// File: example1.cpp - Simple command line tool that uses the crnlib lib and the crn_decomp.h header file library
// to compress, transcode/unpack, and inspect CRN/DDS textures.
// See Copyright Notice and license at the end of inc/crnlib.h
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <algorithm>

#if !defined(_WIN32)
#include <libgen.h>
#endif

// Public crnlib header.
#include "crnlib.h"

// CRN transcoder library.
#include "crn_decomp.h"
// .DDS file format definitions.
#include "dds_defs.h"

#include "crn_core.h"
#include "crn_strutils.h"
#include "crn_file_utils.h"

// stb_image, for loading/saving image files.
#ifdef _MSC_VER
#pragma warning(disable : 4244)  // conversion from 'int' to 'uint8', possible loss of data
#pragma warning(disable : 4100)  // unreferenced formal parameter
#endif

#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"
#define STB_IMAGE_WRITE_IMPLEMENTATION
#include "stb_image_write.h"

#if defined(_WIN32)
// windows.h is only needed here for GetSystemInfo().
#define WIN32_LEAN_AND_MEAN
#define NOMINMAX
#include "windows.h"
#elif defined(__FreeBSD__) || defined(__APPLE__)
#include <unistd.h>
#include <sys/sysctl.h>
#elif defined(__GNUC__)
#include <sys/sysinfo.h>
#endif

using namespace crnlib;

typedef unsigned int uint;

const int cDefaultCRNQualityLevel = 128;

static int print_usage() {
  printf("Description: Simple crnlib API example program.\n");
  printf("Copyright (c) 2010-2016 Richard Geldreich, Jr. and Binomial LLC\n");
  printf("Usage: example1 [mode: i/c/d] [source_file] [options]\n");
  printf("\nModes:\n");
  printf("c: Compress to .DDS or .CRN using the crn_compress() func. in crnlib.h\n");
  printf("   The default output format is .DDS\n");
  printf("   Supported source image formats:\n");
  printf("   Baseline JPEG, PNG, BMP, TGA, PSD, and HDR\n");
  printf("d: Transcodes a .CRN file to .DDS using the crn_decompress_crn_to_dds() func.,\n");
  printf("or unpacks each face and mipmap level in a .DDS file to multiple .TGA files.\n");
  printf("i: Display info about source_file.\n");
  printf("\nOptions:\n");
  printf("-out filename - Force output filename.\n");
  printf("\nCompression mode options:\n");
  printf("-crn - Generate a .CRN file instead of .DDS\n");
  printf("-bitrate # - Specify desired CRN/DDS bits/texel, from [.1-8]\n");
  printf(" When writing .DDS: -bitrate or -quality enable clustered DXTn compression.\n");
  printf("-quality # - Specify CRN/DDS quality level factor, from [0-255]\n");
  printf("-noAdaptiveBlocks - Always use 4x4 blocks instead of up to 8x8 macroblocks\n");
  printf("-nonsrgb - Input is not sRGB: disables gamma filtering, perceptual metrics.\n");
  printf("-nomips - Don't generate mipmaps\n");
  printf("-setalphatoluma - Set alpha channel to luma before compression.\n");
  printf("-converttoluma - Set RGB to luma before compression.\n");
  printf("-pixelformat fmt - Output file's crn_format: DXT1, DXT1A, DXT3, DXT5_CCxY,\n");
  printf(" DXT5_xGxR, DXT5_xGBR, DXT5_AGBR, DXN_XY (ATI 3DC), DXN_YX (ATI 3DC),\n");
  printf(" DXT5A (ATN1N)\n");
  printf(" If no output format is specified, this example uses either DXT1 or DXT5.\n");
  return EXIT_FAILURE;
}

static int error(const char* pMsg, ...) {
  va_list args;
  va_start(args, pMsg);
  char buf[512];
  crnlib_vsnprintf(buf, sizeof(buf), pMsg, args);
  va_end(args);
  printf("%s", buf);
  return EXIT_FAILURE;
}

// Loads an entire file into an allocated memory block.
static crn_uint8* read_file_into_buffer(const char* pFilename, crn_uint32& size) {
  size = 0;

