Function GatherOutputs

shadercompiler/EffectCompilerMetal.cpp:2449–2499

Given a function header, gathers all function outputs into a flat structure

// Given a function header, gathers all function outputs into a flat structure
void GatherOutputs( ASTNode* destStruct, std::vector<ASTNode*>& accessors, const std::vector<Symbol*>& params, ASTNode* header, ParserState& state )
{
	for( size_t i = 0; i < header->GetChildrenCount(); ++i )
	{
		auto arg = header->GetChild( i );

		if( IsUniformInputArgument( arg ) || arg->GetSymbol()->addressSpace != AddressSpace::None )
		{
			continue;
		}

		bool isIn = arg->GetToken() == 0 || arg->GetToken()->type == OP_IN;
		if( isIn )
		{
			continue;
		}

		Symbol* symbol = arg->GetSymbol();
		if( symbol == nullptr )
		{
			continue;
		}

		auto access = NewVarIdentifier( state, params[i] );

		if( symbol->type.IsStruct() )
		{
			GatherFields( destStruct, accessors, access, symbol->type.symbol->definition, state );
		}
		else if( symbol->type.IsScalarOrVector() )
		{
			destStruct->AddChild( NewStructMember( state, symbol ) );
			accessors.push_back( access );
		}
	}
	if( header->GetType().IsStruct() || header->GetType().IsScalarOrVector() )
	{
		Symbol* symbol = header->GetSymbol();
		auto access = NewVarIdentifier( state, params.back() );

		if( symbol->type.IsStruct() )
		{
			GatherFields( destStruct, accessors, access, symbol->type.symbol->definition, state );
		}
		else
		{
			destStruct->AddChild( NewStructMember( state, symbol ) );
			accessors.push_back( access );
		}
	}
}

// Patches VPOS usages for pixel shaders: a common Dx9 legacy pattern of passing both POSITION (from
// vertex shader) and VPOS. Function remaps VPOS inputs to POSION so that there are no duplicate semantics