diff --git a/demo.cc b/demo.cc
index 8fb8699..de356c6 100644
--- a/demo.cc
+++ b/demo.cc
@@ -68,7 +68,7 @@ void T_Demo::makeUI( )
 
 void T_Demo::render( )
 {
-	if ( !context ) {
+	if ( program && !context ) {
 		runInit( );
 	}
 
@@ -198,6 +198,16 @@ bool T_Demo::loadProgram( )
 		program = compiler.compile( *parser.result( ) );
 		return true;
 	}
+
+	T_StringBuilder sb;
+	sb << "- PARSE ERRORS -------------------------\n";
+	const auto nErrors( parser.errors( ).size( ) );
+	for ( auto i = 0u ; i < nErrors ; i ++ ) {
+		WriteSRDError( sb , parser.errors( )[ i ] );
+	}
+	sb << "----------------------------------------\n";
+	sb << '\0';
+	fprintf( stderr , "%s" , sb.data( ) );
 	return false;
 }
 
@@ -219,6 +229,10 @@ void T_Demo::runInit( )
 	for ( auto i = 0u ; i < n ; i ++ ) {
 		Globals::Sync( ).addInput( program->inputs[ i ] ,
 				context->initialInputs[ i ] );
+#ifdef INVASIVE_TRACES
+		printf( "#%d %s pos %d\n" , i , program->inputs[ i ].toOSString( ).data( ) ,
+				Globals::Sync( ).inputPos( program->inputs[ i ] ) );
+#endif //INVASIVE_TRACES
 	}
 	Globals::Sync( ).updateCurveCaches( );
 }
diff --git a/demo.srd b/demo.srd
index 2f19931..ee5d3b5 100644
--- a/demo.srd
+++ b/demo.srd
@@ -44,7 +44,6 @@
 		(color tx-scene-depth))
 
 	(program prg-scene-p1 "scene.f.glsl")
-	(uniforms prg-scene-p1 1 $vp-width $vp-height)
 	(pipeline pl-scene-p1 prg-fullscreen prg-scene-p1)
 
 	(odbg tx-scene-output hdr "Scene output")
@@ -52,7 +51,7 @@
 
 	(input camera-pos-x 0)
 	(input camera-pos-y 0)
-	(input camera-pos-z -5)
+	(input camera-pos-z 30)
 	(input camera-lookat-x 0)
 	(input camera-lookat-y 0)
 	(input camera-lookat-z 0)
@@ -72,6 +71,10 @@
 
 (fn scene-render ()
 	(profiling "Scene render"
+		# FIXME temp - we'll need to do init right before this
+		# can be moved back to initialisation
+		(uniforms prg-scene-p1 1 $vp-width $vp-height)
+
 		(uniforms prg-scene-p1 0 $time)
 		(uniforms prg-scene-p1 2
 			(get-input camera-pos-x)
@@ -134,10 +137,6 @@
 	# Programs
 	(program prg-dof-pass1 "dof-pass1.f.glsl")
 	(program prg-dof-pass2 "dof-pass2.f.glsl")
-	(uniforms-i prg-dof-pass1 0 1)
-	(uniforms-i prg-dof-pass1 1 1)
-	(uniforms-i prg-dof-pass2 0 1)
-	(uniforms-i prg-dof-pass2 1 1)
 
 	# Pipelines
 	(pipeline pl-dof-pass1 prg-fullscreen prg-dof-pass1)
@@ -177,6 +176,13 @@
 	(profiling "Depth of Field"
 		(use-texture 1 in-depth smp-dof)
 
+		# FIXME temp - we'll need to do init right before this
+		# can be moved back to initialisation
+		(uniforms-i prg-dof-pass1 0 0)
+		(uniforms-i prg-dof-pass1 1 1)
+		(uniforms-i prg-dof-pass2 0 0)
+		(uniforms-i prg-dof-pass2 1 1)
+
 		# First pass
 		(call dof-set-uniforms prg-dof-pass1)
 		(use-texture 0 in-image smp-dof)
@@ -202,6 +208,8 @@
 	# Samplers
 	(sampler smp-bloom-blur
 		(sampling linear)
+		(mipmaps linear)
+		(lod 0 100)
 		(wrapping clamp-edge)
 	)
 	(sampler smp-bloom-input
@@ -226,23 +234,19 @@
 	(framebuffer rt-bloom2-lod3 (color tx-bloom2 3))
 	(framebuffer rt-bloom2-lod4 (color tx-bloom2 4))
 	(framebuffer rt-bloom2-lod5 (color tx-bloom2 5))
+	(odbg tx-bloom2 hdr "Bloom (partial)")
 
