Enable generation of the needed composition shader.

Proving that I've forgotten something about vertex attribute bindings.

Outputs/OpenGL/CompositionShader.cpp

@@ -387,30 +387,30 @@ OpenGL::Shader OpenGL::composition_shader(
 	//
 	// Enable vertex attributes.
 	//
-	BufferingScanTarget::Scan scan;
-	const auto enable = [&](const std::string &name, auto &element, const bool normalise) {
-		assert(sizeof(element) == 1 || sizeof(element) == 2);
-		shader.enable_vertex_attribute_with_pointer(
-			name,
-			1,
-			sizeof(element) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_BYTE,
-			normalise ? GL_TRUE : GL_FALSE,
-			sizeof(scan),
-			reinterpret_cast<void *>((reinterpret_cast<uint8_t *>(&element) - reinterpret_cast<uint8_t *>(&scan))),
-			1
-		);
-	};
-
-	for(int c = 0; c < 2; c++) {
-		const std::string endpoint = std::string("scanEndpoint") + std::to_string(c);
-		enable(endpoint + "DataOffset", scan.scan.end_points[c].data_offset, false);
-		enable(endpoint + "CyclesSinceRetrace", scan.scan.end_points[c].cycles_since_end_of_horizontal_retrace, false);
-		enable(endpoint + "CompositeAngle", scan.scan.end_points[c].composite_angle, false);
-	}
-
-	enable("scanDataY", scan.data_y, false);
-	enable("scanLine", scan.line, false);
-	enable("scanCompositeAmplitude", scan.scan.composite_amplitude, true);
+//	BufferingScanTarget::Scan scan;
+//	const auto enable = [&](const std::string &name, auto &element, const bool normalise) {
+//		assert(sizeof(element) == 1 || sizeof(element) == 2);
+//		shader.enable_vertex_attribute_with_pointer(
+//			name,
+//			1,
+//			sizeof(element) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_BYTE,
+//			normalise ? GL_TRUE : GL_FALSE,
+//			sizeof(scan),
+//			reinterpret_cast<void *>((reinterpret_cast<uint8_t *>(&element) - reinterpret_cast<uint8_t *>(&scan))),
+//			1
+//		);
+//	};
+//
+//	for(int c = 0; c < 2; c++) {
+//		const std::string endpoint = std::string("scanEndpoint") + std::to_string(c);
+//		enable(endpoint + "DataOffset", scan.scan.end_points[c].data_offset, false);
+//		enable(endpoint + "CyclesSinceRetrace", scan.scan.end_points[c].cycles_since_end_of_horizontal_retrace, false);
+//		enable(endpoint + "CompositeAngle", scan.scan.end_points[c].composite_angle, false);
+//	}
+//
+//	enable("scanDataY", scan.data_y, false);
+//	enable("scanLine", scan.line, false);
+//	enable("scanCompositeAmplitude", scan.scan.composite_amplitude, true);
 
 	//
 	// Set uniforms.

Outputs/OpenGL/Primitives/Shader.cpp

@@ -156,7 +156,7 @@ void Shader::init(
 	}
 }
 
-Shader::Shader(Shader &&rhs) {
+Shader &Shader::operator =(Shader &&rhs) {
 	api_ = rhs.api_;
 	shader_program_ = rhs.shader_program_;
 
@@ -164,6 +164,11 @@ Shader::Shader(Shader &&rhs) {
 		bound_shader = this;
 	}
 	rhs.shader_program_ = 0;
+	return *this;
+}
+
+Shader::Shader(Shader &&rhs) {
+	*this = std::move(rhs);
 }
 
 Shader::~Shader() {

Outputs/OpenGL/Primitives/Shader.hpp

@@ -65,8 +65,10 @@ public:
 	);
 	~Shader();
 
-	// Allow moves.
+	// Allow moves, including move assignment, and default construction to create something vacant.
 	Shader(Shader&&);
+	Shader &operator =(Shader &&);
+	Shader() = default;
 
 	/*!
 		Performs an @c glUseProgram to make this the active shader unless:
@@ -146,7 +148,7 @@ private:
 
 	GLuint compile_shader(const std::string &source, GLenum type);
 	API api_;
-	GLuint shader_program_;
+	GLuint shader_program_ = 0;
 
 	void flush_functions() const;
 	mutable std::vector<std::function<void(void)>> enqueued_functions_;

Outputs/OpenGL/ScanTarget.cpp

@@ -244,6 +244,31 @@ void ScanTarget::setup_pipeline() {
 		input_shader_->set_uniform("textureName", GLint(SourceDataTextureUnit - GL_TEXTURE0));
 	}
 
+	//
+	// New pipeline starts here!
+	//
+	const auto buffer_width = FilterGenerator::SuggestedBufferWidth;
+	const float sample_multiplier =
+		FilterGenerator::suggested_sample_multiplier(227.5f, 1320);
+
+	if(
+		!existing_modals_ ||
+		existing_modals_->input_data_type != modals.input_data_type ||
+		existing_modals_->display_type != modals.display_type ||
+		existing_modals_->composite_colour_space != modals.composite_colour_space
+	) {
+		composition_shader_ = OpenGL::composition_shader(
+			api_,
+			modals.input_data_type,
+			modals.display_type,
+			modals.composite_colour_space,
+			sample_multiplier,
+			2048, 2048,
+			buffer_width, 2048,
+			GL_TEXTURE0
+		);
+	}
+
 	existing_modals_ = modals;
 }
 
@@ -277,10 +302,13 @@ void ScanTarget::update(int, int output_height) {
 
 		// Establish the pipeline if necessary.
 		const auto new_modals = BufferingScanTarget::new_modals();
-		const bool did_setup_pipeline = bool(new_modals);
-		if(did_setup_pipeline) {
-			setup_pipeline();
-		}
+		const bool did_setup_pipeline = [&] {
+			if(bool(new_modals)) {
+				setup_pipeline();
+				return true;
+			}
+			return false;
+		} ();
 
 		// Determine the start time of this submission group and the number of lines it will contain.
 		line_submission_begin_time_ = std::chrono::high_resolution_clock::now();

Outputs/OpenGL/ScanTarget.hpp

@@ -121,6 +121,8 @@ private:
 	std::unique_ptr<Shader> output_shader_;
 	std::unique_ptr<Shader> qam_separation_shader_;
 
+	Shader composition_shader_;
+
 	/*!
 		Produces a shader that composes fragment of the input stream to a single buffer,
 		normalising the data into one of four forms: RGB, 8-bit luminance,