X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Fprogramcompiler.cpp;h=3cb8611c0192be3d08d67798aa9c1c0d6407f09a;hb=acec85413f86c58ff262fbc26c2c1aa8726b5c58;hp=2dae07c8f4d3ecc049c153e66de8793d347e3134;hpb=fd103d76d7546f7e22aefc18c090a844fc67409f;p=libs%2Fgl.git

diff --git a/source/programcompiler.cpp b/source/programcompiler.cpp
index 2dae07c8..3cb8611c 100644
--- a/source/programcompiler.cpp
+++ b/source/programcompiler.cpp
@@ -4,27 +4,51 @@
 #include "error.h"
 #include "program.h"
 #include "programcompiler.h"
+#include "resources.h"
 #include "shader.h"
 
 using namespace std;
 
+namespace {
+
+const char builtins_src[] =
+	"////// vertex\n"
+	"out gl_PerVertex {\n"
+	"  vec4 gl_Position;\n"
+	"  float gl_ClipDistance[];\n"
+	"};"
+	"////// geometry\n"
+	"in gl_PerVertex {\n"
+	"  vec4 gl_Position;\n"
+	"  float gl_ClipDistance[];\n"
+	"} gl_in[];\n"
+	"out gl_PerVertex {\n"
+	"  vec4 gl_Position;\n"
+	"  float gl_ClipDistance[];\n"
+	"};\n";
+
+}
+
 namespace Msp {
 namespace GL {
 
 using namespace ProgramSyntax;
 
 ProgramCompiler::ProgramCompiler():
+	resources(0),
 	module(0)
 { }
 
 void ProgramCompiler::compile(const string &source)
 {
+	resources = 0;
 	module = &parser.parse(source);
 	process();
 }
 
-void ProgramCompiler::compile(IO::Base &io)
+void ProgramCompiler::compile(IO::Base &io, Resources *res)
 {
+	resources = res;
 	module = &parser.parse(io);
 	process();
 }
@@ -35,12 +59,15 @@ void ProgramCompiler::add_shaders(Program &program)
 		throw invalid_operation("ProgramCompiler::add_shaders");
 
 	string head = "#version 150\n";
-	if(module->vertex_stage.present)
-		program.attach_shader_owned(new VertexShader(head+format_stage(module->vertex_stage)));
-	if(module->geometry_stage.present)
-		program.attach_shader_owned(new GeometryShader(head+format_stage(module->geometry_stage)));
-	if(module->fragment_stage.present)
-		program.attach_shader_owned(new FragmentShader(head+format_stage(module->fragment_stage)));
+	for(list<Stage>::iterator i=module->stages.begin(); i!=module->stages.end(); ++i)
+	{
+		if(i->type==VERTEX)
+			program.attach_shader_owned(new VertexShader(head+apply<Formatter>(*i)));
+		else if(i->type==GEOMETRY)
+			program.attach_shader_owned(new GeometryShader(head+apply<Formatter>(*i)));
+		else if(i->type==FRAGMENT)
+			program.attach_shader_owned(new FragmentShader(head+apply<Formatter>(*i)));
+	}
 
 	program.bind_attribute(VERTEX4, "vertex");
 	program.bind_attribute(NORMAL3, "normal");
@@ -48,52 +75,108 @@ void ProgramCompiler::add_shaders(Program &program)
 	program.bind_attribute(TEXCOORD4, "texcoord");
 }
 
-void ProgramCompiler::process()
+Module *ProgramCompiler::create_builtins_module()
 {
-	if(module->vertex_stage.present)
-		generate(module->vertex_stage);
-	if(module->geometry_stage.present)
-		generate(module->geometry_stage);
-	if(module->fragment_stage.present)
-		generate(module->fragment_stage);
+	ProgramParser parser;
+	Module *module = new Module(parser.parse(builtins_src));
+	for(list<Stage>::iterator i=module->stages.begin(); i!=module->stages.end(); ++i)
+	{
+		VariableResolver resolver;
+		i->content.visit(resolver);
+		for(map<string, VariableDeclaration *>::iterator j=i->content.variables.begin(); j!=i->content.variables.end(); ++j)
+			j->second->linked_declaration = j->second;
+	}
+	return module;
+}
 
-	if(module->vertex_stage.present)
-		optimize(module->vertex_stage);
-	if(module->geometry_stage.present)
-		optimize(module->geometry_stage);
-	if(module->fragment_stage.present)
-		optimize(module->fragment_stage);
+Module &ProgramCompiler::get_builtins_module()
+{
+	static RefPtr<Module> builtins_module = create_builtins_module();
+	return *builtins_module;
 }
 
-void ProgramCompiler::generate(Stage &stage)
+Stage *ProgramCompiler::get_builtins(StageType type)
 {
-	inject_block(stage.content, module->shared.content);
+	Module &module = get_builtins_module();
+	for(list<Stage>::iterator i=module.stages.begin(); i!=module.stages.end(); ++i)
+		if(i->type==type)
+			return &*i;
+	return 0;
+}
 
