An easy to use 2D engine to load model with objects that you can select, highlight, hide, update shapes...

!CI

Quick start

Simple example

This simple example shows how to load the engine with two simple objects and interact with them.

``html











`

The result:

!simple example

More complex example

Of course you can do more that just drawing circles and lines.
In this example, a complete building storey is drawn and doors and space names are displayed using addons.
These addons are simple javascript code that use the 2D Engine API.

!complex example

To see more about these addons:

- FPS
- Grid
- Scale

Features

The 2D Engine provide tools to customise and interact with models/objects you load.

- Draw object shapes with line and texture cutsomization.
- Show, hide, select and highlight objects.
- The camera can scale, rotate, pan and fitview objects/models.
- ...

See the API reference to know all available features.

Install

NPM

`bash
npm i @bimdata/2d-engine
`

`javascript
import makeViewer from "@bimdata/2d-engine";
`

`

Add makeViewer available on the window object.

Or with a
`

API

Init factory

The package default export is a factory function that create an Engine 2D instance:

`javascript
import makeViewer from "@bimdata/2d-engine";

const canvas = document.getElementById("canvas");
const viewer = makeViewer({ canvas });
`

You must pass a canvas to the factory and some additional options can be provided to customize the Engine 2D behavior:

| Property | Type | Description |
| :------------ | :------------------ | :---------------------------------------------------------------------------------------- |
| canvas | HTMLCanvasElement | Required. |
| autoStart | boolean | Default: true. If false you must call viewer.ticker.start() to start rendering. |
| select | boolean | Default: true. If false objects are not selectable. |
| highlight | boolean | Default: true. If false objects are not highlighted on hover. |
| picking | boolean | Default: true. If false objects are not pickable. |
| showPicking | boolean | Default: false. |
| snap | boolean | Default: true. If false snap is not enabled. |
| showSnap | boolean | Default: false. |
| text | boolean | Default: true. If false objects text are not displayed. |

The factory returns a Viewer object with the following interface:

`typescript
interface Viewer extends {
camera: Camera;
canvas: HTMLCanvasElement;
constants: Constants;
scene: Scene;
picker: Picker;
renderer: Renderer;
settings: Settings;
ticker: Ticker;
ui: UI;
utils: {
vector2D: Vector2DUtils;
};
destroy(): void;
}
`

Scene

The viewer scene is where model and objects lives.
You can add/remove models and objects to/from the scene.
Objects can be accessed/modified in batch via specific getters and setters.

The Scene has the following interface:

`typescript
interface Scene {
readonly viewer: Viewer;

// Models
readonly models: Model[];
readonly modelsMap: Map;
addModel(modelData: ModelData): Promise;
removeModel(modelId: string): boolean;

// Objects
readonly objects: SceneObject[];
readonly objectsMap: Map;
addObject(objectData: SceneObjectData, model?: Model): SceneObject;
removeObject(objectId: string): boolean;

// Object getters
readonly shownObjects: SceneObject[];
readonly hiddenObjects: SceneObject[];
readonly selectedObjects: SceneObject[];
readonly unselectedObjects: SceneObject[];
readonly highlightedObjects: SceneObject[];
readonly unhighlightedObjects: SceneObject[];
readonly pickableObjects: SceneObject[];
readonly unpickableObjects: SceneObject[];

// Objects setters
showObjects(ids: number[]): void;
hideObjects(ids: number[]): void;
selectObjects(ids: number[]): void;
deselectObjects(ids: number[]): void;
highlightObjects(ids: number[]): void;
unhighlightObjects(ids: number[]): void;
setObjectsPickable(ids: number[]): void;
setObjectsUnpickable(ids: number[]): void;
}
`

$3

Model and Object have the following interfaces:

`typescript
interface Model {
readonly id: string;
readonly scene: Scene;
readonly objects: SceneObject[];
addObject(objectData: SceneObjectData): SceneObject;
removeObject(objectId: string): boolean;

readonly center: Point;
readonly aabb: AABB;
}

interface SceneObject {
readonly id: string;
readonly scene: Scene;
readonly model: Model;
readonly shapes: Shape[];
readonly zIndex: number;
readonly pickingZIndex: number;

// Scene state properties
visible: boolean;
selected: boolean;
highlighted: boolean;
pickable: boolean;
}
`

Objects have shapes. A shape have the following interface:

`typescript
interface Shape {
readonly id: number;
readonly object: SceneObject;
readonly center: Point;
readonly aabb: AABB;
readonly paths: Path[];
getPath(index?: number): Path | undefined;
addPath(pathData: PathData, index?: number): Path;
removePath(index?: number): Path | undefined;
}
`

The viewer handle three types of shape: line, arc and curve.

