Update SkLightingShader to support rotation

Update SkLightingShader to support rotation

This also:
makes the SkLightingShader handle normal maps where the rects aren't aligned between the diffuse and normal maps.

adds a light aggregating class (Lights) to SkLightingShader (along with a Builder nested class).

Split out of https://codereview.chromium.org/1261433009/ (Add SkCanvas::drawLitAtlas call)

Committed: https://skia.googlesource.com/skia/+/45b59ed6e4e231814dbdb9f707b3d2a7ee50de84

Committed: https://skia.googlesource.com/skia/+/2f0dbc761a626473c19db7de561c7072b12953c5

[robertphillips, 2015-08-18 14:00:18]

robertphillips@google.com changed reviewers:
+ bsalomon@google.com, reed@google.com

[robertphillips, 2015-08-18 14:00:49]

robertphillips@google.com changed reviewers:
+ jvanverth@google.com

[reed1, 2015-08-19 12:57:56]

lgtm

[jvanverth1, 2015-08-19 13:57:48]

Just a few comments.

https://codereview.chromium.org/1291783003/diff/60001/src/core/SkLightingShad...
File src/core/SkLightingShader.cpp (right):

https://codereview.chromium.org/1291783003/diff/60001/src/core/SkLightingShad...
src/core/SkLightingShader.cpp:216: fpb->codeAppend("normal =
normalize(m*normal);");
It's more efficient to multiply the light direction by the transpose of the
normal matrix in the vertex shader (i.e. transform the light direction from
world space into object space, rather than transform all the normals from object
space into world space). Or perhaps just pre-transform the light direction on
the CPU before setting the uniform.

https://codereview.chromium.org/1291783003/diff/60001/src/core/SkLightingShad...
File src/core/SkLightingShader.h (right):

https://codereview.chromium.org/1291783003/diff/60001/src/core/SkLightingShad...
src/core/SkLightingShader.h:25: class Builder {
This class is new -- can you mention it in the change description?

https://codereview.chromium.org/1291783003/diff/60001/src/core/SkLightingShad...
src/core/SkLightingShader.h:33: void add(const SkLight& light) {
I think we'll need a way to limit the number of directional lights you can add.

[robertphillips, 2015-08-19 16:17:57]

https://codereview.chromium.org/1291783003/diff/60001/src/core/SkLightingShad...
File src/core/SkLightingShader.cpp (right):

https://codereview.chromium.org/1291783003/diff/60001/src/core/SkLightingShad...
src/core/SkLightingShader.cpp:216: fpb->codeAppend("normal =
normalize(m*normal);");
I've added a TODO.

https://codereview.chromium.org/1291783003/diff/60001/src/core/SkLightingShad...
File src/core/SkLightingShader.h (right):

https://codereview.chromium.org/1291783003/diff/60001/src/core/SkLightingShad...
src/core/SkLightingShader.h:25: class Builder {
On 2015/08/19 13:57:48, jvanverth1 wrote:
> This class is new -- can you mention it in the change description?

Done.

https://codereview.chromium.org/1291783003/diff/60001/src/core/SkLightingShad...
src/core/SkLightingShader.h:33: void add(const SkLight& light) {
I've added a TODO.

[robertphillips, 2015-08-19 16:18:04]

The CQ bit was checked by robertphillips@google.com to run a CQ dry run

[commit-bot: I haz the power, 2015-08-19 16:18:11]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1291783003/80001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1291783003/80001

[commit-bot: I haz the power, 2015-08-19 16:19:23]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-19 16:19:23]

Dry run: Try jobs failed on following builders:
  Build-Ubuntu-GCC-x86_64-Release-Trybot on client.skia.compile (JOB_FAILED,
http://build.chromium.org/p/client.skia.compile/builders/Build-Ubuntu-GCC-x86...)

[bsalomon, 2015-08-19 16:38:20]

lgtm

[robertphillips, 2015-08-19 17:14:07]

The CQ bit was checked by robertphillips@google.com to run a CQ dry run

[commit-bot: I haz the power, 2015-08-19 17:14:15]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1291783003/120001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1291783003/120001

[commit-bot: I haz the power, 2015-08-19 17:20:53]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-19 17:20:54]

Dry run: This issue passed the CQ dry run.

[robertphillips, 2015-08-19 17:34:24]

The CQ bit was checked by robertphillips@google.com

[robertphillips, 2015-08-19 17:34:24]

The patchset sent to the CQ was uploaded after l-g-t-m from reed@google.com,
bsalomon@google.com
Link to the patchset: https://codereview.chromium.org/1291783003/#ps120001
(title: "Fix compilation complaint")

[commit-bot: I haz the power, 2015-08-19 17:34:37]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1291783003/120001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1291783003/120001

[commit-bot: I haz the power, 2015-08-19 17:35:17]

Committed patchset #7 (id:120001) as
https://skia.googlesource.com/skia/+/45b59ed6e4e231814dbdb9f707b3d2a7ee50de84

[robertphillips, 2015-08-19 20:59:41]

Patchset #9 (id:160001) has been deleted

[robertphillips, 2015-08-19 20:59:58]

Patchset #8 (id:140001) has been deleted

[robertphillips, 2015-08-19 21:27:49]

Patchset #8 (id:180001) has been deleted

[robertphillips, 2015-08-19 21:49:25]

The CQ bit was checked by robertphillips@google.com to run a CQ dry run

[commit-bot: I haz the power, 2015-08-19 21:49:44]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1291783003/220001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1291783003/220001

[commit-bot: I haz the power, 2015-08-19 21:56:23]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-19 21:56:24]

Dry run: This issue passed the CQ dry run.

[robertphillips, 2015-08-20 12:14:20]

The CQ bit was checked by robertphillips@google.com

[robertphillips, 2015-08-20 12:14:21]

The patchset sent to the CQ was uploaded after l-g-t-m from bsalomon@google.com,
reed@google.com
Link to the patchset: https://codereview.chromium.org/1291783003/#ps220001
(title: "Fix gyp file")

[commit-bot: I haz the power, 2015-08-20 12:14:33]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1291783003/220001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1291783003/220001

[commit-bot: I haz the power, 2015-08-20 12:15:12]

Committed patchset #9 (id:220001) as
https://skia.googlesource.com/skia/+/2f0dbc761a626473c19db7de561c7072b12953c5