Metal: MTLShader and MTLShaderGenerator implementation.

Full support for translation and compilation of shaders in Metal, using
GPUShaderCreateInfo. Includes render pipeline state creation and management,
enabling all standard GPU viewport rendering features in Metal.

Authored by Apple: Michael Parkin-White, Marco Giordano

Ref T96261

Reviewed By: fclem

Maniphest Tasks: T96261

Differential Revision: https://developer.blender.org/D15563

source/blender/gpu/intern/gpu_shader_create_info.hh

@@ -32,6 +32,7 @@ namespace blender::gpu::shader {
 #endif
 
 enum class Type {
+  /* Types supported natively across all GPU backends. */
   FLOAT = 0,
   VEC2,
   VEC3,
@@ -47,6 +48,21 @@ enum class Type {
   IVEC3,
   IVEC4,
   BOOL,
+  /* Additionally supported types to enable data optimisation and native
+   * support in some GPUBackends.
+   * NOTE: These types must be representable in all APIs. E.g. VEC3_101010I2 is aliased as vec3 in
+   * the GL backend, as implicit type conversions from packed normal attribute data to vec3 is
+   * supported. UCHAR/CHAR types are natively supported in Metal and can be used to avoid
+   * additional data conversions for GPU_COMP_U8 vertex attributes. */
+  VEC3_101010I2,
+  UCHAR,
+  UCHAR2,
+  UCHAR3,
+  UCHAR4,
+  CHAR,
+  CHAR2,
+  CHAR3,
+  CHAR4
 };
 
 /* All of these functions is a bit out of place */
@@ -86,6 +102,40 @@ static inline std::ostream &operator<<(std::ostream &stream, const Type type)
       return stream << "mat3";
     case Type::MAT4:
       return stream << "mat4";
+    case Type::VEC3_101010I2:
+      return stream << "vec3_1010102_Inorm";
+    case Type::UCHAR:
+      return stream << "uchar";
+    case Type::UCHAR2:
+      return stream << "uchar2";
+    case Type::UCHAR3:
+      return stream << "uchar3";
+    case Type::UCHAR4:
+      return stream << "uchar4";
+    case Type::CHAR:
+      return stream << "char";
+    case Type::CHAR2:
+      return stream << "char2";
+    case Type::CHAR3:
+      return stream << "char3";
+    case Type::CHAR4:
+      return stream << "char4";
+    case Type::INT:
+      return stream << "int";
+    case Type::IVEC2:
+      return stream << "ivec2";
+    case Type::IVEC3:
+      return stream << "ivec3";
+    case Type::IVEC4:
+      return stream << "ivec4";
+    case Type::UINT:
+      return stream << "uint";
+    case Type::UVEC2:
+      return stream << "uvec2";
+    case Type::UVEC3:
+      return stream << "uvec3";
+    case Type::UVEC4:
+      return stream << "uvec4";
     default:
       BLI_assert(0);
       return stream;
@@ -228,6 +278,8 @@ enum class PrimitiveOut {
   POINTS = 0,
   LINE_STRIP,
   TRIANGLE_STRIP,
+  LINES,
+  TRIANGLES,
 };
 
 struct StageInterfaceInfo {