Clone the state & flip viewport vertically (#16)

* implement texture get data

* reset all state before blit & clone state

* format

* support blit regions

* implement source region for blit

* replace bottom with top

* account for 0 size

* support image flipping

* revert presentation fixes & y flip

* revert

* flip viewport vertically

* switch face winding

* comment

* use SetBytes for texture clear

* implement missing compute builtins

* change storage and texture buffer alignment

* correct compute builtins

* don't use nullable for textures and samplers

* remove incorrect texture get data implementation

* Cleanup IntPtrs

---------

Co-authored-by: Isaac Marovitz <isaacryu@icloud.com>

src/Ryujinx.Graphics.Metal/Constants.cs

@@ -14,5 +14,7 @@ namespace Ryujinx.Graphics.Metal
         public const int MaxVertexAttributes = 16;
         // TODO: Check this value
         public const int MaxVertexLayouts = 16;
+        public const int MaxTextures = 31;
+        public const int MaxSamplers = 31;
     }
 }