Handle shader construction failures gracefully

Handle shader construction failures gracefully

If we cannot instantiate a shader (due to e.g. a non-invertible local
matrix), the expectation is to not draw anything.  We're currently
filling with black.

This unblocks https://skia-review.googlesource.com/c/7885/, which
prevents creation of shaders with non-invertible matrices.

R=reed@google.com

Review-Url: https://codereview.chromium.org/2677633004
Cr-Commit-Position: refs/heads/master@{#448018}
Committed: https://chromium.googlesource.com/chromium/src/+/e1e7aedf7841db60e01c5bd8574559a7bdd7f041

[f(malita), 2017-02-03 14:43:10]

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

[commit-bot: I haz the power, 2017-02-03 14:43:22]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[f(malita), 2017-02-03 14:47:12]

Description was changed from

==========
Only paint background patterns when the shader construction succeeds

If we cannot instantiate a shader (due to e.g. a non-invertible local
matrix), the expectation is to not draw anything.  We're currently
filling with black.

R=reed@google.com
==========

to

==========
Only paint background patterns when the shader construction succeeds

If we cannot instantiate a shader (due to e.g. a non-invertible local
matrix), the expectation is to not draw anything.  We're currently
filling with black.

This unblocks https://skia-review.googlesource.com/c/7885/, which
prevents creation of shaders with a non-invertible matrix.

R=reed@google.com
==========

[f(malita), 2017-02-03 14:47:40]

Description was changed from

==========
Only paint background patterns when the shader construction succeeds

If we cannot instantiate a shader (due to e.g. a non-invertible local
matrix), the expectation is to not draw anything.  We're currently
filling with black.

This unblocks https://skia-review.googlesource.com/c/7885/, which
prevents creation of shaders with a non-invertible matrix.

R=reed@google.com
==========

to

==========
Only paint background patterns when the shader construction succeeds

If we cannot instantiate a shader (due to e.g. a non-invertible local
matrix), the expectation is to not draw anything.  We're currently
filling with black.

This unblocks https://skia-review.googlesource.com/c/7885/, which
prevents creation of shaders with non-invertible matrices.

R=reed@google.com
==========

[f(malita), 2017-02-03 15:02:31]

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

[commit-bot: I haz the power, 2017-02-03 15:02:48]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[f(malita), 2017-02-03 15:05:36]

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

[commit-bot: I haz the power, 2017-02-03 15:05:49]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[f(malita), 2017-02-03 15:11:17]

Description was changed from

==========
Only paint background patterns when the shader construction succeeds

If we cannot instantiate a shader (due to e.g. a non-invertible local
matrix), the expectation is to not draw anything.  We're currently
filling with black.

This unblocks https://skia-review.googlesource.com/c/7885/, which
prevents creation of shaders with non-invertible matrices.

R=reed@google.com
==========

to

==========
Handle shader construction failures gracefully

If we cannot instantiate a shader (due to e.g. a non-invertible local
matrix), the expectation is to not draw anything.  We're currently
filling with black.

This unblocks https://skia-review.googlesource.com/c/7885/, which
prevents creation of shaders with non-invertible matrices.

R=reed@google.com
==========

[f(malita), 2017-02-03 15:18:55]

The CQ bit was unchecked by fmalita@chromium.org

[reed1, 2017-02-03 15:23:55]

so, its ok to fill with something (if there is a funny compositOp like src)
instead of not drawing anything? You could still get black (or other things like
punching transparent into the dst).

[f(malita), 2017-02-03 15:38:43]

On 2017/02/03 15:23:55, reed1 wrote:
> so, its ok to fill with something (if there is a funny compositOp like src)
> instead of not drawing anything? You could still get black (or other things
like
> punching transparent into the dst).

I'm guessing yes.

The current expectation appears to be degenerate_shader == transparent
background.  Since these low-level routines also take a composite op, it seems
we should apply it.

There are no tests to decide this one way or another AFAICT, so maybe this is
overly cautious.

[reed1, 2017-02-03 16:10:45]

lgtm

[f(malita), 2017-02-03 16:48:55]

The CQ bit was checked by fmalita@chromium.org

[commit-bot: I haz the power, 2017-02-03 16:49:09]

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, 2017-02-03 17:39:09]

CQ is committing da patch.

Bot data: {"patchset_id": 40001, "attempt_start_ts": 1486140535783870,
"parent_rev": "cb6d69f2601372a0fbc8760fbb62c7f6e0cc3cd8", "commit_rev":
"e1e7aedf7841db60e01c5bd8574559a7bdd7f041"}

[commit-bot: I haz the power, 2017-02-03 17:39:48]

Description was changed from

==========
Handle shader construction failures gracefully

If we cannot instantiate a shader (due to e.g. a non-invertible local
matrix), the expectation is to not draw anything.  We're currently
filling with black.

This unblocks https://skia-review.googlesource.com/c/7885/, which
prevents creation of shaders with non-invertible matrices.

R=reed@google.com
==========

to

==========
Handle shader construction failures gracefully

If we cannot instantiate a shader (due to e.g. a non-invertible local
matrix), the expectation is to not draw anything.  We're currently
filling with black.

This unblocks https://skia-review.googlesource.com/c/7885/, which
prevents creation of shaders with non-invertible matrices.

R=reed@google.com

Review-Url: https://codereview.chromium.org/2677633004
Cr-Commit-Position: refs/heads/master@{#448018}
Committed:
https://chromium.googlesource.com/chromium/src/+/e1e7aedf7841db60e01c5bd85745...
==========

[commit-bot: I haz the power, 2017-02-03 17:39:49]

Committed patchset #3 (id:40001) as
https://chromium.googlesource.com/chromium/src/+/e1e7aedf7841db60e01c5bd85745...