GPU: Add fallback when 16-bit formats are not supported (#4108)

* Add conversion for 16 bit RGBA formats (not supported in Rosetta)

* Rebase fix

Rebase fix

* Forgot to remove this

* Fix RGBA16 format conversion

* Add RGBA4 -> RGBA8 conversion

* Handle host stride alignment

* Address Feedback Part 1

* Can't count

* Don't zero out rgb when alpha is 0

* Separate RGBA4 and 5-bit component formats

Not sure of a better way to name them...

* Add A1B5G5R5 conversion

* Put this in the right place.

* Make format naming consistent for capabilities

* Change method names

2 files changed, 27 insertions, 0 deletions

diff --git a/Ryujinx.Graphics.GAL/Capabilities.cs b/Ryujinx.Graphics.GAL/Capabilities.cs
index bc93908b..abacdcfa 100644
--- a/Ryujinx.Graphics.GAL/Capabilities.cs
+++ b/Ryujinx.Graphics.GAL/Capabilities.cs
@@ -18,7 +18,9 @@ namespace Ryujinx.Graphics.GAL
         public readonly bool Supports3DTextureCompression;
         public readonly bool SupportsBgraFormat;
         public readonly bool SupportsR4G4Format;
+        public readonly bool SupportsR4G4B4A4Format;
         public readonly bool SupportsSnormBufferTextureFormat;
+        public readonly bool Supports5BitComponentFormat;
         public readonly bool SupportsFragmentShaderInterlock;
         public readonly bool SupportsFragmentShaderOrderingIntel;
         public readonly bool SupportsGeometryShaderPassthrough;
@@ -55,7 +57,9 @@ namespace Ryujinx.Graphics.GAL
             bool supports3DTextureCompression,
             bool supportsBgraFormat,
             bool supportsR4G4Format,
+            bool supportsR4G4B4A4Format,
             bool supportsSnormBufferTextureFormat,
+            bool supports5BitComponentFormat,
             bool supportsFragmentShaderInterlock,
             bool supportsFragmentShaderOrderingIntel,
             bool supportsGeometryShaderPassthrough,
@@ -89,7 +93,9 @@ namespace Ryujinx.Graphics.GAL
             Supports3DTextureCompression = supports3DTextureCompression;
             SupportsBgraFormat = supportsBgraFormat;
             SupportsR4G4Format = supportsR4G4Format;
+            SupportsR4G4B4A4Format = supportsR4G4B4A4Format;
             SupportsSnormBufferTextureFormat = supportsSnormBufferTextureFormat;
+            Supports5BitComponentFormat = supports5BitComponentFormat;
             SupportsFragmentShaderInterlock = supportsFragmentShaderInterlock;
             SupportsFragmentShaderOrderingIntel = supportsFragmentShaderOrderingIntel;
             SupportsGeometryShaderPassthrough = supportsGeometryShaderPassthrough;
diff --git a/Ryujinx.Graphics.GAL/Format.cs b/Ryujinx.Graphics.GAL/Format.cs
index 87d08803..5e0274e5 100644
--- a/Ryujinx.Graphics.GAL/Format.cs
+++ b/Ryujinx.Graphics.GAL/Format.cs
@@ -449,6 +449,27 @@ namespace Ryujinx.Graphics.GAL
         }
 
         /// <summary>
+        /// Checks if the texture format is 16 bit packed.
+        /// </summary>
+        /// <param name="format">Texture format</param>
+        /// <returns>True if the texture format is 16 bit packed, false otherwise</returns>
+        public static bool Is16BitPacked(this Format format)
+        {
+            switch (format)
+            {
+                case Format.B5G6R5Unorm:
+                case Format.B5G5R5A1Unorm:
+                case Format.R5G5B5X1Unorm:
+                case Format.R5G5B5A1Unorm:
+                case Format.R5G6B5Unorm:
+                case Format.R4G4B4A4Unorm:
+                    return true;
+            }
+
+            return false;
+        }
+
+        /// <summary>
         /// Checks if the texture format is an ASTC format.
         /// </summary>
         /// <param name="format">Texture format</param>