  FILE* pFile = NULL;
  crn_fopen(&pFile, pFilename, "rb");
  if (!pFile)
    return NULL;

  fseek(pFile, 0, SEEK_END);
  size = ftell(pFile);
  fseek(pFile, 0, SEEK_SET);

  crn_uint8* pSrc_file_data = static_cast<crn_uint8*>(malloc(std::max(1U, size)));
  if ((!pSrc_file_data) || (fread(pSrc_file_data, size, 1, pFile) != 1)) {
    fclose(pFile);
    free(pSrc_file_data);
    size = 0;
    return NULL;
  }

  fclose(pFile);
  return pSrc_file_data;
}

// Cracks a CRN's file header using the helper functions in crn_decomp.h.
static bool print_crn_info(const crn_uint8* pData, crn_uint32 data_size) {
  crnd::crn_file_info file_info;
  if (!crnd::crnd_validate_file(pData, data_size, &file_info))
    return false;

  printf("crnd_validate_file:\n");
  printf("File size: %u\nActualDataSize: %u\nHeaderSize: %u\nTotalPaletteSize: %u\nTablesSize: %u\nLevels: %u\n", data_size,
         file_info.m_actual_data_size, file_info.m_header_size, file_info.m_total_palette_size, file_info.m_tables_size, file_info.m_levels);

  printf("LevelCompressedSize: ");
  for (crn_uint32 i = 0; i < cCRNMaxLevels; i++)
    printf("%u ", file_info.m_level_compressed_size[i]);
  printf("\n");

  printf("ColorEndpointPaletteSize: %u\n", file_info.m_color_endpoint_palette_entries);
  printf("ColorSelectorPaletteSize: %u\n", file_info.m_color_selector_palette_entries);
  printf("AlphaEndpointPaletteSize: %u\n", file_info.m_alpha_endpoint_palette_entries);
  printf("AlphaSelectorPaletteSize: %u\n", file_info.m_alpha_selector_palette_entries);

  printf("crnd_get_texture_info:\n");
  crnd::crn_texture_info tex_info;
  if (!crnd::crnd_get_texture_info(pData, data_size, &tex_info))
    return false;

  printf("Dimensions: %ux%u\nLevels: %u\nFaces: %u\nBytesPerBlock: %u\nUserData0: %u\nUserData1: %u\nCrnFormat: %s\n",
         tex_info.m_width, tex_info.m_height, tex_info.m_levels, tex_info.m_faces, tex_info.m_bytes_per_block, tex_info.m_userdata0, tex_info.m_userdata1, crn_get_format_string(tex_info.m_format));

  return true;
}

// Cracks the DDS header and dump its contents.
static bool print_dds_info(const void* pData, crn_uint32 data_size) {
  if ((data_size < 128) || (*reinterpret_cast<const crn_uint32*>(pData) != crnlib::cDDSFileSignature))
    return false;

  const crnlib::DDSURFACEDESC2& desc = *reinterpret_cast<const crnlib::DDSURFACEDESC2*>((reinterpret_cast<const crn_uint8*>(pData) + sizeof(crn_uint32)));
  if (desc.dwSize != sizeof(crnlib::DDSURFACEDESC2))
    return false;

  printf("DDS file information:\n");
  printf("File size: %u\nDimensions: %ux%u\nPitch/LinearSize: %u\n", data_size, desc.dwWidth, desc.dwHeight, desc.dwLinearSize);
  printf("MipMapCount: %u\nAlphaBitDepth: %u\n", desc.dwMipMapCount, desc.dwAlphaBitDepth);

  const char* pDDSDFlagNames[] =
      {
          "DDSD_CAPS", "DDSD_HEIGHT", "DDSD_WIDTH", "DDSD_PITCH",
          NULL, "DDSD_BACKBUFFERCOUNT", "DDSD_ZBUFFERBITDEPTH", "DDSD_ALPHABITDEPTH",
          NULL, NULL, NULL, "DDSD_LPSURFACE",
          "DDSD_PIXELFORMAT", "DDSD_CKDESTOVERLAY", "DDSD_CKDESTBLT", "DDSD_CKSRCOVERLAY",
          "DDSD_CKSRCBLT", "DDSD_MIPMAPCOUNT", "DDSD_REFRESHRATE", "DDSD_LINEARSIZE",
          "DDSD_TEXTURESTAGE", "DDSD_FVF", "DDSD_SRCVBHANDLE", "DDSD_DEPTH"};