-	resolve_variables(stage);
+void ProgramCompiler::process()
+{
+	list<Import *> imports = apply<NodeGatherer<Import> >(module->shared);
+	for(list<Import *>::iterator i=imports.end(); i!=imports.begin(); )
+		import((*--i)->module);
+	apply<NodeRemover>(module->shared, set<Node *>(imports.begin(), imports.end()));
+
+	for(list<Stage>::iterator i=module->stages.begin(); i!=module->stages.end(); ++i)
+		generate(*i);
+	for(list<Stage>::iterator i=module->stages.begin(); i!=module->stages.end(); )
+	{
+		if(optimize(*i))
+			i = module->stages.begin();
+		else
+			++i;
+	}
+}
 
-	InterfaceGenerator generator;
-	generator.visit(stage);
+void ProgramCompiler::import(const string &name)
+{
+	if(!resources)
+		throw runtime_error("no resources");
+	RefPtr<IO::Seekable> io = resources->open_raw(name+".glsl");
+	if(!io)
+		throw runtime_error(format("module %s not found", name));
+	ProgramParser import_parser;
+	Module &imported_module = import_parser.parse(*io);
+
+	inject_block(module->shared.content, imported_module.shared.content);
+	apply<DeclarationCombiner>(module->shared);
+	for(list<Stage>::iterator i=imported_module.stages.begin(); i!=imported_module.stages.end(); ++i)
+	{
+		list<Stage>::iterator j;
+		for(j=module->stages.begin(); (j!=module->stages.end() && j->type<i->type); ++j) ;
+		if(j==module->stages.end() || j->type>i->type)
+		{
+			j = module->stages.insert(j, *i);
+			list<Stage>::iterator k = j;
+			if(++k!=module->stages.end())
+				k->previous = &*j;
+			if(j!=module->stages.begin())
+				j->previous = &*--(k=j);
+		}
+		else
+		{
+			inject_block(j->content, i->content);
+			apply<DeclarationCombiner>(*j);
+		}
+	}
+}
 
-	resolve_variables(stage);
+void ProgramCompiler::generate(Stage &stage)
+{
+	inject_block(stage.content, module->shared.content);
 
-	VariableRenamer renamer;
-	stage.content.visit(renamer);
+	apply<FunctionResolver>(stage);
+	apply<VariableResolver>(stage);
+	apply<InterfaceGenerator>(stage);
+	apply<VariableResolver>(stage);
+	apply<VariableRenamer>(stage);
 }
 
-void ProgramCompiler::optimize(Stage &stage)
+bool ProgramCompiler::optimize(Stage &stage)
 {
-	while(1)
-	{
-		UnusedVariableLocator unused_locator;
-		unused_locator.visit(stage);
+	apply<ConstantConditionEliminator>(stage);
+	apply<VariableResolver>(stage);
 
-		NodeRemover remover;
-		remover.to_remove = unused_locator.unused_nodes;
-		remover.visit(stage);
+	set<Node *> unused = apply<UnusedVariableLocator>(stage);
+	set<Node *> unused2 = apply<UnusedFunctionLocator>(stage);
+	unused.insert(unused2.begin(), unused2.end());
+	apply<NodeRemover>(stage, unused);
 
-		if(!remover.n_removed)
-			break;
-	}
+	return !unused.empty();
 }
 
 void ProgramCompiler::inject_block(Block &target, const Block &source)
@@ -103,24 +186,38 @@ void ProgramCompiler::inject_block(Block &target, const Block &source)
 		target.body.insert(insert_point, (*i)->clone());
 }
 
-void ProgramCompiler::resolve_variables(Stage &stage)
+template<typename T>
+typename T::ResultType ProgramCompiler::apply(Stage &stage)
 {
-	VariableResolver resolver;
-	stage.content.visit(resolver);
+	T visitor;
+	visitor.apply(stage);
+	return visitor.get_result();
 }
 
-string ProgramCompiler::format_stage(Stage &stage)
+template<typename T, typename A>
+typename T::ResultType ProgramCompiler::apply(Stage &stage, const A &arg)
 {
-	Formatter formatter;
-	stage.content.visit(formatter);
-	return formatter.formatted;
+	T visitor(arg);
+	visitor.apply(stage);
+	return visitor.get_result();
+}
+
+
+ProgramCompiler::Visitor::Visitor():
+	stage(0)
+{ }
+
+void ProgramCompiler::Visitor::apply(Stage &s)
+{
+	SetForScope<Stage *> set(stage, &s);
+	stage->content.visit(*this);
 }
 