`typescript
interface Path {
type: PathType;
close: boolean; // If true, the shape draw is closed after this path and the next path restart the draw. Equivalent of the svg command "Z".
start: boolean; // If true, a new draw is started before drawing this path. Equivalent of the svg command "M".
}

enum PathType {
line = "line",
arc = "arc",
curve = "curve",
}
`

By default, a draw is automatically started before the first path of a shape, and after a close path command.
This behaviour can be changed using the start property.

`typescript
interface Point {
x: number;
y: number;
}

interface Line {
readonly type: PathType.line;
readonly points: Point[];
getPoint(index?: number): Point | undefined;
addPoint(point: Point, index?: number): Point;
removePoint(index?: number): Point | undefined;
}

interface Arc {
readonly type: PathType.arc;
x: number;
y: number;
radius: number;
startAngle: number;
endAngle: number;
anticlockwise?: boolean;
}

interface Curve {
readonly type: PathType.curve;
x: number;
y: number;
cpX1: number;
cpY1: number;
cpX2: number;
cpY2: number;
toX: number;
toY: number;
}
`

When adding objects on a scene, shapes can be provided to object using the shapes property.
Note: array of numbers will be displayed as lines by default.

`javascript
const model = await viewer.scene.addModel({
objects: [
{
shapes: [
{
paths: [
[0, 0, 50, 50], // a line
{
type: "line", // another line
points: [0, 50, 50, 0],
},
{
type: "arc", // a default arc => full circle
x: 25,
y: 25,
radius: 20,
},
]
}
],
},
],
});
`

$3

The following events are emitted by the Scene :

| Event | Payload |
| ------------------ | ------------------------- |
| "model-added" | The added model. |
| "model-removed" | The removed model. |
| "object-added" | The added object. |
| "object-removed" | The removed object. |
| "object-update" | { object, property, value?, oldValue? }. No value and oldValue for the "shapes" property. |

Events can be listened using scene.on():

`javascript
viewer.scene.on("model-added", model =>
console.log(A model is loaded with the id ${model.id})
);
`

Camera

The camera is binded on the mouse events. It has the following interface:

`typescript
interface Camera extends Readonly> {
fitView(positionable: Positionable | Positionable[]): void;
destroy(): void;
controller: CameraController;
/**
* @param factor ]-Infinity, +Infinity[
* @param origin the zoom transform center.
*/
zoomIn(factor: number, origin: Point): void;
/**
* @param factor ]-Infinity, +Infinity[
* @param origin the zoom transform center.
*/
zoomOut(factor: number, origin: Point): void;
/**
* @param angle in degree clockwise.
* @param origin the rotation transform center.
*/
rotate(angle: number, origin: Point): void;
translate(dx: number, dy: number): void;
/**
* @param ds delta scale ]0, +Infinity[
* @param origin the scale transform center.
*/
scale(ds: number, origin: Point): void;
move(position: Point): void;
transform: PIXIMatrix;
position: Point;
/**
* @returns { number } the camera rotation angle in degree clockwise.
*/
rotation: number;
/**
* @returns { number } ]-Infinity, +Infinity[
*/
getScale(): number;
/**
* @returns { number } ]0, +Infinity[
*/
zoom: number;
/**
* Returns the position of the given canvas position.
*/
getPosition(canvasPosition: Point): Point;
/**
* Returns the canvas position of the given position.
*/
getCanvasPosition(position: Point): Point;
getViewpoint(): Viewpoint;
setViewpoint(viewpoint: Viewpoint): Viewpoint;
}
`

It is possible to customise the camera behaviour by changing the properties of the camera.controller that has the following interface:

`typescript
interface CameraController {
translatable: boolean;
rotatable: boolean;
scallable: boolean;
}
`

All properties are true by default.

