axmol/cocos/2d/CCFontFreeType.cpp

/****************************************************************************
Copyright (c) 2013      Zynga Inc.
Copyright (c) 2013-2016 Chukong Technologies Inc.
Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.
Copyright (c) 2021 Bytedance Inc.

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****************************************************************************/

#include "2d/CCFontFreeType.h"

#include "freetype/ftfntfmt.h"

#include FT_BBOX_H
#include "2d/CCFontAtlas.h"
#include "base/CCDirector.h"
#include "base/ccUTF8.h"
#include "freetype/internal/tttypes.h"
#include "platform/CCFileUtils.h"
#include "platform/CCFileStream.h"

NS_CC_BEGIN

FT_Library FontFreeType::_FTlibrary;
bool FontFreeType::_FTInitialized           = false;
#if !defined(__ANDROID__)
bool FontFreeType::_streamParsingEnabled    = true;
#else
bool FontFreeType::_streamParsingEnabled    = false;
#endif
bool FontFreeType::_doNativeBytecodeHinting = true;
const int FontFreeType::DistanceMapSpread   = 6;

using namespace std::string_view_literals;
constexpr std::string_view _glyphASCII =
    "\"!#$%&'()*+,-./"
    "0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~"
    "¡¢£¤¥¦§¨©ª«¬­®¯°±²³´µ¶·¸¹º»¼½¾¿ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþ "sv;
constexpr std::string_view _glyphNEHE =
    "!\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~ "sv;

typedef struct _DataRef
{
    Data data;
    unsigned int referenceCount = 0;
} DataRef;

static std::unordered_map<std::string, DataRef> s_cacheFontData;

// ------ freetype2 stream parsing support ---
static unsigned long ft_stream_read_callback(FT_Stream stream,
                                             unsigned long offset,
                                             unsigned char* buf,
                                             unsigned long size)
{
    auto fd = (FileStream*)stream->descriptor.pointer;
    if (!fd)
        return 1;
    if (!size && offset >= stream->size)
        return 1;

    if (stream->pos != offset)
        fd->seek(offset, SEEK_SET);

    if (buf)
        return fd->read(buf, size);

    return 0;
}

static void ft_stream_close_callback(FT_Stream stream)
{
    const auto* fd = (FileStream*)stream->descriptor.pointer;
    delete fd;
    stream->size               = 0;
    stream->descriptor.pointer = nullptr;
}

FontFreeType* FontFreeType::create(std::string_view fontName,
                                   float fontSize,
                                   GlyphCollection glyphs,
                                   std::string_view customGlyphs,
                                   bool distanceFieldEnabled /* = false */,
                                   float outline /* = 0 */)
{
    FontFreeType* tempFont = new (std::nothrow) FontFreeType(distanceFieldEnabled, outline);

    if (!tempFont)
        return nullptr;

    tempFont->setGlyphCollection(glyphs, customGlyphs);

    if (tempFont->loadFontFace(fontName, fontSize))
    {
        tempFont->autorelease();
        return tempFont;
    }
    
    delete tempFont;
    return nullptr;
}

bool FontFreeType::initFreeType()
{
    if (!_FTInitialized)
    {
        // begin freetype
        if (FT_Init_FreeType(&_FTlibrary))
            return false;

        const FT_Int spread = DistanceMapSpread;
        FT_Property_Set(_FTlibrary, "sdf", "spread", &spread);
        FT_Property_Set(_FTlibrary, "bsdf", "spread", &spread);

        _FTInitialized = true;
    }

    return _FTInitialized;
}

void FontFreeType::shutdownFreeType()
{
    if (_FTInitialized)
    {
        FT_Done_FreeType(_FTlibrary);
        s_cacheFontData.clear();
        _FTInitialized = false;
    }
}

FT_Library FontFreeType::getFTLibrary()
{
    initFreeType();
    return _FTlibrary;
}

