From c2a7dffa7d21f0f5d6369ab69f4e0ca91c57f1a5 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Sat, 22 Jul 2017 23:02:28 -0400
Subject: [PATCH] Converted the ZX80/81 video component into a ClockReceiver.
 As it happens, it's most convenient to take the half-cycle bus here.

---
 Machines/ZX8081/Video.cpp  |  4 ++--
 Machines/ZX8081/Video.hpp  |  7 ++++---
 Machines/ZX8081/ZX8081.cpp | 10 +++++-----
 3 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/Machines/ZX8081/Video.cpp b/Machines/ZX8081/Video.cpp
index 5531e7dee..766c6a1f6 100644
--- a/Machines/ZX8081/Video.cpp
+++ b/Machines/ZX8081/Video.cpp
@@ -29,9 +29,9 @@ Video::Video() :
 	crt_->set_visible_area(Outputs::CRT::Rect(0.1f, 0.1f, 0.8f, 0.8f));
 }
 
-void Video::run_for_cycles(int number_of_cycles) {
+void Video::run_for(const HalfCycles &half_cycles) {
 	// Just keep a running total of the amount of time that remains owed to the CRT.
-	cycles_since_update_ += (unsigned int)number_of_cycles << 1;
+	cycles_since_update_ += (unsigned int)int(half_cycles);
 }
 
 void Video::flush() {
diff --git a/Machines/ZX8081/Video.hpp b/Machines/ZX8081/Video.hpp
index 9c63021ba..9ae254b8d 100644
--- a/Machines/ZX8081/Video.hpp
+++ b/Machines/ZX8081/Video.hpp
@@ -10,6 +10,7 @@
 #define Machines_ZX8081_Video_hpp
 
 #include "../../Outputs/CRT/CRT.hpp"
+#include "../../Components/ClockReceiver.hpp"
 
 namespace ZX8081 {
 
@@ -23,15 +24,15 @@ namespace ZX8081 {
 	a 1-bit graphic and output over the next 4 cycles, picking between the white level
 	and the black level.
 */
-class Video {
+class Video: public ClockReceiver<Video> {
 	public:
 		/// Constructs an instance of the video feed; a CRT is also created.
 		Video();
 		/// @returns The CRT this video feed is feeding.
 		std::shared_ptr<Outputs::CRT::CRT> get_crt();
 
-		/// Advances time by @c number_of_cycles cycles.
-		void run_for_cycles(int number_of_cycles);
+		/// Advances time by @c cycles.
+		void run_for(const HalfCycles &);
 		/// Forces output to catch up to the current output position.
 		void flush();
 
diff --git a/Machines/ZX8081/ZX8081.cpp b/Machines/ZX8081/ZX8081.cpp
index 8d0d2b42a..1c0475698 100644
--- a/Machines/ZX8081/ZX8081.cpp
+++ b/Machines/ZX8081/ZX8081.cpp
@@ -34,23 +34,23 @@ int Machine::perform_machine_cycle(const CPU::Z80::PartialMachineCycle &cycle) {
 	horizontal_counter_ += cycle.length;
 
 	if(previous_counter < vsync_start_cycle_ && horizontal_counter_ >= vsync_start_cycle_) {
-		video_->run_for_cycles(vsync_start_cycle_ - previous_counter);
+		video_->run_for(Cycles(vsync_start_cycle_ - previous_counter));
 		set_hsync(true);
 		line_counter_ = (line_counter_ + 1) & 7;
 		if(nmi_is_enabled_) {
 			set_non_maskable_interrupt_line(true);
 		}
-		video_->run_for_cycles(horizontal_counter_ - vsync_start_cycle_);
+		video_->run_for(Cycles(horizontal_counter_ - vsync_start_cycle_));
 	} else if(previous_counter < vsync_end_cycle_ && horizontal_counter_ >= vsync_end_cycle_) {
-		video_->run_for_cycles(vsync_end_cycle_ - previous_counter);
+		video_->run_for(Cycles(vsync_end_cycle_ - previous_counter));
 		set_hsync(false);
 		if(nmi_is_enabled_) {
 			set_non_maskable_interrupt_line(false);
 			set_wait_line(false);
 		}
-		video_->run_for_cycles(horizontal_counter_ - vsync_end_cycle_);
+		video_->run_for(Cycles(horizontal_counter_ - vsync_end_cycle_));
 	} else {
-		video_->run_for_cycles(cycle.length);
+		video_->run_for(Cycles(cycle.length));
 	}
 
 	if(is_zx81_) horizontal_counter_ %= 207;