DS GX: Fix bitmap textures when no palette is mapped (fixes #628)

CHANGES

@@ -17,6 +17,7 @@ Bugfixes:
  - DS Video: Fix extended mode 0 without extended palettes
  - DS Video: Fix caputre stride
  - DS Video: Fix affine transformations in video capture
+ - DS GX: Fix bitmap textures when no palette is mapped (fixes mgba.io/i/628)
 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/software.c

@@ -458,18 +458,18 @@ static void _preparePoly(struct DSGXRenderer* renderer, struct DSGXVertex* verts
 	poly->texBase = NULL;
 	poly->palBase = NULL;
 	if (renderer->tex[DSGXTexParamsGetVRAMBase(poly->texParams) >> VRAM_BLOCK_OFFSET]) {
+		poly->texBase = &renderer->tex[DSGXTexParamsGetVRAMBase(poly->poly->texParams) >> VRAM_BLOCK_OFFSET][(DSGXTexParamsGetVRAMBase(poly->poly->texParams) << 2) & 0xFFFF];
 		switch (poly->texFormat) {
 		case 0:
+		poly->texBase = NULL;
 			break;
 		case 2:
 			if (renderer->texPal[poly->poly->palBase >> 11]) {
-				poly->texBase = &renderer->tex[DSGXTexParamsGetVRAMBase(poly->poly->texParams) >> VRAM_BLOCK_OFFSET][(DSGXTexParamsGetVRAMBase(poly->poly->texParams) << 2) & 0xFFFF];
 				poly->palBase = &renderer->texPal[poly->poly->palBase >> 11][(poly->poly->palBase << 2) & 0x1FFF];
 			}
 			break;
 		default:
 			if (renderer->texPal[poly->poly->palBase >> 10]) {
-				poly->texBase = &renderer->tex[DSGXTexParamsGetVRAMBase(poly->poly->texParams) >> VRAM_BLOCK_OFFSET][(DSGXTexParamsGetVRAMBase(poly->poly->texParams) << 2) & 0xFFFF];
 				poly->palBase = &renderer->texPal[poly->poly->palBase >> 10][(poly->poly->palBase << 3) & 0x1FFF];
 			}
 			break;