[whatwg] clarification on createRadialGradient( x0, y0, r0, x1, y1, r1 )
Mathieu HENRI
p01 at opera.com
Mon Nov 27 09:41:47 PST 2006
Hi,
The current specification of the createRadialGradient( x0, y0, r0, x1,
y1, r1 ) [1] is a bit ambiguous about the colour to use in the disc
defined by x0, y0, r0 when a colorStop is set for the offset 0. Should
the disc be transparent black or should it be filled with the color
defined for the offset 0 ?
It seems more sense to fill the it with the color set at the offset 0.
And if the developers want to have a 'holed' radial gradient they can
easily set the first colorStop to rgba( R, G, B, 0 )
Regards,
[1]
http://www.whatwg.org/specs/web-apps/current-work/#createradialgradientx0
" _Radial gradients are rendered such that a cone is created from the
two circles_ , so that at the circumference of the starting circle the
colour at offset 0 is used, that at the circumference around the ending
circle the color at offset 1 is used, that the circumference of a circle
drawn a certain fraction of the way along the line between the two
origins with a radius the same fraction of the way between the two radii
has the colour at that offset, that the end circle appear to be above
the start circle when the end circle is not completely enclosed by the
start circle, and that _any points not described by the gradient are a
transparent black_.
If a gradient has no stops defined, then the gradient is treated as a
solid transparent black. Gradients are, naturally, only painted where
the stroking or filling effect requires that they be drawn. "
--
Mathieu 'p01' HENRI
JavaScript developer, Opera Software ASA
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