Add shadow mapping with support for spot shadow casters

[tomas7770]

Description

Implements shadows for spot lights, including support for multiple lights and soft shadows.

• shadowAtlasPlugin creates and manages the shadow atlas, a large texture that holds the shadow maps for each spot light.
• shadowAtlasRasterizerPlugin draws to the shadow maps.
• deferredShadingPlugin has been modified to read from the shadow atlas, in order to draw shadows.

Checklist

• [x] Self-review changes.
• [ ] Evaluate impact on the documentation.
• [ ] Ensure test coverage.
• [x] Write new samples.
• [x] Add entry to the changelog's unreleased section.

[github-actions[bot]]

PR Preview Action v1.4.7 :---: :rocket: Deployed preview to https://GameDevTecnico.github.io/cubos/preview/pr-1287/ on branch gh-pages at 2024-07-25 18:31 UTC

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 0% with 186 lines in your changes missing coverage. Please review.

Project coverage is 35.95%. Comparing base (e20a16c) to head (74f960d).

Files	Patch %	Lines
...gine/src/render/shadow_atlas_rasterizer/plugin.cpp	0.00%	86 Missing :warning:
engine/src/render/shadow_atlas/plugin.cpp	0.00%	47 Missing :warning:
engine/src/render/deferred_shading/plugin.cpp	0.00%	25 Missing :warning:
engine/src/render/shadow_atlas/shadow_atlas.cpp	0.00%	15 Missing :warning:
core/src/gl/ogl_render_device.cpp	0.00%	4 Missing :warning:
.../cubos/engine/render/shadow_atlas/shadow_atlas.hpp	0.00%	4 Missing :warning:
engine/src/render/defaults/plugin.cpp	0.00%	3 Missing :warning:
...hadow_atlas_rasterizer/shadow_atlas_rasterizer.cpp	0.00%	2 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1287 +/- ## ========================================== - Coverage 36.16% 35.95% -0.21% ========================================== Files 380 385 +5 Lines 30945 31124 +179 ========================================== Hits 11191 11191 - Misses 19754 19933 +179 ```

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[diogomsmiranda]

On another note, is there a way to test this functionality?

[tomas7770]

On another note, is there a way to test this functionality?

I'm not sure how the testing framework works, but I figure the shadowAtlasPlugin should be testable. The rest probably has the risk of slightly different behavior on different GPUs.

[RiscadoA]

On another note, is there a way to test this functionality?

I'm not sure how the testing framework works, but I figure the shadowAtlasPlugin should be testable. The rest probably has the risk of slightly different behavior on different GPUs.

The CI can't handle GPU stuff properly, so yeah, it's not worth the hassle to write tests for these kind of stuff. Do ensure that we have good samples for these features though! If could add a new render sample focused on shadows, it would be great. Structure wise we should probably rename the previous render sample to render.main or something, and add new samples under it, such as render.shadows