react-gbajs: add hacks

Author: macabeus

src/emulator/gba.js

@@ -20,6 +20,8 @@ function GameBoyAdvance() {
 	this.keypad = new GameBoyAdvanceKeypad();
 	this.sio = new GameBoyAdvanceSIO();
 
+	this.frozenAddresses = {};
+
 	// TODO: simplify this graph
 	this.cpu.mmu = this.mmu;
 	this.cpu.irq = this.irq;
@@ -71,6 +73,14 @@ function GameBoyAdvance() {
 
 window.GameBoyAdvance = GameBoyAdvance
 
+GameBoyAdvance.prototype.addFreezeAddress = function({ address, size, value }) {
+	this.frozenAddresses[address] = { size, value };
+};
+
+GameBoyAdvance.prototype.removeFreezeAddress = function(address) {
+	delete this.frozenAddresses[address];
+};
+
 GameBoyAdvance.prototype.setCanvas = function(canvas) {
 	var self = this;
 	if (canvas.offsetWidth != 240 || canvas.offsetHeight != 160) {
@@ -144,8 +154,26 @@ GameBoyAdvance.prototype.reset = function() {
 };
 
 GameBoyAdvance.prototype.step = function() {
+	const mmuMemoryIram = this.mmu.memory[this.mmu.REGION_WORKING_IRAM];
+
 	while (this.doStep()) {
 		this.cpu.step();
+
+		for (const address in this.frozenAddresses) {
+			const { size, value } = this.frozenAddresses[address];
+
+			switch (size) {
+				case 8:
+					mmuMemoryIram.store8(address, value);
+					break;
+				case 16:
+					mmuMemoryIram.store16(address, value);
+					break;
+				case 16:
+					mmuMemoryIram.store32(address, value);
+					break;
+			}
+		}
 	}
 };
 

src/react/gba-provider.js

@@ -8,6 +8,7 @@ const GbaProvider = ({ children }) => {
   const [gba, setGba] = useState()
   const [volume, setVolume] = useState(null)
   const [romBufferMemory, setRomBufferMemory] = useState()
+  const [frozenAddresses, setFrozenAddresses] = useState({})
 
   const play = (newRomBufferMemory) => {
     setRomBufferMemory(newRomBufferMemory)
@@ -25,13 +26,25 @@ const GbaProvider = ({ children }) => {
     gba.runStable()
   }
 
+  const updateFrozenAddreses = () =>
+    setFrozenAddresses(cloneDeep(gba.frozenAddresses))
+
   return (
     <GbaContext.Provider value={{
       gba,
       setRomBufferMemory,
       play,
       saveState,
       restoreState,
+      frozenAddresses,
+      addFreezeAddress: gba && ((args) => {
+        gba.addFreezeAddress(args)
+        updateFrozenAddreses()
+      }),
+      removeFreezeAddress: gba && ((args) => {
+        gba.removeFreezeAddress(args)
+        updateFrozenAddreses()
+      }),
     }}
     >
       {children}