Settings

Settings are predefined values/keys that define the Engine behaviour. It has the following interface:

`typescript
interface Settings {
dragKey: string; // default "shift"
rotateKey: string; // default "shift"
clickMaxOffset: number; // default 5
scaleSpeed: number; // default 0.002
rotateSpeed: number; // default 0.1
maxScale: number; // default 100
minScale: number; // default 0.1
fitViewRatio: number; // 1
curves: {
adaptive: boolean;
maxLength: number;
maxSegments: number;
minSegments: number;
};
}
`

Ticker

Use viewer.ticker.start/stop() to start or stop the rendering.

Use viewer.ticker.add/addOnce(name: string, callback: Function) to schedule a callback on the next tick.
The callback will be called with dt, the delta time since the next tick.
WARNING: adding many tasks with the same name will override the previous tasks and only the last added will be called on the next tick.
This is to avoid a callback to be executed more than once per tick.

Renderer

Renderer emits events you can use for addons:

| Event | Payload | Description |
| ------------------ | ---------------------------- | ----------- |
| "resize" | { dx: number, dy: number } | Emited when the renderer resizes. |
| "pre-draw" | None | Emited before the draw phase. |
| "post-draw" | None | Emited after the draw phase. |

Styles

Styles define how objects are drawn by default when they are visible, selected and highlighted.
It can be customized by changing the default styles or loading objects with non default style.
WARNING: updating styles.default won't affect already loaded objects.

The Style object has the following interface:

`typescript
interface Style {
// LINE
lineWidth?: number;
lineColor?: number;
lineOpacity?: number;
lineDash?: number[];
lineCap?: Constants.LINE_CAP;
lineJoin?: Constants.LINE_JOIN;
// FILL
fill?: number | string; // number for hex color, string for a registered texture name
fillOpacity?: number;
// TEXTURE
texture?: string;
textureTint?: number;
textureOpacity?: number;
}
`

You can change textureTint and lineColor using hexadecimal numbers.

`javascript
viewer.styles.default.textureTint = 0xff0000; // For red. (RGB)
`

textureOpacity and lineOpacity are numbers between 0 and 1.

lineDash is an array of numbers describing the dash pattern you want to use.
See here for more informations.

Texture Manager

The Texture Manager has the following interface:

`typescript
interface TextureManager {
textureMatrix: TextureMatrix;
load(name: string, src: string, width?: number, height?: number): Object;
}

// and the interface of the texture matrix
interface TextureMatrix {
translate(x: number, y: number): void;
rotate(angle: number): void;
scale(x: number, y?: number): void;
}
`

The viewer only have "solid" texture built in but it is possible to load more:

`javascript
await viewer.textureManager.load(
"myTextureName",
"./my/textures/folder/myTexture.png"
);
`

NOTE: this is async code and must be awaited in order to the texture to be available in the viewer.

This is what you can get: (wall are textured using a cross hatch texture)

Notice that the textrure is aligned with the axis. If the model is not aligned with the axis,
you can use the Texture Manager textureMatrix to rotate the textures.

`javascript
viewer.textureManager.textureMatrix.rotate(30);
`

Vector2DUtils

The Viewer.utils.vector2D object exposes some methods to work with 2D vectors:

`typescript
interface Vector2DUtils {
distance(v1: Vector2D, v2: Vector2D): number;
sub(v1: Vector2D, v2: Vector2D): Vector2D;
add(v1: Vector2D, v2: Vector2D): Vector2D;
normalize(v: Vector2D): Vector2D;
length(v: Vector2D): number;
dot(v1: Vector2D, v2: Vector2D): number;
cross(v1: Vector2D, v2: Vector2D): number;
rotateAround(v: Vector2D, center: Vector2D, angle: number): Vector2D;
angle(v1: Vector2D, v2: Vector2D): number;
scale(v1: Vector2D, origin: Point, factor: number): Vector2D;
}
`

Development

$3

`
npm run dev
`

$3

`
npm run test:unit
`

$3

`
npm run build:prod
npm run test:e2e
`

Or in dev mode (will open a browser):

`
npm run test:e2e-dev
`

Publish

To publish a new version of the package you need to:

- 1) Upgrade pakage version using npm version
- 2) Push the version commit and tag to main in order to trigger the CI that will publish the new version on the NPM registry

`
npm version [patch | minor | major]
git push --tags origin main
``