//--------------------------------------------------------------------------------------
// File: Texassemble.cpp
//
// DirectX Texture assembler for cube maps, volume maps, and arrays
//
// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License.
//
// http://go.microsoft.com/fwlink/?LinkId=248926
//--------------------------------------------------------------------------------------

#pragma warning(push)
#pragma warning(disable : 4005)
#define WIN32_LEAN_AND_MEAN
#define NOMINMAX
#define NODRAWTEXT
#define NOGDI
#define NOMCX
#define NOSERVICE
#define NOHELP
#pragma warning(pop)

#include <cassert>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cwchar>
#include <fstream>
#include <iterator>
#include <memory>
#include <list>
#include <utility>
#include <vector>

#include <wrl/client.h>

#include <dxgiformat.h>

#include <DirectXPackedVector.h>
#include <wincodec.h>

#pragma warning(disable : 4619 4616 26812)

#include "DirectXTex.h"

//Uncomment to add support for OpenEXR (.exr)
//#define USE_OPENEXR

#ifdef USE_OPENEXR
// See <https://github.com/Microsoft/DirectXTex/wiki/Adding-OpenEXR> for details
#include "DirectXTexEXR.h"
#endif

using namespace DirectX;
using Microsoft::WRL::ComPtr;

namespace
{
    enum COMMANDS
    {
        CMD_CUBE = 1,
        CMD_VOLUME,
        CMD_ARRAY,
        CMD_CUBEARRAY,
        CMD_H_CROSS,
        CMD_V_CROSS,
        CMD_H_STRIP,
        CMD_V_STRIP,
        CMD_MERGE,
        CMD_GIF,
        CMD_ARRAY_STRIP,
        CMD_MAX
    };

    enum OPTIONS
    {
        OPT_RECURSIVE = 1,
        OPT_FILELIST,
        OPT_WIDTH,
        OPT_HEIGHT,
        OPT_FORMAT,
        OPT_FILTER,
        OPT_SRGBI,
        OPT_SRGBO,
        OPT_SRGB,
        OPT_OUTPUTFILE,
        OPT_TOLOWER,
        OPT_OVERWRITE,
        OPT_USE_DX10,
        OPT_NOLOGO,
        OPT_SEPALPHA,
        OPT_NO_WIC,
        OPT_DEMUL_ALPHA,
        OPT_TA_WRAP,
        OPT_TA_MIRROR,
        OPT_FEATURE_LEVEL,
        OPT_TONEMAP,
        OPT_GIF_BGCOLOR,
        OPT_SWIZZLE,
        OPT_MAX
    };

    static_assert(OPT_MAX <= 32, "dwOptions is a DWORD bitfield");

    struct SConversion
    {
        wchar_t szSrc[MAX_PATH];
    };

    struct SValue
    {
        LPCWSTR pName;
        DWORD dwValue;
    };

    //////////////////////////////////////////////////////////////////////////////
    //////////////////////////////////////////////////////////////////////////////
    //////////////////////////////////////////////////////////////////////////////

    const SValue g_pCommands[] =
    {
        { L"cube",          CMD_CUBE },
        { L"volume",        CMD_VOLUME },
        { L"array",         CMD_ARRAY },
        { L"cubearray",     CMD_CUBEARRAY },
        { L"h-cross",       CMD_H_CROSS },
        { L"v-cross",       CMD_V_CROSS },
        { L"h-strip",       CMD_H_STRIP },
        { L"v-strip",       CMD_V_STRIP },
        { L"merge",         CMD_MERGE },
        { L"gif",           CMD_GIF },
        { L"array-strip",   CMD_ARRAY_STRIP },
        { nullptr,          0 }
    };

    const SValue g_pOptions[] =
    {
        { L"r",         OPT_RECURSIVE },
        { L"flist",     OPT_FILELIST },
        { L"w",         OPT_WIDTH },
        { L"h",         OPT_HEIGHT },
        { L"f",         OPT_FORMAT },
        { L"if",        OPT_FILTER },
        { L"srgbi",     OPT_SRGBI },
        { L"srgbo",     OPT_SRGBO },
        { L"srgb",      OPT_SRGB },
        { L"o",         OPT_OUTPUTFILE },
        { L"l",         OPT_TOLOWER },
        { L"y",         OPT_OVERWRITE },
        { L"dx10",      OPT_USE_DX10 },
        { L"nologo",    OPT_NOLOGO },
        { L"sepalpha",  OPT_SEPALPHA },
        { L"nowic",     OPT_NO_WIC },
        { L"alpha",     OPT_DEMUL_ALPHA },
        { L"wrap",      OPT_TA_WRAP },
        { L"mirror",    OPT_TA_MIRROR },
        { L"fl",        OPT_FEATURE_LEVEL },
        { L"tonemap",   OPT_TONEMAP },
        { L"bgcolor",   OPT_GIF_BGCOLOR },
        { L"swizzle",   OPT_SWIZZLE },
        { nullptr,      0 }
    };

#define DEFFMT(fmt) { L## #fmt, DXGI_FORMAT_ ## fmt }

    const SValue g_pFormats[] =
    {
        // List does not include _TYPELESS or depth/stencil formats
        DEFFMT(R32G32B32A32_FLOAT),
        DEFFMT(R32G32B32A32_UINT),
        DEFFMT(R32G32B32A32_SINT),
        DEFFMT(R32G32B32_FLOAT),
        DEFFMT(R32G32B32_UINT),
        DEFFMT(R32G32B32_SINT),
        DEFFMT(R16G16B16A16_FLOAT),
        DEFFMT(R16G16B16A16_UNORM),
        DEFFMT(R16G16B16A16_UINT),
        DEFFMT(R16G16B16A16_SNORM),
        DEFFMT(R16G16B16A16_SINT),
        DEFFMT(R32G32_FLOAT),
        DEFFMT(R32G32_UINT),
        DEFFMT(R32G32_SINT),
        DEFFMT(R10G10B10A2_UNORM),
        DEFFMT(R10G10B10A2_UINT),
        DEFFMT(R11G11B10_FLOAT),
        DEFFMT(R8G8B8A8_UNORM),
        DEFFMT(R8G8B8A8_UNORM_SRGB),
        DEFFMT(R8G8B8A8_UINT),
        DEFFMT(R8G8B8A8_SNORM),
        DEFFMT(R8G8B8A8_SINT),
        DEFFMT(R16G16_FLOAT),
        DEFFMT(R16G16_UNORM),
        DEFFMT(R16G16_UINT),
        DEFFMT(R16G16_SNORM),
        DEFFMT(R16G16_SINT),
        DEFFMT(R32_FLOAT),
        DEFFMT(R32_UINT),
        DEFFMT(R32_SINT),
        DEFFMT(R8G8_UNORM),
        DEFFMT(R8G8_UINT),
        DEFFMT(R8G8_SNORM),
        DEFFMT(R8G8_SINT),
        DEFFMT(R16_FLOAT),
        DEFFMT(R16_UNORM),
        DEFFMT(R16_UINT),
        DEFFMT(R16_SNORM),
        DEFFMT(R16_SINT),
        DEFFMT(R8_UNORM),
        DEFFMT(R8_UINT),
        DEFFMT(R8_SNORM),
        DEFFMT(R8_SINT),
        DEFFMT(A8_UNORM),
        //DEFFMT(R1_UNORM)
        DEFFMT(R9G9B9E5_SHAREDEXP),
        DEFFMT(R8G8_B8G8_UNORM),
        DEFFMT(G8R8_G8B8_UNORM),
        DEFFMT(B5G6R5_UNORM),
        DEFFMT(B5G5R5A1_UNORM),

        // DXGI 1.1 formats
        DEFFMT(B8G8R8A8_UNORM),
        DEFFMT(B8G8R8X8_UNORM),
        DEFFMT(R10G10B10_XR_BIAS_A2_UNORM),
        DEFFMT(B8G8R8A8_UNORM_SRGB),
        DEFFMT(B8G8R8X8_UNORM_SRGB),

        // DXGI 1.2 formats
        DEFFMT(AYUV),
        DEFFMT(Y410),
        DEFFMT(Y416),
        DEFFMT(YUY2),
        DEFFMT(Y210),
        DEFFMT(Y216),
        // No support for legacy paletted video formats (AI44, IA44, P8, A8P8)
        DEFFMT(B4G4R4A4_UNORM),

