From b3e71de19f35773c22391151ebb02062d6894bc9 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sat, 12 Nov 2016 02:00:09 +0200
Subject: [PATCH] Process existing inputs in passthrough

Vertex shader inputs are not linked to any outputs so they weren't being
recognized for passthrough.  Also, some inputs might have already been
declared either explicitly or implicitly so those declarations should be
preferred over creating new ones.
---
 source/programcompiler.cpp | 65 ++++++++++++++++++++++++--------------
 source/programcompiler.h   |  2 +-
 2 files changed, 42 insertions(+), 25 deletions(-)

diff --git a/source/programcompiler.cpp b/source/programcompiler.cpp
index d518ef3a..79031e41 100644
--- a/source/programcompiler.cpp
+++ b/source/programcompiler.cpp
@@ -452,7 +452,7 @@ void ProgramCompiler::InterfaceGenerator::visit(Block &block)
 
 		if(scope_level==1)
 		{
-			for(map<string, Node *>::iterator j=iface_declarations.begin(); j!=iface_declarations.end(); ++j)
+			for(map<string, VariableDeclaration *>::iterator j=iface_declarations.begin(); j!=iface_declarations.end(); ++j)
 			{
 				list<NodePtr<Node> >::iterator k = block.body.insert(i, j->second);
 				(*k)->visit(*this);
@@ -478,22 +478,22 @@ string ProgramCompiler::InterfaceGenerator::change_prefix(const string &name, co
 	return prefix+name.substr(offset);
 }
 
-bool ProgramCompiler::InterfaceGenerator::generate_interface(VariableDeclaration &out, const string &iface, const string &name)
+bool ProgramCompiler::InterfaceGenerator::generate_interface(VariableDeclaration &var, const string &iface, const string &name)
 {
 	const map<string, VariableDeclaration *> &stage_vars = (iface=="in" ? stage->in_variables : stage->out_variables);
 	if(stage_vars.count(name) || iface_declarations.count(name))
 		return false;
 
 	VariableDeclaration* iface_var = new VariableDeclaration;
-	iface_var->sampling = out.sampling;
+	iface_var->sampling = var.sampling;
 	iface_var->interface = iface;
-	iface_var->type = out.type;
-	iface_var->type_declaration = out.type_declaration;
+	iface_var->type = var.type;
+	iface_var->type_declaration = var.type_declaration;
 	iface_var->name = name;
-	iface_var->array = (out.array || (stage->type==GEOMETRY && iface=="in"));
-	iface_var->array_size = out.array_size;
+	iface_var->array = (var.array || (stage->type==GEOMETRY && iface=="in"));
+	iface_var->array_size = var.array_size;
 	if(iface=="in")
-		iface_var->linked_declaration = &out;
+		iface_var->linked_declaration = &var;
 	iface_declarations[name] = iface_var;
 
 	return true;
@@ -564,31 +564,48 @@ void ProgramCompiler::InterfaceGenerator::visit(VariableDeclaration &var)
 
 void ProgramCompiler::InterfaceGenerator::visit(Passthrough &pass)
 {
+	vector<VariableDeclaration *> pass_vars;
+
+	for(map<string, VariableDeclaration *>::const_iterator i=stage->in_variables.begin(); i!=stage->in_variables.end(); ++i)
+		pass_vars.push_back(i->second);
+	for(map<string, VariableDeclaration *>::const_iterator i=iface_declarations.begin(); i!=iface_declarations.end(); ++i)
+		if(i->second->interface=="in")
+			pass_vars.push_back(i->second);
+
 	if(stage->previous)
 	{
 		const map<string, VariableDeclaration *> &prev_out = stage->previous->out_variables;
 		for(map<string, VariableDeclaration *>::const_iterator i=prev_out.begin(); i!=prev_out.end(); ++i)
 		{
-			string out_name = change_prefix(i->second->name, out_prefix);
-			generate_interface(*i->second, "in", i->second->name);
-			generate_interface(*i->second, "out", out_name);
+			bool linked = false;
+			for(vector<VariableDeclaration *>::const_iterator j=pass_vars.begin(); (!linked && j!=pass_vars.end()); ++j)
+				linked = ((*j)->linked_declaration==i->second);
 
-			VariableReference *ref = new VariableReference;
-			ref->name = i->first;
-			if(pass.subscript)
-			{
-				BinaryExpression *subscript = new BinaryExpression;
-				subscript->left = ref;
-				subscript->oper = "[";
-				subscript->right = pass.subscript;
-				subscript->after = "]";
-				insert_assignment(out_name, subscript);
-			}
-			else
-				insert_assignment(out_name, ref);
+			if(!linked && generate_interface(*i->second, "in", i->second->name))
+				pass_vars.push_back(i->second);
 		}
 	}
 
+	for(vector<VariableDeclaration *>::const_iterator i=pass_vars.begin(); i!=pass_vars.end(); ++i)
+	{
+		string out_name = change_prefix((*i)->name, out_prefix);
+		generate_interface(**i, "out", out_name);
+
+		VariableReference *ref = new VariableReference;
+		ref->name = (*i)->name;
+		if(pass.subscript)
+		{
+			BinaryExpression *subscript = new BinaryExpression;
+			subscript->left = ref;
+			subscript->oper = "[";
+			subscript->right = pass.subscript;
+			subscript->after = "]";
+			insert_assignment(out_name, subscript);
+		}
+		else
+			insert_assignment(out_name, ref);
+	}
+
 	remove_node = true;
 }
 
diff --git a/source/programcompiler.h b/source/programcompiler.h
index db7aefe9..3b63c5e9 100644
--- a/source/programcompiler.h
+++ b/source/programcompiler.h
@@ -72,7 +72,7 @@ private:
 		std::string in_prefix;
 		std::string out_prefix;
 		unsigned scope_level;
-		std::map<std::string, ProgramSyntax::Node *> iface_declarations;
+		std::map<std::string, ProgramSyntax::VariableDeclaration *> iface_declarations;
 		bool remove_node;
 		std::list<ProgramSyntax::Node *> insert_nodes;
 
-- 
2.43.0