 	# High pass program
 	(program prg-bloom-highpass "bloom-highpass.f.glsl")
 	(pipeline pl-bloom-highpass prg-fullscreen prg-bloom-highpass)
-	(uniforms-i prg-bloom-highpass 0 0)
-	(uniforms-i prg-bloom-highpass 1 0)
-	(uniforms prg-bloom-highpass 2 $vp-width $vp-height)
 
 	# Downsampling program
 	(program prg-bloom-downsample "downsample.f.glsl")
 	(pipeline pl-bloom-downsample prg-fullscreen prg-bloom-downsample)
-	(uniforms-i prg-bloom-downsample 0 0)
 
 	# Blur pass
 	(program prg-bloom-blur "blur-pass.f.glsl")
 	(pipeline pl-bloom-blur prg-fullscreen prg-bloom-blur)
-	(uniforms-i prg-bloom-blur 0 0)
 
 	# Inputs that control the high pass filter
 	# FIXME I don't remember what they actually do, rename them later
@@ -262,6 +266,14 @@
 
 (fn bloom-render (in-scene)
 	(profiling "BLOOOOM!"
+		# FIXME temp - we'll need to do init right before this
+		# can be moved back to initialisation
+		(uniforms-i prg-bloom-highpass 0 0)
+		(uniforms-i prg-bloom-highpass 1 0)
+		(uniforms prg-bloom-highpass 2 $vp-width $vp-height)
+		(uniforms-i prg-bloom-downsample 0 0)
+		(uniforms-i prg-bloom-blur 0 0)
+
 		# High pass
 		(use-texture 0 in-scene smp-bloom-input)
 		(uniforms prg-bloom-highpass 3
@@ -273,8 +285,15 @@
 		(viewport 0 0 $vp-width $vp-height)
 		(fullscreen)
 
+		# Set up blur weights
+		(uniforms prg-bloom-blur 4
+			(get-input bloom-bw0)
+			(get-input bloom-bw1)
+			(get-input bloom-bw2)
+			(get-input bloom-bw3))
+
 		# Blur & downsample
-		(uniforms prg-bloom-downsample 1 $vp-width $vp-height)
+		(uniforms prg-bloom-blur 1 $vp-width $vp-height)
 		(call bloom-blur-pass 0 rt-bloom1-lod0 rt-bloom2-lod0)
 		(call bloom-downsample rt-bloom1-lod1 1)
 		(call bloom-blur-pass 1 rt-bloom1-lod1 rt-bloom2-lod1)
@@ -333,13 +352,14 @@
 (fn combine-init ()
 	# Assets
 	(sampler smp-combine-input (sampling nearest))
+	(sampler smp-combine-bloom
+		(sampling linear)
+		(mipmaps nearest)
+		(lod 0 100))
 	(texture tx-combined rgba-nu8 $vp-width $vp-height)
 	(odbg tx-combined ldr-alpha "Combined output")
 	(framebuffer rt-combined tx-combined)
 	(program prg-combine "combine.f.glsl")
-	(uniforms-i prg-combine 0 0)
-	(uniforms-i prg-combine 1 1)
-	(uniforms prg-combine 2 $vp-width $vp-height)
 	(pipeline pl-combine prg-fullscreen prg-combine)
 
 	# Bloom parameters
@@ -368,10 +388,16 @@
 
 (fn combine-render (in-main in-bloom)
 	(profiling "Combine"
+		# FIXME temp - we'll need to do init right before this
+		# can be moved back to initialisation
+		(uniforms-i prg-combine 0 0)
+		(uniforms-i prg-combine 1 1)
+		(uniforms prg-combine 2 $vp-width $vp-height)
+
 		(use-pipeline pl-combine)
 		(use-framebuffer rt-combined)
 		(use-texture 0 in-main smp-combine-input)
-		(use-texture 1 in-bloom smp-combine-input)
+		(use-texture 1 in-bloom smp-combine-bloom)
 		(uniforms prg-combine 3
 			(get-input bloom-strength)
 			(get-input bloom-attenuation))
@@ -407,8 +433,6 @@
 (fn fxaa-init ()
 	(program prg-fxaa "fxaa.f.glsl")
 	(pipeline pl-fxaa prg-fullscreen prg-fxaa)
-	(uniforms-i prg-fxaa 0 0)
-	(uniforms prg-fxaa 1 $vp-width $vp-height)
 
