From d9c6b3bcf7bdb876731b957477ffaa7133a56db2 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Tue, 25 Jul 2017 22:13:41 -0400
Subject: [PATCH] Corrected TIA's WSYNC lookahead to accept `Cycles`.

---
 Machines/Atari2600/Cartridges/Cartridge.hpp         | 4 ++--
 Machines/Atari2600/Cartridges/CartridgePitfall2.hpp | 7 +++----
 Machines/Atari2600/TIA.cpp                          | 4 ++--
 Machines/Atari2600/TIA.hpp                          | 2 +-
 4 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/Machines/Atari2600/Cartridges/Cartridge.hpp b/Machines/Atari2600/Cartridges/Cartridge.hpp
index 2c0acde4f..1b3b19890 100644
--- a/Machines/Atari2600/Cartridges/Cartridge.hpp
+++ b/Machines/Atari2600/Cartridges/Cartridge.hpp
@@ -24,7 +24,7 @@ template<class T> class Cartridge:
 
 		void run_for(const Cycles &cycles) { CPU::MOS6502::Processor<Cartridge<T>>::run_for(cycles); }
 		void set_reset_line(bool state) { CPU::MOS6502::Processor<Cartridge<T>>::set_reset_line(state); }
-		void advance_cycles(unsigned int cycles) {}
+		void advance_cycles(int cycles) {}
 
 		// to satisfy CPU::MOS6502::Processor
 		unsigned int perform_bus_operation(CPU::MOS6502::BusOperation operation, uint16_t address, uint8_t *value) {
@@ -41,7 +41,7 @@ template<class T> class Cartridge:
 			cycles_since_speaker_update_ += Cycles(cycles_run_for);
 			cycles_since_video_update_ += Cycles(cycles_run_for);
 			cycles_since_6532_update_ += Cycles(cycles_run_for / 3);
-			static_cast<T *>(this)->advance_cycles((unsigned int)cycles_run_for / 3);
+			static_cast<T *>(this)->advance_cycles(cycles_run_for / 3);
 
 			if(operation != CPU::MOS6502::BusOperation::Ready) {
 				// give the cartridge a chance to respond to the bus access
diff --git a/Machines/Atari2600/Cartridges/CartridgePitfall2.hpp b/Machines/Atari2600/Cartridges/CartridgePitfall2.hpp
index dfd8c73ea..7921a918a 100644
--- a/Machines/Atari2600/Cartridges/CartridgePitfall2.hpp
+++ b/Machines/Atari2600/Cartridges/CartridgePitfall2.hpp
@@ -22,7 +22,7 @@ class CartridgePitfall2: public Cartridge<CartridgePitfall2> {
 			rom_ptr_ = rom_.data();
 		}
 
-		void advance_cycles(unsigned int cycles) {
+		void advance_cycles(int cycles) {
 			cycles_since_audio_update_ += cycles;
 		}
 
@@ -105,8 +105,7 @@ class CartridgePitfall2: public Cartridge<CartridgePitfall2> {
 
 		inline uint8_t update_audio() {
 			const unsigned int clock_divisor = 57;
-			unsigned int cycles_to_run_for = cycles_since_audio_update_ / clock_divisor;
-			cycles_since_audio_update_ %= clock_divisor;
+			int cycles_to_run_for = cycles_since_audio_update_.divide(clock_divisor).as_int();
 
 			int table_position = 0;
 			for(int c = 0; c < 3; c++) {
@@ -126,7 +125,7 @@ class CartridgePitfall2: public Cartridge<CartridgePitfall2> {
 		uint8_t random_number_generator_;
 		uint8_t *rom_ptr_;
 		uint8_t audio_channel_[3];
-		unsigned int cycles_since_audio_update_;
+		Cycles cycles_since_audio_update_;
 };
 
 }
diff --git a/Machines/Atari2600/TIA.cpp b/Machines/Atari2600/TIA.cpp
index aedbb6bcf..270a495f6 100644
--- a/Machines/Atari2600/TIA.cpp
+++ b/Machines/Atari2600/TIA.cpp
@@ -198,8 +198,8 @@ void TIA::set_blank(bool blank) {
 void TIA::reset_horizontal_counter() {
 }
 
-int TIA::get_cycles_until_horizontal_blank(unsigned int from_offset) {
-	return (cycles_per_line - (horizontal_counter_ + (int)from_offset) % cycles_per_line) % cycles_per_line;
+int TIA::get_cycles_until_horizontal_blank(const Cycles &from_offset) {
+	return (cycles_per_line - (horizontal_counter_ + from_offset.as_int()) % cycles_per_line) % cycles_per_line;
 }
 
 void TIA::set_background_colour(uint8_t colour) {
diff --git a/Machines/Atari2600/TIA.hpp b/Machines/Atari2600/TIA.hpp
index 9e45af447..8e7f50826 100644
--- a/Machines/Atari2600/TIA.hpp
+++ b/Machines/Atari2600/TIA.hpp
@@ -43,7 +43,7 @@ class TIA: public ClockReceiver<TIA> {
 			@returns the number of cycles between (current TIA time) + from_offset to the current or
 			next horizontal blanking period. Returns numbers in the range [0, 227].
 		*/
-		int get_cycles_until_horizontal_blank(unsigned int from_offset);
+		int get_cycles_until_horizontal_blank(const Cycles &from_offset);
 
 		void set_background_colour(uint8_t colour);