Clipping issue with different child stencils

[rh101]

• axmol version:
• devices test on: Windows 10
• developing environments
  • NDK version: r23c
  • Xcode version: 14.2+
  • Visual Studio:
    • VS version: 2022 (17.9+)
    • MSVC version: 19.39+
    • Windows SDK version: 10.0.22621.0+
  • cmake version: Steps to Reproduce:

If different stencils are added as children of a parent stencil, then the last child stencil added is applied to all other stencil positions.

For example, in the cpp-tests void HoleDemo::pokeHoleAtPoint(Vec2 point), change this line:

auto holeStencil = Sprite::create("Images/hole_stencil.png");

to this: auto holeStencil = RandomHelper::random_int(0, 1) == 0 ? Sprite::create("Images/hole_stencil.png") : Sprite::create("Images/hole_stencil2.png");

Add this hole_stencil2.png image to the to the axmol\tests\cpp-tests\Content\Images folder:

Run cpp-tests, then click on "29:Node: Clipping" test. Then navigate to "2:Hole Demo". Click on the spinning square image, and you will see the following:

MP4 video of issue: https://github.com/axmolengine/axmol/assets/8603230/5c82dd9a-be6d-4246-8193-9b0217f3329e

The problem is that the last image used as a stencil is applied to all other existing stencils.

The expected output is that each new stencil would not affect the previous stencils applied, so there should be a mix of round and square holes in that image.

Is this a limitation of the ClippingNode, or is this a bug?

[rh101]

I think this has something to do with the ProgramState being set on all child stencil nodes. They are all being set to the same ProgramState instance, but if this is changed to be a unique instance per child, then the problem is fixed, but memory usage goes up because of some other issue that I'm trying to track down.

[rh101]

Issue should now be fixed in PR #1957

The resulting output is now this:

To reproduce this output, then in addition to the cpp-tests changes mentioned in the initial post above, also change this line: holesClipper->setStencil(_holesStencil);

to this: holesClipper->setStencil(_holesStencil, true);