 
 ProgramCompiler::Formatter::Formatter():
 	indent(0),
 	parameter_list(false),
-	else_if(false)
+	else_if(0)
 { }
 
 void ProgramCompiler::Formatter::visit(Literal &literal)
@@ -158,14 +255,18 @@ void ProgramCompiler::Formatter::visit(UnaryExpression &unary)
 void ProgramCompiler::Formatter::visit(BinaryExpression &binary)
 {
 	binary.left->visit(*this);
-	if(binary.assignment)
-		formatted += format(" %s ", binary.oper);
-	else
-		formatted += binary.oper;
+	formatted += binary.oper;
 	binary.right->visit(*this);
 	formatted += binary.after;
 }
 
+void ProgramCompiler::Formatter::visit(Assignment &assign)
+{
+	assign.left->visit(*this);
+	formatted += format(" %s ", assign.oper);
+	assign.right->visit(*this);
+}
+
 void ProgramCompiler::Formatter::visit(FunctionCall &call)
 {
 	formatted += format("%s(", call.name);
@@ -186,31 +287,32 @@ void ProgramCompiler::Formatter::visit(ExpressionStatement &expr)
 
 void ProgramCompiler::Formatter::visit(Block &block)
 {
-	if(block.use_braces)
-	{
-		if(else_if)
-		{
-			formatted += '\n';
-			else_if = false;
-		}
-		formatted += format("%s{\n", string(indent*2, ' '));
-	}
+	if(else_if)
+		--else_if;
+
+	unsigned brace_indent = indent;
+	bool use_braces = (block.use_braces || (indent && block.body.size()!=1));
+	if(use_braces)
+		formatted += format("%s{\n", string(brace_indent*2, ' '));
 
-	bool change_indent = (!formatted.empty() && !else_if);
-	indent += change_indent;
+	SetForScope<unsigned> set(indent, indent+!formatted.empty());
 	string spaces(indent*2, ' ');
 	for(list<NodePtr<Node> >::iterator i=block.body.begin(); i!=block.body.end(); ++i)
 	{
 		if(i!=block.body.begin())
 			formatted += '\n';
-		if(!else_if)
-			formatted += spaces;
+		formatted += spaces;
 		(*i)->visit(*this);
+		else_if = 0;
 	}
-	indent -= change_indent;
 
-	if(block.use_braces)
-		formatted += format("\n%s}", string(indent*2, ' '));
+	if(use_braces)
+		formatted += format("\n%s}", string(brace_indent*2, ' '));
+}
+
+void ProgramCompiler::Formatter::visit(Import &import)
+{
+	formatted += format("import %s;", import.module);
 }
 
 void ProgramCompiler::Formatter::visit(Layout &layout)
@@ -240,7 +342,7 @@ void ProgramCompiler::Formatter::visit(VariableDeclaration &var)
 		formatted += "const ";
 	if(!var.sampling.empty())
 		formatted += format("%s ", var.sampling);
-	if(!var.interface.empty())
+	if(!var.interface.empty() && var.interface!=block_interface)
 		formatted += format("%s ", var.interface);
 	formatted += format("%s %s", var.type, var.name);
 	if(var.array)
@@ -261,6 +363,7 @@ void ProgramCompiler::Formatter::visit(VariableDeclaration &var)
 
 void ProgramCompiler::Formatter::visit(InterfaceBlock &iface)
 {
+	SetForScope<string> set(block_interface, iface.interface);
 	formatted += format("%s %s\n", iface.interface, iface.name);
 	iface.members.visit(*this);
 	formatted += ';';
@@ -277,7 +380,7 @@ void ProgramCompiler::Formatter::visit(FunctionDeclaration &func)
 		(*i)->visit(*this);
 	}
 	formatted += ')';
-	if(func.definition)
+	if(func.definition==&func)
 	{
 		formatted += '\n';
 		func.body.visit(*this);
@@ -289,10 +392,9 @@ void ProgramCompiler::Formatter::visit(FunctionDeclaration &func)
 void ProgramCompiler::Formatter::visit(Conditional &cond)
 {
 	if(else_if)
-	{
-		formatted += ' ';
-		else_if = false;
-	}
+		formatted.replace(formatted.rfind('\n'), string::npos, 1, ' ');
+
+	indent -= else_if;
 
 	formatted += "if(";
 	cond.condition->visit(*this);
@@ -301,8 +403,8 @@ void ProgramCompiler::Formatter::visit(Conditional &cond)
 	cond.body.visit(*this);
 	if(!cond.else_body.body.empty())
 	{
-		formatted += format("\n%selse", string(indent*2, ' '));
-		SetFlag set(else_if);
+		formatted += format("\n%selse\n", string(indent*2, ' '));
+		SetForScope<unsigned> set(else_if, 2);
 		cond.else_body.visit(*this);
 	}
 }
@@ -327,10 +429,74 @@ void ProgramCompiler::Formatter::visit(Return &ret)
 }
 