        { nullptr, DXGI_FORMAT_UNKNOWN }
    };

    const SValue g_pFormatAliases[] =
    {
        { L"RGBA", DXGI_FORMAT_R8G8B8A8_UNORM },
        { L"BGRA", DXGI_FORMAT_B8G8R8A8_UNORM },

        { L"FP16", DXGI_FORMAT_R16G16B16A16_FLOAT },
        { L"FP32", DXGI_FORMAT_R32G32B32A32_FLOAT },

        { nullptr, DXGI_FORMAT_UNKNOWN }
    };

    const SValue g_pFilters[] =
    {
        { L"POINT",                     TEX_FILTER_POINT },
        { L"LINEAR",                    TEX_FILTER_LINEAR },
        { L"CUBIC",                     TEX_FILTER_CUBIC },
        { L"FANT",                      TEX_FILTER_FANT },
        { L"BOX",                       TEX_FILTER_BOX },
        { L"TRIANGLE",                  TEX_FILTER_TRIANGLE },
        { L"POINT_DITHER",              TEX_FILTER_POINT | TEX_FILTER_DITHER },
        { L"LINEAR_DITHER",             TEX_FILTER_LINEAR | TEX_FILTER_DITHER },
        { L"CUBIC_DITHER",              TEX_FILTER_CUBIC | TEX_FILTER_DITHER },
        { L"FANT_DITHER",               TEX_FILTER_FANT | TEX_FILTER_DITHER },
        { L"BOX_DITHER",                TEX_FILTER_BOX | TEX_FILTER_DITHER },
        { L"TRIANGLE_DITHER",           TEX_FILTER_TRIANGLE | TEX_FILTER_DITHER },
        { L"POINT_DITHER_DIFFUSION",    TEX_FILTER_POINT | TEX_FILTER_DITHER_DIFFUSION },
        { L"LINEAR_DITHER_DIFFUSION",   TEX_FILTER_LINEAR | TEX_FILTER_DITHER_DIFFUSION },
        { L"CUBIC_DITHER_DIFFUSION",    TEX_FILTER_CUBIC | TEX_FILTER_DITHER_DIFFUSION },
        { L"FANT_DITHER_DIFFUSION",     TEX_FILTER_FANT | TEX_FILTER_DITHER_DIFFUSION },
        { L"BOX_DITHER_DIFFUSION",      TEX_FILTER_BOX | TEX_FILTER_DITHER_DIFFUSION },
        { L"TRIANGLE_DITHER_DIFFUSION", TEX_FILTER_TRIANGLE | TEX_FILTER_DITHER_DIFFUSION },
        { nullptr,                      TEX_FILTER_DEFAULT                              }
    };

#define CODEC_DDS 0xFFFF0001
#define CODEC_TGA 0xFFFF0002
#define CODEC_HDR 0xFFFF0005

#ifdef USE_OPENEXR
#define CODEC_EXR 0xFFFF0006
#endif

    const SValue g_pExtFileTypes[] =
    {
        { L".BMP",  WIC_CODEC_BMP },
        { L".JPG",  WIC_CODEC_JPEG },
        { L".JPEG", WIC_CODEC_JPEG },
        { L".PNG",  WIC_CODEC_PNG },
        { L".DDS",  CODEC_DDS },
        { L".TGA",  CODEC_TGA },
        { L".HDR",  CODEC_HDR },
        { L".TIF",  WIC_CODEC_TIFF },
        { L".TIFF", WIC_CODEC_TIFF },
        { L".WDP",  WIC_CODEC_WMP },
        { L".HDP",  WIC_CODEC_WMP },
        { L".JXR",  WIC_CODEC_WMP },
        #ifdef USE_OPENEXR
        { L"EXR",   CODEC_EXR },
        #endif
        { nullptr,  CODEC_DDS }
    };

    const SValue g_pFeatureLevels[] =   // valid feature levels for -fl for maximimum size
    {
        { L"9.1",  2048 },
        { L"9.2",  2048 },
        { L"9.3",  4096 },
        { L"10.0", 8192 },
        { L"10.1", 8192 },
        { L"11.0", 16384 },
        { L"11.1", 16384 },
        { L"12.0", 16384 },
        { L"12.1", 16384 },
        { nullptr, 0 },
    };

    const SValue g_pFeatureLevelsCube[] = // valid feature levels for -fl for maximum cubemap size
    {
        { L"9.1",  512 },
        { L"9.2",  512 },
        { L"9.3",  4096 },
        { L"10.0", 8192 },
        { L"10.1", 8192 },
        { L"11.0", 16384 },
        { L"11.1", 16384 },
        { L"12.0", 16384 },
        { L"12.1", 16384 },
        { nullptr, 0 },
    };

    const SValue g_pFeatureLevelsArray[] = // valid feature levels for -fl for maximum array size
    {
        { L"9.1",  1 },
        { L"9.2",  1 },
        { L"9.3",  1 },
        { L"10.0", 512 },
        { L"10.1", 512 },
        { L"11.0", 2048 },
        { L"11.1", 2048 },
        { L"12.0", 2048 },
        { L"12.1", 2048 },
        { nullptr, 0 },
    };

    const SValue g_pFeatureLevelsVolume[] = // valid feature levels for -fl for maximum depth size
    {
        { L"9.1",  256 },
        { L"9.2",  256 },
        { L"9.3",  256 },
        { L"10.0", 2048 },
        { L"10.1", 2048 },
        { L"11.0", 2048 },
        { L"11.1", 2048 },
        { L"12.0", 2048 },
        { L"12.1", 2048 },
        { nullptr, 0 },
    };
}

//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////

HRESULT LoadAnimatedGif(const wchar_t* szFile,
    std::vector<std::unique_ptr<ScratchImage>>& loadedImages,
    bool usebgcolor);

//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////

namespace
{
    inline HANDLE safe_handle(HANDLE h) noexcept { return (h == INVALID_HANDLE_VALUE) ? nullptr : h; }

    struct find_closer { void operator()(HANDLE h) noexcept { assert(h != INVALID_HANDLE_VALUE); if (h) FindClose(h); } };

    using ScopedFindHandle = std::unique_ptr<void, find_closer>;

#ifdef _PREFAST_
#pragma prefast(disable : 26018, "Only used with static internal arrays")
#endif

    DWORD LookupByName(const wchar_t *pName, const SValue *pArray)
    {
        while (pArray->pName)
        {
            if (!_wcsicmp(pName, pArray->pName))
                return pArray->dwValue;

            pArray++;
        }

        return 0;
    }


    void SearchForFiles(const wchar_t* path, std::list<SConversion>& files, bool recursive)
    {
        // Process files
        WIN32_FIND_DATAW findData = {};
        ScopedFindHandle hFile(safe_handle(FindFirstFileExW(path,
            FindExInfoBasic, &findData,
            FindExSearchNameMatch, nullptr,
            FIND_FIRST_EX_LARGE_FETCH)));
        if (hFile)
        {
            for (;;)
            {
                if (!(findData.dwFileAttributes & (FILE_ATTRIBUTE_HIDDEN | FILE_ATTRIBUTE_SYSTEM | FILE_ATTRIBUTE_DIRECTORY)))
                {
                    wchar_t drive[_MAX_DRIVE] = {};
                    wchar_t dir[_MAX_DIR] = {};
                    _wsplitpath_s(path, drive, _MAX_DRIVE, dir, _MAX_DIR, nullptr, 0, nullptr, 0);

                    SConversion conv = {};
                    _wmakepath_s(conv.szSrc, drive, dir, findData.cFileName, nullptr);
                    files.push_back(conv);
                }

                if (!FindNextFileW(hFile.get(), &findData))
                    break;
            }
        }

        // Process directories
        if (recursive)
        {
            wchar_t searchDir[MAX_PATH] = {};
            {
                wchar_t drive[_MAX_DRIVE] = {};
                wchar_t dir[_MAX_DIR] = {};
                _wsplitpath_s(path, drive, _MAX_DRIVE, dir, _MAX_DIR, nullptr, 0, nullptr, 0);
                _wmakepath_s(searchDir, drive, dir, L"*", nullptr);
            }

            hFile.reset(safe_handle(FindFirstFileExW(searchDir,
                FindExInfoBasic, &findData,
                FindExSearchLimitToDirectories, nullptr,
                FIND_FIRST_EX_LARGE_FETCH)));
            if (!hFile)
                return;

            for (;;)
            {
                if (findData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
                {
                    if (findData.cFileName[0] != L'.')
                    {
                        wchar_t subdir[MAX_PATH] = {};

