alttp: fix SRAM data reads to be more predictable and much more frequ…

…ent; updated ROM patcher to only disallow 3 modules for receiving updates

games/alttp/patcher.go

@@ -13,7 +13,7 @@ import (
 )
 
 const (
-	preMainLen = 0x26
+	preMainLen = 0x1E
 	// SRAM address of preMain routine called nearly every frame before `JSL GameModes`
 	preMainAddr        = uint32(0x708000 - preMainLen)
 	preMainJSRAddr     = uint32(0x707FFA)
@@ -139,32 +139,29 @@ func (p *Patcher) Patch() (err error) {
 		taMain.AssumeSEP(0x30)
 
 		taMain.Label("moduleCheck")
-
-		// build a reversed bitmask because our bitmask lookup table is reversed:
-		mask := uint16(0)
-		for m := range modulesOKForSync {
-			mask |= uint16(1 << (15 - (m - 0x07)))
-		}
-		log.Printf("mask: %04X\n", mask)
-
-		taMain.Comment("only sync during modules 07,09,0B,0E,0F,10,11,13,15,16:")
+		taMain.Comment("only update during safe modules:")
 		taMain.LDA_dp(0x10)
-		taMain.CMP_imm8_b(0x17)
+		// >= $19    : bad
+		taMain.CMP_imm8_b(0x19)
 		taMain.BCS("syncExit")
+		// <= $06    : bad
 		taMain.SBC_imm8_b(0x07 - 1)
 		taMain.BMI("syncExit")
-		taMain.ASL()
-		taMain.TAX()
-		taMain.REP(0x20)
-		// DungeonMask#_0098C0 is a uin16[16] of bit masks from $8000 down to $0001
-		taMain.LDA_long_x(0x00_98C0)
-		taMain.AND_imm16_w(mask)
-		taMain.SEP(0x20)
+		// == $08    : bad
+		taMain.CMP_imm8_b(0x08)
 		taMain.BEQ("syncExit")
+		// == $0A    : bad
+		taMain.CMP_imm8_b(0x0A)
+		taMain.BEQ("syncExit")
+		// == $14    : bad
+		taMain.CMP_imm8_b(0x14)
+		taMain.BEQ("syncExit")
+		// ok:
 		taMain.Label("linkCheck")
-		taMain.Comment("don't update if Link is frozen:")
-		taMain.LDA_abs(0x02E4)
-		taMain.BNE("syncExit")
+
+		//taMain.Comment("don't update if Link is frozen:")
+		//taMain.LDA_abs(0x02E4)
+		//taMain.BNE("syncExit")
 
 		jsr := taMain.Label("syncStart")
 		if preMainJSRAddr != jsr+2 {

games/alttp/run.go

@@ -122,7 +122,7 @@ func (g *Game) run() {
 
 	// kick off initial WRAM read request:
 	g.priorityReadsMu.Lock()
-	q = g.enqueueWRAMReads(q)
+	q = g.queueReads(q)
 	// must always read module number LAST to validate the prior reads:
 	q = g.enqueueMainRead(q)
 	g.priorityReads[2] = q
@@ -195,29 +195,11 @@ func (g *Game) run() {
 				if stg == 0 {
 					// make sure a read request is always in flight to keep our main loop running:
 					timeSinceRead := time.Now().Sub(g.lastReadCompleted)
-					if timeSinceRead < time.Millisecond*512 {
-						// read SRAM data:
-						g.priorityReadsMu.Lock()
-						q := make([]snes.Read, 0, 12)
-						q = g.enqueueSRAMRead(q)
-
-						if debugSprites {
-							// DEBUG read sprite WRAM:
-							q = g.readEnqueue(q, 0xF50D00, 0xF0, 1) // [$0D00..$0DEF]
-							q = g.readEnqueue(q, 0xF50DF0, 0xF0, 1) // [$0DF0..$0EDF]
-							q = g.readEnqueue(q, 0xF50EE0, 0xC0, 1) // [$0EE0..$0F9F]
-						}
-
-						// must always read module number LAST to validate the prior reads:
-						q = g.enqueueMainRead(q)
-						g.priorityReads[1] = q
-						g.priorityReadsMu.Unlock()
-					} else {
+					if timeSinceRead > time.Millisecond*250 {
 						g.priorityReadsMu.Lock()
 						log.Printf("alttp: fastbeat: enqueue main reads; %d msec since last read\n", timeSinceRead.Milliseconds())
 						q := make([]snes.Read, 0, 12)
-						q = g.enqueueWRAMReads(q)
-						// must always read module number LAST to validate the prior reads:
+						q = g.queueReads(q)
 						q = g.enqueueMainRead(q)
 						g.priorityReads[2] = q
 						g.priorityReadsMu.Unlock()
@@ -334,6 +316,25 @@ func (g *Game) enqueueMainRead(q []snes.Read) []snes.Read {
 	return q
 }
 
