BlenderThumb.cpp

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/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */
 
#include <new>
#include <shlwapi.h>
#include <thumbcache.h>  // For IThumbnailProvider.
 
#pragma comment(lib, "shlwapi.lib")
 
// this thumbnail provider implements IInitializeWithStream to enable being hosted
// in an isolated process for robustness
 
class CBlendThumb : public IInitializeWithStream, public IThumbnailProvider {
 public:
  CBlendThumb() : _cRef(1), _pStream(NULL)
  {
  }
 
  virtual ~CBlendThumb()
  {
    if (_pStream) {
      _pStream->Release();
    }
  }
 
  // IUnknown
  IFACEMETHODIMP QueryInterface(REFIID riid, void **ppv)
  {
    static const QITAB qit[] = {
        QITABENT(CBlendThumb, IInitializeWithStream),
        QITABENT(CBlendThumb, IThumbnailProvider),
        {0},
    };
    return QISearch(this, qit, riid, ppv);
  }
 
  IFACEMETHODIMP_(ULONG) AddRef()
  {
    return InterlockedIncrement(&_cRef);
  }
 
  IFACEMETHODIMP_(ULONG) Release()
  {
    ULONG cRef = InterlockedDecrement(&_cRef);
    if (!cRef) {
      delete this;
    }
    return cRef;
  }
 
  // IInitializeWithStream
  IFACEMETHODIMP Initialize(IStream *pStream, DWORD grfMode);
 
  // IThumbnailProvider
  IFACEMETHODIMP GetThumbnail(UINT cx, HBITMAP *phbmp, WTS_ALPHATYPE *pdwAlpha);
 
 private:
  long _cRef;
  IStream *_pStream;  // provided during initialization.
};
 
HRESULT CBlendThumb_CreateInstance(REFIID riid, void **ppv)
{
  CBlendThumb *pNew = new (std::nothrow) CBlendThumb();
  HRESULT hr = pNew ? S_OK : E_OUTOFMEMORY;
  if (SUCCEEDED(hr)) {
    hr = pNew->QueryInterface(riid, ppv);
    pNew->Release();
  }
  return hr;
}
 
// IInitializeWithStream
IFACEMETHODIMP CBlendThumb::Initialize(IStream *pStream, DWORD)
{
  HRESULT hr = E_UNEXPECTED;  // can only be inited once
  if (_pStream == NULL) {
    // take a reference to the stream if we have not been inited yet
    hr = pStream->QueryInterface(&_pStream);
  }
  return hr;
}
 
#include "Wincodec.h"
#include <math.h>
#include <zlib.h>
const unsigned char gzip_magic[3] = {0x1f, 0x8b, 0x08};
 
// IThumbnailProvider
IFACEMETHODIMP CBlendThumb::GetThumbnail(UINT cx, HBITMAP *phbmp, WTS_ALPHATYPE *pdwAlpha)
{
  ULONG BytesRead;
  HRESULT hr = S_FALSE;
  LARGE_INTEGER SeekPos;
 
  // Compressed?
  unsigned char in_magic[3];
  _pStream->Read(&in_magic, 3, &BytesRead);
  bool gzipped = true;
  for (int i = 0; i < 3; i++)
    if (in_magic[i] != gzip_magic[i]) {
      gzipped = false;
      break;
    }
 
  if (gzipped) {
    // Zlib inflate
    z_stream stream;
    stream.zalloc = Z_NULL;
    stream.zfree = Z_NULL;
    stream.opaque = Z_NULL;
 
    // Get compressed file length
    SeekPos.QuadPart = 0;
    _pStream->Seek(SeekPos, STREAM_SEEK_END, NULL);
 
    // Get compressed and uncompressed size
    uLong source_size;
    uLongf dest_size;
    // SeekPos.QuadPart = -4; // last 4 bytes define size of uncompressed file
    // ULARGE_INTEGER Tell;
    //_pStream->Seek(SeekPos,STREAM_SEEK_END,&Tell);
    // source_size = (uLong)Tell.QuadPart + 4; // src
    //_pStream->Read(&dest_size,4,&BytesRead); // dest
    dest_size = 1024 * 70;  // thumbnail is currently always inside the first 65KB...if it moves or
                            // enlargens this line will have to change or go!
    source_size = (uLong)max(SeekPos.QuadPart, dest_size);  // for safety, assume no compression
 
    // Input
    Bytef *src = new Bytef[source_size];
    stream.next_in = (Bytef *)src;
    stream.avail_in = (uInt)source_size;
 
    // Output
    Bytef *dest = new Bytef[dest_size];
    stream.next_out = (Bytef *)dest;
    stream.avail_out = dest_size;
 
    // IStream to src
    SeekPos.QuadPart = 0;
    _pStream->Seek(SeekPos, STREAM_SEEK_SET, NULL);
    _pStream->Read(src, source_size, &BytesRead);
 
    // Do the inflation
    int err;
    err = inflateInit2(&stream, 16);  // 16 means "gzip"...nice!
    err = inflate(&stream, Z_FINISH);
    err = inflateEnd(&stream);
 
    // Replace the IStream, which is read-only
    _pStream->Release();
    _pStream = SHCreateMemStream(dest, dest_size);
 
    delete[] src;
    delete[] dest;
  }
 
  // Blender version, early out if sub 2.5
  SeekPos.QuadPart = 9;
  _pStream->Seek(SeekPos, STREAM_SEEK_SET, NULL);
  char version[4];
  version[3] = '\0';
  _pStream->Read(&version, 3, &BytesRead);
  if (BytesRead != 3) {
    return E_UNEXPECTED;
  }
  int iVersion = atoi(version);
  if (iVersion < 250) {
    return S_FALSE;
  }
 
