DS GX: Reset polygon attributes between buffer swaps

CHANGES

@@ -8,6 +8,7 @@ Bugfixes:
  - DS Video: Capture with alpha bit set
  - DS Video: Bitmap sprites use alpha bit for transparent
  - DS GX: Fix 4-color texture coordinates
+ - DS GX: Reset polygon attributes between buffer swaps
 Misc:
  - DS: Set boot complete bit in RAM on boot (fixes mgba.io/i/576, mgba.io/i/580, mgba.io/i/586)
  - DS Memory: Ensure DS9 I/O is 8-byte aligned

src/ds/gx.c

@@ -1175,6 +1175,8 @@ static void _fifoRun(struct mTiming* timing, void* context, uint32_t cyclesLate)
 			memset(&gx->currentVertex, 0, sizeof(gx->currentVertex));
 			memset(&gx->nextPoly, 0, sizeof(gx-> nextPoly));
 			gx->currentVertex.color = 0x7FFF;
+			gx->currentPoly.polyParams = 0x001F00C0;
+			gx->nextPoly.polyParams = 0x001F00C0;
 			break;
 		case DS_GX_CMD_VIEWPORT:
 			gx->viewportX1 = (uint8_t) entry.params[0];
@@ -1279,6 +1281,8 @@ void DSGXReset(struct DSGX* gx) {
 	memset(&gx->currentVertex, 0, sizeof(gx->currentVertex));
 	memset(&gx->nextPoly, 0, sizeof(gx-> nextPoly));
 	gx->currentVertex.color = 0x7FFF;
+	gx->currentPoly.polyParams = 0x001F00C0;
+	gx->nextPoly.polyParams = 0x001F00C0;
 	gx->dmaSource = -1;
 }