diff --git a/c-buildcfg.cc b/c-buildcfg.cc
index dd0d4c1..93a2572 100644
--- a/c-buildcfg.cc
+++ b/c-buildcfg.cc
@@ -79,6 +79,22 @@ bool BCLResolutions_( T_SRDParserData const& data )
 
 /*----------------------------------------------------------------------------*/
 
+F_SRDHandler BCLToggle_(
+		ptrdiff_t const fldOffset ) noexcept
+{
+	return [=]( T_SRDParserData const& d ) -> bool {
+		auto const& in{ *d.input };
+		char* bCfg{ (char*) &d.currentData->value< T_BuildConfiguration >( ) };
+		*(bool*)( bCfg + fldOffset ) = ( in[ 1 ].stringValue( ) == "on" );
+		return true;
+	};
+}
+
+#define M_BCL_TOGGLE_( N ) \
+	BCLToggle_( offsetof( T_BuildConfiguration , N ) )
+
+/*----------------------------------------------------------------------------*/
+
 T_SRDParserConfig BCLInitDefinitions_( ) noexcept
 {
 	using namespace ebcl::SRD;
@@ -116,40 +132,20 @@ T_SRDParserConfig BCLInitDefinitions_( ) noexcept
 
 	defs.context( "optim" )
 		<< ( Rule( ) << "constant-folding" << "off"
-			<< []( T_SRDParserData const& d ) -> bool {
-				auto& bCfg{ d.currentData->value< T_BuildConfiguration >( ) };
-				bCfg.constantFolding = false;
-				return true;
-			} )
+			<< M_BCL_TOGGLE_( constantFolding ) )
 		<< ( Rule( ) << "constant-folding" << "on" << EnterContext( "opt-cf" )
-			<< []( T_SRDParserData const& d ) -> bool {
-				auto& bCfg{ d.currentData->value< T_BuildConfiguration >( ) };
-				bCfg.constantFolding = true;
-				return true;
-			} )
+			<< M_BCL_TOGGLE_( constantFolding ) )
+		<< ( Rule( ) << "constant-propagation" << Enum( "on-off" )
+			<< M_BCL_TOGGLE_( constantPropagation ) )
 		<< ( Rule( ) << "dead-code-elimination" << Enum( "on-off" )
-			<< []( T_SRDParserData const& d ) -> bool {
-				auto& bCfg{ d.currentData->value< T_BuildConfiguration >( ) };
-				bCfg.deadCodeElimination = true;
-				return true;
-			} )
+			<< M_BCL_TOGGLE_( deadCodeElimination ) )
 	;
 
 	defs.context( "opt-cf" )
 		<< ( Rule( ) << "fixed-resolution" << Enum( "on-off" )
-			<< []( T_SRDParserData const& d ) -> bool {
-				auto const& in{ *d.input };
-				auto& bCfg{ d.currentData->value< T_BuildConfiguration >( ) };
-				bCfg.cfFixedSize = ( in[ 1 ].stringValue( ) == "on" );
-				return true;
-			} )
+			<< M_BCL_TOGGLE_( cfFixedSize ) )
 		<< ( Rule( ) << "inputs" << Enum( "on-off" )
-			<< []( T_SRDParserData const& d ) -> bool {
-				auto const& in{ *d.input };
-				auto& bCfg{ d.currentData->value< T_BuildConfiguration >( ) };
-				bCfg.cfInputs = ( in[ 1 ].stringValue( ) == "on" );
-				return true;
-			} )
+			<< M_BCL_TOGGLE_( cfInputs ) )
 	;
 
 	return T_SRDParserConfig{ defs };
diff --git a/c-buildcfg.hh b/c-buildcfg.hh
index aa908e4..a6ca6aa 100644
--- a/c-buildcfg.hh
+++ b/c-buildcfg.hh
@@ -27,6 +27,10 @@ struct T_BuildConfiguration
 		// Get rid of (get-input) for constant or undefined curves
 		bool cfInputs{ false };
 
+	// Constant propagation ------------------------------------------------
+
+		bool constantPropagation{ false };
+
 	// Dead code elimination -----------------------------------------------
 
 		bool deadCodeElimination{ false };
diff --git a/c-opcomp.cc b/c-opcomp.cc
index afd9523..4a5ba16 100644
--- a/c-opcomp.cc
+++ b/c-opcomp.cc
@@ -16,13 +16,17 @@ namespace {
 
 struct T_CompilerImpl_
 {
-	T_CompilerImpl_( F_OPLogger* logger ) noexcept
-		: logger( *logger ) {}
+	T_CompilerImpl_( F_OPLogger* const logger ,
+			const bool noUIInstructions ) noexcept
+		: logger( *logger ) , noUIInstructions( noUIInstructions )
+	{}
 
