Feature/canvas addon

[sc0ttj]

A new add-on, for extending the features of the <canvas> 2d context.

Features:

• extra drawing methods:
  • arrows and arced arrows
  • cardinals splines (smooth curves, with segments and optional points)
  • circles & ellipses
  • gradient-filled rectangles (linear) and circles (radial)
  • grids
  • polygons from any array of points
  • polyshapes, like hexagons, etc
  • rounded corner rectangles
  • rings (doughnuts)
  • spirals
  • stars
  • triangles
  • more..
• a simple camera:
  • pan, scale, rotate
• chainable API:
  • all methods are chainable unless they return something (see regular canvas API)
• maths helper functions:
  • convert between radians/degrees, get distances, etc
• save to image and video:
  • embed SVG as code, Element or file with ctx.drawImg(), which handles caching for you
  • save canvas as an image with ctx.canvas.image.saveAs('filename.png')
  • record canvas to video with ctx.canvas.video.record()
  • save the video with ctx.canvas.video.saveAs('filename.webm')
• less than 5kb, minified & gzipped

Note:

• only extends the 2dContext of Component canvases - it won't affect other <canvas>s.
• only works in browser, unless <canvas> 2d context is polyfilled in your NodeJS app.