Upgrade WebGLImageConversion to ES3: Part II.

Upgrade WebGLImageConversion to ES3: Part II.

Add unpack/pack functions for ES3 texture formats.

The actual implementation of these functions will be added in the next CL.

BUG=497352
TEST=webgl conformance tests
R=kbr@chromium.org,bajones@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=197674

[Zhenyao Mo, 2015-06-19 21:04:34]

bajones,kbr: please review.

[bajones, 2015-06-19 21:13:10]

On 2015/06/19 21:04:34, Zhenyao Mo wrote:
> bajones,kbr: please review.

LGTM, given that the implementations are incoming.

[Zhenyao Mo, 2015-06-19 23:17:13]

Updated according to our offline discussion.

Please take a look.

[Ken Russell (switch to Gerrit), 2015-06-20 02:42:24]

LGTM. Thanks for continuing to improve this code. One comment/question.

https://codereview.chromium.org/1190423002/diff/100001/Source/platform/graphi...
File Source/platform/graphics/gpu/WebGLImageConversion.cpp (right):

https://codereview.chromium.org/1190423002/diff/100001/Source/platform/graphi...
Source/platform/graphics/gpu/WebGLImageConversion.cpp:1128: template<> void
pack<WebGLImageConversion::DataFormatRGBA8_S,
WebGLImageConversion::AlphaDoUnmultiply, int8_t, int8_t>(const int8_t* source,
int8_t* destination, unsigned pixelsPerRow)
The only situation where un-multiplication is needed is when uploading data from
a canvas element, where the color data is stored in premultiplied form. Per our
offline discussion, we were talking about not supporting uploading HTML elements
to the signed texture formats, among others. Does this mean that this pack
template (and its caller) can be removed? Same basic question for all of the new
AlphaDoUnmultiply variants here.

Basically, I wonder whether the use of FORMATCONVERTER_CASE_DSTFORMAT can be
broken up in the "convert" template function below to handle
AlphaDoPremultiply/AlphaDoNothing separately from AlphaDoUnmultiply, which
should be much more rare, and thereby reduce the size of the code.

[Zhenyao Mo, 2015-06-23 19:12:00]

https://codereview.chromium.org/1190423002/diff/100001/Source/platform/graphi...
File Source/platform/graphics/gpu/WebGLImageConversion.cpp (right):

https://codereview.chromium.org/1190423002/diff/100001/Source/platform/graphi...
Source/platform/graphics/gpu/WebGLImageConversion.cpp:1128: template<> void
pack<WebGLImageConversion::DataFormatRGBA8_S,
WebGLImageConversion::AlphaDoUnmultiply, int8_t, int8_t>(const int8_t* source,
int8_t* destination, unsigned pixelsPerRow)
On 2015/06/20 02:42:23, Ken Russell wrote:
> The only situation where un-multiplication is needed is when uploading data
from
> a canvas element, where the color data is stored in premultiplied form. Per
our
> offline discussion, we were talking about not supporting uploading HTML
elements
> to the signed texture formats, among others. Does this mean that this pack
> template (and its caller) can be removed? Same basic question for all of the
new
> AlphaDoUnmultiply variants here.
> 
> Basically, I wonder whether the use of FORMATCONVERTER_CASE_DSTFORMAT can be
> broken up in the "convert" template function below to handle
> AlphaDoPremultiply/AlphaDoNothing separately from AlphaDoUnmultiply, which
> should be much more rare, and thereby reduce the size of the code.

Agree.  Will revise in a followup.

[Zhenyao Mo, 2015-06-23 19:12:05]

The CQ bit was checked by zmo@chromium.org

[Zhenyao Mo, 2015-06-23 19:12:05]

The patchset sent to the CQ was uploaded after l-g-t-m from bajones@chromium.org
Link to the patchset: https://codereview.chromium.org/1190423002/#ps100001
(title: " ")

[commit-bot: I haz the power, 2015-06-23 19:12:29]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1190423002/100001

[commit-bot: I haz the power, 2015-06-23 21:17:03]

Committed patchset #6 (id:100001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=197674