                        {
                            wchar_t drive[_MAX_DRIVE] = {};
                            wchar_t dir[_MAX_DIR] = {};
                            wchar_t fname[_MAX_FNAME] = {};
                            wchar_t ext[_MAX_FNAME] = {};
                            _wsplitpath_s(path, drive, dir, fname, ext);
                            wcscat_s(dir, findData.cFileName);
                            _wmakepath_s(subdir, drive, dir, fname, ext);
                        }

                        SearchForFiles(subdir, files, recursive);
                    }
                }

                if (!FindNextFileW(hFile.get(), &findData))
                    break;
            }
        }
    }


    void PrintFormat(DXGI_FORMAT Format)
    {
        for (const SValue *pFormat = g_pFormats; pFormat->pName; pFormat++)
        {
            if (static_cast<DXGI_FORMAT>(pFormat->dwValue) == Format)
            {
                wprintf(L"%ls", pFormat->pName);
                break;
            }
        }
    }


    void PrintInfo(const TexMetadata& info)
    {
        wprintf(L" (%zux%zu", info.width, info.height);

        if (TEX_DIMENSION_TEXTURE3D == info.dimension)
            wprintf(L"x%zu", info.depth);

        if (info.mipLevels > 1)
            wprintf(L",%zu", info.mipLevels);

        if (info.arraySize > 1)
            wprintf(L",%zu", info.arraySize);

        wprintf(L" ");
        PrintFormat(info.format);

        switch (info.dimension)
        {
        case TEX_DIMENSION_TEXTURE1D:
            wprintf(L"%ls", (info.arraySize > 1) ? L" 1DArray" : L" 1D");
            break;

        case TEX_DIMENSION_TEXTURE2D:
            if (info.IsCubemap())
            {
                wprintf(L"%ls", (info.arraySize > 6) ? L" CubeArray" : L" Cube");
            }
            else
            {
                wprintf(L"%ls", (info.arraySize > 1) ? L" 2DArray" : L" 2D");
            }
            break;

        case TEX_DIMENSION_TEXTURE3D:
            wprintf(L" 3D");
            break;
        }

        switch (info.GetAlphaMode())
        {
        case TEX_ALPHA_MODE_OPAQUE:
            wprintf(L" \x0e0:Opaque");
            break;
        case TEX_ALPHA_MODE_PREMULTIPLIED:
            wprintf(L" \x0e0:PM");
            break;
        case TEX_ALPHA_MODE_STRAIGHT:
            wprintf(L" \x0e0:NonPM");
            break;
        case TEX_ALPHA_MODE_CUSTOM:
            wprintf(L" \x0e0:Custom");
            break;
        case TEX_ALPHA_MODE_UNKNOWN:
            break;
        }

        wprintf(L")");
    }


    void PrintList(size_t cch, const SValue *pValue)
    {
        while (pValue->pName)
        {
            size_t cchName = wcslen(pValue->pName);

            if (cch + cchName + 2 >= 80)
            {
                wprintf(L"\n      ");
                cch = 6;
            }

            wprintf(L"%ls ", pValue->pName);
            cch += cchName + 2;
            pValue++;
        }

        wprintf(L"\n");
    }


    void PrintLogo()
    {
        wchar_t version[32] = {};

        wchar_t appName[_MAX_PATH] = {};
        if (GetModuleFileNameW(nullptr, appName, static_cast<DWORD>(std::size(appName))))
        {
            DWORD size = GetFileVersionInfoSizeW(appName, nullptr);
            if (size > 0)
            {
                auto verInfo = std::make_unique<uint8_t[]>(size);
                if (GetFileVersionInfoW(appName, 0, size, verInfo.get()))
                {
                    LPVOID lpstr = nullptr;
                    UINT strLen = 0;
                    if (VerQueryValueW(verInfo.get(), L"\\StringFileInfo\\040904B0\\ProductVersion", &lpstr, &strLen))
                    {
                        wcsncpy_s(version, reinterpret_cast<const wchar_t*>(lpstr), strLen);
                    }
                }
            }
        }

        if (!*version || wcscmp(version, L"1.0.0.0") == 0)
        {
            swprintf_s(version, L"%03d (library)", DIRECTX_TEX_VERSION);
        }

        wprintf(L"Microsoft (R) DirectX Texture Assembler [DirectXTex] Version %ls\n", version);
        wprintf(L"Copyright (C) Microsoft Corp. All rights reserved.\n");
#ifdef _DEBUG
        wprintf(L"*** Debug build ***\n");
#endif
        wprintf(L"\n");
    }


    void PrintUsage()
    {
        PrintLogo();

        wprintf(L"Usage: texassemble <command> <options> <files>\n\n");
        wprintf(L"   cube                create cubemap\n");
        wprintf(L"   volume              create volume map\n");
        wprintf(L"   array               create texture array\n");
        wprintf(L"   cubearray           create cubemap array\n");
        wprintf(L"   h-cross or v-cross  create a cross image from a cubemap\n");
        wprintf(L"   h-strip or v-strip  create a strip image from a cubemap\n");
        wprintf(L"   array-strip         creates a strip image from a 1D/2D array\n");
        wprintf(L"   merge               create texture from rgb image and alpha image\n");
        wprintf(L"   gif                 create array from animated gif\n\n");
        wprintf(L"   -r                  wildcard filename search is recursive\n");
        wprintf(L"   -flist <filename>   use text file with a list of input files (one per line)\n");
        wprintf(L"   -w <n>              width\n");
        wprintf(L"   -h <n>              height\n");
        wprintf(L"   -f <format>         format\n");
        wprintf(L"   -if <filter>        image filtering\n");
        wprintf(L"   -srgb{i|o}          sRGB {input, output}\n");
        wprintf(L"   -o <filename>       output filename\n");
        wprintf(L"   -l                  force output filename to lower case\n");
        wprintf(L"   -y                  overwrite existing output file (if any)\n");
        wprintf(L"   -sepalpha           resize alpha channel separately from color channels\n");
        wprintf(L"   -nowic              Force non-WIC filtering\n");
        wprintf(L"   -wrap, -mirror      texture addressing mode (wrap, mirror, or clamp)\n");
        wprintf(L"   -alpha              convert premultiplied alpha to straight alpha\n");
        wprintf(L"   -dx10               Force use of 'DX10' extended header\n");
        wprintf(L"   -nologo             suppress copyright message\n");
        wprintf(L"   -fl <feature-level> Set maximum feature level target (defaults to 11.0)\n");
        wprintf(L"   -tonemap            Apply a tonemap operator based on maximum luminance\n");
        wprintf(L"\n                       (gif only)\n");
        wprintf(L"   -bgcolor            Use background color instead of transparency\n");
        wprintf(L"\n                       (merge only)\n");
        wprintf(L"   -swizzle <rgba>     Select channels for merge (defaults to rgbB)\n");

        wprintf(L"\n   <format>: ");
        PrintList(13, g_pFormats);
        wprintf(L"      ");
        PrintList(13, g_pFormatAliases);

        wprintf(L"\n   <filter>: ");
        PrintList(13, g_pFilters);

        wprintf(L"\n   <feature-level>: ");
        PrintList(13, g_pFeatureLevels);
    }


    HRESULT SaveImageFile(const Image& img, DWORD fileType, const wchar_t* szOutputFile)
    {
        switch (fileType)
        {
        case CODEC_DDS:
            return SaveToDDSFile(img, DDS_FLAGS_NONE, szOutputFile);

        case CODEC_TGA:
            return SaveToTGAFile(img, TGA_FLAGS_NONE, szOutputFile);

        case CODEC_HDR:
            return SaveToHDRFile(img, szOutputFile);

