[svgwg] How to handle feColorMatrix with type=saturate and values outside a 0..1 range (#723)

RazrFalcon has just created a new issue for https://github.com/w3c/svgwg:

== How to handle feColorMatrix with type=saturate and values outside a 0..1 range ==
- https://www.w3.org/TR/SVG11/filters.html#feColorMatrixElement
- https://www.w3.org/TR/filter-effects-1/#feColorMatrixElement

SVG 1.1 spec states that:

>For type="saturate", ‘values’ is a single real number value (0 to 1).

but in Filter Effects Module Level 1:

>Values outside the 0..1 range under- or oversaturates the filter input image respectively.

And the real results are even more strange:

```xml
<svg viewBox="0 0 200 200" xmlns="http://www.w3.org/2000/svg">
    <linearGradient id="lg1">
        <stop offset="0" stop-color="#cc00cc"/>
        <stop offset=".33" stop-color="#228822"/>
        <stop offset=".67" stop-color="#400000"/>
        <stop offset="1" stop-color="#a0a0ff"/>
    </linearGradient>
    <filter id="filter1">
        <feColorMatrix type="saturate" values="-0.5"/>
    </filter>
    <rect id="rect1" x="20" y="20" width="160" height="160" fill="url(#lg1)" filter="url(#filter1)"/>
</svg>
```

![e-feColorMatrix-008](https://user-images.githubusercontent.com/725494/62837639-44ee2300-bc7a-11e9-8f8f-df34a7883340.png)

And with `values="99999"`:

![e-feColorMatrix-009](https://user-images.githubusercontent.com/725494/62837641-47e91380-bc7a-11e9-923b-dc550f37f846.png)


Please view or discuss this issue at https://github.com/w3c/svgwg/issues/723 using your GitHub account

Received on Sunday, 11 August 2019 17:55:05 UTC