 
+ProgramCompiler::DeclarationCombiner::DeclarationCombiner():
+	toplevel(true),
+	remove_node(false)
+{ }
+
+void ProgramCompiler::DeclarationCombiner::visit(Block &block)
+{
+	if(!toplevel)
+		return;
+
+	SetForScope<bool> set(toplevel, false);
+	for(list<NodePtr<Node> >::iterator i=block.body.begin(); i!=block.body.end(); )
+	{
+		remove_node = false;
+		(*i)->visit(*this);
+		if(remove_node)
+			block.body.erase(i++);
+		else
+			++i;
+	}
+}
+
+void ProgramCompiler::DeclarationCombiner::visit(FunctionDeclaration &func)
+{
+	vector<FunctionDeclaration *> &decls = functions[func.name];
+	if(func.definition)
+	{
+		for(vector<FunctionDeclaration *>::iterator i=decls.begin(); i!=decls.end(); ++i)
+		{
+			(*i)->definition = func.definition;
+			(*i)->body.body.clear();
+		}
+	}
+	decls.push_back(&func);
+}
+
+void ProgramCompiler::DeclarationCombiner::visit(VariableDeclaration &var)
+{
+	VariableDeclaration *&ptr = variables[var.name];
+	if(ptr)
+	{
+		if(var.init_expression)
+			ptr->init_expression = var.init_expression;
+		remove_node = true;
+	}
+	else
+		ptr = &var;
+}
+
+
 ProgramCompiler::VariableResolver::VariableResolver():
-	anonymous(false)
+	anonymous(false),
+	record_target(false),
+	assignment_target(0),
+	self_referencing(false)
 { }
 
+void ProgramCompiler::VariableResolver::apply(Stage &s)
+{
+	SetForScope<Stage *> set(stage, &s);
+	Stage *builtins = get_builtins(stage->type);
+	if(builtins)
+		blocks.push_back(&builtins->content);
+	stage->content.visit(*this);
+	if(builtins)
+		blocks.pop_back();
+}
+
 void ProgramCompiler::VariableResolver::visit(Block &block)
 {
 	blocks.push_back(&block);
@@ -354,6 +520,19 @@ void ProgramCompiler::VariableResolver::visit(VariableReference &var)
 			break;
 		}
 	}
+
+	if(record_target)
+	{
+		if(assignment_target)
+		{
+			record_target = false;
+			assignment_target = 0;
+		}
+		else
+			assignment_target = var.declaration;
+	}
+	else if(var.declaration && var.declaration==assignment_target)
+		self_referencing = true;
 }
 
 void ProgramCompiler::VariableResolver::visit(MemberAccess &memacc)
@@ -378,7 +557,10 @@ void ProgramCompiler::VariableResolver::visit(BinaryExpression &binary)
 {
 	if(binary.oper=="[")
 	{
-		binary.right->visit(*this);
+		{
+			SetForScope<bool> set(record_target, false);
+			binary.right->visit(*this);
+		}
 		type = 0;
 		binary.left->visit(*this);
 	}
@@ -389,6 +571,21 @@ void ProgramCompiler::VariableResolver::visit(BinaryExpression &binary)
 	}
 }
 
+void ProgramCompiler::VariableResolver::visit(Assignment &assign)
+{
+	{
+		SetFlag set(record_target);
+		assignment_target = 0;
+		assign.left->visit(*this);
+	}
+
+	self_referencing = false;
+	assign.right->visit(*this);
+
+	assign.self_referencing = (self_referencing || assign.oper!="=");
+	assign.target_declaration = assignment_target;
+}
+
 void ProgramCompiler::VariableResolver::visit(StructDeclaration &strct)
 {
 	TraversingVisitor::visit(strct);
@@ -405,6 +602,9 @@ void ProgramCompiler::VariableResolver::visit(VariableDeclaration &var)
 			var.type_declaration = j->second;
 	}
 
+	if(!block_interface.empty() && var.interface.empty())
+		var.interface = block_interface;
+
 	TraversingVisitor::visit(var);
 	blocks.back()->variables[var.name] = &var;
 	if(anonymous && blocks.size()>1)
@@ -414,16 +614,77 @@ void ProgramCompiler::VariableResolver::visit(VariableDeclaration &var)
 void ProgramCompiler::VariableResolver::visit(InterfaceBlock &iface)
 {
 	SetFlag set(anonymous);
+	SetForScope<string> set2(block_interface, iface.interface);
 	TraversingVisitor::visit(iface);
 }
 
 
-ProgramCompiler::InterfaceGenerator::InterfaceGenerator():
-	stage(0),
-	scope_level(0),
+void ProgramCompiler::FunctionResolver::visit(FunctionCall &call)
+{
+	map<string, vector<FunctionDeclaration *> >::iterator i = functions.find(call.name);
+	if(i!=functions.end())
+		call.declaration = i->second.back();
+
+	TraversingVisitor::visit(call);
+}
+
+void ProgramCompiler::FunctionResolver::visit(FunctionDeclaration &func)
+{
+	vector<FunctionDeclaration *> &decls = functions[func.name];
+	if(func.definition)
+	{
+		for(vector<FunctionDeclaration *>::iterator i=decls.begin(); i!=decls.end(); ++i)
+			(*i)->definition = func.definition;
+		decls.clear();
+		decls.push_back(&func);
+	}
+	else if(!decls.empty() && decls.back()->definition)
+		func.definition = decls.back()->definition;
+	else
+		decls.push_back(&func);
+
+	TraversingVisitor::visit(func);
+}
+
+
+ProgramCompiler::BlockModifier::BlockModifier():
 	remove_node(false)
 { }
 