#ifdef USE_OPENEXR
        case CODEC_EXR:
            return SaveToEXRFile(img, szOutputFile);
#endif

        default:
            return SaveToWICFile(img, WIC_FLAGS_NONE, GetWICCodec(static_cast<WICCodecs>(fileType)), szOutputFile);
        }
    }


    bool ParseSwizzleMask(_In_reads_(4) const wchar_t* mask, _Out_writes_(4) uint32_t* permuteElements)
    {
        if (!mask || !permuteElements)
            return false;

        if (!mask[0])
            return false;

        for (size_t j = 0; j < 4; ++j)
        {
            if (!mask[j])
                break;

            switch (mask[j])
            {
            case L'r':
            case L'x':
                for (size_t k = j; k < 4; ++k)
                    permuteElements[k] = 0;
                break;

            case L'R':
            case L'X':
                for (size_t k = j; k < 4; ++k)
                    permuteElements[k] = 4;
                break;

            case L'g':
            case L'y':
                for (size_t k = j; k < 4; ++k)
                    permuteElements[k] = 1;
                break;

            case L'G':
            case L'Y':
                for (size_t k = j; k < 4; ++k)
                    permuteElements[k] = 5;
                break;

            case L'b':
            case L'z':
                for (size_t k = j; k < 4; ++k)
                    permuteElements[k] = 2;
                break;

            case L'B':
            case L'Z':
                for (size_t k = j; k < 4; ++k)
                    permuteElements[k] = 6;
                break;

            case L'a':
            case L'w':
                for (size_t k = j; k < 4; ++k)
                    permuteElements[k] = 3;
                break;

            case L'A':
            case L'W':
                for (size_t k = j; k < 4; ++k)
                    permuteElements[k] = 7;
                break;

            default:
                return false;
            }
        }

        return true;
    }
}

//--------------------------------------------------------------------------------------
// Entry-point
//--------------------------------------------------------------------------------------
#ifdef _PREFAST_
#pragma prefast(disable : 28198, "Command-line tool, frees all memory on exit")
#endif

int __cdecl wmain(_In_ int argc, _In_z_count_(argc) wchar_t* argv[])
{
    // Parameters and defaults
    size_t width = 0;
    size_t height = 0;

    DXGI_FORMAT format = DXGI_FORMAT_UNKNOWN;
    TEX_FILTER_FLAGS dwFilter = TEX_FILTER_DEFAULT;
    TEX_FILTER_FLAGS dwSRGB = TEX_FILTER_DEFAULT;
    TEX_FILTER_FLAGS dwFilterOpts = TEX_FILTER_DEFAULT;
    DWORD fileType = WIC_CODEC_BMP;
    DWORD maxSize = 16384;
    DWORD maxCube = 16384;
    DWORD maxArray = 2048;
    DWORD maxVolume = 2048;

    // DXTex's Open Alpha onto Surface always loaded alpha from the blue channel
    uint32_t permuteElements[4] = { 0, 1, 2, 6 };

    wchar_t szOutputFile[MAX_PATH] = {};

    // Initialize COM (needed for WIC)
    HRESULT hr = hr = CoInitializeEx(nullptr, COINIT_MULTITHREADED);
    if (FAILED(hr))
    {
        wprintf(L"Failed to initialize COM (%08X)\n", static_cast<unsigned int>(hr));
        return 1;
    }

    // Process command line
    if (argc < 2)
    {
        PrintUsage();
        return 0;
    }

    DWORD dwCommand = LookupByName(argv[1], g_pCommands);
    switch (dwCommand)
    {
    case CMD_CUBE:
    case CMD_VOLUME:
    case CMD_ARRAY:
    case CMD_CUBEARRAY:
    case CMD_H_CROSS:
    case CMD_V_CROSS:
    case CMD_H_STRIP:
    case CMD_V_STRIP:
    case CMD_MERGE:
    case CMD_GIF:
    case CMD_ARRAY_STRIP:
        break;

    default:
        wprintf(L"Must use one of: cube, volume, array, cubearray,\n   h-cross, v-cross, h-strip, v-strip, array-strip\n   merge, gif\n\n");
        return 1;
    }

    DWORD dwOptions = 0;
    std::list<SConversion> conversion;

    for (int iArg = 2; iArg < argc; iArg++)
    {
        PWSTR pArg = argv[iArg];

        if (('-' == pArg[0]) || ('/' == pArg[0]))
        {
            pArg++;
            PWSTR pValue;

            for (pValue = pArg; *pValue && (':' != *pValue); pValue++);

            if (*pValue)
                *pValue++ = 0;

            DWORD dwOption = LookupByName(pArg, g_pOptions);

            if (!dwOption || (dwOptions & (1 << dwOption)))
            {
                PrintUsage();
                return 1;
            }

            dwOptions |= 1 << dwOption;

            // Handle options with additional value parameter
            switch (dwOption)
            {
            case OPT_FILELIST:
            case OPT_WIDTH:
            case OPT_HEIGHT:
            case OPT_FORMAT:
            case OPT_FILTER:
            case OPT_OUTPUTFILE:
            case OPT_FEATURE_LEVEL:
            case OPT_SWIZZLE:
                if (!*pValue)
                {
                    if ((iArg + 1 >= argc))
                    {
                        PrintUsage();
                        return 1;
                    }

                    iArg++;
                    pValue = argv[iArg];
                }
                break;

            default:
                break;
            }

            switch (dwOption)
            {
            case OPT_WIDTH:
                if (swscanf_s(pValue, L"%zu", &width) != 1)
                {
                    wprintf(L"Invalid value specified with -w (%ls)\n", pValue);
                    return 1;
                }
                break;

            case OPT_HEIGHT:
                if (swscanf_s(pValue, L"%zu", &height) != 1)
                {
                    wprintf(L"Invalid value specified with -h (%ls)\n", pValue);
                    return 1;
                }
                break;

            case OPT_FORMAT:
                format = static_cast<DXGI_FORMAT>(LookupByName(pValue, g_pFormats));
                if (!format)
                {
                    format = static_cast<DXGI_FORMAT>(LookupByName(pValue, g_pFormatAliases));
                    if (!format)
                    {
                        wprintf(L"Invalid value specified with -f (%ls)\n", pValue);
                        return 1;
                    }
                }
                break;

            case OPT_FILTER:
                dwFilter = static_cast<TEX_FILTER_FLAGS>(LookupByName(pValue, g_pFilters));
                if (!dwFilter)
                {
                    wprintf(L"Invalid value specified with -if (%ls)\n", pValue);
                    return 1;
                }
                break;

            case OPT_SRGBI:
                dwSRGB |= TEX_FILTER_SRGB_IN;
                break;

            case OPT_SRGBO:
                dwSRGB |= TEX_FILTER_SRGB_OUT;
                break;

            case OPT_SRGB:
                dwSRGB |= TEX_FILTER_SRGB;
                break;

            case OPT_SEPALPHA:
                dwFilterOpts |= TEX_FILTER_SEPARATE_ALPHA;
                break;

            case OPT_NO_WIC:
                dwFilterOpts |= TEX_FILTER_FORCE_NON_WIC;
                break;

            case OPT_OUTPUTFILE:
            {
                wcscpy_s(szOutputFile, MAX_PATH, pValue);

                wchar_t ext[_MAX_EXT] = {};
                _wsplitpath_s(szOutputFile, nullptr, 0, nullptr, 0, nullptr, 0, ext, _MAX_EXT);

                fileType = LookupByName(ext, g_pExtFileTypes);

                switch (dwCommand)
                {
                case CMD_H_CROSS:
                case CMD_V_CROSS:
                case CMD_H_STRIP:
                case CMD_V_STRIP:
                case CMD_MERGE:
                case CMD_ARRAY_STRIP:
                    break;

                default:
                    if (fileType != CODEC_DDS)
                    {
                        wprintf(L"Assembled output file must be a dds\n");
                        return 1;
                    }
                }
                break;
            }

            case OPT_TA_WRAP:
                if (dwFilterOpts & TEX_FILTER_MIRROR)
                {
                    wprintf(L"Can't use -wrap and -mirror at same time\n\n");
                    PrintUsage();
                    return 1;
                }
                dwFilterOpts |= TEX_FILTER_WRAP;
                break;

            case OPT_TA_MIRROR:
                if (dwFilterOpts & TEX_FILTER_WRAP)
                {
                    wprintf(L"Can't use -wrap and -mirror at same time\n\n");
                    PrintUsage();
                    return 1;
                }
                dwFilterOpts |= TEX_FILTER_MIRROR;
                break;

            case OPT_FILELIST:
            {
                std::wifstream inFile(pValue);
                if (!inFile)
                {
                    wprintf(L"Error opening -flist file %ls\n", pValue);
                    return 1;
                }
                wchar_t fname[1024] = {};
                for (;;)
                {
                    inFile >> fname;
                    if (!inFile)
                        break;

