Mesh shader support (#2464)

* Add gdb generated files to .gitignore

* Switch to c++17

TODO: Ellie update coding style doc

* WIP mesh shaders

* Add MeshOutputType and mesh output decorations

* Lift array type layout creation out of _createTypeLayout

in preparation for sharing it elsewhere

* Initial pass at GLSL legalization for mesh shaders

* Create output types for builtin mesh outputs

This should be rendered as an out paramter block

* Handle writes to member fields in mesh shader output

* Per primitive output from mesh shaders

* Add mesh shader tests

* Redeclare mesh output builtins

* Remove unused instruction

* Emit explicit mesh output max max size

* Add unimplemented warning for array members in mesh output

* Implement mesh output splitting for GLSL in terms of getSubscriptVal

* Allow HLSL syntax for mesh output modifiers

* Improve error messages for mesh output

* Add test for HLSL style mesh output syntax

* Emit explicit mesh output indices max size

* HLSL generation support for mesh shaders

* Better errors for mesh shader misuse

* Neaten comments

* Regenerate vs2019 project files

* Fix build on vs2019

* Retreat on c++17

Will make the change in a separate PR

* slang-glslang binary dep 11.10.0 -> 11.12.0-32

* Fixes for msvc compiler

* Update msvc project

1 files changed, 46 insertions, 1 deletions

diff --git a/source/slang/slang-ir.cpp b/source/slang/slang-ir.cpp
index 7aa51f31b..1a8f20f1a 100644
--- a/source/slang/slang-ir.cpp
+++ b/source/slang/slang-ir.cpp
@@ -2029,6 +2029,19 @@ namespace Slang
         }
     }
 
+    void IRBuilder::setInsertAfter(IRInst* insertAfter)
+    {
+        auto next = insertAfter->getNextInst();
+        if(next)
+        {
+            setInsertBefore(next);
+        }
+        else
+        {
+            setInsertInto(insertAfter->parent);
+        }
+    }
+
     IRConstant* IRBuilder::_findOrEmitConstant(
         IRConstant&     keyInst)
     {
@@ -2853,6 +2866,15 @@ namespace Slang
             operands);
     }
 
+    IRGLSLOutputParameterGroupType* IRBuilder::getGLSLOutputParameterGroupType(IRType* elementType)
+    {
+        IRInst* operands[] = { elementType };
+        return (IRGLSLOutputParameterGroupType*) getType(
+          kIROp_GLSLOutputParameterGroupType,
+          1,
+          operands);
+    }
+
     IRConstExprRate* IRBuilder::getConstExprRate()
     {
         return (IRConstExprRate*)getType(kIROp_ConstExprRate);
@@ -5836,7 +5858,29 @@ namespace Slang
         // _isTypeOperandEqual handles comparison of types so can defer to it
         return _isTypeOperandEqual(a, b);
     }
-     
+
+    bool isIntegralType(IRType *t)
+    {
+        if(auto basic = as<IRBasicType>(t))
+        {
+            switch(basic->getBaseType())
+            {
+            case BaseType::Int8:
+            case BaseType::Int16:
+            case BaseType::Int:
+            case BaseType::Int64:
+            case BaseType::UInt8:
+            case BaseType::UInt16:
+            case BaseType::UInt:
+            case BaseType::UInt64:
+                return true;
+            default:
+                return false;
+            }
+        }
+        return false;
+    }
+
     void findAllInstsBreadthFirst(IRInst* inst, List<IRInst*>& outInsts)
     {
         Index index = outInsts.getCount();
@@ -6275,6 +6319,7 @@ namespace Slang
         case kIROp_FieldAddress:
         case kIROp_getElement:
         case kIROp_getElementPtr:
+        case kIROp_MeshOutputRef:
         case kIROp_constructVectorFromScalar:
         case kIROp_swizzle:
         case kIROp_swizzleSet:  // Doesn't actually "set" anything - just returns the resulting vector