Reworked GenerateMipsCS.csh Vulkan shader to be convertible to MSL on Mac and iOS. According to this discussion https://github.com/KhronosGroup/SPIRV-Cross/issues/888 this will fix https://github.com/DiligentGraphics/DiligentCore/issues/66

3 files changed, 27 insertions, 14 deletions

diff --git a/Graphics/GraphicsEngineVulkan/shaders/GenerateMipsCS.csh b/Graphics/GraphicsEngineVulkan/shaders/GenerateMipsCS.csh
index 4dd756ea..be18f341 100644
--- a/Graphics/GraphicsEngineVulkan/shaders/GenerateMipsCS.csh
+++ b/Graphics/GraphicsEngineVulkan/shaders/GenerateMipsCS.csh
@@ -10,7 +10,10 @@
 #define IMG_FORMAT rgba8
 #endif
 
-layout(IMG_FORMAT) uniform writeonly image2DArray OutMip[4];
+layout(IMG_FORMAT) uniform writeonly image2DArray OutMip0;
+layout(IMG_FORMAT) uniform writeonly image2DArray OutMip1;
+layout(IMG_FORMAT) uniform writeonly image2DArray OutMip2;
+layout(IMG_FORMAT) uniform writeonly image2DArray OutMip3;
 
 uniform sampler2DArray SrcMip;
 
@@ -134,7 +137,7 @@ void main()
         Src1 *= 0.25;
 #endif
 
-        imageStore(OutMip[0], ivec3(GlobalInd.xy, ArraySlice), PackColor(Src1));
+        imageStore(OutMip0, ivec3(GlobalInd.xy, ArraySlice), PackColor(Src1));
     }
 
     // A scalar (constant) branch can exit all threads coherently.
@@ -164,7 +167,7 @@ void main()
             vec4 Src4 = LoadColor(LocalInd + 0x09u);
             Src1 = 0.25 * (Src1 + Src2 + Src3 + Src4);
 
-            imageStore(OutMip[1], ivec3(GlobalInd.xy / 2u, ArraySlice), PackColor(Src1));
+            imageStore(OutMip1, ivec3(GlobalInd.xy / 2u, ArraySlice), PackColor(Src1));
             StoreColor(LocalInd, Src1);
         }
     }
@@ -184,7 +187,7 @@ void main()
             vec4 Src4 = LoadColor(LocalInd + 0x12u);
             Src1 = 0.25 * (Src1 + Src2 + Src3 + Src4);
 
-            imageStore(OutMip[2], ivec3(GlobalInd.xy / 4u, ArraySlice), PackColor(Src1));
+            imageStore(OutMip2, ivec3(GlobalInd.xy / 4u, ArraySlice), PackColor(Src1));
             StoreColor(LocalInd, Src1);
         }
     }
@@ -205,7 +208,7 @@ void main()
             vec4 Src4 = LoadColor(LocalInd + 0x24u);
             Src1 = 0.25 * (Src1 + Src2 + Src3 + Src4);
 