  printf("DDSD Flags: 0x%08X ", desc.dwFlags);
  for (size_t i = 0; i < sizeof(pDDSDFlagNames) / sizeof(pDDSDFlagNames[0]); i++)
    if ((pDDSDFlagNames[i]) && (desc.dwFlags & (1 << i)))
      printf("%s ", pDDSDFlagNames[i]);
  printf("\n\n");

  printf("ddpfPixelFormat.dwFlags: 0x%08X ", desc.ddpfPixelFormat.dwFlags);
  if (desc.ddpfPixelFormat.dwFlags & DDPF_ALPHAPIXELS)
    printf("DDPF_ALPHAPIXELS ");
  if (desc.ddpfPixelFormat.dwFlags & DDPF_ALPHA)
    printf("DDPF_ALPHA ");
  if (desc.ddpfPixelFormat.dwFlags & DDPF_FOURCC)
    printf("DDPF_FOURCC ");
  if (desc.ddpfPixelFormat.dwFlags & DDPF_PALETTEINDEXED8)
    printf("DDPF_PALETTEINDEXED8 ");
  if (desc.ddpfPixelFormat.dwFlags & DDPF_RGB)
    printf("DDPF_RGB ");
  if (desc.ddpfPixelFormat.dwFlags & DDPF_LUMINANCE)
    printf("DDPF_LUMINANCE ");
  printf("\n");

  printf("ddpfPixelFormat.dwFourCC: 0x%08X '%c' '%c' '%c' '%c'\n",
         desc.ddpfPixelFormat.dwFourCC,
         std::max(32U, desc.ddpfPixelFormat.dwFourCC & 0xFF),
         std::max(32U, (desc.ddpfPixelFormat.dwFourCC >> 8) & 0xFF),
         std::max(32U, (desc.ddpfPixelFormat.dwFourCC >> 16) & 0xFF),
         std::max(32U, (desc.ddpfPixelFormat.dwFourCC >> 24) & 0xFF));

  printf("dwRGBBitCount: %u 0x%08X\n",
         desc.ddpfPixelFormat.dwRGBBitCount, desc.ddpfPixelFormat.dwRGBBitCount);

  printf("dwRGBBitCount as FOURCC: '%c' '%c' '%c' '%c'\n",
         std::max(32U, desc.ddpfPixelFormat.dwRGBBitCount & 0xFF),
         std::max(32U, (desc.ddpfPixelFormat.dwRGBBitCount >> 8) & 0xFF),
         std::max(32U, (desc.ddpfPixelFormat.dwRGBBitCount >> 16) & 0xFF),
         std::max(32U, (desc.ddpfPixelFormat.dwRGBBitCount >> 24) & 0xFF));

  printf("dwRBitMask: 0x%08X\ndwGBitMask: 0x%08X\ndwBBitMask: 0x%08X\ndwRGBAlphaBitMask: 0x%08X\n",
         desc.ddpfPixelFormat.dwRBitMask, desc.ddpfPixelFormat.dwGBitMask, desc.ddpfPixelFormat.dwBBitMask, desc.ddpfPixelFormat.dwRGBAlphaBitMask);

  printf("\n");
  printf("ddsCaps.dwCaps: 0x%08X ", desc.ddsCaps.dwCaps);
  if (desc.ddsCaps.dwCaps & DDSCAPS_COMPLEX)
    printf("DDSCAPS_COMPLEX ");
  if (desc.ddsCaps.dwCaps & DDSCAPS_TEXTURE)
    printf("DDSCAPS_TEXTURE ");
  if (desc.ddsCaps.dwCaps & DDSCAPS_MIPMAP)
    printf("DDSCAPS_MIPMAP");
  printf("\n");

