Implement shader caching

* Shader compilation is now cached. Subsequent loads take less than a millisecond.
* Improved game, editor and project manager startup time.
* Editor uses .godot/shader_cache to store shaders.
* Game uses user://shader_cache
* Project manager uses $config_dir/shader_cache
* Options to tweak shader caching in project settings.
* Editor path configuration moved from EditorSettings to new class, EditorPaths, so it can be available early on (before shaders are compiled).
* Reworked ShaderCompilerRD to ensure deterministic shader code creation (else shader may change and cache will be invalidated).
* Added shader compression with SMOLV: https://github.com/aras-p/smol-v

4 files changed, 65 insertions, 9 deletions

diff --git a/doc/classes/EditorInterface.xml b/doc/classes/EditorInterface.xml
index a5328ce382..3f324bf1a0 100644
--- a/doc/classes/EditorInterface.xml
+++ b/doc/classes/EditorInterface.xml
@@ -57,6 +57,12 @@
 				[b]Note:[/b] This returns the main editor control containing the whole editor, not the 2D or 3D viewports specifically.
 			</description>
 		</method>
+		<method name="get_editor_paths">
+			<return type="EditorPaths">
+			</return>
+			<description>
+			</description>
+		</method>
 		<method name="get_editor_scale" qualifiers="const">
 			<return type="float">
 			</return>
diff --git a/doc/classes/EditorPaths.xml b/doc/classes/EditorPaths.xml
new file mode 100644
index 0000000000..b92927fd53
--- /dev/null
+++ b/doc/classes/EditorPaths.xml
@@ -0,0 +1,49 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="EditorPaths" inherits="Object" version="4.0">
+	<brief_description>
+	</brief_description>
+	<description>
+	</description>
+	<tutorials>
+	</tutorials>
+	<methods>
+		<method name="get_cache_dir" qualifiers="const">
+			<return type="String">
+			</return>
+			<description>
+			</description>
+		</method>
+		<method name="get_config_dir" qualifiers="const">
+			<return type="String">
+			</return>
+			<description>
+			</description>
+		</method>
+		<method name="get_data_dir" qualifiers="const">
+			<return type="String">
+			</return>
+			<description>
+			</description>
+		</method>
+		<method name="get_self_contained_file" qualifiers="const">
+			<return type="String">
+			</return>
+			<description>
+			</description>
+		</method>
+		<method name="get_settings_dir" qualifiers="const">
+			<return type="String">
+			</return>
+			<description>
+			</description>
+		</method>
+		<method name="is_self_contained" qualifiers="const">
+			<return type="bool">
+			</return>
+			<description>
+			</description>
+		</method>
+	</methods>
+	<constants>
+	</constants>
+</class>
diff --git a/doc/classes/EditorSettings.xml b/doc/classes/EditorSettings.xml
index 016d0128eb..e732223516 100644
--- a/doc/classes/EditorSettings.xml
+++ b/doc/classes/EditorSettings.xml
@@ -124,15 +124,6 @@
 				Returns the value of the setting specified by [code]name[/code]. This is equivalent to using [method Object.get] on the EditorSettings instance.
 			</description>
 		</method>
-		<method name="get_settings_dir" qualifiers="const">
-			<return type="String">
-			</return>
-			<description>
-				Gets the global settings path for the engine. Inside this path, you can find some standard paths such as:
-				[code]settings/tmp[/code] - Used for temporary storage of files
-				[code]settings/templates[/code] - Where export templates are located
-			</description>
-		</method>
 		<method name="has_setting" qualifiers="const">
 			<return type="bool">
 			</return>
diff --git a/doc/classes/ProjectSettings.xml b/doc/classes/ProjectSettings.xml
index f6ade5583e..73899daaea 100644
--- a/doc/classes/ProjectSettings.xml
+++ b/doc/classes/ProjectSettings.xml
@@ -1502,6 +1502,16 @@
 		<member name="rendering/reflections/sky_reflections/texture_array_reflections.mobile" type="bool" setter="" getter="" default="false">
 			Lower-end override for [member rendering/reflections/sky_reflections/texture_array_reflections] on mobile devices, due to performance concerns or driver support.
 		</member>
+		<member name="rendering/shader_compiler/shader_cache/compress" type="bool" setter="" getter="" default="true">
+		</member>
+		<member name="rendering/shader_compiler/shader_cache/enabled" type="bool" setter="" getter="" default="true">
+		</member>
+		<member name="rendering/shader_compiler/shader_cache/strip_debug" type="bool" setter="" getter="" default="false">
+		</member>
+		<member name="rendering/shader_compiler/shader_cache/strip_debug.release" type="bool" setter="" getter="" default="true">
+		</member>
+		<member name="rendering/shader_compiler/shader_cache/use_zstd_compression" type="bool" setter="" getter="" default="true">
+		</member>
 		<member name="rendering/shading/overrides/force_blinn_over_ggx" type="bool" setter="" getter="" default="false">
 			If [code]true[/code], uses faster but lower-quality Blinn model to generate blurred reflections instead of the GGX model.
 		</member>