Acts as if it is going to submit scans, at least.

OSBindings/Mac/Clock Signal/Machine/CSMachine.mm

@@ -73,44 +73,6 @@ struct ActivityObserver: public Activity::Observer {
 	__unsafe_unretained CSMachine *machine;
 };
 
-//class ScanTarget: public Outputs::Display::ScanTarget {
-//	public:
-//		void set_modals(Modals m) {
-//			modals_ = m;
-//		}
-//
-//		Scan *get_scan() {
-//			scans_.emplace_back();
-//			return &scans_.back();
-//		}
-//
-//		uint8_t *allocate_write_area(size_t required_length, size_t required_alignment) {
-//			write_area_.resize(required_length);
-//			return write_area_.data();
-//		}
-//
-//		void submit(bool only_if_no_allocation_failures) {
-//			for(const auto &scan: scans_) {
-//				printf("%0.2f %0.2f [%0.2f] -> %0.2f %0.2f [%0.2f] => %0.2f\n",
-//					float(scan.end_points[0].x) / float(modals_.output_scale.x),
-//					float(scan.end_points[0].y) / float(modals_.output_scale.y),
-//					float(scan.end_points[0].composite_angle) / 64.0f,
-//					float(scan.end_points[1].x) / float(modals_.output_scale.x),
-//					float(scan.end_points[1].y) / float(modals_.output_scale.y),
-//					float(scan.end_points[1].composite_angle) / 64.0f,
-//					(float(scan.end_points[1].composite_angle - scan.end_points[0].composite_angle) / 64.0f) / (float(scan.end_points[1].x - scan.end_points[0].x) / float(modals_.output_scale.x))
-//				);
-//			}
-//
-//			scans_.clear();
-//		}
-//
-//	private:
-//		std::vector<Scan> scans_;
-//		std::vector<uint8_t> write_area_;
-//		Modals modals_;
-//};
-
 @implementation CSMachine {
 	SpeakerDelegate _speakerDelegate;
 	ActivityObserver _activityObserver;
@@ -124,7 +86,7 @@ struct ActivityObserver: public Activity::Observer {
 	std::bitset<65536> _depressedKeys;
 	NSMutableArray<NSString *> *_leds;
 
-	Outputs::Display::OpenGL::ScanTarget _scanTarget;
+	std::unique_ptr<Outputs::Display::OpenGL::ScanTarget> _scanTarget;
 }
 
 - (instancetype)initWithAnalyser:(CSStaticAnalyser *)result {
@@ -273,7 +235,8 @@ struct ActivityObserver: public Activity::Observer {
 }
 
 - (void)setupOutputWithAspectRatio:(float)aspectRatio {
-	_machine->crt_machine()->setup_output(&_scanTarget);
+	_scanTarget.reset(new Outputs::Display::OpenGL::ScanTarget);
+	_machine->crt_machine()->setup_output(_scanTarget.get());
 
 	// Since OS X v10.6, Macs have had a gamma of 2.2.
 //	_machine->crt_machine()->get_crt()->set_output_gamma(2.2f);
@@ -281,6 +244,7 @@ struct ActivityObserver: public Activity::Observer {
 }
 
 - (void)drawViewForPixelSize:(CGSize)pixelSize onlyIfDirty:(BOOL)onlyIfDirty {
+	_scanTarget->draw();
 //	_machine->crt_machine()->get_crt()->draw_frame((unsigned int)pixelSize.width, (unsigned int)pixelSize.height, onlyIfDirty ? true : false);
 }
 

Outputs/OpenGL/ScanTarget.cpp

@@ -7,6 +7,7 @@
 //
 
 #include "ScanTarget.hpp"
+#include "Primitives/Rectangle.hpp"
 
 using namespace Outputs::Display::OpenGL;
 
@@ -17,6 +18,19 @@ const int WriteAreaHeight = 2048;
 
 }
 
+ScanTarget::ScanTarget() {
+	// Allocate space for the spans.
+	glGenBuffers(1, &scan_buffer_name_);
+	glBindBuffer(GL_ARRAY_BUFFER, scan_buffer_name_);
+	const auto buffer_size = scan_buffer_.size() * sizeof(Scan);
+	glBufferData(GL_ARRAY_BUFFER, GLsizeiptr(buffer_size), NULL, GL_STREAM_DRAW);
+}
+
+ScanTarget::~ScanTarget() {
+	// Release span space.
+	glDeleteBuffers(1, &scan_buffer_name_);
+}
+
 void ScanTarget::set_modals(Modals modals) {
 	// TODO: consider resizing the write_area_texture_, and setting
 	// write_area_texture_line_length_ appropriately.
@@ -89,5 +103,25 @@ void ScanTarget::reduce_previous_allocation_to(size_t actual_length) {
 }
 
 void ScanTarget::submit() {
-	// TODO.
+	if(allocation_has_failed_) {
+		// Reset all pointers to where they were.
+		scan_buffer_pointers_.write_pointer = scan_buffer_pointers_.submit_pointer;
+	} else {
+		// Advance submit pointer.
+		scan_buffer_pointers_.submit_pointer = scan_buffer_pointers_.write_pointer;
+	}
+
+	allocation_has_failed_ = false;
+}
+
+void ScanTarget::draw() {
+	// Submit spans.
+	if(scan_buffer_pointers_.submit_pointer != scan_buffer_pointers_.read_pointer) {
+		// TODO: submit all scans from scan_buffer_pointers_.read_pointer to scan_buffer_pointers_.submit_pointer.
+		scan_buffer_pointers_.read_pointer = scan_buffer_pointers_.submit_pointer;
+	}
+
+	glClear(GL_COLOR_BUFFER_BIT);
+	::OpenGL::Rectangle rect(-0.8f, -0.8f, 1.6f, 1.6f);
+	rect.draw(1, 1, 0);
 }

Outputs/OpenGL/ScanTarget.hpp

@@ -10,6 +10,7 @@
 #define ScanTarget_hpp
 
 #include "../ScanTarget.hpp"
+#include "OpenGL.hpp"
 
 #include <array>
 #include <atomic>
@@ -22,6 +23,11 @@ namespace OpenGL {
 
 class ScanTarget: public Outputs::Display::ScanTarget {
 	public:
+		ScanTarget();
+		~ScanTarget();
+		void draw();
+
+		// Outputs::Display::ScanTarget overrides.
 		void set_modals(Modals) override;
 		Scan *get_scan() override;
 		uint8_t *allocate_write_area(size_t required_length, size_t required_alignment) override;
@@ -39,10 +45,10 @@ class ScanTarget: public Outputs::Display::ScanTarget {
 		};
 
 		template <typename T> struct PointerSet {
-			/// A pointer to the final thing currently cleared for submission.
-			T submit_pointer;
 			/// A pointer to the next thing that should be provided to the caller for data.
 			T write_pointer;
+			/// A pointer to the final thing currently cleared for submission.
+			T submit_pointer;
 			/// A pointer to the first thing not yet submitted for display.
 			std::atomic<T> read_pointer;
 		};
@@ -50,6 +56,7 @@ class ScanTarget: public Outputs::Display::ScanTarget {
 		// Maintains a buffer of the most recent 3072 scans.
 		std::array<Scan, 3072> scan_buffer_;
 		PointerSet<size_t> scan_buffer_pointers_;
+		GLuint scan_buffer_name_ = 0;
 
 		// Uses a texture to vend write areas.
 		std::vector<uint8_t> write_area_texture_;