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

@@ -52,6 +52,7 @@ DECL_BITS(DSGXPolygonAttrs, Lights, 0, 4);
 DECL_BITS(DSGXPolygonAttrs, Mode, 4, 2);
 DECL_BIT(DSGXPolygonAttrs, FrontFace, 6);
 DECL_BIT(DSGXPolygonAttrs, BackFace, 7);
+DECL_BIT(DSGXPolygonAttrs, UpdateDepth, 11);
 // TODO
 DECL_BITS(DSGXPolygonAttrs, Alpha, 16, 5);
 

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

@@ -631,15 +631,11 @@ if (softwareRenderer->wSort) {
 					if (span->ep[0].w < softwareRenderer->depthBuffer[x]) {
 						softwareRenderer->depthBuffer[x] = span->ep[0].w;
 						scanline[x] = color;
-					} else if (b < 0x1F) {
-						scanline[x] = _mix32(b, current, 0x1F - b, color) | a << 27;
 					}
 				} else {
 					if (span->ep[0].z < softwareRenderer->depthBuffer[x]) {
 						softwareRenderer->depthBuffer[x] = span->ep[0].z;
 						scanline[x] = color;
-					} else if (b < 0x1F) {
-						scanline[x] = _mix32(b, current, 0x1F - b, color) | a << 27;
 					}
 				}
 			} else if (a) {
@@ -650,17 +646,17 @@ color |= ab << 27;
 				}
 				if (softwareRenderer->wSort) {
 					if (span->ep[0].w < softwareRenderer->depthBuffer[x]) {
-						softwareRenderer->depthBuffer[x] = span->ep[0].w;
+						if (DSGXPolygonAttrsIsUpdateDepth(span->poly->poly->polyParams)) {
+							softwareRenderer->depthBuffer[x] = span->ep[0].w;
+						}
 						scanline[x] = color;
-					} else if (b < 0x1F) {
-						scanline[x] = _mix32(b, current, 0x1F - b, color) | ab << 27;
 					}
 				} else {
 					if (span->ep[0].z < softwareRenderer->depthBuffer[x]) {
-						softwareRenderer->depthBuffer[x] = span->ep[0].z;
+						if (DSGXPolygonAttrsIsUpdateDepth(span->poly->poly->polyParams)) {
+							softwareRenderer->depthBuffer[x] = span->ep[0].z;
+						}
 						scanline[x] = color;
-					} else if (b < 0x1F) {
-						scanline[x] = _mix32(b, current, 0x1F - b, color) | ab << 27;
 					}
 				}
 			}