Fix mipmapped cubemaps

which had broken faces (other than the first face)
because the slice pitch calculation did not account for mipmaps.
We are iterating the mipmaps already, so just calculate the slice pitch directly
rather than trying to generalize CxbxGetPixelContainerMeasures

src/core/hle/D3D8/Direct3D9/Direct3D9.cpp

@@ -5848,6 +5848,7 @@ void CreateHostResource(xbox::X_D3DResource *pResource, DWORD D3DUsage, int iTex
 			blockSize = X_Format == xbox::X_D3DFMT_DXT1 ? 8 : 16;
 		}
 
+		DWORD actualSlicePitch = dwSlicePitch;
 		for (int face = D3DCUBEMAP_FACE_POSITIVE_X; face <= last_face; face++) {
 			// As we iterate through mipmap levels, we'll adjust the source resource offset
 			DWORD dwMipOffset = 0;
@@ -5924,6 +5925,11 @@ void CreateHostResource(xbox::X_D3DResource *pResource, DWORD D3DUsage, int iTex
 
 				uint8_t *pSrc = (uint8_t *)VirtualAddr + dwCubeFaceOffset + dwMipOffset;
 
+				// If this is the final mip of the first cube face, set the cube face size
+				if (face == D3DCUBEMAP_FACE_POSITIVE_X && mipmap_level >= dwMipMapLevels - 1) {
+					actualSlicePitch = ROUND_UP(((UINT)pSrc + mipSlicePitch) - (UINT)VirtualAddr, X_D3DTEXTURE_CUBEFACE_ALIGNMENT);
+				}
+
 				// Copy texture data to the host resource
 				if (bConvertToARGB) {
 					EmuLog(LOG_LEVEL::DEBUG, "Unsupported texture format, expanding to D3DFMT_A8R8G8B8");
@@ -6023,7 +6029,7 @@ void CreateHostResource(xbox::X_D3DResource *pResource, DWORD D3DUsage, int iTex
 				}
 			} // for mipmap levels
 
-			dwCubeFaceOffset += dwSlicePitch;
+			dwCubeFaceOffset += actualSlicePitch;
 		} // for cube faces
 
 

src/core/hle/D3D8/XbConvert.cpp

@@ -1614,6 +1614,7 @@ void CxbxGetPixelContainerMeasures
 	UINT* pHeight,
 	UINT* pDepth,
 	UINT* pRowPitch,
+	// Slice pitch (does not include mipmaps!)
 	UINT* pSlicePitch
 )
 {