  printf("ddsCaps.dwCaps2: 0x%08X ", desc.ddsCaps.dwCaps2);
  const char* pDDCAPS2FlagNames[] =
      {
          NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
          NULL, "DDSCAPS2_CUBEMAP", "DDSCAPS2_CUBEMAP_POSITIVEX", "DDSCAPS2_CUBEMAP_NEGATIVEX",
          "DDSCAPS2_CUBEMAP_POSITIVEY", "DDSCAPS2_CUBEMAP_NEGATIVEY", "DDSCAPS2_CUBEMAP_POSITIVEZ", "DDSCAPS2_CUBEMAP_NEGATIVEZ",
          NULL, NULL, NULL, NULL,
          NULL, "DDSCAPS2_VOLUME"};
  for (size_t i = 0; i < sizeof(pDDCAPS2FlagNames) / sizeof(pDDCAPS2FlagNames[0]); i++)
    if ((pDDCAPS2FlagNames[i]) && (desc.ddsCaps.dwCaps2 & (1 << i)))
      printf("%s ", pDDCAPS2FlagNames[i]);
  printf("\n");

  printf("ddsCaps.dwCaps3: 0x%08X\nddsCaps.dwCaps4: 0x%08X\n",
         desc.ddsCaps.dwCaps3, desc.ddsCaps.dwCaps4);

  return true;
}

// CRN/DDS compression callback function.
static crn_bool progress_callback_func(crn_uint32 phase_index, crn_uint32 total_phases, crn_uint32 subphase_index, crn_uint32 total_subphases, void* pUser_data_ptr) {
  int percentage_complete = (int)(.5f + (phase_index + float(subphase_index) / total_subphases) * 100.0f) / total_phases;
  printf("\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\bProcessing: %u%%", std::min(100, std::max(0, percentage_complete)));
  return true;
}

int main(int argc, char* argv[]) {
  printf("example1 - Version v%u.%02u Built " __DATE__ ", " __TIME__ "\n", CRNLIB_VERSION / 100, CRNLIB_VERSION % 100);

  if (argc < 3)
    return print_usage();

  // Parse command line options
  int mode = argv[1][0];
  if ((mode != 'c') && (mode != 'd') && (mode != 'i'))
    return error("Invalid mode!\n");

  const char* pSrc_filename = argv[2];
  char out_filename[FILENAME_MAX] = {'\0'};

  float bitrate = 0.0f;
  int quality_level = -1;
  bool srgb_colorspace = true;
  bool create_mipmaps = true;
  bool output_crn = false;
  crn_format fmt = cCRNFmtInvalid;
  bool use_adaptive_block_sizes = true;
  bool set_alpha_to_luma = false;
  bool convert_to_luma = false;
  bool enable_dxt1a = false;

  for (int i = 3; i < argc; i++) {
    if (argv[i][0] == '/')
      argv[i][0] = '-';

    if (!crnlib_stricmp(argv[i], "-crn")) {
      output_crn = true;
    } else if (!crnlib_stricmp(argv[i], "-pixelformat")) {
      if (++i >= argc)
        return error("Expected pixel format!");

      if (!crnlib_stricmp(argv[i], "dxt1a")) {
        enable_dxt1a = true;
        fmt = cCRNFmtDXT1;
      } else {
        uint f;
        for (f = 0; f < cCRNFmtTotal; f++) {
          if (!crnlib_stricmp(argv[i], crn_get_format_string(static_cast<crn_format>(f)))) {
            fmt = static_cast<crn_format>(f);
            break;
          }
        }
        if (f == cCRNFmtTotal)
          return error("Unrecognized pixel format: %s\n", argv[i]);
      }
    } else if (!crnlib_stricmp(argv[i], "-bitrate")) {
      if (++i >= argc)
        return error("Invalid bitrate!");

      bitrate = (float)atof(argv[i]);
      if ((bitrate < .1f) || (bitrate > 8.0f))
        return error("Invalid bitrate!");
    } else if (!crnlib_stricmp(argv[i], "-quality")) {
      if (++i >= argc)
        return error("Invalid quality level!");

      quality_level = atoi(argv[i]);
      if ((quality_level < 0) || (quality_level > cCRNMaxQualityLevel))
        return error("Invalid quality level!");
    } else if (!crnlib_stricmp(argv[i], "-out")) {
      if (++i >= argc)
        return error("Expected output filename!");

