From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 22 Aug 2016 12:33:42 +0000 (+0300)
Subject: Support custom functions in ProgramBuilder
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=commitdiff_plain;h=91b86d70b598193201a28c5cd6e6c4b180fda45a

Support custom functions in ProgramBuilder
---

diff --git a/source/programbuilder.cpp b/source/programbuilder.cpp
index 5379abf2..195d410f 100644
--- a/source/programbuilder.cpp
+++ b/source/programbuilder.cpp
@@ -162,7 +162,7 @@ const ProgramBuilder::VariableDefinition ProgramBuilder::standard_variables[] =
 	{ NO_SCOPE, 0, 0, 0, 0 }
 };
 
-const char ProgramBuilder::interfaces[] = { 0, 0, 0, 0, 'v', 0 };
+const char ProgramBuilder::interfaces[] = { 0, 0, 0, 0, 0, 'v', 0 };
 
 ProgramBuilder::ProgramBuilder(const StandardFeatures &f):
 	features(f),
@@ -211,6 +211,8 @@ ProgramBuilder::ProgramBuilder(const StandardFeatures &f):
 						var.scope = VERTEX;
 					else if(!strcmp(word, "fragment"))
 						var.scope = FRAGMENT;
+					else if(!strcmp(word, "function"))
+						var.scope = FUNCTION;
 					else
 						throw invalid_variable_definition(word);
 				}
@@ -220,18 +222,29 @@ ProgramBuilder::ProgramBuilder(const StandardFeatures &f):
 					var.name = word;
 
 				start = features.custom.find_first_not_of(whitespace, word_end+1);
-				if(start>=decl_end)
+				if(start>=decl_end || (var.scope==FUNCTION && features.custom[start]=='('))
 					break;
 			}
 
 			if(equals!=string::npos)
 			{
+				if(var.scope==FUNCTION)
+					throw invalid_variable_definition("function with expression");
 				start = features.custom.find_first_not_of(whitespace, equals+1);
 				if(start>=semicolon)
 					throw invalid_variable_definition("no expression");
 				features.custom[semicolon] = 0;
 				var.expression = &features.custom[start];
 			}
+			else if(var.scope==FUNCTION)
+			{
+				string::size_type left_paren = features.custom.find('(', start);
+				string::size_type right_paren = features.custom.find(')', start);
+				if(left_paren>semicolon || right_paren>semicolon)
+					throw invalid_variable_definition("no argument list");
+				features.custom[right_paren] = 0;
+				var.expression = &features.custom[left_paren+1];
+			}
 			else
 				var.expression = 0;
 
@@ -415,7 +428,13 @@ string ProgramBuilder::create_source(const list<ShaderVariable *> &variables, Va
 	set<const VariableDefinition *> declared_types;
 	set<string> uniform_blocks;
 	for(list<ShaderVariable *>::const_iterator i=variables.begin(); i!=variables.end(); ++i)
-		if((*i)->variable->scope==UNIFORM && (*i)->is_referenced_from(scope) && !(*i)->inlined)
+	{
+		if(!(*i)->is_referenced_from(scope))
+			continue;
+
+		if((*i)->variable->scope==FUNCTION)
+			source += format("%s;\n", (*i)->create_declaration());
+		else if((*i)->variable->scope==UNIFORM && !(*i)->inlined)
 		{
 			if((*i)->type && !declared_types.count((*i)->type))
 			{
@@ -428,6 +447,7 @@ string ProgramBuilder::create_source(const list<ShaderVariable *> &variables, Va
 			else
 				source += format("uniform %s;\n", (*i)->create_declaration());
 		}
+	}
 
 	for(set<string>::const_iterator i=uniform_blocks.begin(); i!=uniform_blocks.end(); ++i)
 	{
@@ -921,7 +941,7 @@ void ProgramBuilder::ShaderVariable::update_reference(ShaderVariable &from, Shad
 
 void ProgramBuilder::ShaderVariable::check_inline(bool allow_legacy, bool trivial_only)
 {
-	if(variable->expression)
+	if(variable->expression && variable->scope>=UNIFORM)
 	{
 		if(array_sum && array_size>1)
 			return;
@@ -995,7 +1015,7 @@ ProgramBuilder::InterfaceFlags ProgramBuilder::ShaderVariable::get_interface_fla
 {
 	/* Uniforms are available to all stages and are not passed through
 	interfaces */
-	if(variable->scope==UNIFORM)
+	if(variable->scope<=UNIFORM)
 		return NO_INTERFACE;
 
 	int flags = NO_INTERFACE;
@@ -1035,6 +1055,9 @@ string ProgramBuilder::ShaderVariable::create_type_declaration() const
 
 string ProgramBuilder::ShaderVariable::create_declaration(char iface, bool loop) const
 {
+	if(variable->scope==FUNCTION)
+		return format("%s %s(%s)", variable->type, resolved_name, variable->expression);
+
 	if(variable->scope==UNIFORM && !array_subscript.empty())
 	{
 		const char *bracket = strrchr(variable->type, '[');
diff --git a/source/programbuilder.h b/source/programbuilder.h
index 97a706e0..e61e9942 100644
--- a/source/programbuilder.h
+++ b/source/programbuilder.h
@@ -121,6 +121,7 @@ private:
 	{
 		NO_SCOPE,
 		TYPE,
+		FUNCTION,
 		UNIFORM,
 		ATTRIBUTE,
 		VERTEX,