  // 32 or 64 bit blend?
  SeekPos.QuadPart = 7;
  _pStream->Seek(SeekPos, STREAM_SEEK_SET, NULL);
 
  char _PointerSize;
  _pStream->Read(&_PointerSize, 1, &BytesRead);
 
  int PointerSize = _PointerSize == '_' ? 4 : 8;
  int HeaderSize = 16 + PointerSize;
 
  // Find and read thumbnail ("TEST") block
  SeekPos.QuadPart = 12;
  _pStream->Seek(SeekPos, STREAM_SEEK_SET, NULL);
  int BlockOffset = 12;
  while (_pStream) {
    // Scan current block
    char BlockName[5];
    BlockName[4] = '\0';
    int BlockSize = 0;
 
    if (_pStream->Read(BlockName, 4, &BytesRead) == S_OK &&
        _pStream->Read((void *)&BlockSize, 4, &BytesRead) == S_OK) {
      if (strcmp(BlockName, "TEST") != 0) {
        SeekPos.QuadPart = BlockOffset += HeaderSize + BlockSize;
        _pStream->Seek(SeekPos, STREAM_SEEK_SET, NULL);
        continue;
      }
    }
    else {
      break;  // eof
    }
 
    // Found the block
    SeekPos.QuadPart = BlockOffset + HeaderSize;
    _pStream->Seek(SeekPos, STREAM_SEEK_SET, NULL);
 
    int width, height;
    _pStream->Read((char *)&width, 4, &BytesRead);
    _pStream->Read((char *)&height, 4, &BytesRead);
    BlockSize -= 8;
 
    // Isolate RGBA data
    char *pRGBA = new char[BlockSize];
    _pStream->Read(pRGBA, BlockSize, &BytesRead);
 
    if (BytesRead != (ULONG)BlockSize) {
      return E_UNEXPECTED;
    }
 
    // Convert to BGRA for Windows
    for (int i = 0; i < BlockSize; i += 4) {
#define RED_BYTE pRGBA[i]
#define BLUE_BYTE pRGBA[i + 2]
 
      char red = RED_BYTE;
      RED_BYTE = BLUE_BYTE;
      BLUE_BYTE = red;
    }
 
    // Flip vertically (Blender stores it upside-down)
    unsigned int LineSize = width * 4;
    char *FlippedImage = new char[BlockSize];
    for (int i = 0; i < height; i++) {
      if (0 != memcpy_s(&FlippedImage[(height - i - 1) * LineSize],
                        LineSize,
                        &pRGBA[i * LineSize],
                        LineSize)) {
        return E_UNEXPECTED;
      }
    }
    delete[] pRGBA;
    pRGBA = FlippedImage;
 
    // Create image
    *phbmp = CreateBitmap(width, height, 1, 32, pRGBA);
    if (!*phbmp) {
      return E_FAIL;
    }
    *pdwAlpha = WTSAT_ARGB;  // it's actually BGRA, not sure why this works
 
    // Scale down if required
    if ((unsigned)width > cx || (unsigned)height > cx) {
      float scale = 1.0f / (max(width, height) / (float)cx);
      LONG NewWidth = (LONG)(width * scale);
      LONG NewHeight = (LONG)(height * scale);
 
#ifdef _DEBUG
#  if 0
      MessageBox(0, "Attach now", "Debugging", MB_OK);
#  endif
#endif
      IWICImagingFactory *pImgFac;
      hr = CoCreateInstance(
          CLSID_WICImagingFactory, NULL, CLSCTX_INPROC_SERVER, IID_PPV_ARGS(&pImgFac));
 
      IWICBitmap *WICBmp;
      hr = pImgFac->CreateBitmapFromHBITMAP(*phbmp, 0, WICBitmapUseAlpha, &WICBmp);
 
      BITMAPINFO bmi = {};
      bmi.bmiHeader.biSize = sizeof(bmi.bmiHeader);
      bmi.bmiHeader.biWidth = NewWidth;
      bmi.bmiHeader.biHeight = -NewHeight;
      bmi.bmiHeader.biPlanes = 1;
      bmi.bmiHeader.biBitCount = 32;
      bmi.bmiHeader.biCompression = BI_RGB;
 
      BYTE *pBits;
      HBITMAP ResizedHBmp = CreateDIBSection(NULL, &bmi, DIB_RGB_COLORS, (void **)&pBits, NULL, 0);
      hr = ResizedHBmp ? S_OK : E_OUTOFMEMORY;
      if (SUCCEEDED(hr)) {
        IWICBitmapScaler *pIScaler;
        hr = pImgFac->CreateBitmapScaler(&pIScaler);
        hr = pIScaler->Initialize(WICBmp, NewWidth, NewHeight, WICBitmapInterpolationModeFant);
 
        WICRect rect = {0, 0, NewWidth, NewHeight};
        hr = pIScaler->CopyPixels(&rect, NewWidth * 4, NewWidth * NewHeight * 4, pBits);
 
        if (SUCCEEDED(hr)) {
          DeleteObject(*phbmp);
          *phbmp = ResizedHBmp;
        }
        else {
          DeleteObject(ResizedHBmp);
        }
 
        pIScaler->Release();
      }
      WICBmp->Release();
      pImgFac->Release();
    }
    else {
      hr = S_OK;
    }
    break;
  }
  return hr;
}