DDS cube map that DirectXTex corrupts faces when extracting

[0xC0000054]

The following DDS image has the 2nd through 6th cube map faces corrupted when trying to extract it.

https://github.com/vsg-dev/vsgExamples/blob/master/data/textures/skybox.dds

DirectXTex output (horizontal cross):

DDSView renders the image correctly:

The API call I am using to extract the top-level faces is:

const DirectX::Image* face = image.GetImage(0, i, 0);

[walbourn]

Thank you for the report and repro. It also loads correctly in Visual Studio which uses DirectXTex. I'll look into it.

[walbourn]

DDS Dump output for this file:

(size: 124) Flags 0002100f: CAPS HEIGHT WIDTH PITCH PIXELFORMAT MIPMAPCOUNT
512 x 512
Pitch: 2048
Mipmap count: 10
Surface flags: 00401008: COMPLEX TEXTURE MIPMAP
Cubemap flags: 0000fe00: CUBEMAP POSX POSY POSZ NEGX NEGY NEGZ
PIXELFORMAT (size 32): 00000004: FOURCC
FourCC = 808540228 'DX10'
dxgiFormat = 28: DXGI_FORMAT_R8G8B8A8_UNORM
resourceDim = 3: DDS_DIMENSION_TEXTURE2D
miscFlag = 00000004: TEXTURECUBE
arraySize = 1

[walbourn]

Well, texassemble's hcross operation works fine.

And this code does:

            for (size_t index = 0; index < 6; ++index)
            {
                auto img = (*src)->GetImage(0, index, 0);

So basically the same thing as you.

What are you doing with each face->rowPitch and face->pixels value to produce your corrupted image?

[0xC0000054]

What are you doing with each face->rowPitch and face->pixels value to produce your corrupted image?

Calling DirectXTex::SaveToWICFile. My test application is: https://github.com/0xC0000054/DumpDdsCubeMapFaces/blob/main/DumpDdsCubeMapFaces.cpp

The bug was initially reported in my Paint.NET plugin, it treats face->rowPitch as the stride and face->pixels as a pointer to the start of the first row (scan0).

[0xC0000054]

I discovered the source of the bug, it is the presence of the DirectX::DDS_FLAGS_IGNORE_MIPS flag. It appears that the presence of that flag is causing DirectXTex to read the wrong image data when loading a cube map with mipmaps.

I can remove that flag as a workaround. but ideally the DirectX::DDS_FLAGS_IGNORE_MIPS flag behavior with decoding multiple images should be fixed.

[walbourn]

Thanks! yes, I see that ignoremips doesn't work an array, cubemap, or cubemap array as written.

It will work fine for 1D, 2D, and 3D textures which have the data in miplevel order (volumes store depth in 'slices' with one slice per mip).

[walbourn]

The purpose of ignoremips is a simple header hack for some malformed files. I'm making it so that flag is ignored for all arrays/cubemaps.