From bf852bf402cf1cc6604816ae958c7dcf2655addc Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 25 Feb 2021 21:15:08 +0200
Subject: [PATCH] Only generate or link interfaces in the correct scope

---
 source/glsl/generate.cpp | 12 +++++++++---
 source/glsl/generate.h   |  1 +
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/source/glsl/generate.cpp b/source/glsl/generate.cpp
index 48de1efc..3ff04eb9 100644
--- a/source/glsl/generate.cpp
+++ b/source/glsl/generate.cpp
@@ -258,7 +258,8 @@ void FunctionResolver::visit(FunctionDeclaration &func)
 
 
 InterfaceGenerator::InterfaceGenerator():
-	stage(0)
+	stage(0),
+	function_scope(false)
 { }
 
 string InterfaceGenerator::get_out_prefix(Stage::Type type)
@@ -369,7 +370,9 @@ void InterfaceGenerator::visit(VariableDeclaration &var)
 {
 	if(var.interface=="out")
 	{
-		if(current_block!=&stage->content && generate_interface(var, "out", change_prefix(var.name, string())))
+		/* For out variables in function scope, generate a global interface and
+		replace the local declaration with an assignment. */
+		if(function_scope && generate_interface(var, "out", var.name))
 		{
 			nodes_to_remove.insert(&var);
 			if(var.init_expression)
@@ -383,7 +386,9 @@ void InterfaceGenerator::visit(VariableDeclaration &var)
 	}
 	else if(var.interface=="in")
 	{
-		if(!var.linked_declaration && stage->previous)
+		/* Try to link in variables in global scope with out variables from
+		previous stage */
+		if(current_block==&stage->content && !var.linked_declaration && stage->previous)
 		{
 			const map<string, VariableDeclaration *> &prev_vars = stage->previous->content.variables;
 			map<string, VariableDeclaration *>::const_iterator i = prev_vars.find(var.name);
@@ -400,6 +405,7 @@ void InterfaceGenerator::visit(VariableDeclaration &var)
 
 void InterfaceGenerator::visit(FunctionDeclaration &func)
 {
+	SetFlag set_scope(function_scope, true);
 	// Skip parameters because they're not useful here
 	func.body.visit(*this);
 }
diff --git a/source/glsl/generate.h b/source/glsl/generate.h
index f904021a..72035b2c 100644
--- a/source/glsl/generate.h
+++ b/source/glsl/generate.h
@@ -84,6 +84,7 @@ private:
 	Stage *stage;
 	std::string in_prefix;
 	std::string out_prefix;
+	bool function_scope;
 	NodeList<Statement>::iterator iface_insert_point;
 	NodeList<Statement>::iterator assignment_insert_point;
 	std::set<Node *> nodes_to_remove;
-- 
2.43.0