texconv: -ignoremips options for reading some invalid DDS files (#484)

DirectXTex/DirectXTex.h

@@ -236,6 +236,9 @@ namespace DirectX
         DDS_FLAGS_PERMISSIVE = 0x80,
         // Allow some file variants due to common bugs in the header written by various leagcy DDS writers
 
+        DDS_FLAGS_IGNORE_MIPS = 0x100,
+        // Allow some files to be read that have incorrect mipcount values in the header by only reading the top-level mip
+
         DDS_FLAGS_FORCE_DX10_EXT = 0x10000,
         // Always use the 'DX10' header extension for DDS writer (i.e. don't try to write DX9 compatible DDS files)
 

DirectXTex/DirectXTexDDS.cpp

@@ -369,8 +369,10 @@ namespace
         }
 
         metadata.mipLevels = pHeader->mipMapCount;
-        if (metadata.mipLevels == 0)
+        if ((metadata.mipLevels == 0) || (flags & DDS_FLAGS_IGNORE_MIPS))
+        {
             metadata.mipLevels = 1;
+        }
 
         // Check for DX10 extension
         if ((pHeader->ddspf.flags & DDS_FOURCC)

Texconv/texconv.cpp

@@ -110,6 +110,7 @@ namespace
         OPT_DDS_DWORD_ALIGN,
         OPT_DDS_BAD_DXTN_TAILS,
         OPT_DDS_PERMISSIVE,
+        OPT_DDS_IGNORE_MIPS,
         OPT_USE_DX10,
         OPT_USE_DX9,
         OPT_TGA20,
@@ -211,6 +212,7 @@ namespace
         { L"dword",         OPT_DDS_DWORD_ALIGN },
         { L"badtails",      OPT_DDS_BAD_DXTN_TAILS },
         { L"permissive",    OPT_DDS_PERMISSIVE },
+        { L"ignoremips",    OPT_DDS_IGNORE_MIPS },
         { L"dx10",          OPT_USE_DX10 },
         { L"dx9",           OPT_USE_DX9 },
         { L"tga20",         OPT_TGA20 },
@@ -1013,6 +1015,7 @@ namespace
             L"   -dword              Use DWORD instead of BYTE alignment\n"
             L"   -badtails           Fix for older DXTn with bad mipchain tails\n"
             L"   -permissive         Allow some DX9 variants with unusual header values\n"
+            L"   -ignoremips         Reads just the top-level mip which reads some invalid files\n"
             L"   -fixbc4x4           Fix for odd-sized BC files that Direct3D can't load\n"
             L"   -xlum               expand legacy L8, L16, and A8P8 formats\n"
             L"\n"
@@ -2240,6 +2243,8 @@ int __cdecl wmain(_In_ int argc, _In_z_count_(argc) wchar_t* argv[])
                     ddsFlags |= DDS_FLAGS_BAD_DXTN_TAILS;
                 if (dwOptions & (uint64_t(1) << OPT_DDS_PERMISSIVE))
                     ddsFlags |= DDS_FLAGS_PERMISSIVE;
+                if (dwOptions & (uint64_t(1) << OPT_DDS_IGNORE_MIPS))
+                    ddsFlags |= DDS_FLAGS_IGNORE_MIPS;
 
                 hr = LoadFromDDSFile(curpath.c_str(), ddsFlags, &info, *image);
             }

Texdiag/texdiag.cpp

@@ -91,6 +91,8 @@ enum OPTIONS : uint32_t
     OPT_FILTER,
     OPT_DDS_DWORD_ALIGN,
     OPT_DDS_BAD_DXTN_TAILS,
+    OPT_DDS_PERMISSIVE,
+    OPT_DDS_IGNORE_MIPS,
     OPT_OUTPUTFILE,
     OPT_TOLOWER,
     OPT_OVERWRITE,
@@ -142,6 +144,8 @@ const SValue g_pOptions[] =
     { L"if",         OPT_FILTER },
     { L"dword",      OPT_DDS_DWORD_ALIGN },
     { L"badtails",   OPT_DDS_BAD_DXTN_TAILS },
+    { L"permissive", OPT_DDS_PERMISSIVE },
+    { L"ignoremips", OPT_DDS_IGNORE_MIPS },
     { L"nologo",     OPT_NOLOGO },
     { L"o",          OPT_OUTPUTFILE },
     { L"l",          OPT_TOLOWER },
@@ -706,6 +710,8 @@ namespace
             L"   -t{u|f}             TYPELESS format is treated as UNORM or FLOAT\n"
             L"   -dword              Use DWORD instead of BYTE alignment\n"
             L"   -badtails           Fix for older DXTn with bad mipchain tails\n"
+            L"   -permissive         Allow some DX9 variants with unusual header values\n"
+            L"   -ignoremips         Reads just the top-level mip which reads some invalid files\n"
             L"   -xlum               expand legacy L8, L16, and A8P8 formats\n"
             L"\n"
             L"                       (diff only)\n"
@@ -805,6 +811,10 @@ namespace
                 ddsFlags |= DDS_FLAGS_EXPAND_LUMINANCE;
             if (dwOptions & (1 << OPT_DDS_BAD_DXTN_TAILS))
                 ddsFlags |= DDS_FLAGS_BAD_DXTN_TAILS;
+            if (dwOptions & (1 << OPT_DDS_PERMISSIVE))
+                ddsFlags |= DDS_FLAGS_PERMISSIVE;
+            if (dwOptions & (1 << OPT_DDS_IGNORE_MIPS))
+                ddsFlags |= DDS_FLAGS_IGNORE_MIPS;
 
             HRESULT hr = LoadFromDDSFile(fileName, ddsFlags, &info, *image);
             if (FAILED(hr))