HdxPickTaskContextParams::depthMaskCallback is OpenGL-only and will not work on Metal - Githubissues

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HdxPickTaskContextParams::depthMaskCallback is OpenGL-only and will not work on Metal #1686

Open vlasovi opened 2 years ago

vlasovi commented 2 years ago

Description of Issue

For stencil buffer masking in HdxPickTask, there exists HdxPickTaskContextParams::depthMaskCallback.
However this feature is OpenGL specific and will not work on Apple hardware.

It would make sense to use Hgi inside HdxPickTask::_ConditionStencilWithGLCallback to set stencil, depth and color mask states.
And then pass the pointer to HgiGraphicsCmds to the depthMaskCallback to draw the required geometry in a platform-independent fashion.
Autodesk requires this functionality for features like "Lasso selection".

Steps to Reproduce

Go to HdxPickTask::_ConditionStencilWithGLCallback
Observe that there are OpenGL calls used there, like 'glStencilFunc'
Also, observe that the variable glGfxCmds is not passed to maskCallback for platform-independent drawing.

System Information (OS, Hardware)

Apple macOS

Package Versions

Latest dev

Build Flags

None

jilliene commented 2 years ago

Filed as internal issue #USD-7029