      strcpy_safe(out_filename, sizeof(out_filename), argv[i]);
    } else if (!crnlib_stricmp(argv[i], "-nonsrgb"))
      srgb_colorspace = false;
    else if (!crnlib_stricmp(argv[i], "-nomips"))
      create_mipmaps = false;
    else if (!crnlib_stricmp(argv[i], "-noAdaptiveBlocks"))
      use_adaptive_block_sizes = false;
    else if (!crnlib_stricmp(argv[i], "-setalphatoluma"))
      set_alpha_to_luma = true;
    else if (!crnlib_stricmp(argv[i], "-converttoluma"))
      convert_to_luma = true;
    else
      return error("Invalid option: %s\n", argv[i]);
  }

  // Split the source filename into its various components.
  dynamic_string drive, dir, fname, ext;

  if (!file_utils::split_path(pSrc_filename, &drive, &dir, &fname, &ext))
    return error("Invalid source filename!\n");

  // Load the source file into memory.
  printf("Loading source file: %s\n", pSrc_filename);
  crn_uint32 src_file_size;
  crn_uint8* pSrc_file_data = read_file_into_buffer(pSrc_filename, src_file_size);
  if (!pSrc_file_data)
    return error("Unable to read source file\n");

  if (mode == 'i') {
    // Information
    if (crnlib_stricmp(ext.get_ptr(), ".crn") == 0) {
      if (!print_crn_info(pSrc_file_data, src_file_size)) {
        free(pSrc_file_data);
        return error("Not a CRN file!\n");
      }
    } else if (crnlib_stricmp(ext.get_ptr(), ".dds") == 0) {
      if (!print_dds_info(pSrc_file_data, src_file_size)) {
        free(pSrc_file_data);
        return error("Not a DDS file!\n");
      }
    } else {
      // Try parsing the source file as a regular image.
      int x, y, actual_comps;
      stbi_uc* p = stbi_load_from_memory(pSrc_file_data, src_file_size, &x, &y, &actual_comps, 4);
      if (!p) {
        free(pSrc_file_data);
        return error("Failed reading image file!\n");
      }
      stbi_image_free(p);

      printf("File size: %u\nDimensions: %ix%i\nActual Components: %i\n", src_file_size, x, y, actual_comps);
    }
  } else if (mode == 'c') {
    // Compression to DDS or CRN.

    // If the user has explicitly specified an output file, check the output file's extension to ensure we write the expected format.
    if (out_filename[0]) {
      dynamic_string out_fname, out_ext;

      file_utils::split_path(out_filename, NULL, NULL, &out_fname, &out_ext);

      if (!crnlib_stricmp(out_ext.get_ptr(), ".crn"))
        output_crn = true;
      else if (!crnlib_stricmp(out_ext.get_ptr(), ".dds"))
        output_crn = false;
    }

    // Load source image
    int width, height, actual_comps;
    crn_uint32* pSrc_image = (crn_uint32*)stbi_load_from_memory(pSrc_file_data, src_file_size, &width, &height, &actual_comps, 4);
    if (!pSrc_image) {
      free(pSrc_file_data);
      return error("Failed reading image file!\n");
    }

    printf("Source file size: %u, Dimensions: %ux%u\nActual Components: %u\n", src_file_size, width, height, actual_comps);

    // Fill in compression parameters struct.
    bool has_alpha_channel = actual_comps > 3;

    if ((fmt == cCRNFmtDXT5A) && (actual_comps <= 3))
      set_alpha_to_luma = true;

    if ((set_alpha_to_luma) || (convert_to_luma)) {
      for (int i = 0; i < width * height; i++) {
        crn_uint32 r = pSrc_image[i] & 0xFF, g = (pSrc_image[i] >> 8) & 0xFF, b = (pSrc_image[i] >> 16) & 0xFF;
        // Compute CCIR 601 luma.
        crn_uint32 y = (19595U * r + 38470U * g + 7471U * b + 32768) >> 16U;
        crn_uint32 a = (pSrc_image[i] >> 24) & 0xFF;
        if (set_alpha_to_luma)
          a = y;
        if (convert_to_luma) {
          r = y;
          g = y;
          b = y;
        }
        pSrc_image[i] = r | (g << 8) | (b << 16) | (a << 24);
      }
    }