                    if (*fname == L'#')
                    {
                        // Comment
                    }
                    else if (*fname == L'-')
                    {
                        wprintf(L"Command-line arguments not supported in -flist file\n");
                        return 1;
                    }
                    else if (wcspbrk(fname, L"?*") != nullptr)
                    {
                        wprintf(L"Wildcards not supported in -flist file\n");
                        return 1;
                    }
                    else
                    {
                        SConversion conv = {};
                        wcscpy_s(conv.szSrc, MAX_PATH, fname);
                        conversion.push_back(conv);
                    }

                    inFile.ignore(1000, '\n');
                }
                inFile.close();
            }
            break;

            case OPT_FEATURE_LEVEL:
                maxSize = LookupByName(pValue, g_pFeatureLevels);
                maxCube = LookupByName(pValue, g_pFeatureLevelsCube);
                maxArray = LookupByName(pValue, g_pFeatureLevelsArray);
                maxVolume = LookupByName(pValue, g_pFeatureLevelsVolume);
                if (!maxSize || !maxCube || !maxArray || !maxVolume)
                {
                    wprintf(L"Invalid value specified with -fl (%ls)\n", pValue);
                    wprintf(L"\n");
                    PrintUsage();
                    return 1;
                }
                break;

            case OPT_GIF_BGCOLOR:
                if (dwCommand != CMD_GIF)
                {
                    wprintf(L"-bgcolor only applies to gif command\n");
                    return 1;
                }
                break;

            case OPT_SWIZZLE:
                if (dwCommand != CMD_MERGE)
                {
                    wprintf(L"-swizzle only applies to merge command\n");
                    return 1;
                }
                if (!*pValue || wcslen(pValue) > 4)
                {
                    wprintf(L"Invalid value specified with -swizzle (%ls)\n\n", pValue);
                    PrintUsage();
                    return 1;
                }
                else if (!ParseSwizzleMask(pValue, permuteElements))
                {
                    wprintf(L"-swizzle requires a 1 to 4 character mask composed of these letters: r, g, b, a, x, y, w, z.\n    Lowercase letters are from the first image, upper-case letters are from the second image.\n");
                    return 1;
                }
                break;

            default:
                break;
            }
        }
        else if (wcspbrk(pArg, L"?*") != nullptr)
        {
            size_t count = conversion.size();
            SearchForFiles(pArg, conversion, (dwOptions & (1 << OPT_RECURSIVE)) != 0);
            if (conversion.size() <= count)
            {
                wprintf(L"No matching files found for %ls\n", pArg);
                return 1;
            }
        }
        else
        {
            SConversion conv = {};
            wcscpy_s(conv.szSrc, MAX_PATH, pArg);

            conversion.push_back(conv);
        }
    }

    if (conversion.empty())
    {
        PrintUsage();
        return 0;
    }

    if (~dwOptions & (1 << OPT_NOLOGO))
        PrintLogo();

    switch (dwCommand)
    {
    case CMD_H_CROSS:
    case CMD_V_CROSS:
    case CMD_H_STRIP:
    case CMD_V_STRIP:
    case CMD_GIF:
    case CMD_ARRAY_STRIP:
        if (conversion.size() > 1)
        {
            wprintf(L"ERROR: cross/strip/gif output only accepts 1 input file\n");
            return 1;
        }
        break;

    case CMD_MERGE:
        if (conversion.size() > 2)
        {
            wprintf(L"ERROR: merge output only accepts 2 input files\n");
            return 1;
        }
        break;

    default:
        break;
    }

    // Convert images
    size_t images = 0;

    std::vector<std::unique_ptr<ScratchImage>> loadedImages;

    if (dwCommand == CMD_GIF)
    {
        wchar_t ext[_MAX_EXT] = {};
        wchar_t fname[_MAX_FNAME] = {};
        _wsplitpath_s(conversion.front().szSrc, nullptr, 0, nullptr, 0, fname, _MAX_FNAME, ext, _MAX_EXT);

        wprintf(L"reading %ls", conversion.front().szSrc);
        fflush(stdout);

        if (!*szOutputFile)
        {
            _wmakepath_s(szOutputFile, nullptr, nullptr, fname, L".dds");
        }

        hr = LoadAnimatedGif(conversion.front().szSrc, loadedImages, (dwOptions & (1 << OPT_GIF_BGCOLOR)) != 0);
        if (FAILED(hr))
        {
            wprintf(L" FAILED (%x)\n", static_cast<unsigned int>(hr));
            return 1;
        }
    }
    else
    {
        for (auto pConv = conversion.begin(); pConv != conversion.end(); ++pConv)
        {
            wchar_t ext[_MAX_EXT] = {};
            wchar_t fname[_MAX_FNAME] = {};
            _wsplitpath_s(pConv->szSrc, nullptr, 0, nullptr, 0, fname, _MAX_FNAME, ext, _MAX_EXT);

            // Load source image
            if (pConv != conversion.begin())
                wprintf(L"\n");
            else if (!*szOutputFile)
            {
                switch (dwCommand)
                {
                case CMD_H_CROSS:
                case CMD_V_CROSS:
                case CMD_H_STRIP:
                case CMD_V_STRIP:
                case CMD_ARRAY_STRIP:
                    _wmakepath_s(szOutputFile, nullptr, nullptr, fname, L".bmp");
                    break;

                default:
                    if (_wcsicmp(ext, L".dds") == 0)
                    {
                        wprintf(L"ERROR: Need to specify output file via -o\n");
                        return 1;
                    }

                    _wmakepath_s(szOutputFile, nullptr, nullptr, fname, L".dds");
                    break;
                }
            }

            wprintf(L"reading %ls", pConv->szSrc);
            fflush(stdout);

            TexMetadata info;
            std::unique_ptr<ScratchImage> image(new (std::nothrow) ScratchImage);
            if (!image)
            {
                wprintf(L"\nERROR: Memory allocation failed\n");
                return 1;
            }

            switch (dwCommand)
            {
            case CMD_H_CROSS:
            case CMD_V_CROSS:
            case CMD_H_STRIP:
            case CMD_V_STRIP:
                if (_wcsicmp(ext, L".dds") == 0)
                {
                    hr = LoadFromDDSFile(pConv->szSrc, DDS_FLAGS_ALLOW_LARGE_FILES, &info, *image);
                    if (FAILED(hr))
                    {
                        wprintf(L" FAILED (%x)\n", static_cast<unsigned int>(hr));
                        return 1;
                    }

                    if (!info.IsCubemap())
                    {
                        wprintf(L"\nERROR: Input must be a cubemap\n");
                        return 1;
                    }
                    else if (info.arraySize != 6)
                    {
                        wprintf(L"\nWARNING: Only the first cubemap in an array is written out as a cross/strip\n");
                    }
                }
                else
                {
                    wprintf(L"\nERROR: Input must be a dds of a cubemap\n");
                    return 1;
                }
                break;

            case CMD_ARRAY_STRIP:
                if (_wcsicmp(ext, L".dds") == 0)
                {
                    hr = LoadFromDDSFile(pConv->szSrc, DDS_FLAGS_ALLOW_LARGE_FILES, &info, *image);
                    if (FAILED(hr))
                    {
                        wprintf(L" FAILED (%x)\n", static_cast<unsigned int>(hr));
                        return 1;
                    }

                    if (info.dimension == TEX_DIMENSION_TEXTURE3D || info.arraySize < 2 || info.IsCubemap())
                    {
                        wprintf(L"\nERROR: Input must be a 1D/2D array\n");
                        return 1;
                    }
                }
                else
                {
                    wprintf(L"\nERROR: Input must be a dds of a 1D/2D array\n");
                    return 1;
                }
                break;

            default:
                if (_wcsicmp(ext, L".dds") == 0)
                {
                    hr = LoadFromDDSFile(pConv->szSrc, DDS_FLAGS_ALLOW_LARGE_FILES, &info, *image);
                    if (FAILED(hr))
                    {
                        wprintf(L" FAILED (%x)\n", static_cast<unsigned int>(hr));
                        return 1;
                    }