// clang-format off
FontFreeType::FontFreeType(bool distanceFieldEnabled /* = false */, float outline /* = 0 */)
: _fontFace(nullptr)
, _stroker(nullptr)
, _encoding(FT_ENCODING_UNICODE)
, _distanceFieldEnabled(distanceFieldEnabled)
, _outlineSize(0.0f)
, _ascender(0)
, _descender(0)
, _lineHeight(0)
, _usedGlyphs(GlyphCollection::ASCII)
{
    if (outline > 0.0f)
    {
        _outlineSize = outline * CC_CONTENT_SCALE_FACTOR();
        FT_Stroker_New(FontFreeType::getFTLibrary(), &_stroker);
        FT_Stroker_Set(_stroker,
            (int)(_outlineSize * 64),
            FT_STROKER_LINECAP_ROUND,
            FT_STROKER_LINEJOIN_ROUND,
            0);
    }
}
// clang-format on

bool FontFreeType::loadFontFace(std::string_view fontName, float fontSize)
{
    FT_Face face;
    // save font name locally
    _fontName = fontName;
    _fontSize = fontSize;

    if (_streamParsingEnabled)
    {
        auto fullPath = FileUtils::getInstance()->fullPathForFilename(_fontName);
        if (fullPath.empty())
            return false;

        auto fs = FileUtils::getInstance()->openFileStream(fullPath, FileStream::Mode::READ);
        if (!fs)
        {
            return false;
        }

        std::unique_ptr<FT_StreamRec> fts(new FT_StreamRec());
        fts->read               = ft_stream_read_callback;
        fts->close              = ft_stream_close_callback;
        fts->size               = static_cast<unsigned long>(fs->size());
        fts->descriptor.pointer = fs.release(); // transfer ownership to FT_Open_Face

        FT_Open_Args args = {0};
        args.flags        = FT_OPEN_STREAM;
        args.stream       = fts.get();

        if (FT_Open_Face(getFTLibrary(), &args, 0, &face))
            return false;

        _fontStream = std::move(fts);
    }
    else
    {
        DataRef* sharableData;
        auto it = s_cacheFontData.find(_fontName);
        if (it != s_cacheFontData.end())
        {
            sharableData = &it->second;
        }
        else
        {
            sharableData       = &s_cacheFontData[_fontName];
            sharableData->data = FileUtils::getInstance()->getDataFromFile(_fontName);
        }

        ++sharableData->referenceCount;
        auto& data = sharableData->data;
        if (data.isNull() || FT_New_Memory_Face(getFTLibrary(), data.getBytes(),
                                                static_cast<FT_Long>(data.getSize()), 0, &face))
            return false;
    }

    if (FT_Select_Charmap(face, FT_ENCODING_UNICODE))
    {
        int foundIndex = -1;
        for (int charmapIndex = 0; charmapIndex < face->num_charmaps; charmapIndex++)
        {
            if (face->charmaps[charmapIndex]->encoding != FT_ENCODING_NONE)
            {
                foundIndex = charmapIndex;
                break;
            }
        }

        if (foundIndex == -1)
        {
            return false;
        }

        _encoding = face->charmaps[foundIndex]->encoding;
        if (FT_Select_Charmap(face, _encoding))
        {
            return false;
        }
    }

    // set the requested font size
    int dpi            = 72;
    int fontSizePoints = (int)(64.f * fontSize * CC_CONTENT_SCALE_FACTOR());
    if (FT_Set_Char_Size(face, fontSizePoints, fontSizePoints, dpi, dpi))
        return false;

    // store the face globally
    _fontFace = face;

    // Notes:
    //  a. Since freetype 2.8.1 the TT matrics isn't sync to size_matrics, see the function 'tt_size_request' in
    //  truetype/ttdriver.c b. The TT spec always asks for ROUND, not FLOOR or CEIL, see also the function
    //  'tt_size_reset' in truetype/ttobjs.c
    // ** Please see description of FT_Size_Metrics_ in freetype.h about this solution
    auto& size_metrics = _fontFace->size->metrics;
    if (_doNativeBytecodeHinting && !strcmp(FT_Get_Font_Format(face), "TrueType"))
    {
        _ascender  = FT_PIX_ROUND(FT_MulFix(face->ascender, size_metrics.y_scale));
        _descender = FT_PIX_ROUND(FT_MulFix(face->descender, size_metrics.y_scale));
    }
    else
    {
        _ascender  = size_metrics.ascender;
        _descender = size_metrics.descender;
    }