    crn_comp_params comp_params;
    comp_params.m_width = width;
    comp_params.m_height = height;
    comp_params.set_flag(cCRNCompFlagPerceptual, srgb_colorspace);
    comp_params.set_flag(cCRNCompFlagDXT1AForTransparency, enable_dxt1a && has_alpha_channel);
    comp_params.set_flag(cCRNCompFlagHierarchical, use_adaptive_block_sizes);
    comp_params.m_file_type = output_crn ? cCRNFileTypeCRN : cCRNFileTypeDDS;
    comp_params.m_format = (fmt != cCRNFmtInvalid) ? fmt : (has_alpha_channel ? cCRNFmtDXT5 : cCRNFmtDXT1);

    // Important note: This example only feeds a single source image to the compressor, and it internaly generates mipmaps from that source image.
    // If you want, there's nothing stopping you from generating the mipmaps on your own, then feeding the multiple source images
    // to the compressor. Just set the crn_mipmap_params::m_mode member (set below) to cCRNMipModeUseSourceMips.
    comp_params.m_pImages[0][0] = pSrc_image;

    if (bitrate > 0.0f)
      comp_params.m_target_bitrate = bitrate;
    else if (quality_level >= 0)
      comp_params.m_quality_level = quality_level;
    else if (output_crn) {
      // Set a default quality level for CRN, otherwise we'll get the default (highest quality) which leads to huge compressed palettes.
      comp_params.m_quality_level = cDefaultCRNQualityLevel;
    }

    // Determine the # of helper threads (in addition to the main thread) to use during compression. NumberOfCPU's-1 is reasonable.
    int number_of_processors = 1;
#if defined(_WIN32)
    SYSTEM_INFO g_system_info;
    GetSystemInfo(&g_system_info);
    number_of_processors = std::max<int>(1, (int)g_system_info.dwNumberOfProcessors);
#elif defined(__FreeBSD__) || defined(__APPLE__)
    number_of_processors = std::max<int>(1, sysconf(_SC_NPROCESSORS_ONLN));
#elif defined(__GNUC__)
    number_of_processors = std::max<int>(1, get_nprocs());
#endif
    comp_params.m_num_helper_threads = std::min(number_of_processors - 1, (int)cCRNMaxHelperThreads);

    comp_params.m_pProgress_func = progress_callback_func;

    // Fill in mipmap parameters struct.
    crn_mipmap_params mip_params;
    mip_params.m_gamma_filtering = srgb_colorspace;
    mip_params.m_mode = create_mipmaps ? cCRNMipModeGenerateMips : cCRNMipModeNoMips;

    crn_uint32 actual_quality_level;
    float actual_bitrate;
    crn_uint32 output_file_size;

    printf("Compressing to %s\n", crn_get_format_string(comp_params.m_format));

    // Now compress to DDS or CRN.
    void* pOutput_file_data = crn_compress(comp_params, mip_params, output_file_size, &actual_quality_level, &actual_bitrate);
    printf("\n");

    if (!pOutput_file_data) {
      stbi_image_free(pSrc_image);
      free(pSrc_file_data);
      return error("Compression failed!");
    }

    printf("Compressed to %u bytes, quality level: %u, effective bitrate: %f\n", output_file_size, actual_quality_level, actual_bitrate);

    // Write the output file.
    char dst_filename[FILENAME_MAX];
    crnlib_snprintf(dst_filename, sizeof(dst_filename), "%s%s%s%s", drive.get_ptr(), dir.get_ptr(), fname.get_ptr(), output_crn ? ".crn" : ".dds");
    if (out_filename[0])
      strcpy_safe(dst_filename, sizeof(dst_filename), out_filename);

    printf("Writing %s file: %s\n", output_crn ? "CRN" : "DDS", dst_filename);
    FILE* pFile = NULL;
    crn_fopen(&pFile, dst_filename, "wb");
    if ((!pFile) || (fwrite(pOutput_file_data, output_file_size, 1, pFile) != 1) || (fclose(pFile) == EOF)) {
      free(pSrc_file_data);
      crn_free_block(pOutput_file_data);
      stbi_image_free(pSrc_image);
      return error("Failed writing to output file!\n");
    }

    crn_free_block(pOutput_file_data);
    stbi_image_free(pSrc_image);
  } else if (crnlib_stricmp(ext.get_ptr(), ".crn") == 0) {
    // Decompress/transcode CRN to DDS.
    printf("Decompressing CRN to DDS\n");

