Gl-plot2d NPM | npm.io

gl-plot2d

A rendering engine for drawing huge 2D plots using WebGL.

Install

With npm,

npm i gl-plot2d

API

Constructor

`var plot = require('gl-plot2d')(options)`

Constructs a new gl-plot2d object.

options is an object containing parameters for constructing the plot

Options can contain the following parameters,

Required properties

Property	Description
`gl`	A `WebGLRenderingContext` object, into which the plot is drawn
`pixelRatio`	A scale factor which is applied to pixel coordinates
`screenBox`	Bounds on the plot within the WebGL context
`viewBox`	Pixel coordinates where the plot is drawn
`dataBox`	Data coordinates for the view of the plot

Note: Coordinates for screenBox, viewBox, dataBox, etc. are given by 4-tuples of bounding box coordinates in the form [xmin, ymin, xmax, ymax].

Border and background colors

Property	Description	Default
`borderColor`	Border color as a normalized RGBA tuple	`[0,0,0,0]`
`backgroundColor`	Background color	`[0,0,0,0]`
`borderLineEnable`	Toggle drawing lines for left,bottom,right,top of border	`[true,true,true,true]`
`borderLineWidth`	Width of border lines	`[2,2,2,2]`
`borderLineColor`	Color of border lines	`[[0,0,0,1], [0,0,0,1], [0,0,0,1], [0,0,0,1]]`

Note: For properties which are specified per-screen direction like borderLineEnable etc., the components are always arranged in the order left,bottom,right,top.

Ticks

Property	Description	Default
`ticks`	See note below	`[[], []]`
`tickEnable`	Turn on display of ticks for a given axis	`[true, true, true, true]`
`tickPad`	Distance between tick text and tick marks	`[15,15,15,15]`
`tickAngle`	Angle to draw ticks at	`[0,0,0,0]`
`tickColor`	Color of tick labels	`[[0,0,0,1], [0,0,0,1], [0,0,0,1], [0,0,0,1]]`
`tickMarkWidth`	Tick marks	`[0,0,0,0]`
`tickMarkLength`		`[0,0,0,0]`
`tickMarkColor`		`[[0,0,0,1],[0,0,0,1],[0,0,0,1],[0,0,0,1]]`

Note: Ticks are encoded as an array of objects, each with the following properties:

x The data coordinate of the tick
text The text associated to the tict mark
font The font for the text
size The font size for the tick

Labels

Property	Description	Default
`labels`	The label text for each axis	`['x', 'y']`
`labelEnable`	Turns on/off rendering for the labels on the left,bottom,top,right	`[true, true, true, true]`
`labelAngle`	Angle to draw label text	`[0,Math.PI/2,0,3.0*Math.PI/2]`
`labelPad`	Padding for labels in pixel coordinates	`[15,15,15,15]`
`labelSize`	Size of labels in pixels	`[12, 12]`
`labelFont`	Font for labels	`['sans-serif', 'sans-serif']`
`labelColor`	Color of labels	`[[0,0,0,1],[0,0,0,1],[0,0,0,1],[0,0,0,1]]`

Title

Property	Description	Default
`title`	Title text	`''`
`titleEnable`	Toggles title rendering	`true`
`titleCenter`	Pixel coordinates for center of title	`[0.5*(viewBox[0]+viewBox[2]), viewBox[3] - 40]`
`titleAngle`	Angle to draw title text	`0`
`titleColor`	Color of title	`[0,0,0,1]`
`titleFont`	Title font	`'sans-serif'`
`titleSize`	Title font size	`18`

Grid lines

Property	Description	Default
`gridLineEnable`	Turns on grid lines per axis	`[true, true]`
`gridLineColor`	Grid line color	`[[0,0,0,0.5], [0,0,0,0.5]]`
`gridLineWidth`	Width of grid lines	`[1, 1]`
`zeroLineEnable`	Toggle rendering of zero line	`[true, true]`
`zeroLineWidth`	Width of zero line in pixels	`[2, 2]`
`zeroLineColor`	Color of zero line	`[[0,0,0,1], [0,0,0,1]]`