M include/mgba/internal/ds/gx.h → include/mgba/internal/ds/gx.h

@@ -121,7 +121,7 @@ int outstandingParams[4];
 	uint8_t outstandingCommand[4];
 
 	int activeParams;
-	int activeEntries[32];
+	struct DSGXEntry activeEntries[32];
 
 	bool swapBuffers;
 	int bufferIndex;

M src/ds/gx.c → src/ds/gx.c

@@ -140,8 +140,13 @@ static void _fifoRun(struct mTiming* timing, void* context, uint32_t cyclesLate) {
 	struct DSGX* gx = context;
 	uint32_t cycles;
 	bool first = true;
-	while (true) {
-		if (gx->swapBuffers) {
+	while (!gx->swapBuffers) {
+		if (CircleBufferSize(&gx->pipe) <= 2 * sizeof(struct DSGXEntry)) {
+			_pullPipe(gx);
+		}
+
+		if (!CircleBufferSize(&gx->pipe)) {
+			cycles = 0;
 			break;
 		}
 
@@ -149,10 +154,6 @@ DSRegGXSTAT gxstat = gx->p->memory.io9[DS9_REG_GXSTAT_LO >> 1];
 		int pvMatrixPointer = DSRegGXSTATGetPVMatrixStackLevel(gxstat);
 		int projMatrixPointer = DSRegGXSTATGetProjMatrixStackLevel(gxstat);
 
-		if (CircleBufferSize(&gx->pipe) <= 2 * sizeof(struct DSGXEntry)) {
-			_pullPipe(gx);
-		}
-
 		struct DSGXEntry entry = { 0 };
 		CircleBufferDump(&gx->pipe, (int8_t*) &entry.command, 1);
 		cycles = _gxCommandCycleBase[entry.command];
@@ -168,6 +169,24 @@ CircleBufferRead8(&gx->pipe, (int8_t*) &entry.params[1]);
 		CircleBufferRead8(&gx->pipe, (int8_t*) &entry.params[2]);
 		CircleBufferRead8(&gx->pipe, (int8_t*) &entry.params[3]);
 
+		if (gx->activeParams) {
+			int index = _gxCommandParams[entry.command] - gx->activeParams;
+			gx->activeEntries[index] = entry;
+			--gx->activeParams;
+		} else {
+			gx->activeParams = _gxCommandParams[entry.command];
+			if (gx->activeParams) {
+				--gx->activeParams;
+			}
+			if (gx->activeParams) {
+				gx->activeEntries[0] = entry;
+			}
+		}
+
+		if (gx->activeParams) {
+			continue;
+		}
+
 		switch (entry.command) {
 		case DS_GX_CMD_MTX_MODE:
 			if (entry.params[0] < 4) {
@@ -249,9 +268,7 @@ gx->p->memory.io9[DS9_REG_GXSTAT_LO >> 1] = gxstat;
 
 		if (cyclesLate >= cycles) {
 			cyclesLate -= cycles;
-		}
-		if (!CircleBufferSize(&gx->pipe)) {
-			cycles = 0;
+		} else {
 			break;
 		}
 	}
@@ -298,6 +315,7 @@ gx->mtxMode = 0;
 
 	memset(gx->outstandingParams, 0, sizeof(gx->outstandingParams));
 	memset(gx->outstandingCommand, 0, sizeof(gx->outstandingCommand));
+	gx->activeParams = 0;
 }
 
 void DSGXAssociateRenderer(struct DSGX* gx, struct DSGXRenderer* renderer) {