Class: Compositor

Defined in:

src/drawing/compositor.coffee

Overview

A utility class to transform an ensemble into a stack of images which can be drawn on a canvas.

Normally accessed via Totem#drawOn.

Instance Method Summary

- (void) constructor(categories) Constructor Create a new compositor.
- (Object) prepare(ensemble) Prepare a complete ensemble for drawing.
- (Array) prepareStack(asset) Prepare an asset for drawing.
- (Object) prepareCell(layer, colours) Prepare an asset layer for drawing.

Constructor Details

- (void) constructor(categories)

Create a new compositor.

Parameters:

categories (Array<string>) — An array of category labels, in order. This is necessary for the compositor to know how to order the ensemble data it's given.

Instance Method Details

- (Object) prepare(ensemble)

Prepare a complete ensemble for drawing. Returns an array of <category>:<stack>, where <category> is a category label, and <stack> is an array of <cells>. Each cell is of form image:<String/HTMLImageElement>, colour:<String>. A cell's image: can be a url or an HTMLImageElement. colour: can be null or a hex colour value.

Parameters:

ensemble (Object) — An ensemble to prepare

Returns:

(Object) — A composite (see above)

- (Array) prepareStack(asset)

Prepare an asset for drawing.

Parameters:

asset (Object) — An asset collapsed to a given representation

Returns:

(Array) — An array of cells (see prepare)

- (Object) prepareCell(layer, colours)

Prepare an asset layer for drawing.

@param