From e423cd45e5805f0d45fceb032eee8bee6d00f1c6 Mon Sep 17 00:00:00 2001
From: Jeffrey Pfau <jeffrey@endrift.com>
Date: Fri, 23 Sep 2016 22:26:01 -0700
Subject: [PATCH] Core: Scheduling should be relative to current cycles

---
 src/core/timing.c |  5 +++--
 src/core/timing.h |  3 ++-
 src/gb/gb.c       | 13 ++++++-------
 src/gb/memory.c   |  2 +-
 4 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/src/core/timing.c b/src/core/timing.c
index 2498ff30b..9ee376fb0 100644
--- a/src/core/timing.c
+++ b/src/core/timing.c
@@ -7,9 +7,10 @@
 
 DEFINE_VECTOR(mTimingEventList, struct mTimingEvent*);
 
-void mTimingInit(struct mTiming* timing) {
+void mTimingInit(struct mTiming* timing, int32_t* relativeCycles) {
 	mTimingEventListInit(&timing->events, 0);
 	timing->masterCycles = 0;
+	timing->relativeCycles = relativeCycles;
 }
 
 void mTimingDeinit(struct mTiming* timing) {
@@ -22,7 +23,7 @@ void mTimingClear(struct mTiming* timing) {
 }
 
 void mTimingSchedule(struct mTiming* timing, struct mTimingEvent* event, int32_t when) {
-	event->when = when + timing->masterCycles;
+	event->when = when + timing->masterCycles + *timing->relativeCycles;
 	size_t e;
 	for (e = 0; e < mTimingEventListSize(&timing->events); ++e) {
 		struct mTimingEvent* next = *mTimingEventListGetPointer(&timing->events, e);
diff --git a/src/core/timing.h b/src/core/timing.h
index 7a085e750..55934c6b4 100644
--- a/src/core/timing.h
+++ b/src/core/timing.h
@@ -23,9 +23,10 @@ struct mTiming {
 	struct mTimingEventList events;
 
 	uint32_t masterCycles;
+	int32_t* relativeCycles;
 };
 
-void mTimingInit(struct mTiming* timing);
+void mTimingInit(struct mTiming* timing, int32_t* relativeCycles);
 void mTimingDeinit(struct mTiming* timing);
 void mTimingClear(struct mTiming* timing);
 void mTimingSchedule(struct mTiming* timing, struct mTimingEvent*, int32_t when);
diff --git a/src/gb/gb.c b/src/gb/gb.c
index 38f281419..d304f3449 100644
--- a/src/gb/gb.c
+++ b/src/gb/gb.c
@@ -83,7 +83,7 @@ static void GBInit(void* cpu, struct mCPUComponent* component) {
 	gb->coreCallbacks = NULL;
 	gb->stream = NULL;
 
-	mTimingInit(&gb->timing);
+	mTimingInit(&gb->timing, &gb->cpu->cycles);
 }
 
 static void GBDeinit(struct mCPUComponent* component) {
@@ -529,9 +529,12 @@ void GBProcessEvents(struct LR35902Core* cpu) {
 	struct GB* gb = (struct GB*) cpu->master;
 	do {
 		int32_t cycles = cpu->nextEvent;
-		int32_t nextEvent = INT_MAX;
+		int32_t nextEvent;
 		int32_t testEvent;
 
+		cpu->cycles -= cycles;
+		cpu->nextEvent = INT_MAX;
+
 		if (gb->eiPending != INT_MAX) {
 			gb->eiPending -= cycles;
 			if (gb->eiPending <= 0) {
@@ -544,10 +547,7 @@ void GBProcessEvents(struct LR35902Core* cpu) {
 		}
 
 		mTimingTick(&gb->timing, cycles);
-		testEvent = mTimingNextEvent(&gb->timing);
-		if (testEvent < nextEvent) {
-			nextEvent = testEvent;
-		}
+		nextEvent = cpu->nextEvent;
 
 		testEvent = GBAudioProcessEvents(&gb->audio, cycles >> gb->doubleSpeed);
 		if (testEvent != INT_MAX) {
@@ -557,7 +557,6 @@ void GBProcessEvents(struct LR35902Core* cpu) {
 			}
 		}
 
-		cpu->cycles -= cycles;
 		cpu->nextEvent = nextEvent;
 
 		if (cpu->halted) {
diff --git a/src/gb/memory.c b/src/gb/memory.c
index f6cb3eb60..ebcd107b5 100644
--- a/src/gb/memory.c
+++ b/src/gb/memory.c
@@ -409,7 +409,6 @@ void _GBMemoryHDMAService(struct mTiming* timing, void* context, uint32_t cycles
 	++gb->memory.hdmaSource;
 	++gb->memory.hdmaDest;
 	--gb->memory.hdmaRemaining;
-	gb->cpu->cycles += 2;
 	if (gb->memory.hdmaRemaining) {
 		mTimingSchedule(timing, &gb->memory.hdmaEvent, 2 - cyclesLate);
 	} else {
@@ -426,6 +425,7 @@ void _GBMemoryHDMAService(struct mTiming* timing, void* context, uint32_t cycles
 			gb->memory.io[REG_HDMA5] = 0xFF;
 		}
 	}
+	gb->cpu->cycles += 2;
 }
 
 struct OAMBlock {