developer responsibility to ensure such events should not happen.

If you absolutely require sophisticated image processing/clipping, you may follow this section to draw a single texture onto a 2D Plane. However it may result in slightly slower performance/higher memory usage.

Draw Layer/Order

JCM's Draw Order/z-index is depicted by the order the image is drawn in. Whichever elements gets drawn later, whichever element goes in-front. See the image below: (z-differences is exaggerated for demonstration purposes)

The number depicts the order in which the element is drawn in. 1 gets drawn first, then 2, 3, 4, 5 and finally 6.

Implementation

Adding a Scripted PIDS Preset

A preset is automatically considered as a Scripted PIDS Preset by specifying either scriptFiles or scriptTexts property in joban_custom_resources.json:

{
  "pids_images": [
    {
      "id": "pids_tut",
      "name": "JS Tutorial Preset",
      "scriptTexts": ["print('Goodbye World');"],
      "scriptFiles": ["jsblock:scripts/pids_tut.js"]
    }
}

scriptFiles points to the list of script file to load.

scriptTexts allows you to directly write JS inside, but should only be used for simple variable declaration.

At the moment, mixing Scripted PIDS Preset and JSON PIDS Preset is not possible.

Check JCM Version

You can obtain JCM version by using Resources.getAddonVersion("jcm").

This would return a string formatted like: 2.0.0-beta.5

Called Functions

Your script should include the following functions that JCM will call as needed:

function create(ctx, state, pids) { ... }
function render(ctx, state, pids) { ... }
function dispose(ctx, state, pids) { ... }

Functions	Description
create	It is called when a PIDS is rendered for the first time and can be used to perform some initialization operations, for example, to create dynamic textures.
render	This function is called at-most once per frame. It is used to draw contents onto the PIDS. In practice however, the code is executed in a separate thread so as not to slow down FPS. If it takes too long to execute the code, it may be called once every few frames instead of every frame.
dispose	Called when a PIDS Block goes out of sight. Can be used for things like releasing the dynamic textures to free up memory.

JCM calls these functions with three parameters, each of which is described below.

Parameter	Description
First (ctx)	Used to pass rendering actions to JCM. Type — PIDSScriptContext.
Second (state)	A JavaScript object associated with a single PIDS Block. The initial value is {}, and its content can be set arbitrarily to store what should be different for each PIDS Block.
Third (pids)	Used to get the status of pids and arrivals. Type — PIDSWrapper

The following lists all the rendering control operations that can be performed and all the information that can be obtained about PIDS.

API Reference

Rendering Related

Text (aka TextWrapper)

Functions And Objects	Description
Text.create() / Text.create(comment: string)	Create a new text object
Text.pos(x: number, y: number): TextWrapper	Set the X and Y position of the element
Text.size(w: number, h: number): TextWrapper	Set the width and height of the element (Used in conjunction with Text.stretchXY() and Text.scaleXY())
Text.text(str: string): TextWrapper	Set the text content to str
Text.scale(i: double): TextWrapper	Set the text's scale to i. Defaults to 1
Text.leftAlign(): TextWrapper	Align the text to the left (Default)
Text.centerAlign(): TextWrapper	Align the text to the center
Text.rightAlign(): TextWrapper	Align the text to the right
Text.shadowed(): TextWrapper	Add shadow to the drawn text
Text.italic(): TextWrapper	Set the text style to Italic
Text.bold(): TextWrapper	Set the text style to Bold
Text.stretchXY(): TextWrapper	Text Overflow Mechanism: When text overflowed beyond it's size, stretch the text on the overflowing axis to fit
Text.scaleXY(): TextWrapper	Text Overflow Mechanism: When the text overflowed beyond it's size, stretch the text on both axis to fit (Keep aspect ratio)
Text.wrapText(): TextWrapper	Text Overflow Mechanism: When the text overflowed beyond it's size, split the text into the next line without any scaling.
Text.marquee(): TextWrapper	Text Overflow Mechanism: When the text overflowed beyond it's size, draw a portion of the text at a time with scrolling animation
Text.fontMC(): TextWrapper	Use vanilla Minecraft's font
Text.font(id: string): TextWrapper / Text.font(id: Identifier): TextWrapper	Set the font by it's ID. Defaults to mtr:mtr The font should be loaded in Minecraft via the font json format. This does not have any effect if Use Custom MTR Font is disabled in MTR Mod's Config.
Text.color(color: number): TextWrapper	Set the text color, in RGB format.
Text.draw(ctx: PIDSScriptContext): void	Mark the text as something that should be rendered to the PIDS.

Texture (aka TextureWrapper)

Functions And Objects	Description
Texture.create() / Texture.create(comment: string)	Create a new texture object
Texture.pos(x: number, y: number): TextureWrapper	Set the X and Y position of the element
Texture.size(w: number, h: number): TextureWrapper	Set the width and height of the element
Texture.texture(id: string): TextureWrapper / Texture.texture(id: Identifier): TextureWrapper	Set the texture ID to draw. Note that the texture ID should point to a PNG file or an .mcmeta file.
Texture.color(color: number): TextureWrapper	Set the text color, in RGB format.
Texture.uv(u2: number, v2: number): TextureWrapper / Texture.uv(u1: number, v1: number, u2: number, v2: number): TextureWrapper	Set the UV coordinates
Texture.draw(ctx: PIDSScriptContext): void	Mark the texture as something that should be rendered to the PIDS.

