canvas-gradient

canvas-gradient

Gradient with canvas.

Installation

npm install canvas-gradient --save

Usage

var cnvsGrad = require('canvas-gradient');

// For linear gradient.
cnvsGrad(ctx, fx, fy, fw, fh).linear(gx1, gy1, gx2, gy2, colorStops);

// For radial gradient.
cnvsGrad(ctx, fx, fy, fw, fh).linear(x0, y0, r0, x1, y1, r1);

API

Setup:

• ctx -> canvas 2D context.

• fx -> Fill start-x. [Optional param, defaults to 0]

• fy -> Fill start-y. [Optional param, defaults to 0]

• fw -> Fill width. [Optional param, defaults to canvas.width]

• fh -> Fill height. [Optional param, defaults to canvas.height]

For linear:

• gx1 -> Gradiant start-x.

• gy1 -> Gradiant start-y.

• gx2 -> Gradiant end-x.

• gy2 -> Gradiant end-y.

• colorStops -> [{color,position}...]

For radail:

• x0 -> x-axis for start circle.

• y0 -> y-axis for end circle.

• r0 -> Radius of the start circle.

• x1 -> x-axis of the end circle.

• y1 -> y-axis of the end circle.

• r1 -> Radius of the end circle.

Checkout the live demo.

var cnvsGrad = require('canvas-gradient');

//canvas setup
var canvas  =  document.createElement('canvas');
canvas.width = '500';
canvas.height = '300';
canvas.style.outline = "1px solid black";
document.body.appendChild(canvas);

// Get the context.
var ctx = canvas.getContext('2d');

// Set up color stop points
var cs = [
  {color:"black", position:0}, 
  {color:"grey",position:0.5},
  {color:"white",position:1}
];

// Draw gradient.
cnvsGrad(ctx).linear(0,0,500,0,cs);

// Similarly for radial 
cnvsGrad(ctx).radial(100,100,100,0,cs);