Normalised on std::vector rather than std::unique_ptr<uint8_t *> as (probably?) more idiomatic. Improved structure slightly. Introduced a container for line data, albeit one that isn't yet used.

Outputs/CRT/Internals/CRTOpenGL.cpp

@@ -80,9 +80,9 @@ static int getCircularRanges(GLsizei *start_pointer, GLsizei *end_pointer, GLsiz
 	}
 }
 
-static GLsizei submitArrayData(GLuint buffer, uint8_t *source, GLsizei *length_pointer)
+static GLsizei submitArrayData(GLuint buffer, uint8_t *source, size_t *length_pointer)
 {
-	GLsizei length = *length_pointer;
+	GLsizei length = (GLsizei)*length_pointer;
 
 	glBindBuffer(GL_ARRAY_BUFFER, buffer);
 	uint8_t *data = (uint8_t *)glMapBufferRange(GL_ARRAY_BUFFER, 0, length, GL_MAP_WRITE_BIT | GL_MAP_UNSYNCHRONIZED_BIT | GL_MAP_FLUSH_EXPLICIT_BIT);
@@ -114,16 +114,15 @@ OpenGLOutputBuilder::OpenGLOutputBuilder(unsigned int buffer_depth) :
 	_cleared_composite_output_y(0),
 	_composite_shader(nullptr),
 	_rgb_shader(nullptr),
-	_output_buffer_data(new uint8_t[OutputVertexBufferDataSize]),
-	_source_buffer_data(new uint8_t[SourceVertexBufferDataSize]),
-	_output_buffer_data_pointer(0),
-	_source_buffer_data_pointer(0),
 	_last_output_width(0),
 	_last_output_height(0),
 	_fence(nullptr)
 {
 	_buffer_builder.reset(new CRTInputBufferBuilder(buffer_depth));
 
+	_output_buffer.data.resize(OutputVertexBufferDataSize);
+	_source_buffer.data.resize(OutputVertexBufferDataSize);
+
 	glBlendFunc(GL_SRC_ALPHA, GL_CONSTANT_COLOR);
 	glBlendColor(0.6f, 0.6f, 0.6f, 1.0f);
 
@@ -224,10 +223,10 @@ void OpenGLOutputBuilder::draw_frame(unsigned int output_width, unsigned int out
 	_output_mutex->lock();
 
 	// release the mapping, giving up on trying to draw if data has been lost
-	GLsizei submitted_output_data = submitArrayData(output_array_buffer, _output_buffer_data.get(), &_output_buffer_data_pointer);
+	GLsizei submitted_output_data = submitArrayData(output_array_buffer, _output_buffer.data.data(), &_output_buffer.pointer);
 
 	// bind and flush the source array buffer
-	GLsizei submitted_source_data = submitArrayData(source_array_buffer, _source_buffer_data.get(), &_source_buffer_data_pointer);
+	GLsizei submitted_source_data = submitArrayData(source_array_buffer, _source_buffer.data.data(), &_source_buffer.pointer);
 
 	// determine how many lines are newly reclaimed; they'll need to be cleared
 	Range clearing_zones[2];

Outputs/CRT/Internals/CRTOpenGL.hpp

@@ -20,6 +20,7 @@
 #include "Shaders/IntermediateShader.hpp"
 
 #include <mutex>
+#include <vector>
 
 namespace Outputs {
 namespace CRT {
@@ -93,6 +94,28 @@ class OpenGLOutputBuilder {
 		OpenGLOutputBuilder(unsigned int buffer_depth);
 		~OpenGLOutputBuilder();
 
+		inline uint8_t *get_next_source_run()
+		{
+			if(_source_buffer.pointer == SourceVertexBufferDataSize) return nullptr;
+			return &_source_buffer.data[_source_buffer.pointer];
+		}
+
+		inline void complete_source_run()
+		{
+			_source_buffer.pointer += SourceVertexSize;
+		}
+
+		inline uint8_t *get_next_output_run()
+		{
+			if(_output_buffer.pointer == OutputVertexBufferDataSize) return nullptr;
+			return &_output_buffer.data[_output_buffer.pointer];
+		}
+
+		inline void complete_output_run()
+		{
+			_output_buffer.pointer += OutputVertexSize;
+		}
+
 		inline void set_colour_format(ColourSpace colour_space, unsigned int colour_cycle_numerator, unsigned int colour_cycle_denominator)
 		{
 			_output_mutex->lock();
@@ -108,31 +131,9 @@ class OpenGLOutputBuilder {
 			_visible_area = visible_area;
 		}
 
-		inline uint8_t *get_next_source_run()
-		{
-			if(_source_buffer_data_pointer == SourceVertexBufferDataSize) return nullptr;
-			return &_source_buffer_data.get()[_source_buffer_data_pointer];
-		}
-
-		inline void complete_source_run()
-		{
-			_source_buffer_data_pointer += SourceVertexSize;
-		}
-
 		inline bool composite_output_run_has_room_for_vertex()
 		{
-			return _output_buffer_data_pointer < OutputVertexBufferDataSize;
+			return _output_buffer.pointer < OutputVertexBufferDataSize;
-		}
-
-		inline uint8_t *get_next_output_run()
-		{
-			if(_output_buffer_data_pointer == OutputVertexBufferDataSize) return nullptr;
-			return &_output_buffer_data.get()[_output_buffer_data_pointer];
-		}
-
-		inline void complete_output_run()
-		{
-			_output_buffer_data_pointer += OutputVertexSize;
 		}
 
 		inline void lock_output()
@@ -199,11 +200,11 @@ class OpenGLOutputBuilder {
 		void set_output_device(OutputDevice output_device);
 		void set_timing(unsigned int input_frequency, unsigned int cycles_per_line, unsigned int height_of_display, unsigned int horizontal_scan_period, unsigned int vertical_scan_period, unsigned int vertical_period_divider);
 
-		std::unique_ptr<uint8_t> _source_buffer_data;
+		struct Buffer {
-		GLsizei _source_buffer_data_pointer;
+			std::vector<uint8_t> data;
-
+			size_t pointer;
-		std::unique_ptr<uint8_t> _output_buffer_data;
+			Buffer() : pointer(0) {}
-		GLsizei _output_buffer_data_pointer;
+		} _line_buffer, _source_buffer, _output_buffer;
 
 		GLsync _fence;
 };