+void ProgramCompiler::BlockModifier::flatten_block(Block &block)
+{
+	for(list<NodePtr<Node> >::iterator i=block.body.begin(); i!=block.body.end(); ++i)
+		insert_nodes.push_back((*i)->clone());
+	remove_node = true;
+}
+
+void ProgramCompiler::BlockModifier::apply_and_increment(Block &block, list<NodePtr<Node> >::iterator &i)
+{
+	for(list<Node *>::iterator j=insert_nodes.begin(); j!=insert_nodes.end(); ++j)
+		block.body.insert(i, *j);
+	insert_nodes.clear();
+
+	if(remove_node)
+		block.body.erase(i++);
+	else
+		++i;
+	remove_node = false;
+}
+
+void ProgramCompiler::BlockModifier::visit(Block &block)
+{
+	for(list<NodePtr<Node> >::iterator i=block.body.begin(); i!=block.body.end(); )
+	{
+		(*i)->visit(*this);
+		apply_and_increment(block, i);
+	}
+}
+
+
+ProgramCompiler::InterfaceGenerator::InterfaceGenerator():
+	scope_level(0)
+{ }
+
 string ProgramCompiler::InterfaceGenerator::get_out_prefix(StageType type)
 {
 	if(type==VERTEX)
@@ -434,7 +695,7 @@ string ProgramCompiler::InterfaceGenerator::get_out_prefix(StageType type)
 		return string();
 }
 
-void ProgramCompiler::InterfaceGenerator::visit(Stage &s)
+void ProgramCompiler::InterfaceGenerator::apply(Stage &s)
 {
 	SetForScope<Stage *> set(stage, &s);
 	if(stage->previous)
@@ -452,7 +713,7 @@ void ProgramCompiler::InterfaceGenerator::visit(Block &block)
 
 		if(scope_level==1)
 		{
-			for(map<string, NodePtr<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);
@@ -460,15 +721,7 @@ void ProgramCompiler::InterfaceGenerator::visit(Block &block)
 			iface_declarations.clear();
 		}
 
-		for(list<NodePtr<Node> >::iterator j=insert_nodes.begin(); j!=insert_nodes.end(); ++j)
-			block.body.insert(i, *j);
-		insert_nodes.clear();
-
-		if(remove_node)
-			block.body.erase(i++);
-		else
-			++i;
-		remove_node = false;
+		apply_and_increment(block, i);
 	}
 }
 
@@ -478,36 +731,39 @@ 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;
+	if(stage->type==GEOMETRY)
+		iface_var->array = ((var.array && var.interface!="in") || iface=="in");
+	else
+		iface_var->array = var.array;
+	if(iface_var->array)
+		iface_var->array_size = var.array_size;
 	if(iface=="in")
-		iface_var->linked_declaration = &out;
-	iface_declarations[iface_var->name] = iface_var;
+		iface_var->linked_declaration = &var;
+	iface_declarations[name] = iface_var;
 
 	return true;
 }
 
 void ProgramCompiler::InterfaceGenerator::insert_assignment(const string &left, ProgramSyntax::Expression *right)
 {
-	BinaryExpression *assign = new BinaryExpression;
+	Assignment *assign = new Assignment;
 	VariableReference *ref = new VariableReference;
 	ref->name = left;
 	assign->left = ref;
 	assign->oper = "=";
 	assign->right = right;
-	assign->assignment = true;
 
 	ExpressionStatement *stmt = new ExpressionStatement;
 	stmt->expression = assign;
@@ -564,31 +820,66 @@ 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);
 		}
 	}
 
+	if(stage->type==GEOMETRY)
+	{
+		VariableReference *ref = new VariableReference;
+		ref->name = "gl_in";
+
+		BinaryExpression *subscript = new BinaryExpression;
+		subscript->left = ref;
+		subscript->oper = "[";
+		subscript->right = pass.subscript;
+		subscript->after = "]";
+
+		MemberAccess *memacc = new MemberAccess;
+		memacc->left = subscript;
+		memacc->member = "gl_Position";
+
+		insert_assignment("gl_Position", memacc);
+	}
+
+	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;
 }
 
@@ -607,28 +898,177 @@ void ProgramCompiler::VariableRenamer::visit(VariableDeclaration &var)
 }
 
