OmniLight3D:
* Fixed lack of precision in cube map mode by scaling the projection's
znear.
* Fixed aliasing issues by making the paraboloids use two square regions instead of two half
squares.
* Fixed shadowmap atlas bleeding by adding padding.
* Fixed sihadow blur's inconsistent radius and unclamped sampling.
SpotLight3D:
* Fixed lack of precision by scaling the projection's znear.
* Fixed normal biasing.
Both:
* Tweaked biasing to make sure it works out of the box in most situations.
* Specialization constants used to disable anything not needed to draw
* Added softshadow and projector support on mobile.
This new approach ensures mobile shaders are smaller and more efficient, but relies on more pipeline versions compiled on demand.
As a result, random stalls can ocur like in Godot 3.x. These will be solved by using background compilation and fallbacks eventually (but needs to be tested first).
* Only apply final actions to attachments used in the last pass.
* Fixes to draw list final action (was using continue instead of read/drop).
* Profiling regions inside draw lists now properly throw errors.
* Ability to enable gpu profile printing from project settings. (used to debug).
* Shadow quality settings now specialization constant.
* Decal and light projector filters can be set.
* Changing those settings forces re-creation of the pipelines.
These changes should help improve performance related to shadow mapping, and allows improving performance by sacrificing decal and light projector quality.
* use valid format for framebuffer: VK_FORMAT_A2B10G10R10_UNORM_PACK32
* Unfortunately cant be used for compute.
* Mobile will need to do refprobe, sky, mipmapblurring using raster.
* Keep track of when projector, softshadow or directional sofshadow were enabled.
* Enable them via specializaton constant where it makes sense.
* Re-implements soft shadows.
* Re-implements light projectors.
