From d170bb14e636c3c1061350b241710c5ae95337aa Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Tue, 17 May 2016 18:21:49 -0400
Subject: [PATCH] Extended scheduling plans, inserted initial events for hmove,
 albeit not yet implemented.

---
 Machines/Atari2600/Atari2600.cpp | 17 +++++++++++++++--
 Machines/Atari2600/Atari2600.hpp | 17 ++++++++++++-----
 2 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/Machines/Atari2600/Atari2600.cpp b/Machines/Atari2600/Atari2600.cpp
index 420da42df..4480bff03 100644
--- a/Machines/Atari2600/Atari2600.cpp
+++ b/Machines/Atari2600/Atari2600.cpp
@@ -21,7 +21,6 @@ Machine::Machine() :
 	_lastOutputState(OutputState::Sync),
 	_piaTimerStatus(0xff),
 	_rom(nullptr),
-	_hMoveWillCount(false),
 	_piaDataValue{0xff, 0xff},
 	_tiaInputValue{0xff, 0xff},
 	_upcomingEventsPointer(0)
@@ -555,7 +554,21 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
 
 					case 0x2a:
 						_vBlankExtend = true;
-						_hMoveWillCount = true;
+
+						// clear any ongoing moves
+						if(_hMoveFlags)
+						{
+							for(int c = 0; c < number_of_upcoming_events; c++)
+							{
+								_upcomingEvents[c].updates &= ~(Event::Action::HMoveCompare | Event::Action::HMoveDecrement);
+							}
+						}
+
+						// schedule new moves
+						_hMoveFlags = 0x1f;
+						_hMoveCounter = 15;
+						_upcomingEvents[(_upcomingEventsPointer + 15)%number_of_upcoming_events].updates |= Event::Action::HMoveCompare;
+						_upcomingEvents[(_upcomingEventsPointer + 17)%number_of_upcoming_events].updates |= Event::Action::HMoveDecrement;
 					break;
 					case 0x2b:
 						_objectMotion[0] =
diff --git a/Machines/Atari2600/Atari2600.hpp b/Machines/Atari2600/Atari2600.hpp
index bc69e5799..a553fb70b 100644
--- a/Machines/Atari2600/Atari2600.hpp
+++ b/Machines/Atari2600/Atari2600.hpp
@@ -16,7 +16,7 @@
 
 namespace Atari2600 {
 
-const unsigned int number_of_upcoming_events = 8;
+const unsigned int number_of_upcoming_events = 18;
 
 class Machine: public CPU6502::Processor<Machine> {
 
@@ -61,11 +61,14 @@ class Machine: public CPU6502::Processor<Machine> {
 		struct Event {
 			enum Action {
 				Playfield		= 1 << 0,
-				Ball			= 1 << 1
+				Ball			= 1 << 1,
+				HMoveCompare	= 1 << 2,
+				HMoveDecrement	= 1 << 3
 			};
-			unsigned int updates;
+			int updates;
 			uint8_t playfieldOutput;
 			OutputState state;
+			Event() : updates(0) {}
 		} _upcomingEvents[number_of_upcoming_events];
 		unsigned int _upcomingEventsPointer;
 
@@ -95,10 +98,14 @@ class Machine: public CPU6502::Processor<Machine> {
 		unsigned int _horizontalTimer;
 		bool _vSyncEnabled, _vBlankEnabled;
 		bool _vBlankExtend;
+
+		// horizontal motion control
 		uint8_t _hMoveCounter;
-		bool _hMoveIsCounting, _hMoveWillCount;
-		uint8_t _objectCounter[5], _objectMotion[5];
 		uint8_t _hMoveFlags;
+		uint8_t _objectMotion[5];
+
+		// object counters
+		uint8_t _objectCounter[5];
 
 		// joystick state
 		uint8_t _piaDataDirection[2];