                    if (info.mipLevels > 1
                        || info.IsVolumemap()
                        || info.IsCubemap())
                    {
                        wprintf(L"\nERROR: Can't assemble complex surfaces\n");
                        return 1;
                    }
                }
                else if (_wcsicmp(ext, L".tga") == 0)
                {
                    hr = LoadFromTGAFile(pConv->szSrc, TGA_FLAGS_NONE, &info, *image);
                    if (FAILED(hr))
                    {
                        wprintf(L" FAILED (%x)\n", static_cast<unsigned int>(hr));
                        return 1;
                    }
                }
                else if (_wcsicmp(ext, L".hdr") == 0)
                {
                    hr = LoadFromHDRFile(pConv->szSrc, &info, *image);
                    if (FAILED(hr))
                    {
                        wprintf(L" FAILED (%x)\n", static_cast<unsigned int>(hr));
                        return 1;
                    }
                }
#ifdef USE_OPENEXR
                else if (_wcsicmp(ext, L".exr") == 0)
                {
                    hr = LoadFromEXRFile(pConv->szSrc, &info, *image);
                    if (FAILED(hr))
                    {
                        wprintf(L" FAILED (%x)\n", static_cast<unsigned int>(hr));
                        continue;
                    }
                }
#endif
                else
                {
                    // WIC shares the same filter values for mode and dither
                    static_assert(static_cast<int>(WIC_FLAGS_DITHER) == static_cast<int>(TEX_FILTER_DITHER), "WIC_FLAGS_* & TEX_FILTER_* should match");
                    static_assert(static_cast<int>(WIC_FLAGS_DITHER_DIFFUSION) == static_cast<int>(TEX_FILTER_DITHER_DIFFUSION), "WIC_FLAGS_* & TEX_FILTER_* should match");
                    static_assert(static_cast<int>(WIC_FLAGS_FILTER_POINT) == static_cast<int>(TEX_FILTER_POINT), "WIC_FLAGS_* & TEX_FILTER_* should match");
                    static_assert(static_cast<int>(WIC_FLAGS_FILTER_LINEAR) == static_cast<int>(TEX_FILTER_LINEAR), "WIC_FLAGS_* & TEX_FILTER_* should match");
                    static_assert(static_cast<int>(WIC_FLAGS_FILTER_CUBIC) == static_cast<int>(TEX_FILTER_CUBIC), "WIC_FLAGS_* & TEX_FILTER_* should match");
                    static_assert(static_cast<int>(WIC_FLAGS_FILTER_FANT) == static_cast<int>(TEX_FILTER_FANT), "WIC_FLAGS_* & TEX_FILTER_* should match");

                    hr = LoadFromWICFile(pConv->szSrc, WIC_FLAGS_ALL_FRAMES | dwFilter, &info, *image);
                    if (FAILED(hr))
                    {
                        wprintf(L" FAILED (%x)\n", static_cast<unsigned int>(hr));
                        return 1;
                    }
                }
                break;
            }

            PrintInfo(info);

            // Convert texture
            fflush(stdout);

            // --- Planar ------------------------------------------------------------------
            if (IsPlanar(info.format))
            {
                auto img = image->GetImage(0, 0, 0);
                assert(img);
                size_t nimg = image->GetImageCount();

                std::unique_ptr<ScratchImage> timage(new (std::nothrow) ScratchImage);
                if (!timage)
                {
                    wprintf(L"\nERROR: Memory allocation failed\n");
                    return 1;
                }

                hr = ConvertToSinglePlane(img, nimg, info, *timage);
                if (FAILED(hr))
                {
                    wprintf(L" FAILED [converttosingleplane] (%x)\n", static_cast<unsigned int>(hr));
                    continue;
                }

                auto& tinfo = timage->GetMetadata();

                info.format = tinfo.format;

                assert(info.width == tinfo.width);
                assert(info.height == tinfo.height);
                assert(info.depth == tinfo.depth);
                assert(info.arraySize == tinfo.arraySize);
                assert(info.mipLevels == tinfo.mipLevels);
                assert(info.miscFlags == tinfo.miscFlags);
                assert(info.dimension == tinfo.dimension);

                image.swap(timage);
            }

            // --- Decompress --------------------------------------------------------------
            if (IsCompressed(info.format))
            {
                const Image* img = image->GetImage(0, 0, 0);
                assert(img);
                size_t nimg = image->GetImageCount();

                std::unique_ptr<ScratchImage> timage(new (std::nothrow) ScratchImage);
                if (!timage)
                {
                    wprintf(L"\nERROR: Memory allocation failed\n");
                    return 1;
                }

                hr = Decompress(img, nimg, info, DXGI_FORMAT_UNKNOWN /* picks good default */, *timage.get());
                if (FAILED(hr))
                {
                    wprintf(L" FAILED [decompress] (%x)\n", static_cast<unsigned int>(hr));
                    continue;
                }

                auto& tinfo = timage->GetMetadata();

                info.format = tinfo.format;

                assert(info.width == tinfo.width);
                assert(info.height == tinfo.height);
                assert(info.depth == tinfo.depth);
                assert(info.arraySize == tinfo.arraySize);
                assert(info.mipLevels == tinfo.mipLevels);
                assert(info.miscFlags == tinfo.miscFlags);
                assert(info.dimension == tinfo.dimension);

                image.swap(timage);
            }

            // --- Undo Premultiplied Alpha (if requested) ---------------------------------
            if ((dwOptions & (1 << OPT_DEMUL_ALPHA))
                && HasAlpha(info.format)
                && info.format != DXGI_FORMAT_A8_UNORM)
            {
                if (info.GetAlphaMode() == TEX_ALPHA_MODE_STRAIGHT)
                {
                    printf("\nWARNING: Image is already using straight alpha\n");
                }
                else if (!info.IsPMAlpha())
                {
                    printf("\nWARNING: Image is not using premultipled alpha\n");
                }
                else
                {
                    auto img = image->GetImage(0, 0, 0);
                    assert(img);
                    size_t nimg = image->GetImageCount();

                    std::unique_ptr<ScratchImage> timage(new (std::nothrow) ScratchImage);
                    if (!timage)
                    {
                        wprintf(L"\nERROR: Memory allocation failed\n");
                        return 1;
                    }

                    hr = PremultiplyAlpha(img, nimg, info, TEX_PMALPHA_REVERSE | dwSRGB, *timage);
                    if (FAILED(hr))
                    {
                        wprintf(L" FAILED [demultiply alpha] (%x)\n", static_cast<unsigned int>(hr));
                        continue;
                    }

                    auto& tinfo = timage->GetMetadata();
                    info.miscFlags2 = tinfo.miscFlags2;

                    assert(info.width == tinfo.width);
                    assert(info.height == tinfo.height);
                    assert(info.depth == tinfo.depth);
                    assert(info.arraySize == tinfo.arraySize);
                    assert(info.mipLevels == tinfo.mipLevels);
                    assert(info.miscFlags == tinfo.miscFlags);
                    assert(info.dimension == tinfo.dimension);

                    image.swap(timage);
                }
            }

            // --- Resize ------------------------------------------------------------------
            if (!width)
            {
                width = info.width;
            }
            if (!height)
            {
                height = info.height;
            }
            if (info.width != width || info.height != height)
            {
                std::unique_ptr<ScratchImage> timage(new (std::nothrow) ScratchImage);
                if (!timage)
                {
                    wprintf(L"\nERROR: Memory allocation failed\n");
                    return 1;
                }

                hr = Resize(image->GetImages(), image->GetImageCount(), image->GetMetadata(), width, height, dwFilter | dwFilterOpts, *timage.get());
                if (FAILED(hr))
                {
                    wprintf(L" FAILED [resize] (%x)\n", static_cast<unsigned int>(hr));
                    return 1;
                }

                auto& tinfo = timage->GetMetadata();

                assert(tinfo.width == width && tinfo.height == height && tinfo.mipLevels == 1);
                info.width = tinfo.width;
                info.height = tinfo.height;
                info.mipLevels = 1;

                assert(info.depth == tinfo.depth);
                assert(info.arraySize == tinfo.arraySize);
                assert(info.miscFlags == tinfo.miscFlags);
                assert(info.format == tinfo.format);
                assert(info.dimension == tinfo.dimension);

                image.swap(timage);
            }

            // --- Tonemap (if requested) --------------------------------------------------
            if (dwOptions & (1 << OPT_TONEMAP))
            {
                std::unique_ptr<ScratchImage> timage(new (std::nothrow) ScratchImage);
                if (!timage)
                {
                    wprintf(L"\nERROR: Memory allocation failed\n");
                    return 1;
                }