-            imageStore(OutMip[3], ivec3(GlobalInd.xy / 8u, ArraySlice), PackColor(Src1));
+            imageStore(OutMip3, ivec3(GlobalInd.xy / 8u, ArraySlice), PackColor(Src1));
         }
     }
 }
diff --git a/Graphics/GraphicsEngineVulkan/shaders/GenerateMipsCS_inc.h b/Graphics/GraphicsEngineVulkan/shaders/GenerateMipsCS_inc.h
index 48c24265..fc307e60 100644
--- a/Graphics/GraphicsEngineVulkan/shaders/GenerateMipsCS_inc.h
+++ b/Graphics/GraphicsEngineVulkan/shaders/GenerateMipsCS_inc.h
@@ -10,7 +10,10 @@
 "#define IMG_FORMAT rgba8\n"
 "#endif\n"
 "\n"
-"layout(IMG_FORMAT) uniform writeonly image2DArray OutMip[4];\n"
+"layout(IMG_FORMAT) uniform writeonly image2DArray OutMip0;\n"
+"layout(IMG_FORMAT) uniform writeonly image2DArray OutMip1;\n"
+"layout(IMG_FORMAT) uniform writeonly image2DArray OutMip2;\n"
+"layout(IMG_FORMAT) uniform writeonly image2DArray OutMip3;\n"
 "\n"
 "uniform sampler2DArray SrcMip;\n"
 "\n"
@@ -134,7 +137,7 @@
 "        Src1 *= 0.25;\n"
 "#endif\n"
 "\n"
-"        imageStore(OutMip[0], ivec3(GlobalInd.xy, ArraySlice), PackColor(Src1));\n"
+"        imageStore(OutMip0, ivec3(GlobalInd.xy, ArraySlice), PackColor(Src1));\n"
 "    }\n"
 "\n"
 "    // A scalar (constant) branch can exit all threads coherently.\n"
@@ -164,7 +167,7 @@
 "            vec4 Src4 = LoadColor(LocalInd + 0x09u);\n"
 "            Src1 = 0.25 * (Src1 + Src2 + Src3 + Src4);\n"
 "\n"
-"            imageStore(OutMip[1], ivec3(GlobalInd.xy / 2u, ArraySlice), PackColor(Src1));\n"
+"            imageStore(OutMip1, ivec3(GlobalInd.xy / 2u, ArraySlice), PackColor(Src1));\n"
 "            StoreColor(LocalInd, Src1);\n"
 "        }\n"
 "    }\n"
@@ -184,7 +187,7 @@
 "            vec4 Src4 = LoadColor(LocalInd + 0x12u);\n"
 "            Src1 = 0.25 * (Src1 + Src2 + Src3 + Src4);\n"
 "\n"
-"            imageStore(OutMip[2], ivec3(GlobalInd.xy / 4u, ArraySlice), PackColor(Src1));\n"
+"            imageStore(OutMip2, ivec3(GlobalInd.xy / 4u, ArraySlice), PackColor(Src1));\n"
 "            StoreColor(LocalInd, Src1);\n"
 "        }\n"
 "    }\n"
@@ -205,7 +208,7 @@
 "            vec4 Src4 = LoadColor(LocalInd + 0x24u);\n"
 "            Src1 = 0.25 * (Src1 + Src2 + Src3 + Src4);\n"
 "\n"
-"            imageStore(OutMip[3], ivec3(GlobalInd.xy / 8u, ArraySlice), PackColor(Src1));\n"
+"            imageStore(OutMip3, ivec3(GlobalInd.xy / 8u, ArraySlice), PackColor(Src1));\n"
 "        }\n"
 "    }\n"
 "}\n"
diff --git a/Graphics/GraphicsEngineVulkan/src/GenerateMipsVkHelper.cpp b/Graphics/GraphicsEngineVulkan/src/GenerateMipsVkHelper.cpp
index 4ae8243e..4282b578 100644
--- a/Graphics/GraphicsEngineVulkan/src/GenerateMipsVkHelper.cpp
+++ b/Graphics/GraphicsEngineVulkan/src/GenerateMipsVkHelper.cpp
@@ -209,7 +209,13 @@ namespace Diligent
 
         const auto& ViewDesc = TexView.GetDesc();
         auto* pSrcMipVar = SRB.GetVariable(SHADER_TYPE_COMPUTE, "SrcMip");
-        auto* pOutMipVar = SRB.GetVariable(SHADER_TYPE_COMPUTE, "OutMip");
+        IShaderResourceVariable* pOutMipVar[4] =
+        {
+            SRB.GetVariable(SHADER_TYPE_COMPUTE, "OutMip0"),
+            SRB.GetVariable(SHADER_TYPE_COMPUTE, "OutMip1"),
+            SRB.GetVariable(SHADER_TYPE_COMPUTE, "OutMip2"),
+            SRB.GetVariable(SHADER_TYPE_COMPUTE, "OutMip3")
+        };
 
         auto& PSOs = FindPSOs(ViewDesc.Format);
 
@@ -295,10 +301,11 @@ namespace Diligent
             }
 
             constexpr const Uint32 MaxMipsHandledByCS = 4; // Max number of mip levels processed by one CS shader invocation
-            std::array<IDeviceObject*, MaxMipsHandledByCS> MipLevelUAVs;
             for (Uint32 u = 0; u < MaxMipsHandledByCS; ++u)
-                MipLevelUAVs[u] = pTexVk->GetMipLevelUAV(std::min(TopMip + u + 1, TexDesc.MipLevels - 1));
-            pOutMipVar->SetArray(MipLevelUAVs.data(), 0, MaxMipsHandledByCS);
+            {
+                auto* MipLevelUAV = pTexVk->GetMipLevelUAV(std::min(TopMip + u + 1, TexDesc.MipLevels - 1));
+                pOutMipVar[u]->Set(MipLevelUAV);
+            }
 
             SubresRange.baseMipLevel = TopMip + 1;
             SubresRange.levelCount = std::min(4u, TexDesc.MipLevels - (TopMip + 1));