PIDS Object Related

PIDSWrapper

Functions And Objects	Description
PIDSWrapper.type: string	Return the type of PIDS used, possible value are: rv_pids rv_pids_sil_1 rv_pids_sil_2 lcd_pids pids_projector pids_1a
PIDSWrapper.width: number	The full width of the available PIDS screen area.
PIDSWrapper.height: number	The full height of the available PIDS screen area.
PIDSWrapper.rows: number	The number of arrival rows supported by the PIDS Block
PIDSWrapper.isRowHidden(i: number): boolean	Returns whether the arrival for that row is hidden. (via PIDS Config)
PIDSWrapper.getCustomMessage(i: number): string	Returns the custom message configured for that row via PIDS Config. Empty string ("") if not set.
PIDSWrapper.isPlatformNumberHidden(): boolean	Returns whether the platform number is set to hidden. (via PIDS Config)
PIDSWrapper.station(): Station	Returns the station area that this PIDS is in. null if not in any station.
PIDSWrapper.arrivals(): ArrivalsWrapper	Returns the arrivals obtained for the PIDS.

ArrivalsWrapper

Functions And Objects	Description
ArrivalsWrapper.get(i: number): ArrivalWrapper?	Returns the ith arrival entry. null if there's no ith arrival entry or no arrival information.
ArrivalsWrapper.mixedCarLength(): boolean	Returns whether the list of arrivals have arrival entry with different cars.
ArrivalsWrapper.platforms(): ObjectArrayList<Platform>	Returns the platforms that all arrival entry is stopping at.

ArrivalWrapper

Functions And Objects	Description
ArrivalWrapper.destination(): string	Returns the destination name of the arrival entry. (Usually the destination's station, or a custom destination string)
ArrivalWrapper.arrivalTime(): number	Returns the epoch time (in Millisecond) the train is arriving at. Use new Date(value: number)to obtain a JS Date object of the arrival time.
ArrivalWrapper.departureTime(): number	Returns the epoch time (in Millisecond) the train is departing at. Use new Date(value: number)to obtain a JS Date object of the departure time.
ArrivalWrapper.deviation(): number	Returns the deviation[?]
ArrivalWrapper.realtime(): boolean	Returns whether the arrival entry is scheduled (i.e. Train not departed), or a real-time estimation (i.e. Train running)
ArrivalWrapper.departureIndex(): number	Returns the departure index[?]
ArrivalWrapper.terminating(): boolean	Returns whether the arrival entry is terminating its service at the current platform.
ArrivalWrapper.route(): Route	Returns the route object of the route that the train is running on.
ArrivalWrapper.routeId(): number	Returns the id of the route that the train is running on.
ArrivalWrapper.routeName(): string	Returns the name of the route that the train is running on.
ArrivalWrapper.routeNumber(): string	Returns the route number string (Previously called LRT Route Number). [TODO: What does empty route number returns?]
ArrivalWrapper.routeColor(): number	Returns the color of the route that the train is running on.
ArrivalWrapper.circularState(): Route.CircularState	Returns the circular state of the route that the train is running on.
ArrivalWrapper.platform(): Platform	Returns the platform object that the train is approaching towards.
ArrivalWrapper.platformId(): number	Returns the id of the platform that the train is approaching towards.
ArrivalWrapper.platformName(): string	Returns the name of the platform that the train is approaching towards.
ArrivalWrapper.carCount(): number	The car length of the train in that arrival entry.
ArrivalWrapper.forEachCar(consumer: Consumer<CarDetails>): void	Allows you to loop through each car of the train in that arrival entry.

Transport Simulation Core Related

Platform

Functions And Objects	Description
Platform.routes: ObjectAVLTreeSet<Route>	A list of routes that goes through this platform.
Platform.routeColors: IntAVLTreeSet	All colors of route that goes through this platform.
Platform.getName(): string	Returns the platform name.
Platform.getId(): number	Returns the platform ID.
Platform.getDwellTime(): number	The dwell time duration of the platform in millisecond.

Route

Functions And Objects	Description
Route.depots: ObjectArrayList<Depot>	A list of depot associated with this route[?]
Route.getName(): string	Returns the platform name.
Route.getId(): number	Returns the route ID.
Route.getColor(): number	Returns the color of the route.
Route.getHidden(): boolean	Returns whether the route is hidden.
Route.getDestination(index: number): string	Returns name of index of the following order: Custom Destination Station Area Name Platform Name
Route.getRouteType(): RouteType	Returns the type of route: NORMAL LIGHT_RAIL HIGH_SPEED

Using AWT Graphics/Dynamic Textures

While not a regular tested use case for PIDS, you can create a Dynamic Textures and draw it onto a PIDS:

importPackage(java.awt);

function create(ctx, state, pids) {
    state.tex = new GraphicsTexture(pids.width, pids.height);
}

function render(ctx, state, pids) {
    let g = state.tex.graphics;
    g.setColor(Color.RED);
    g.fillRect(0, 0, pids.width, pids.height);
    g.setColor(Color.GREEN);
    g.fillRect(0, 0, Math.abs(Math.sin(Timing.elapsed())) * pids.width, pids.height);
    
    state.tex.upload();
    
    Texture.create("Dynamic Texture")
    .texture(state.tex.identifier)
    .size(pids.width, pids.height)
    .draw(ctx);
}

function dispose(ctx, state, pids) {
    state.tex.close();
}