gecko-dev/gfx/thebes/gfxFT2Utils.cpp

99 строки
3.2 KiB
C++

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "gfxFT2FontBase.h"
#include "gfxFT2Utils.h"
#include "mozilla/Likely.h"
#ifdef HAVE_FONTCONFIG_FCFREETYPE_H
#include <fontconfig/fcfreetype.h>
#endif
#include "prlink.h"
uint32_t
gfxFT2LockedFace::GetGlyph(uint32_t aCharCode)
{
if (MOZ_UNLIKELY(!mFace))
return 0;
#ifdef HAVE_FONTCONFIG_FCFREETYPE_H
// FcFreeTypeCharIndex will search starting from the most recently
// selected charmap. This can cause non-determistic behavior when more
// than one charmap supports a character but with different glyphs, as
// with older versions of MS Gothic, for example. Always prefer a Unicode
// charmap, if there is one. (FcFreeTypeCharIndex usually does the
// appropriate Unicode conversion, but some fonts have non-Roman glyphs
// for FT_ENCODING_APPLE_ROMAN characters.)
if (!mFace->charmap || mFace->charmap->encoding != FT_ENCODING_UNICODE) {
FT_Select_Charmap(mFace, FT_ENCODING_UNICODE);
}
return FcFreeTypeCharIndex(mFace, aCharCode);
#else
return FT_Get_Char_Index(mFace, aCharCode);
#endif
}
typedef FT_UInt (*GetCharVariantFunction)(FT_Face face,
FT_ULong charcode,
FT_ULong variantSelector);
uint32_t
gfxFT2LockedFace::GetUVSGlyph(uint32_t aCharCode, uint32_t aVariantSelector)
{
NS_PRECONDITION(aVariantSelector, "aVariantSelector should not be NULL");
if (MOZ_UNLIKELY(!mFace))
return 0;
// This function is available from FreeType 2.3.6 (June 2008).
static CharVariantFunction sGetCharVariantPtr = FindCharVariantFunction();
if (!sGetCharVariantPtr)
return 0;
#ifdef HAVE_FONTCONFIG_FCFREETYPE_H
// FcFreeTypeCharIndex may have changed the selected charmap.
// FT_Face_GetCharVariantIndex needs a unicode charmap.
if (!mFace->charmap || mFace->charmap->encoding != FT_ENCODING_UNICODE) {
FT_Select_Charmap(mFace, FT_ENCODING_UNICODE);
}
#endif
return (*sGetCharVariantPtr)(mFace, aCharCode, aVariantSelector);
}
gfxFT2LockedFace::CharVariantFunction
gfxFT2LockedFace::FindCharVariantFunction()
{
// This function is available from FreeType 2.3.6 (June 2008).
PRLibrary *lib = nullptr;
CharVariantFunction function =
reinterpret_cast<CharVariantFunction>
(PR_FindFunctionSymbolAndLibrary("FT_Face_GetCharVariantIndex", &lib));
if (!lib) {
return nullptr;
}
FT_Int major;
FT_Int minor;
FT_Int patch;
FT_Library_Version(mFace->glyph->library, &major, &minor, &patch);
// Versions 2.4.0 to 2.4.3 crash if configured with
// FT_CONFIG_OPTION_OLD_INTERNALS. Presence of the symbol FT_Alloc
// indicates FT_CONFIG_OPTION_OLD_INTERNALS.
if (major == 2 && minor == 4 && patch < 4 &&
PR_FindFunctionSymbol(lib, "FT_Alloc")) {
function = nullptr;
}
// Decrement the reference count incremented in
// PR_FindFunctionSymbolAndLibrary.
PR_UnloadLibrary(lib);
return function;
}