Fix breaking change from bgfx update that broke morph targets (#1152)

Author: bghgary

Plugins/NativeEngine/Source/ShaderCompilerCommon.cpp

@@ -37,7 +37,7 @@ namespace Babylon::ShaderCompilerCommon
             AppendBytes(bytes, static_cast<uint8_t>(uniform.Name.size()));
             AppendBytes(bytes, uniform.Name);
             AppendBytes(bytes, static_cast<uint8_t>(bgfxType | fragmentBit));
-            AppendBytes(bytes, static_cast<uint8_t>(0)); // Value "num" not used by D3D11 pipeline.
+            AppendBytes(bytes, static_cast<uint8_t>(uniform.ElementLength));
             AppendBytes(bytes, static_cast<uint16_t>(uniform.Offset));
             AppendBytes(bytes, static_cast<uint16_t>(uniform.RegisterSize));
         }
@@ -103,9 +103,14 @@ namespace Babylon::ShaderCompilerCommon
                     throw std::runtime_error{"Unrecognized uniform type."};
                 }
 
-                for (const auto size : spirType.array)
+                if (spirType.array.size() == 1)
                 {
-                    uniform.RegisterSize *= static_cast<uint16_t>(size);
+                    uniform.ElementLength = static_cast<uint8_t>(spirType.array[0]);
+                    uniform.RegisterSize *= uniform.ElementLength;
+                }
+                else if (spirType.array.size() > 1)
+                {
+                    throw std::runtime_error{"Unsupported multidimensional array."};
                 }
             }
         }
@@ -137,9 +142,14 @@ namespace Babylon::ShaderCompilerCommon
                         throw std::runtime_error{"Unrecognized uniform type."};
                     }
 
-                    for (const auto size : type.array)
+                    if (type.array.size() == 1)
+                    {
+                        uniform.ElementLength = static_cast<uint8_t>(type.array[0]);
+                        uniform.RegisterSize *= uniform.ElementLength;
+                    }
+                    else if (type.array.size() > 1)
                     {
-                        uniform.RegisterSize *= static_cast<uint16_t>(size);
+                        throw std::runtime_error{"Unsupported multidimensional array."};
                     }
 
                     info.ByteSize += 4 * uniform.RegisterSize;

Plugins/NativeEngine/Source/ShaderCompilerCommon.h

@@ -45,6 +45,7 @@ namespace Babylon::ShaderCompilerCommon
             };
 
             std::string Name{};
+            uint8_t ElementLength{};
             uint32_t Offset{};
             uint16_t RegisterSize{};
             TypeEnum Type{};