                // Compute max luminosity across all images
                XMVECTOR maxLum = XMVectorZero();
                hr = EvaluateImage(image->GetImages(), image->GetImageCount(), image->GetMetadata(),
                    [&](const XMVECTOR* pixels, size_t w, size_t y)
                    {
                        UNREFERENCED_PARAMETER(y);

                        for (size_t j = 0; j < w; ++j)
                        {
                            static const XMVECTORF32 s_luminance = { { { 0.3f, 0.59f, 0.11f, 0.f } } };

                            XMVECTOR v = *pixels++;

                            v = XMVector3Dot(v, s_luminance);

                            maxLum = XMVectorMax(v, maxLum);
                        }
                    });
                if (FAILED(hr))
                {
                    wprintf(L" FAILED [tonemap maxlum] (%x)\n", static_cast<unsigned int>(hr));
                    return 1;
                }

                // Reinhard et al, "Photographic Tone Reproduction for Digital Images"
                // http://www.cs.utah.edu/~reinhard/cdrom/
                maxLum = XMVectorMultiply(maxLum, maxLum);

                hr = TransformImage(image->GetImages(), image->GetImageCount(), image->GetMetadata(),
                    [&](XMVECTOR* outPixels, const XMVECTOR* inPixels, size_t w, size_t y)
                    {
                        UNREFERENCED_PARAMETER(y);

                        for (size_t j = 0; j < w; ++j)
                        {
                            XMVECTOR value = inPixels[j];

                            XMVECTOR scale = XMVectorDivide(
                                XMVectorAdd(g_XMOne, XMVectorDivide(value, maxLum)),
                                XMVectorAdd(g_XMOne, value));
                            XMVECTOR nvalue = XMVectorMultiply(value, scale);

                            value = XMVectorSelect(value, nvalue, g_XMSelect1110);

                            outPixels[j] = value;
                        }
                    }, *timage);
                if (FAILED(hr))
                {
                    wprintf(L" FAILED [tonemap apply] (%x)\n", static_cast<unsigned int>(hr));
                    return 1;
                }

#ifndef NDEBUG
                auto& tinfo = timage->GetMetadata();
#endif

                assert(info.width == tinfo.width);
                assert(info.height == tinfo.height);
                assert(info.depth == tinfo.depth);
                assert(info.arraySize == tinfo.arraySize);
                assert(info.mipLevels == tinfo.mipLevels);
                assert(info.miscFlags == tinfo.miscFlags);
                assert(info.format == tinfo.format);
                assert(info.dimension == tinfo.dimension);

                image.swap(timage);
            }

            // --- Convert -----------------------------------------------------------------
            if (format == DXGI_FORMAT_UNKNOWN)
            {
                format = info.format;
            }
            else if (info.format != format && !IsCompressed(format))
            {
                std::unique_ptr<ScratchImage> timage(new (std::nothrow) ScratchImage);
                if (!timage)
                {
                    wprintf(L"\nERROR: Memory allocation failed\n");
                    return 1;
                }

                hr = Convert(image->GetImages(), image->GetImageCount(), image->GetMetadata(), format,
                    dwFilter | dwFilterOpts | dwSRGB, TEX_THRESHOLD_DEFAULT, *timage.get());
                if (FAILED(hr))
                {
                    wprintf(L" FAILED [convert] (%x)\n", static_cast<unsigned int>(hr));
                    return 1;
                }

                auto& tinfo = timage->GetMetadata();

                assert(tinfo.format == format);
                info.format = tinfo.format;

                assert(info.width == tinfo.width);
                assert(info.height == tinfo.height);
                assert(info.depth == tinfo.depth);
                assert(info.arraySize == tinfo.arraySize);
                assert(info.mipLevels == tinfo.mipLevels);
                assert(info.miscFlags == tinfo.miscFlags);
                assert(info.dimension == tinfo.dimension);

                image.swap(timage);
            }

            images += info.arraySize;
            loadedImages.emplace_back(std::move(image));
        }
    }

    switch (dwCommand)
    {
    case CMD_CUBE:
        if (images != 6)
        {
            wprintf(L"\nERROR: cube requires six images to form the faces of the cubemap\n");
            return 1;
        }
        break;

    case CMD_CUBEARRAY:
        if ((images < 6) || (images % 6) != 0)
        {
            wprintf(L"cubearray requires a multiple of 6 images to form the faces of the cubemaps\n");
            return 1;
        }
        break;

    case CMD_H_CROSS:
    case CMD_V_CROSS:
    case CMD_H_STRIP:
    case CMD_V_STRIP:
    case CMD_GIF:
        break;

    default:
        if (images < 2)
        {
            wprintf(L"\nERROR: Need at least 2 images to assemble\n\n");
            return 1;
        }
        break;
    }

    // --- Create result ---------------------------------------------------------------
    switch (dwCommand)
    {
    case CMD_H_CROSS:
    case CMD_V_CROSS:
    case CMD_H_STRIP:
    case CMD_V_STRIP:
    {
        size_t twidth = 0;
        size_t theight = 0;

        switch (dwCommand)
        {
        case CMD_H_CROSS:
            //      posy
            // negx posz posx negz
            //      negy
            twidth = width * 4;
            theight = height * 3;
            break;

        case CMD_V_CROSS:
            //      posy
            // posz posx negz
            //      negy
            //      negx
            twidth = width * 3;
            theight = height * 4;
            break;

        case CMD_H_STRIP:
            twidth = width * 6;
            theight = height;
            break;

        case CMD_V_STRIP:
            twidth = width;
            theight = height * 6;
            break;

        default:
            break;
        }

        ScratchImage result;
        hr = result.Initialize2D(format, twidth, theight, 1, 1);
        if (FAILED(hr))
        {
            wprintf(L"FAILED setting up result image (%x)\n", static_cast<unsigned int>(hr));
            return 1;
        }

        memset(result.GetPixels(), 0, result.GetPixelsSize());

        auto src = loadedImages.cbegin();
        auto dest = result.GetImage(0, 0, 0);

        for (size_t index = 0; index < 6; ++index)
        {
            auto img = (*src)->GetImage(0, index, 0);
            if (!img)
            {
                wprintf(L"FAILED: Unexpected error\n");
                return 1;
            }

            Rect rect(0, 0, width, height);

            size_t offsetx = 0;
            size_t offsety = 0;

            switch (dwCommand)
            {
            case CMD_H_CROSS:
            {
                //      posy
                // negx posz posx negz
                //      negy

                static const size_t s_offsetx[6] = { 2, 0, 1, 1, 1, 3 };
                static const size_t s_offsety[6] = { 1, 1, 0, 2, 1, 1 };

                offsetx = s_offsetx[index] * width;
                offsety = s_offsety[index] * height;
                break;
            }

            case CMD_V_CROSS:
            {
                //      posy
                // posz posx negz
                //      negy
                //      negx

                static const size_t s_offsetx[6] = { 1, 1, 1, 1, 0, 2 };
                static const size_t s_offsety[6] = { 1, 3, 0, 2, 1, 1 };

                offsetx = s_offsetx[index] * width;
                offsety = s_offsety[index] * height;
                break;
            }

            case CMD_H_STRIP:
                // posx, negx, posy, negy, posz, negz
                offsetx = index * width;
                break;

            case CMD_V_STRIP:
                // posx, negx, posy, negy, posz, negz
                offsety = index * height;
                break;

            default:
                break;
            }

            hr = CopyRectangle(*img, rect, *dest, dwFilter | dwFilterOpts, offsetx, offsety);
            if (FAILED(hr))
            {
                wprintf(L"FAILED building result image (%x)\n", static_cast<unsigned int>(hr));
                return 1;
            }
        }

