Bug 212871 – Extended Color: Unify rounding / clamping conversions between 0-1 float components and 0-255 byte components

• Status: RESOLVED
• Resolution: FIXED
• Component: New Bugs

[Sam Weinig]

Extended Color: Unify rounding / clamping conversions between 0-1 float components and 0-255 byte components

[Sam Weinig]

Created attachment 401269 [details]
WIP

[Sam Weinig]

Created attachment 401271 [details]
WIP

[Sam Weinig]

Created attachment 401272 [details]
Patch

[Sam Weinig]

Created attachment 401274 [details]
Patch

[Sam Weinig]

Created attachment 401275 [details]
Patch

[Sam Weinig]

Created attachment 401276 [details]
Patch

[Sam Weinig]

Created attachment 401277 [details]
Patch

[Sam Weinig]

Created attachment 401279 [details]
Patch

[Sam Weinig]

Created attachment 401280 [details]
Patch

[Sam Weinig]

Created attachment 401281 [details]
Patch

[Simon Fraser (smfr)]

Comment on attachment 401281 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=401281&action=review

> Source/WebCore/platform/graphics/ColorUtilities.h:54
> +inline uint8_t convertPrescaledToComponentByte(float f)

Not really a fan of "prescaled". Does it mean "in the range 0-1"? Can't think of a better word though.

[Darin Adler]

Probably obvious to both of you but: We do need terminology for 0-1 and 0-255 for floating point components. Sadly it seems we need code that deals with both. And when overloading a function so it can take either integers or floating point, it seems really bad to have a floating point overload that takes 0-1 and an integer ones that takes 0-255, so we’ll want to avoid that.

[EWS]

Committed r262733: <https://trac.webkit.org/changeset/262733>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 401281 [details].

[Radar WebKit Bug Importer]

<rdar://problem/64130839>

[Simon Fraser (smfr)]

(In reply to Darin Adler from comment #12)
> Probably obvious to both of you but: We do need terminology for 0-1 and
> 0-255 for floating point components. Sadly it seems we need code that deals
> with both. And when overloading a function so it can take either integers or
> floating point, it seems really bad to have a floating point overload that
> takes 0-1 and an integer ones that takes 0-255, so we’ll want to avoid that.

Yes!

[Sam Weinig]

We need the one taking 0-255 float values in exactly one place right now, in the CSS parser. Everywhere else is 0-1 float or 0-255 int.

[Sam Weinig]

(In reply to Simon Fraser (smfr) from comment #15)
> (In reply to Darin Adler from comment #12)
> > Probably obvious to both of you but: We do need terminology for 0-1 and
> > 0-255 for floating point components. Sadly it seems we need code that deals
> > with both. And when overloading a function so it can take either integers or
> > floating point, it seems really bad to have a floating point overload that
> > takes 0-1 and an integer ones that takes 0-255, so we’ll want to avoid that.
> 
> Yes!

The naming I was thinking about was:

makeSimpleColorFromSRGBABytes
makeSimpleColorFromSRGBAFloats

(in the patch for https://bugs.webkit.org/show_bug.cgi?id=180620, Darin used makeSimpleColorFromRGBABytes for 0-255 ints and makeSimpleColorFromSRGBA for 0-1 floats).

Not wed to this.