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

@@ -47,6 +47,16 @@ DECL_BITS(DSGXTexParams, Format, 26, 3);
 DECL_BIT(DSGXTexParams, 0Transparent, 29);
 DECL_BITS(DSGXTexParams, CoordTfMode, 30, 2);
 
+DECL_BITFIELD(DSGXPolygonAttrs, uint32_t);
+DECL_BIT(DSGXPolygonAttrs, Light0, 0);
+DECL_BIT(DSGXPolygonAttrs, Light1, 1);
+DECL_BIT(DSGXPolygonAttrs, Light2, 2);
+DECL_BIT(DSGXPolygonAttrs, Light3, 3);
+DECL_BITS(DSGXPolygonAttrs, Mode, 4, 2);
+DECL_BIT(DSGXPolygonAttrs, FrontFace, 6);
+DECL_BIT(DSGXPolygonAttrs, BackFace, 7);
+// TODO
+
 enum DSGXCommand {
 	DS_GX_CMD_NOP = 0,
 	DS_GX_CMD_MTX_MODE = 0x10,

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

@@ -20,6 +20,7 @@ struct DSGXPolygon* poly;
 	uint16_t* texBase;
 	uint16_t* palBase;
 	int texFormat;
+	int blendFormat;
 	int texW;
 	int texH;
 };

M src/ds/gx/software.c → src/ds/gx/software.c

@@ -109,9 +109,20 @@ if (DSGXTexParamsIs0Transparent(poly->poly->texParams) && !texel) {
 		return FLAG_UNWRITTEN;
 	}
 	uint8_t r, g, b;
+	unsigned wr, wg, wb;
 	texel = poly->palBase[texel];
 	_expandColor(texel, &r, &g, &b);
-	return _finishColor(r, g, b);
+	switch (poly->blendFormat) {
+	case 1:
+	default:
+		// TODO: Alpha
+		return _finishColor(r, g, b);
+	case 0:
+		wr = ((r + 1) * (ep->cr + 1) - 1) >> 6;
+		wg = ((g + 1) * (ep->cg + 1) - 1) >> 6;
+		wb = ((b + 1) * (ep->cb + 1) - 1) >> 6;
+		return _finishColor(wr, wg, wb);
+	}
 }
 
 static int _edgeSort(const void* a, const void* b) {
@@ -285,6 +296,7 @@ struct DSGXSoftwarePolygon* poly = DSGXSoftwarePolygonListAppend(&softwareRenderer->activePolys);
 		struct DSGXSoftwareEdge* edge = DSGXSoftwareEdgeListAppend(&softwareRenderer->activeEdges);
 		poly->poly = &polys[i];
 		poly->texFormat = DSGXTexParamsGetFormat(poly->poly->texParams);
+		poly->blendFormat = DSGXPolygonAttrsGetMode(poly->poly->polyParams);
 		poly->texW = 8 << DSGXTexParamsGetSSize(poly->poly->texParams);
 		poly->texH = 8 << DSGXTexParamsGetTSize(poly->poly->texParams);
 		switch (poly->texFormat) {