    _lineHeight = (_ascender - _descender) >> 6;

    // done and good
    return true;
}

FontFreeType::~FontFreeType()
{
    if (_FTInitialized)
    {
        if (_stroker)
        {
            FT_Stroker_Done(_stroker);
        }
        if (_fontFace)
        {
            FT_Done_Face(_fontFace);
        }
    }

    auto iter = s_cacheFontData.find(_fontName);
    if (iter != s_cacheFontData.end())
    {
        iter->second.referenceCount -= 1;
        if (iter->second.referenceCount == 0)
        {
            s_cacheFontData.erase(iter);
        }
    }
}

FontAtlas* FontFreeType::newFontAtlas()
{
    auto fontAtlas = new (std::nothrow) FontAtlas(this);
    if (fontAtlas && _usedGlyphs != GlyphCollection::DYNAMIC)
    {
        std::u32string utf32;
        if (StringUtils::UTF8ToUTF32(getGlyphCollection(), utf32))
        {
            fontAtlas->prepareLetterDefinitions(utf32);
        }
    }
    return fontAtlas;
}

int* FontFreeType::getHorizontalKerningForTextUTF32(const std::u32string& text, int& outNumLetters) const
{
    if (!_fontFace)
        return nullptr;

    outNumLetters = static_cast<int>(text.length());

    if (!outNumLetters)
        return nullptr;

    int* sizes = new (std::nothrow) int[outNumLetters];
    if (!sizes)
        return nullptr;
    memset(sizes, 0, outNumLetters * sizeof(int));

    bool hasKerning = FT_HAS_KERNING(_fontFace) != 0;
    if (hasKerning)
    {
        for (int c = 1; c < outNumLetters; ++c)
        {
            sizes[c] = getHorizontalKerningForChars(text[c - 1], text[c]);
        }
    }

    return sizes;
}

int FontFreeType::getHorizontalKerningForChars(uint64_t firstChar, uint64_t secondChar) const
{
    // get the ID to the char we need
    int glyphIndex1 = FT_Get_Char_Index(_fontFace, static_cast<FT_ULong>(firstChar));

    if (!glyphIndex1)
        return 0;

    // get the ID to the char we need
    int glyphIndex2 = FT_Get_Char_Index(_fontFace, static_cast<FT_ULong>(secondChar));

    if (!glyphIndex2)
        return 0;

    FT_Vector kerning;

    if (FT_Get_Kerning(_fontFace, glyphIndex1, glyphIndex2, FT_KERNING_DEFAULT, &kerning))
        return 0;

    return (static_cast<int>(kerning.x >> 6));
}

int FontFreeType::getFontAscender() const
{
    return _ascender >> 6;
}

const char* FontFreeType::getFontFamily() const
{
    if (!_fontFace)
        return nullptr;

    return _fontFace->family_name;
}

unsigned char* FontFreeType::getGlyphBitmap(uint32_t theChar,
                                            int32_t& outWidth,
                                            int32_t& outHeight,
                                            Rect& outRect,
                                            int& xAdvance)
{
    unsigned char* ret = nullptr;

    do
    {
        if (_fontFace == nullptr)
            break;