 	P_OpProgram compile( T_OpsParserOutput const& input ) noexcept;
 
     private:
 	F_OPLogger& logger;
+	const bool noUIInstructions;
+
 	T_Visitor< A_Node > astVisitor{ ASTVisitorBrowser };
 	T_Set< uint32_t > constants{ UseTag< IndexBacked< > >( ) };
 	T_KeyValueTable< T_String , uint32_t > locations;
@@ -650,6 +654,9 @@ bool T_CompilerImpl_::compileNode(
 	    //- DEBUGGING / UI CONTROLS -----------------------------------------------------------
 
 	    case A_Node::OP_PROFILE:
+		if ( noUIInstructions ) {
+			break;
+		}
 		if ( exit ) {
 			addInstruction( OP_UI_PEXIT , node.location( ) );
 		} else {
@@ -663,6 +670,9 @@ bool T_CompilerImpl_::compileNode(
 		break;
 
 	    case A_Node::OP_INPUT:
+		if ( noUIInstructions ) {
+			break;
+		}
 		if ( exit ) {
 			auto& in( (T_InputInstrNode&) node );
 			T_OpValue value;
@@ -675,6 +685,9 @@ bool T_CompilerImpl_::compileNode(
 		break;
 
 	    case A_Node::OP_ODBG:
+		if ( noUIInstructions ) {
+			break;
+		}
 		if ( exit ) {
 			auto& n( (T_OutputDebugInstrNode&) node );
 			if ( ! output->uiStrings.contains( n.description( ) ) ) {
@@ -689,6 +702,9 @@ bool T_CompilerImpl_::compileNode(
 		break;
 
 	    case A_Node::OP_OVERRIDES:
+		if ( noUIInstructions ) {
+			break;
+		}
 		if ( exit ) {
 			auto& n{ (T_OverridesInstrNode&) node };
 			const auto idx{ output->overrides.add( n.extractRoot( ) ) };
@@ -917,8 +933,9 @@ void T_CompilerImpl_::applyStackEffects(
 
 /*= T_OpsCompiler ==============================================================*/
 
-T_OpsCompiler::T_OpsCompiler( ) noexcept
-	: A_PrivateImplementation( new T_CompilerImpl_( &logger_ ) )
+T_OpsCompiler::T_OpsCompiler(
+		const bool noUIInstructions ) noexcept
+	: A_PrivateImplementation( new T_CompilerImpl_( &logger_ , noUIInstructions ) )
 { }
 
 P_OpProgram T_OpsCompiler::compile(
diff --git a/c-opcomp.hh b/c-opcomp.hh
index 4a5afa7..85ddb96 100644
--- a/c-opcomp.hh
+++ b/c-opcomp.hh
@@ -57,7 +57,7 @@ class T_OpsCompiler : public ebcl::A_PrivateImplementation
 	F_OPLogger logger_{ []( auto , auto ) { } };
 
     public:
-	T_OpsCompiler( ) noexcept;
+	T_OpsCompiler( bool noUIInstructions = false ) noexcept;
 
 	void setLogger( F_OPLogger logger )
 	{
diff --git a/c-opopt.cc b/c-opopt.cc
index ee45246..bb8ef11 100644
--- a/c-opopt.cc
+++ b/c-opopt.cc
@@ -392,6 +392,27 @@ bool opopt::FoldConstants(
 }
 
 
+/*= CONSTANT PROPAGATION =====================================================*/
+
+bool opopt::PropagateConstants(
+		T_OpsParserOutput& program ,
+		T_OptData& optData ) noexcept
+{
+	// We need to follow the general execution flow of the program. This is
+	// not as straightforward as it seems.
+	//	- Handling locals is rather easy as they "die" at the end of
+	// the function in which they are defined.
+	//	- Handling variables in init and functions that are called only
+	// from init is not too hard: once a variable is set to a constant, it
+	// can be substituted until the next set instruction.
+	//	- Other variables need additional checks before propagating.
+	// For example, if a variable is set to a constant during init, but is
+	// updated at the end of the frame function, the value cannot be
+	// propagated.
+	return false;
+}
+
+
 /*= DEAD CODE REMOVAL ========================================================*/
 
 bool opopt::RemoveDeadCode(
diff --git a/c-opopt.hh b/c-opopt.hh
index ccd749a..695d337 100644
--- a/c-opopt.hh
+++ b/c-opopt.hh
@@ -39,18 +39,28 @@ struct T_OptData
 	void findInputDecls( T_OpsParserOutput& program ) noexcept;
 };
 