 	(sampler smp-fxaa
 		(sampling linear)
@@ -421,6 +445,11 @@
 
 (fn fxaa-render (in-image)
 	(profiling "FXAA"
+		# FIXME temp - we'll need to do init right before this
+		# can be moved back to initialisation
+		(uniforms-i prg-fxaa 0 0)
+		(uniforms prg-fxaa 1 $vp-width $vp-height)
+
 		(main-output)
 		(viewport 0 0 $width $height)
 		(clear 0 0 0 0)
diff --git a/opcomp.cc b/opcomp.cc
index 9df2c73..13c0b8f 100644
--- a/opcomp.cc
+++ b/opcomp.cc
@@ -433,7 +433,6 @@ bool T_CompilerImpl_::compileNode(
 			const auto cpos( output->ops.sizeOf( funcIndex ) );
 			const auto ppos( condJumps.last( ).prevCase );
 			const auto diff( cpos - ppos );
-			assert( diff > 1 );
 			output->ops.get( funcIndex , ppos ).args[ 0 ] = diff - 1;
 		} else {
 			// If there is a previous skip location, insert the skip instruction
@@ -648,9 +647,9 @@ bool T_CompilerImpl_::compileNode(
 			T_OpValue value;
 			value.f = in.defValue( );
 			addInstruction( OP_UI_INPUT_DFT , {
-						uint32_t( output->inputs.indexOf( in.id( ) ) ) ,
-						uint32_t( constants.indexOf( value.u ) + 3 ) } ,
-					node.location( ) );
+					uint32_t( output->inputs.indexOf( in.id( ) ) ) ,
+					uint32_t( constants.indexOf( value.u ) + 3 + output->nVariables ) } ,
+				node.location( ) );
 		}
 		break;
 
diff --git a/ops.cc b/ops.cc
index fc46631..60919b6 100644
--- a/ops.cc
+++ b/ops.cc
@@ -393,7 +393,7 @@ void T_OpContext::run(
 
 		    case OP_GET_INPUT:
 			ensureFpuStack( instr , 0 , 1 );
-			x87stack[ x87sp ++ ] = Globals::Sync( ).inputs( )[ instr.args[ 0 ] + 1 ];
+			x87stack[ x87sp ++ ] = Globals::Sync( ).inputs( )[ instr.args[ 0 ] ];
 			break;
 
 		    case OP_FP_LOAD:
@@ -786,11 +786,14 @@ void T_OpContext::run(
 
 			const auto ss( stack.size( ) );
 			T_OpValue values[ 4 ];
+//			printf( "OP_UNIFORMS %d %d" , instr.args[ 0 ] , instr.args[ 1 ] );
 			for ( auto i = 0u ; i <= instr.args[ 0 ] ; i ++ ) {
 				if ( instr.args[ 1 ] ) {
 					values[ i ] = uint32_t( stack[ ss - 3 - i ].f );
+//					printf( " %d" , values[ i ].i );
 				} else {
 					values[ i ] = stack[ ss - 3 - i ];
+//					printf( " %f" , values[ i ].f );
 				}
 			}
 
@@ -798,6 +801,7 @@ void T_OpContext::run(
 			if ( sv == 0 || sv > programs.size( ) || !programs[ sv - 1 ] ) {
 				throw X_OpFailure{ instr , "invalid program" };
 			}
+//			printf( " -> %s %d\n" , programs[ sv - 1 ]->name( ).toOSString( ).data( ) , stack[ ss - 2 ].u );
 
 			typedef void (*F_SetUniform_)( int , int , int , void* );
 			void const* const funcs[] = {
@@ -815,8 +819,10 @@ void T_OpContext::run(
 		    {
 			ensureStack( instr , 4 );
 			const auto ss( stack.size( ) );
-			glViewport( stack[ ss - 1 ].f , stack[ ss - 2 ].f ,
-					stack[ ss - 3 ].f , stack[ ss - 4 ].f );
+			glViewport( int32_t( stack[ ss - 1 ].f ) ,
+					int32_t( stack[ ss - 2 ].f ) ,
+					int32_t( stack[ ss - 3 ].f ) ,
+					int32_t( stack[ ss - 4 ].f ) );
 			stack.resize( ss - 4 );
 			break;
 		    }