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.
* Make sure shaders are named, to aid in debug in case of failure
* SceneRenderRD was being wrongly initialized (virtual functions being called when derivative class not initialized).
* Fixed some bugs resulting on the above being corrected.
* 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).
The project setting wasn't being used anywhere.
This also tweaks the property hints to denote that these properties
are only effective after a restart.
* 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).
* Simplified code a lot, bias based on normalized cascade size.
* Lets scale cascades, max distance, etc. without creating acne.
* Fixed normal biasing in directional shadows.
I removed normal biasing in both omni and spot shadows, since the technique can't be easily implemented there.
Will need to be replaced by something else.
* Added an extra stage before compiling shader, which is generating a binary blob.
* On Vulkan, this allows caching the SPIRV reflection information, which is expensive to parse.
* On other (future) RenderingDevices, it allows caching converted binary data, such as DXIL or MSL.
This PR makes the shader cache include the reflection information, hence editor startup times are significantly improved.
I tested this well and it appears to work, and I added a lot of consistency checks, but because it includes writing and reading binary information, rare bugs may pop up, so be aware.
There was not much of a choice for storing the reflection information, given shaders can be a lot, take a lot of space and take time to parse.