+func (g *Game) queueReads(q []snes.Read) []snes.Read {
+	if g.monotonicFrameTime&7 == 7 {
+		// read SRAM data less frequently:
+		q = g.enqueueSRAMRead(q)
+
+		if debugSprites {
+			// DEBUG read sprite WRAM:
+			q = g.readEnqueue(q, 0xF50D00, 0xF0, 1) // [$0D00..$0DEF]
+			q = g.readEnqueue(q, 0xF50DF0, 0xF0, 1) // [$0DF0..$0EDF]
+			q = g.readEnqueue(q, 0xF50EE0, 0xC0, 1) // [$0EE0..$0F9F]
+		}
+	} else {
+		// normally read just WRAM data:
+		q = g.enqueueWRAMReads(q)
+	}
+
+	return q
+}
+
 // called when all reads are completed:
 func (g *Game) readMainComplete(rsps []snes.Response) {
 	g.stateLock.Lock()
@@ -442,6 +443,11 @@ func (g *Game) readMainComplete(rsps []snes.Response) {
 		newFrame := g.wram[0x1A]
 		g.lastGameFrame = lastFrame
 
+		// should wrap around 255 to 0:
+		g.monotonicFrameTime++
+
+		//log.Printf("server now(): %v\n", g.ServerNow())
+
 		// assign local variables from WRAM:
 		local := g.LocalPlayer()
 
@@ -489,7 +495,7 @@ func (g *Game) readMainComplete(rsps []snes.Response) {
 		local.PriorModule = Module(g.wram[0x010C])
 
 		// only sample location during sub-module 0 for any module; keeps location more stable:
-		if local.SubModule == 0 {
+		if local.Module == 0x15 || local.SubModule == 0 {
 			inDungeon := g.wram[0x1B]
 			overworldArea := g.wramU16(0x8A)
 			dungeonRoom := g.wramU16(0xA0)
@@ -587,11 +593,6 @@ func (g *Game) readMainComplete(rsps []snes.Response) {
 			return
 		}
 
-		// should wrap around 255 to 0:
-		g.monotonicFrameTime++
-
-		//log.Printf("server now(): %v\n", g.ServerNow())
-
 		// handle WRAM reads:
 		g.readWRAM()
 		g.notFirstWRAMRead = true
@@ -689,8 +690,7 @@ func (g *Game) readMainComplete(rsps []snes.Response) {
 		return
 	}
 
-	// do all the normal WRAM reads:
-	q = g.enqueueWRAMReads(q)
+	q = g.queueReads(q)
 	q = g.enqueueMainRead(q)
 	g.priorityReads[2] = q
 

games/alttp/sync.go

@@ -15,9 +15,12 @@ var modulesOKForSync = map[uint8]struct{}{
 	0x0F: {},
 	0x10: {},
 	0x11: {},
+	0x12: {},
 	0x13: {},
 	0x15: {},
 	0x16: {},
+	0x17: {},
+	0x18: {},
 }
 
 var dungeonNames = []string{

games/alttp/syncsmallkeys.go

@@ -79,7 +79,7 @@ func (g *Game) readWRAM() {
 	nowTs := timestampFromTime(now)
 
 	// copy current dungeon small key counter to specific dungeon:
-	if g.wramFresh[0xF36F] && local.IsInDungeon() {
+	if g.wramFresh[0xF36F] && local.IsInDungeon() && local.SubModule == 0 {
 		dungeonNumber := local.Dungeon
 		if dungeonNumber != 0xFF && dungeonNumber < 0x20 {
 			currentKeyCount := g.wram[0xF36F]