 
+ProgramCompiler::ExpressionEvaluator::ExpressionEvaluator():
+	variable_values(0),
+	result(0.0f),
+	result_valid(false)
+{ }
+
+ProgramCompiler::ExpressionEvaluator::ExpressionEvaluator(const ValueMap &v):
+	variable_values(&v),
+	result(0.0f),
+	result_valid(false)
+{ }
+
+void ProgramCompiler::ExpressionEvaluator::visit(Literal &literal)
+{
+	if(literal.token=="true")
+		result = 1.0f;
+	else if(literal.token=="false")
+		result = 0.0f;
+	else
+		result = lexical_cast<float>(literal.token);
+	result_valid = true;
+}
+
+void ProgramCompiler::ExpressionEvaluator::visit(VariableReference &var)
+{
+	if(!var.declaration)
+		return;
+
+	if(variable_values)
+	{
+		ValueMap::const_iterator i = variable_values->find(var.declaration);
+		if(i!=variable_values->end())
+			i->second->visit(*this);
+	}
+	else if(var.declaration->init_expression)
+		var.declaration->init_expression->visit(*this);
+}
+
+void ProgramCompiler::ExpressionEvaluator::visit(UnaryExpression &unary)
+{
+	result_valid = false;
+	unary.expression->visit(*this);
+	if(!result_valid)
+		return;
+
+	if(unary.oper=="!")
+		result = !result;
+	else
+		result_valid = false;
+}
+
+void ProgramCompiler::ExpressionEvaluator::visit(BinaryExpression &binary)
+{
+	result_valid = false;
+	binary.left->visit(*this);
+	if(!result_valid)
+		return;
+
+	float left_result = result;
+	result_valid = false;
+	binary.right->visit(*this);
+	if(!result_valid)
+		return;
+
+	if(binary.oper=="<")
+		result = (left_result<result);
+	else if(binary.oper=="<=")
+		result = (left_result<=result);
+	else if(binary.oper==">")
+		result = (left_result>result);
+	else if(binary.oper==">=")
+		result = (left_result>=result);
+	else if(binary.oper=="==")
+		result = (left_result==result);
+	else if(binary.oper=="!=")
+		result = (left_result!=result);
+	else if(binary.oper=="&&")
+		result = (left_result && result);
+	else if(binary.oper=="||")
+		result = (left_result || result);
+	else
+		result_valid = false;
+}
+
+
+ProgramCompiler::ConstantConditionEliminator::ConstantConditionEliminator():
+	scope_level(0)
+{ }
+
+void ProgramCompiler::ConstantConditionEliminator::visit(Block &block)
+{
+	SetForScope<unsigned> set(scope_level, scope_level+1);
+	BlockModifier::visit(block);
+
+	for(map<string, VariableDeclaration *>::const_iterator i=block.variables.begin(); i!=block.variables.end(); ++i)
+		variable_values.erase(i->second);
+}
+
+void ProgramCompiler::ConstantConditionEliminator::visit(Assignment &assign)
+{
+	variable_values.erase(assign.target_declaration);
+}
+
+void ProgramCompiler::ConstantConditionEliminator::visit(VariableDeclaration &var)
+{
+	if(var.constant || scope_level>1)
+		variable_values[&var] = &*var.init_expression;
+}
+
+void ProgramCompiler::ConstantConditionEliminator::visit(Conditional &cond)
+{
+	ExpressionEvaluator eval(variable_values);
+	cond.condition->visit(eval);
+	if(eval.result_valid)
+		flatten_block(eval.result ? cond.body : cond.else_body);
+	else
+		TraversingVisitor::visit(cond);
+}
+
+void ProgramCompiler::ConstantConditionEliminator::visit(Iteration &iter)
+{
+	if(iter.condition)
+	{
+		ExpressionEvaluator eval;
+		iter.condition->visit(eval);
+		if(eval.result_valid && !eval.result)
+		{
+			remove_node = true;
+			return;
+		}
+	}
+
+	TraversingVisitor::visit(iter);
+}
+
+
 ProgramCompiler::UnusedVariableLocator::UnusedVariableLocator():
-	stage(0),
-	assignment(false),
-	assignment_target(0)
+	aggregate(0),
+	assignment(0),
+	assignment_target(false)
 { }
 
-void ProgramCompiler::UnusedVariableLocator::visit(Stage &s)
+void ProgramCompiler::UnusedVariableLocator::apply(Stage &s)
 {
-	stage = &s;
-	stage->content.visit(*this);
+	assignments.push_back(BlockAssignmentMap());
+	Visitor::apply(s);
+	assignments.pop_back();
 }
 
 void ProgramCompiler::UnusedVariableLocator::visit(VariableReference &var)
 {
-	if(assignment)
-		assignment_target = var.declaration;
-	else
+	unused_nodes.erase(var.declaration);
+
+	map<VariableDeclaration *, Node *>::iterator i = aggregates.find(var.declaration);
+	if(i!=aggregates.end())
+		unused_nodes.erase(i->second);
+
+	if(assignment_target)
+		return;
+
+	for(vector<BlockAssignmentMap>::iterator j=assignments.end(); j!=assignments.begin(); )
 	{
-		unused_nodes.erase(var.declaration);
-		map<VariableDeclaration *, Node *>::iterator i = assignments.find(var.declaration);
-		if(i!=assignments.end())
-			unused_nodes.erase(i->second);
+		--j;
+		BlockAssignmentMap::iterator k = j->find(var.declaration);
+		if(k!=j->end())
+		{
+			for(vector<Node *>::iterator l=k->second.nodes.begin(); l!=k->second.nodes.end(); ++l)
+				unused_nodes.erase(*l);
+			j->erase(k);
+			break;
+		}
 	}
 }
 
