hb-directwrite.hh - mozsearch

Enable keyboard shortcuts

/*

 *  This is part of HarfBuzz, a text shaping library.

 * Permission is hereby granted, without written agreement and without

 * license or royalty fees, to use, copy, modify, and distribute this

 * software and its documentation for any purpose, provided that the

 * above copyright notice and the following two paragraphs appear in

 * all copies of this software.

 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR

 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES

 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN

 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH

 * DAMAGE.

 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,

 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS

 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO

 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

 * Author(s): Behdad Esfahbod

*/

#ifndef HB_DIRECTWRITE_HH

#define HB_DIRECTWRITE_HH

#include "hb.hh"

#include "hb-directwrite.h"

#include "hb-mutex.hh"

#include "hb-map.hh"

/*

 * DirectWrite font stream helpers

*/

// Have a look at to NativeFontResourceDWrite.cpp in Mozilla

/* Declare object creator for dynamic support of DWRITE */

typedef HRESULT (WINAPI *t_DWriteCreateFactory)(

  DWRITE_FACTORY_TYPE factoryType,

  REFIID              iid,

  IUnknown            **factory

);

class DWriteFontFileLoader : public IDWriteFontFileLoader

private:

  hb_reference_count_t mRefCount;

  hb_mutex_t mutex;

  hb_hashmap_t<uint64_t, IDWriteFontFileStream *> mFontStreams;

  uint64_t mNextFontFileKey = 0;

public:

  DWriteFontFileLoader ()

    mRefCount.init ();

  uint64_t RegisterFontFileStream (IDWriteFontFileStream *fontFileStream)

    fontFileStream->AddRef ();

    auto lock = hb_lock_t (mutex);

    mFontStreams.set (mNextFontFileKey, fontFileStream);

    return mNextFontFileKey++;

  void UnregisterFontFileStream (uint64_t fontFileKey)

    auto lock = hb_lock_t (mutex);

    IDWriteFontFileStream *stream = mFontStreams.get (fontFileKey);

    if (stream)

      mFontStreams.del (fontFileKey);

      stream->Release ();

  // IUnknown interface

  IFACEMETHOD (QueryInterface) (IID const& iid, OUT void** ppObject)

  { return S_OK; }

  IFACEMETHOD_ (ULONG, AddRef) ()

    return mRefCount.inc () + 1;

  IFACEMETHOD_ (ULONG, Release) ()

    signed refCount = mRefCount.dec () - 1;

    assert (refCount >= 0);

    if (refCount)

      return refCount;

    delete this;

    return 0;

  // IDWriteFontFileLoader methods

  virtual HRESULT STDMETHODCALLTYPE

  CreateStreamFromKey (void const* fontFileReferenceKey,

		       uint32_t fontFileReferenceKeySize,

		       OUT IDWriteFontFileStream** fontFileStream)

    if (fontFileReferenceKeySize != sizeof (uint64_t))

      return E_INVALIDARG;

    uint64_t fontFileKey = * (uint64_t *) fontFileReferenceKey;

    IDWriteFontFileStream *stream = mFontStreams.get (fontFileKey);

    if (!stream)

      return E_FAIL;

    stream->AddRef ();

    *fontFileStream = stream;

    return S_OK;

  virtual ~DWriteFontFileLoader()

    for (auto v : mFontStreams.values ())

      v->Release ();

};

class DWriteFontFileStream : public IDWriteFontFileStream

private:

  hb_reference_count_t mRefCount;

  hb_blob_t *mBlob;

  uint8_t *mData;

  unsigned mSize;

  DWriteFontFileLoader *mLoader;

public:

  uint64_t fontFileKey;

public:

  DWriteFontFileStream (hb_blob_t *blob);

  // IUnknown interface

  IFACEMETHOD (QueryInterface) (IID const& iid, OUT void** ppObject)

  { return S_OK; }

  IFACEMETHOD_ (ULONG, AddRef) ()

    return mRefCount.inc () + 1;

  IFACEMETHOD_ (ULONG, Release) ()

    signed refCount = mRefCount.dec () - 1;

    assert (refCount >= 0);

    if (refCount)

      return refCount;

    delete this;

    return 0;

  // IDWriteFontFileStream methods

  virtual HRESULT STDMETHODCALLTYPE

  ReadFileFragment (void const** fragmentStart,

		    UINT64 fileOffset,

		    UINT64 fragmentSize,

		    OUT void** fragmentContext)

    // We are required to do bounds checking.

    if (fileOffset + fragmentSize > mSize) return E_FAIL;

    // truncate the 64 bit fileOffset to size_t sized index into mData

    size_t index = static_cast<size_t> (fileOffset);

    // We should be alive for the duration of this.

    *fragmentStart = &mData[index];

    *fragmentContext = nullptr;

    return S_OK;

  virtual void STDMETHODCALLTYPE

  ReleaseFileFragment (void* fragmentContext) {}

  virtual HRESULT STDMETHODCALLTYPE

  GetFileSize (OUT UINT64* fileSize)

    *fileSize = mSize;

    return S_OK;

  virtual HRESULT STDMETHODCALLTYPE

  GetLastWriteTime (OUT UINT64* lastWriteTime) { return E_NOTIMPL; }

  virtual ~DWriteFontFileStream();

};

struct hb_directwrite_global_t

  hb_directwrite_global_t ()

    dwrite_dll = LoadLibraryW (L"DWrite.dll");

#if defined(__GNUC__) || defined(__clang__)

#pragma GCC diagnostic push

#pragma GCC diagnostic ignored "-Wcast-function-type"

#endif

    t_DWriteCreateFactory p_DWriteCreateFactory = (t_DWriteCreateFactory)

			    GetProcAddress (dwrite_dll, "DWriteCreateFactory");

#if defined(__GNUC__) || defined(__clang__)

#pragma GCC diagnostic pop

#endif

    if (unlikely (!p_DWriteCreateFactory))

      return;

    HRESULT hr = p_DWriteCreateFactory (DWRITE_FACTORY_TYPE_SHARED, __uuidof (IDWriteFactory),

					(IUnknown**) &dwriteFactory);

    if (unlikely (hr != S_OK))

      return;

    fontFileLoader = new DWriteFontFileLoader ();

    dwriteFactory->RegisterFontFileLoader (fontFileLoader);

    success = true;

  ~hb_directwrite_global_t ()

    if (fontFileLoader)

      fontFileLoader->Release ();

    if (dwriteFactory)

      dwriteFactory->Release ();

    if (dwrite_dll)

      FreeLibrary (dwrite_dll);

  bool success = false;

  HMODULE dwrite_dll;

  IDWriteFactory *dwriteFactory;

  DWriteFontFileLoader *fontFileLoader;

};

HB_INTERNAL hb_directwrite_global_t *

get_directwrite_global ();

HB_INTERNAL IDWriteFontFace *

dw_face_create (hb_blob_t *blob, unsigned index);

#endif /* HB_DIRECTWRITE_HH */