commit d9e8586d23f8673e2d8dbcae68064a3b35e896be
author Florin Malita <fmalita@chromium.org> Thu Oct 17 13:46:33 2019 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Thu Oct 17 20:57:09 2019 +0000
tree 7ebafd2322acfb3ba1704454b72e44c1b72501b3
parent ad82b407089d4387fab892f64239c31bfd7efc96

[skottie] Fix camera/3D layer transform interactions

Currently, the camera view transform is attached to the render tree as a
TransformEffect.  This means it gets "flattened" to an SkMatrix in isolation,
and does not compose with other layer transforms in 4x4 format.

Refactor the implementation to

  - build the camera transform upfront
  - compose (chain) all layer transforms from this camera transform

This ensures that transform composition happens in SkMatrix44.

E.g. render tree topology change (TE == TransformEffect)

Before:

                      [root]
                        |
                      [TE]<---[CameraT]
                        |
       ------------------------------------
      |                                    |
      |                                    |
    [TE]<--[Layer1T]          [Layer2T]-->[TE]
      |                                    |
  [Layer1]                              [Layer2]
      |                                    |



After:
                      [root]
                        |
                        |
       ------------------------------------
      |                                    |
      |             [CameraT]              |
      |                / \                 |
    [TE]<--[Layer1T]<--   --->[Layer2T]-->[TE]
      |                                    |
  [Layer1]                              [Layer2]
      |                                    |


TBR=
Bug: skia:8914
Change-Id: Idd407712f75c48623b5299a4284ddb17b98c155f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/249217
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Florin Malita <fmalita@chromium.org>