        // Write cross/strip
        wprintf(L"\nWriting %ls ", szOutputFile);
        PrintInfo(result.GetMetadata());
        wprintf(L"\n");
        fflush(stdout);

        if (dwOptions & (1 << OPT_TOLOWER))
        {
            (void)_wcslwr_s(szOutputFile);
        }

        if (~dwOptions & (1 << OPT_OVERWRITE))
        {
            if (GetFileAttributesW(szOutputFile) != INVALID_FILE_ATTRIBUTES)
            {
                wprintf(L"\nERROR: Output file already exists, use -y to overwrite\n");
                return 1;
            }
        }

        hr = SaveImageFile(*dest, fileType, szOutputFile);
        if (FAILED(hr))
        {
            wprintf(L" FAILED (%x)\n", static_cast<unsigned int>(hr));
            return 1;
        }
        break;
    }

    case CMD_MERGE:
    {
        // Capture data from our second source image
        ScratchImage tempImage;
        hr = Convert(*loadedImages[1]->GetImage(0, 0, 0), DXGI_FORMAT_R32G32B32A32_FLOAT,
            dwFilter | dwFilterOpts | dwSRGB, TEX_THRESHOLD_DEFAULT, tempImage);
        if (FAILED(hr))
        {
            wprintf(L" FAILED [convert second input] (%x)\n", static_cast<unsigned int>(hr));
            return 1;
        }

        const Image& img = *tempImage.GetImage(0, 0, 0);

        // Merge with our first source image
        const Image& rgb = *loadedImages[0]->GetImage(0, 0, 0);

        ScratchImage result;
        hr = TransformImage(rgb, [&](XMVECTOR* outPixels, const XMVECTOR* inPixels, size_t w, size_t y)
            {
                const XMVECTOR *inPixels2 = reinterpret_cast<XMVECTOR*>(img.pixels + img.rowPitch * y);

                for (size_t j = 0; j < w; ++j)
                {
                    outPixels[j] = XMVectorPermute(inPixels[j], inPixels2[j],
                        permuteElements[0], permuteElements[1], permuteElements[2], permuteElements[3]);
                }
            }, result);
        if (FAILED(hr))
        {
            wprintf(L" FAILED [merge image] (%x)\n", static_cast<unsigned int>(hr));
            return 1;
        }

        // Write merged texture
        wprintf(L"\nWriting %ls ", szOutputFile);
        PrintInfo(result.GetMetadata());
        wprintf(L"\n");
        fflush(stdout);

        if (dwOptions & (1 << OPT_TOLOWER))
        {
            (void)_wcslwr_s(szOutputFile);
        }

        if (~dwOptions & (1 << OPT_OVERWRITE))
        {
            if (GetFileAttributesW(szOutputFile) != INVALID_FILE_ATTRIBUTES)
            {
                wprintf(L"\nERROR: Output file already exists, use -y to overwrite\n");
                return 1;
            }
        }

        hr = SaveImageFile(*result.GetImage(0, 0, 0), fileType, szOutputFile);
        if (FAILED(hr))
        {
            wprintf(L" FAILED (%x)\n", static_cast<unsigned int>(hr));
            return 1;
        }
        break;
    }

    case CMD_ARRAY_STRIP:
    {
        size_t twidth = width;
        size_t theight = height * images;

        ScratchImage result;
        hr = result.Initialize2D(format, twidth, theight, 1, 1);
        if (FAILED(hr))
        {
            wprintf(L"FAILED setting up result image (%x)\n", static_cast<unsigned int>(hr));
            return 1;
        }

        memset(result.GetPixels(), 0, result.GetPixelsSize());

        auto src = loadedImages.cbegin();
        auto dest = result.GetImage(0, 0, 0);

        for (size_t index = 0; index < images; ++index)
        {
            auto img = (*src)->GetImage(0, index, 0);
            if (!img)
            {
                wprintf(L"FAILED: Unexpected error\n");
                return 1;
            }

            Rect rect(0, 0, width, height);

            size_t offsetx = 0;
            size_t offsety = 0;

            offsety = index * height;

            hr = CopyRectangle(*img, rect, *dest, dwFilter | dwFilterOpts, offsetx, offsety);
            if (FAILED(hr))
            {
                wprintf(L"FAILED building result image (%x)\n", static_cast<unsigned int>(hr));
                return 1;
            }
        }

        // Write array strip
        wprintf(L"\nWriting %ls ", szOutputFile);
        PrintInfo(result.GetMetadata());
        wprintf(L"\n");
        fflush(stdout);

        if (dwOptions & (1 << OPT_TOLOWER))
        {
            (void)_wcslwr_s(szOutputFile);
        }

        if (~dwOptions & (1 << OPT_OVERWRITE))
        {
            if (GetFileAttributesW(szOutputFile) != INVALID_FILE_ATTRIBUTES)
            {
                wprintf(L"\nERROR: Output file already exists, use -y to overwrite\n");
                return 1;
            }
        }

        hr = SaveImageFile(*dest, fileType, szOutputFile);
        if (FAILED(hr))
        {
            wprintf(L" FAILED (%x)\n", static_cast<unsigned int>(hr));
            return 1;
        }
        break;
    }
    default:
    {
        std::vector<Image> imageArray;
        imageArray.reserve(images);

        for (auto it = loadedImages.cbegin(); it != loadedImages.cend(); ++it)
        {
            const ScratchImage* simage = it->get();
            assert(simage != nullptr);
            for (size_t j = 0; j < simage->GetMetadata().arraySize; ++j)
            {
                const Image* img = simage->GetImage(0, j, 0);
                assert(img != nullptr);
                imageArray.push_back(*img);
            }
        }

        switch (dwCommand)
        {
        case CMD_CUBE:
            if (imageArray[0].width > maxCube || imageArray[0].height > maxCube)
            {
                wprintf(L"\nWARNING: Target size exceeds maximum cube dimensions for feature level (%lu)\n", maxCube);
            }
            break;

        case CMD_VOLUME:
            if (imageArray[0].width > maxVolume || imageArray[0].height > maxVolume || imageArray.size() > maxVolume)
            {
                wprintf(L"\nWARNING: Target size exceeds volume extent for feature level (%lu)\n", maxVolume);
            }
            break;

        case CMD_ARRAY:
            if (imageArray[0].width > maxSize || imageArray[0].height > maxSize || imageArray.size() > maxArray)
            {
                wprintf(L"\nWARNING: Target size exceeds maximum size for feature level (size %lu, array %lu)\n", maxSize, maxArray);
            }
            break;

        case CMD_CUBEARRAY:
            if (imageArray[0].width > maxCube || imageArray[0].height > maxCube || imageArray.size() > maxArray)
            {
                wprintf(L"\nWARNING: Target size exceeds maximum cube dimensions for feature level (size %lu, array %lu)\n", maxCube, maxArray);
            }
            break;

        default:
            if (imageArray[0].width > maxSize || imageArray[0].height > maxSize)
            {
                wprintf(L"\nWARNING: Target size exceeds maximum size for feature level (%lu)\n", maxSize);
            }
            break;
        }

        ScratchImage result;
        switch (dwCommand)
        {
        case CMD_VOLUME:
            hr = result.Initialize3DFromImages(&imageArray[0], imageArray.size());
            break;

        case CMD_ARRAY:
        case CMD_GIF:
            hr = result.InitializeArrayFromImages(&imageArray[0], imageArray.size(), (dwOptions & (1 << OPT_USE_DX10)) != 0);
            break;

        case CMD_CUBE:
        case CMD_CUBEARRAY:
            hr = result.InitializeCubeFromImages(&imageArray[0], imageArray.size());
            break;

        default:
            break;
        }

        if (FAILED(hr))
        {
            wprintf(L"FAILED building result image (%x)\n", static_cast<unsigned int>(hr));
            return 1;
        }

        // Write texture
        wprintf(L"\nWriting %ls ", szOutputFile);
        PrintInfo(result.GetMetadata());
        wprintf(L"\n");
        fflush(stdout);

        if (dwOptions & (1 << OPT_TOLOWER))
        {
            (void)_wcslwr_s(szOutputFile);
        }

        if (~dwOptions & (1 << OPT_OVERWRITE))
        {
            if (GetFileAttributesW(szOutputFile) != INVALID_FILE_ATTRIBUTES)
            {
                wprintf(L"\nERROR: Output file already exists, use -y to overwrite\n");
                return 1;
            }
        }

        hr = SaveToDDSFile(result.GetImages(), result.GetImageCount(), result.GetMetadata(),
            (dwOptions & (1 << OPT_USE_DX10)) ? (DDS_FLAGS_FORCE_DX10_EXT | DDS_FLAGS_FORCE_DX10_EXT_MISC2) : DDS_FLAGS_NONE,
            szOutputFile);
        if (FAILED(hr))
        {
            wprintf(L"\nFAILED (%x)\n", static_cast<unsigned int>(hr));
            return 1;
        }
        break;
    }
    }

    return 0;
}