Setting clip_area is broken.

anura-engine / anura

Anura Engine

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Setting clip_area is broken. #340

Open DDR0 opened 2 years ago

DDR0 commented 2 years ago

To reproduce: Check out Frogatto's minimal-clip-area-bug branch. Run ./anura --level=test.cfg.

The coin on screen should turn invisible, but instead of just darkens as a result of the set(brightness, 128) call right before the set(clip_area, ...) call.

Notes:

The call does "apply" clip_area if you enter the editor. This is confirmed in the positive and negative case.
The bug has existed for more than three months or so, now.
In some cases, something happens which causes this bug to not reproduce on more complicated objects.

DDR0 commented 2 years ago

And now, coming at it from the other end, we have Frogatto's maximal-clip-area-bug branch. It seems that tweaking the liquid shader's end_zorder is enough to fix or break clip_area.

DDR0 commented 2 years ago

identity_op works too.

DDR0 commented 2 years ago

In level.cpp, commenting out shaders.emplace_back(e.shader); in frameBufferEnterZorder() stops the "fix" from working.

DDR0 commented 2 years ago

I think shaders are setting something elsewhere, as as far as I can tell the critical path for them is shader->setUniformValue(shader->getPVUniform(), glm::value_ptr(pvmat)); in DeviceOGL.cpp's DisplayDeviceOpenGL::render.

DDR0 commented 1 year ago

I have applied a general hack around this for Frogatto. Search for the _add_shader_fix_for_clip_area_to_fix_anura_issue_340 in the FFL there.