@@ -640,80 +1080,194 @@ void ProgramCompiler::UnusedVariableLocator::visit(MemberAccess &memacc)
 
 void ProgramCompiler::UnusedVariableLocator::visit(BinaryExpression &binary)
 {
-	if(binary.assignment)
+	if(binary.oper=="[")
 	{
-		binary.right->visit(*this);
-		assignment = true;
 		binary.left->visit(*this);
+		SetForScope<bool> set(assignment_target, false);
+		binary.right->visit(*this);
 	}
 	else
 		TraversingVisitor::visit(binary);
 }
 
+void ProgramCompiler::UnusedVariableLocator::visit(Assignment &assign)
+{
+	{
+		SetForScope<bool> set(assignment_target, !assign.self_referencing);
+		assign.left->visit(*this);
+	}
+	assign.right->visit(*this);
+	assignment = &assign;
+}
+
+void ProgramCompiler::UnusedVariableLocator::record_assignment(VariableDeclaration &var, Node &node, bool self_ref)
+{
+	unused_nodes.insert(&node);
+	BlockAssignmentMap &block_assignments = assignments.back();
+	AssignmentList &var_assignments = block_assignments[&var];
+	if(!self_ref)
+		var_assignments.nodes.clear();
+	var_assignments.nodes.push_back(&node);
+	var_assignments.conditional = false;
+	var_assignments.self_referencing = self_ref;
+}
+
 void ProgramCompiler::UnusedVariableLocator::visit(ExpressionStatement &expr)
 {
-	assignment = false;
-	assignment_target = 0;
+	assignment = 0;
 	TraversingVisitor::visit(expr);
-	if(assignment && assignment_target)
+	if(assignment && assignment->target_declaration)
+		record_assignment(*assignment->target_declaration, expr, assignment->self_referencing);
+}
+
+void ProgramCompiler::UnusedVariableLocator::visit(StructDeclaration &strct)
+{
+	SetForScope<Node *> set(aggregate, &strct);
+	unused_nodes.insert(&strct);
+	TraversingVisitor::visit(strct);
+}
+
+void ProgramCompiler::UnusedVariableLocator::visit(VariableDeclaration &var)
+{
+	if(aggregate)
+		aggregates[&var] = aggregate;
+	else
+	{
+		unused_nodes.insert(&var);
+		if(var.init_expression)
+			record_assignment(var, *var.init_expression, false);
+	}
+	unused_nodes.erase(var.type_declaration);
+	TraversingVisitor::visit(var);
+}
+
+void ProgramCompiler::UnusedVariableLocator::visit(InterfaceBlock &iface)
+{
+	SetForScope<Node *> set(aggregate, &iface);
+	unused_nodes.insert(&iface);
+	TraversingVisitor::visit(iface);
+}
+
+void ProgramCompiler::UnusedVariableLocator::visit(FunctionDeclaration &func)
+{
+	assignments.push_back(BlockAssignmentMap());
+
+	for(vector<NodePtr<VariableDeclaration> >::iterator i=func.parameters.begin(); i!=func.parameters.end(); ++i)
+		(*i)->visit(*this);
+	func.body.visit(*this);
+
+	BlockAssignmentMap &block_assignments = assignments.back();
+	for(map<string, VariableDeclaration *>::iterator i=func.body.variables.begin(); i!=func.body.variables.end(); ++i)
+		block_assignments.erase(i->second);
+	for(BlockAssignmentMap::iterator i=block_assignments.begin(); i!=block_assignments.end(); ++i)
+	{
+		if(i->first->interface=="out" && stage->type!=FRAGMENT && !i->first->linked_declaration)
+			continue;
+
+		for(vector<Node *>::iterator j=i->second.nodes.begin(); j!=i->second.nodes.end(); ++j)
+			unused_nodes.erase(*j);
+	}
+
+	assignments.pop_back();
+}
+
+void ProgramCompiler::UnusedVariableLocator::merge_down_assignments()
+{
+	BlockAssignmentMap &parent_assignments = assignments[assignments.size()-2];
+	BlockAssignmentMap &block_assignments = assignments.back();
+	for(BlockAssignmentMap::iterator i=block_assignments.begin(); i!=block_assignments.end(); ++i)
 	{
-		if(assignment_target->interface!="out" || (stage->type!=FRAGMENT && !assignment_target->linked_declaration))
+		BlockAssignmentMap::iterator j = parent_assignments.find(i->first);
+		if(j==parent_assignments.end())
+			parent_assignments.insert(*i);
+		else if(i->second.self_referencing || i->second.conditional)
 		{
-			unused_nodes.insert(&expr);
-			assignments[assignment_target] = &expr;
+			j->second.nodes.insert(j->second.nodes.end(), i->second.nodes.begin(), i->second.nodes.end());
+			j->second.conditional |= i->second.conditional;
+			j->second.self_referencing |= i->second.self_referencing;
 		}
 		else
-			unused_nodes.erase(assignment_target);
+			j->second = i->second;
 	}
-	assignment = false;
+	assignments.pop_back();
 }
 