-/*----------------------------------------------------------------------------*/
 
-// Attempts to fold constant expressions into single constants. Returns true if
-// transformations were made, false if not.
+/*= INDIVIDUAL OPTIMISATIONS =================================================*/
+// All functions below return true if transformations were made, false if not.
+
+// Attempts to fold constant expressions into single constants.
 //
-bool FoldConstants( T_OpsParserOutput& program ,
+bool FoldConstants(
+		T_OpsParserOutput& program ,
+		T_OptData& optData ) noexcept;
+
+// Attempts to propagate values from variables that contain constants to the
+// locations at which they are used.
+//
+bool PropagateConstants(
+		T_OpsParserOutput& program ,
 		T_OptData& optData ) noexcept;
 
 // Attempt to remove blocks of code that will not be executed because of
-// constant conditions. Returns true if transformations were made, false if not.
+// constant conditions.
 //
-bool RemoveDeadCode( T_OpsParserOutput& program ,
+bool RemoveDeadCode(
+		T_OpsParserOutput& program ,
 		T_OptData& optData ) noexcept;
 
 
diff --git a/m-builder.cc b/m-builder.cc
index 6601caa..d5a98d3 100644
--- a/m-builder.cc
+++ b/m-builder.cc
@@ -132,7 +132,7 @@ int main( int argc , char** argv )
 			break;
 
 		    case 'c':
-			if ( oSrcPath ) {
+			if ( oBuildCfg ) {
 				fprintf( stderr , "Duplicate build configuration\n" );
 				return EXIT_FAILURE;
 			}
@@ -252,22 +252,18 @@ int main( int argc , char** argv )
 		bool doneStuff;
 		do {
 			doneStuff = false;
-			if ( cfg.constantFolding ) {
-				while ( opopt::FoldConstants( *parsed , od ) ) {
-					doneStuff = true;
-				}
+			if ( cfg.constantFolding && opopt::FoldConstants( *parsed , od ) ) {
+				doneStuff = true;
 			}
-			if ( cfg.deadCodeElimination ) {
-				while ( opopt::RemoveDeadCode( *parsed , od ) ) {
-					doneStuff = true;
-				}
+			if ( cfg.deadCodeElimination && opopt::RemoveDeadCode( *parsed , od ) ) {
+				doneStuff = true;
 			}
 		} while ( doneStuff );
 	}
 
 	// Compile
 	M_LOGSTR( "Compiling script" , 1 );
-	T_OpsCompiler compiler;
+	T_OpsCompiler compiler( true );
 	compiler.setLogger( logger );
 	compiler.compile( *parsed );
 	return 0;
diff --git a/test/build.srd b/test/build.srd
index 48fd338..c2c68ca 100644
--- a/test/build.srd
+++ b/test/build.srd
@@ -1,4 +1,4 @@
-(cfg "Default"
+(cfg "Optimized"
 	(resolutions
 		(1280 720)
 		(1920 1080)
@@ -7,3 +7,11 @@
 		(constant-folding on)
 	)
 )
+
+(cfg "Basic"
+	(resolutions
+		(1280 720)
+		(1920 1080)
+	)
+	(optimizer off)
+)
diff --git a/test/curves.srd b/test/curves.srd
index 4eff85b..a18440f 100644
--- a/test/curves.srd
+++ b/test/curves.srd
@@ -1,7 +1,7 @@
 (duration 0.133333 450)
 
 (camera-nearplane
-	(segment linear
+	(segment smooth
 		(values 1.1547 1.1547 4.82843)
 		(durations 225 225)
 	)
@@ -9,7 +9,7 @@
 
 (camera-pos-x
 	(segment linear
-		(values -300 -150 0)
+		(values -4000 -2000 0)
 		(durations 225 225)
 	)
 )
@@ -51,7 +51,7 @@
 
 (camera-lookat-x
 	(segment linear
-		(values -300 -150 0)
+		(values -4000 -2000 0)
 		(durations 225 225)
 	)
 )