[whatwg] Canvas: Rendering radial gradients beyond the terminal stops

[Andreas Kling]

Greetings!

The current draft of HTML5 [1] says about rendering radial gradients:

"This effectively creates a cone, touched by the two circles defined in 
the creation of the gradient, with the part of the cone before the start 
circle (0.0) using the color of the first offset, the part of the cone 
after the end circle (1.0) using the color of the last offset, and areas 
outside the cone untouched by the gradient (transparent black)."

I find this behavior of "transparent spread" rather strange and it 
doesn't match any of the SVG gradient's spreadMethod [2] options.

The sensible behavior here IMO is "pad spread" (SVG default, and what 
most browsers implementing <canvas> currently do) which means repeating 
the terminal color stops indefinitely.

- Kling

[1] 
http://www.whatwg.org/specs/web-apps/current-work/#dom-context-2d-createradialgradient
[2] 
http://www.w3.org/TR/SVG/pservers.html#RadialGradientElementSpreadMethodAttribute