[PATCH] Document invalid nStop value

[Andrea Canciani]

On Thu, Nov 4, 2010 at 2:50 AM, Soeren Sandmann <sandmann at daimi.au.dk> wrote:
> Andrea Canciani <ranma42 at gmail.com> writes:
>
>> Gradients must have at least one stop.
>> ---
>>  renderproto.txt |    6 ++++++
>>  1 files changed, 6 insertions(+), 0 deletions(-)
>>
>> diff --git a/renderproto.txt b/renderproto.txt
>> index 9f1f231..f6a9884 100644
>> --- a/renderproto.txt
>> +++ b/renderproto.txt
>> @@ -1089,6 +1089,8 @@ CreateLinearGradient
>>       The gradient has nstops stop points between 0 and 1, each
>>       having a stop color defined in stop_colors.
>>
>> +     If nStop is 0, a Value error is generated.
>> +
>
> It's probably better to use the "nstops" spelling like the rest of the
> protocol spec.

Oops! You're right. The attached patch should be better.

>
> Also, while the change to allow one-stop gradients is good, shouldn't
> the spec say what actually happens in that case?

Yes/no. The spec doesn't explain at all what happens with the stops
(for example what happens when the stops don't range from 0 to 1
exactly). I think that if such an explanation existed, it would also solve
the problem of the one-stop gradients.
This would be more generic and very useful (last time I had to find out
how this worked, I had to look at the code pixman instead of render
spec), but can probably be a different patch.

Andrea
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