-void ProgramCompiler::UnusedVariableLocator::visit(VariableDeclaration &var)
+void ProgramCompiler::UnusedVariableLocator::visit(Conditional &cond)
 {
-	unused_nodes.insert(&var);
-	TraversingVisitor::visit(var);
+	cond.condition->visit(*this);
+	assignments.push_back(BlockAssignmentMap());
+	cond.body.visit(*this);
+
+	BlockAssignmentMap if_assignments;
+	swap(assignments.back(), if_assignments);
+	cond.else_body.visit(*this);
+
+	BlockAssignmentMap &else_assignments = assignments.back();
+	for(BlockAssignmentMap::iterator i=else_assignments.begin(); i!=else_assignments.end(); ++i)
+	{
+		BlockAssignmentMap::iterator j = if_assignments.find(i->first);
+		if(j!=if_assignments.end())
+		{
+			i->second.nodes.insert(i->second.nodes.end(), j->second.nodes.begin(), j->second.nodes.end());
+			i->second.conditional |= j->second.conditional;
+			i->second.self_referencing |= j->second.self_referencing;
+			if_assignments.erase(j);
+		}
+		else
+			i->second.conditional = true;
+	}
+
+	for(BlockAssignmentMap::iterator i=if_assignments.begin(); i!=if_assignments.end(); ++i)
+	{
+		i->second.conditional = true;
+		else_assignments.insert(*i);
+	}
+
+	merge_down_assignments();
 }
 
+void ProgramCompiler::UnusedVariableLocator::visit(Iteration &iter)
+{
+	assignments.push_back(BlockAssignmentMap());
+	TraversingVisitor::visit(iter);
+	merge_down_assignments();
+}
 
-ProgramCompiler::NodeRemover::NodeRemover():
-	stage(0),
-	n_removed(0),
-	immutable_block(false),
-	remove_block(false)
-{ }
 
-void ProgramCompiler::NodeRemover::visit(Stage &s)
+void ProgramCompiler::UnusedFunctionLocator::visit(FunctionCall &call)
 {
-	stage = &s;
-	stage->content.visit(*this);
+	TraversingVisitor::visit(call);
+
+	unused_nodes.erase(call.declaration);
+	if(call.declaration && call.declaration->definition!=call.declaration)
+		used_definitions.insert(call.declaration->definition);
+}
+
+void ProgramCompiler::UnusedFunctionLocator::visit(FunctionDeclaration &func)
+{
+	TraversingVisitor::visit(func);
+
+	if(func.name!="main" && !used_definitions.count(&func))
+		unused_nodes.insert(&func);
 }
 
+
+ProgramCompiler::NodeRemover::NodeRemover(const set<Node *> &r):
+	to_remove(r)
+{ }
+
 void ProgramCompiler::NodeRemover::visit(Block &block)
 {
-	remove_block = immutable_block;
 	for(list<NodePtr<Node> >::iterator i=block.body.begin(); i!=block.body.end(); )
 	{
-		bool remove = to_remove.count(&**i);
-		if(!remove)
-			remove_block = false;
 		(*i)->visit(*this);
-
-		if(remove ? !immutable_block : remove_block)
-		{
+		if(to_remove.count(&**i))
 			block.body.erase(i++);
-			++n_removed;
-		}
 		else
 			++i;
 	}
 }
 
-void ProgramCompiler::NodeRemover::visit(StructDeclaration &strct)
-{
-	SetFlag set(immutable_block);
-	TraversingVisitor::visit(strct);
-}
-
 void ProgramCompiler::NodeRemover::visit(VariableDeclaration &var)
 {
 	if(to_remove.count(&var))
@@ -723,12 +1277,8 @@ void ProgramCompiler::NodeRemover::visit(VariableDeclaration &var)
 		if(var.linked_declaration)
 			var.linked_declaration->linked_declaration = 0;
 	}
-}
-
-void ProgramCompiler::NodeRemover::visit(InterfaceBlock &iface)
-{
-	SetFlag set(immutable_block);
-	TraversingVisitor::visit(iface);
+	else if(var.init_expression && to_remove.count(&*var.init_expression))
+		var.init_expression = 0;
 }
 
 } // namespace GL