[vr] Use ELEMENT_ARRAY_BUFFERS for quads in VrShellRenderer

[vr] Use ELEMENT_ARRAY_BUFFERS for quads in VrShellRenderer

This is a minor cleanup to prepare for similar changes in future.
With this change, we also remove the need for texture coordinate
attributes in many cases since they can be derived from positions.

NOPRESUBMIT=true
BUG=739158
Review-Url: https://codereview.chromium.org/2970663006
Cr-Commit-Position: refs/heads/master@{#484154}
Committed: https://chromium.googlesource.com/chromium/src/+/28cbda8e680f987b98c22a8f5382a60f40ce06fc

[Ian Vollick, 2017-07-04 12:40:31]

The CQ bit was checked by vollick@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-07-04 12:40:41]

Dry run: CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[Ian Vollick, 2017-07-04 12:43:18]

Description was changed from

==========
[vr] Use ELEMENT_ARRAY_BUFFERS for quads in VrShellRenderer

This is a minor cleanup to prepare for similar changes in future.

BUG=739158
==========

to

==========
[vr] Use ELEMENT_ARRAY_BUFFERS for quads in VrShellRenderer

This is a minor cleanup to prepare for similar changes in future.
With this change, we also remove the need for texture coordinate
attributes in many cases since they can be derived from positions.

BUG=739158
==========

[Ian Vollick, 2017-07-04 12:43:31]

vollick@chromium.org changed reviewers:
+ cjgrant@chromium.org, mthiesse@chromium.org

[commit-bot: I haz the power, 2017-07-04 12:48:49]

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

[commit-bot: I haz the power, 2017-07-04 12:48:50]

Dry run: Try jobs failed on following builders:
  chromium_presubmit on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[Ian Vollick, 2017-07-04 20:14:10]

vollick@chromium.org changed reviewers:
+ bajones@chromium.org

[Ian Vollick, 2017-07-04 20:14:11]

Brandon, if you have a moment to look at this, would love your opinion.

[cjgrant, 2017-07-04 20:29:02]

lgtm

[Ian Vollick, 2017-07-04 20:32:36]

The CQ bit was checked by vollick@chromium.org

[commit-bot: I haz the power, 2017-07-04 20:32:45]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-07-04 20:40:57]

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

[commit-bot: I haz the power, 2017-07-04 20:40:58]

Try jobs failed on following builders:
  chromium_presubmit on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[Ian Vollick, 2017-07-04 20:45:54]

Description was changed from

==========
[vr] Use ELEMENT_ARRAY_BUFFERS for quads in VrShellRenderer

This is a minor cleanup to prepare for similar changes in future.
With this change, we also remove the need for texture coordinate
attributes in many cases since they can be derived from positions.

BUG=739158
==========

to

==========
[vr] Use ELEMENT_ARRAY_BUFFERS for quads in VrShellRenderer

This is a minor cleanup to prepare for similar changes in future.
With this change, we also remove the need for texture coordinate
attributes in many cases since they can be derived from positions.

NOPRESUBMIT=true
BUG=739158
==========

[Ian Vollick, 2017-07-04 20:45:59]

The CQ bit was checked by vollick@chromium.org

[commit-bot: I haz the power, 2017-07-04 20:46:08]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-07-04 20:46:33]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1499201159027890, "parent_rev":
"772ace0703fb420097d1c14b53a5f186d2027771", "commit_rev":
"28cbda8e680f987b98c22a8f5382a60f40ce06fc"}

[commit-bot: I haz the power, 2017-07-04 20:46:49]

Description was changed from

==========
[vr] Use ELEMENT_ARRAY_BUFFERS for quads in VrShellRenderer

This is a minor cleanup to prepare for similar changes in future.
With this change, we also remove the need for texture coordinate
attributes in many cases since they can be derived from positions.

NOPRESUBMIT=true
BUG=739158
==========

to

==========
[vr] Use ELEMENT_ARRAY_BUFFERS for quads in VrShellRenderer

This is a minor cleanup to prepare for similar changes in future.
With this change, we also remove the need for texture coordinate
attributes in many cases since they can be derived from positions.

NOPRESUBMIT=true
BUG=739158

Review-Url: https://codereview.chromium.org/2970663006
Cr-Commit-Position: refs/heads/master@{#484154}
Committed:
https://chromium.googlesource.com/chromium/src/+/28cbda8e680f987b98c22a8f5382...
==========

[commit-bot: I haz the power, 2017-07-04 20:46:49]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/28cbda8e680f987b98c22a8f5382...

[bajones1, 2017-07-05 19:37:57]

LGTM FWIW.

One semi-related very high level comment that doesn't really apply to this CL:
While the changes here definitely feel like a net win we should generally be
cautious any time we're adding work to the vertex shaders. The amount of
per-vertex work done on any scene doubles when in VR vs mono, while the
per-fragment work only increases something like 1.2x (in the optimal case).
Doesn't have as much effect of us because the UI is largely simple quads, but if
we get into mesh backgrounds or anything like that it's something to be aware
of.