    // Transcode the CRN file to a DDS file in memory.
    crn_uint32 dds_file_size = src_file_size;
    void* pDDS_file_data = crn_decompress_crn_to_dds(pSrc_file_data, dds_file_size);
    if (!pDDS_file_data) {
      free(pSrc_file_data);
      return error("Failed decompressing CRN file!\n");
    }

    // Now write the DDS file to disk.
    char dst_filename[FILENAME_MAX];
    crnlib_snprintf(dst_filename, sizeof(dst_filename), "%s%s%s.dds", drive.get_ptr(), dir.get_ptr(), fname.get_ptr());
    if (out_filename[0])
      strcpy_safe(dst_filename, sizeof(dst_filename), out_filename);

    printf("Writing file: %s\n", dst_filename);
    FILE* pFile = NULL;
    crn_fopen(&pFile, dst_filename, "wb");
    if ((!pFile) || (fwrite(pDDS_file_data, dds_file_size, 1, pFile) != 1) || (fclose(pFile) == EOF)) {
      crn_free_block(pDDS_file_data);
      free(pSrc_file_data);
      return error("Failed writing to output file!\n");
    }

    printf("\n");

    print_dds_info(pDDS_file_data, dds_file_size);

    crn_free_block(pDDS_file_data);
  } else if (crnlib_stricmp(ext.get_ptr(), ".dds") == 0) {
    // Unpack DDS to one or more TGA's.
    if (out_filename[0]) {
      file_utils::split_path(out_filename, &drive, &dir, &fname, &ext);
    }

    crn_texture_desc tex_desc;
    crn_uint32* pImages[cCRNMaxFaces * cCRNMaxLevels];
    if (!crn_decompress_dds_to_images(pSrc_file_data, src_file_size, pImages, tex_desc)) {
      free(pSrc_file_data);
      return error("Failed unpacking DDS file!\n");
    }

    printf("Decompressed texture Dimensions: %ux%u, Faces: %u, Levels: %u, FourCC: 0x%08X '%c' '%c' '%c' '%c'\n",
           tex_desc.m_width, tex_desc.m_height, tex_desc.m_faces, tex_desc.m_levels, tex_desc.m_fmt_fourcc,
           std::max(32U, tex_desc.m_fmt_fourcc & 0xFF),
           std::max(32U, (tex_desc.m_fmt_fourcc >> 8) & 0xFF),
           std::max(32U, (tex_desc.m_fmt_fourcc >> 16) & 0xFF),
           std::max(32U, (tex_desc.m_fmt_fourcc >> 24) & 0xFF));

    for (crn_uint32 face_index = 0; face_index < tex_desc.m_faces; face_index++) {
      for (crn_uint32 level_index = 0; level_index < tex_desc.m_levels; level_index++) {
        int width = std::max(1U, tex_desc.m_width >> level_index);
        int height = std::max(1U, tex_desc.m_height >> level_index);

        char dst_filename[FILENAME_MAX];
        crnlib_snprintf(dst_filename, sizeof(dst_filename), "%s%s%s_face%u_mip%u.tga", drive.get_ptr(), dir.get_ptr(), fname.get_ptr(), face_index, level_index);

        printf("Writing file: %s\n", dst_filename);
        if (!stbi_write_tga(dst_filename, width, height, 4, pImages[level_index + face_index * tex_desc.m_levels])) {
          crn_free_all_images(pImages, tex_desc);
          free(pSrc_file_data);

          return error("Failed writing output file!\n");
        }
      }
    }

    crn_free_all_images(pImages, tex_desc);
  } else {
    free(pSrc_file_data);
    return error("Decompression mode only supports .dds or .crn files!\n");
  }

  free(pSrc_file_data);

  return EXIT_SUCCESS;
}