        // @remark: glyphIndex=0 means charactor is mssing on current font face
        auto glyphIndex = FT_Get_Char_Index(_fontFace, static_cast<FT_ULong>(theChar));
#if defined(COCOS2D_DEBUG) && COCOS2D_DEBUG > 0
        if (glyphIndex == 0)
        {
            char32_t ntcs[2] = {theChar, (char32_t)0};
            std::u32string_view charUTF32(ntcs, 1);
            std::string charUTF8;
            cocos2d::StringUtils::UTF32ToUTF8(charUTF32, charUTF8);

            if (charUTF8 == "\n")
                charUTF8 = "\\n";
            cocos2d::log("The font face: %s doesn't contains char: <%s>", _fontFace->charmap->face->family_name,
                         charUTF8.c_str());
            return nullptr;
        }
#endif
        if (FT_Load_Glyph(_fontFace, glyphIndex, FT_LOAD_RENDER | FT_LOAD_NO_AUTOHINT))
            break;
        if (_distanceFieldEnabled && _fontFace->glyph->bitmap.buffer)
        {
            // Require freetype version > 2.11.0, because freetype 2.11.0 sdf has memory access bug, see: https://gitlab.freedesktop.org/freetype/freetype/-/issues/1077
            FT_Render_Glyph(_fontFace->glyph, FT_Render_Mode::FT_RENDER_MODE_SDF);
        }

        auto& metrics       = _fontFace->glyph->metrics;
        outRect.origin.x    = static_cast<float>(metrics.horiBearingX >> 6);
        outRect.origin.y    = static_cast<float>(-(metrics.horiBearingY >> 6));
        outRect.size.width  = static_cast<float>((metrics.width >> 6));
        outRect.size.height = static_cast<float>((metrics.height >> 6));

        xAdvance = (static_cast<int>(_fontFace->glyph->metrics.horiAdvance >> 6));

        outWidth  = _fontFace->glyph->bitmap.width;
        outHeight = _fontFace->glyph->bitmap.rows;
        ret       = _fontFace->glyph->bitmap.buffer;

        if (_outlineSize > 0 && outWidth > 0 && outHeight > 0)
        {
            auto copyBitmap = new (std::nothrow) unsigned char[outWidth * outHeight];
            memcpy(copyBitmap, ret, outWidth * outHeight * sizeof(unsigned char));

            FT_BBox bbox;
            auto outlineBitmap = getGlyphBitmapWithOutline(glyphIndex, bbox);
            if (outlineBitmap == nullptr)
            {
                ret = nullptr;
                delete[] copyBitmap;
                break;
            }

            int glyphMinX = (int)outRect.origin.x;
            int glyphMaxX = (int)(outRect.origin.x + outWidth);
            int glyphMinY = (int)(-outHeight - outRect.origin.y);
            int glyphMaxY = (int)-outRect.origin.y;

            auto outlineMinX   = bbox.xMin >> 6;
            auto outlineMaxX   = bbox.xMax >> 6;
            auto outlineMinY   = bbox.yMin >> 6;
            auto outlineMaxY   = bbox.yMax >> 6;
            auto outlineWidth  = outlineMaxX - outlineMinX;
            auto outlineHeight = outlineMaxY - outlineMinY;

            auto blendImageMinX = MIN(outlineMinX, glyphMinX);
            auto blendImageMaxY = MAX(outlineMaxY, glyphMaxY);
            auto blendWidth     = MAX(outlineMaxX, glyphMaxX) - blendImageMinX;
            auto blendHeight    = blendImageMaxY - MIN(outlineMinY, glyphMinY);

            outRect.origin.x = (float)blendImageMinX;
            outRect.origin.y = -blendImageMaxY + _outlineSize;

            unsigned char* blendImage = nullptr;
            if (blendWidth > 0 && blendHeight > 0)
            {
                FT_Pos index, index2;
                auto imageSize = blendWidth * blendHeight * 2;
                blendImage     = new (std::nothrow) unsigned char[imageSize];
                memset(blendImage, 0, imageSize);

                auto px = outlineMinX - blendImageMinX;
                auto py = blendImageMaxY - outlineMaxY;
                for (int x = 0; x < outlineWidth; ++x)
                {
                    for (int y = 0; y < outlineHeight; ++y)
                    {
                        index                 = px + x + ((py + y) * blendWidth);
                        index2                = x + (y * outlineWidth);
                        blendImage[2 * index] = outlineBitmap[index2];
                    }
                }

                px = glyphMinX - blendImageMinX;
                py = blendImageMaxY - glyphMaxY;
                for (int x = 0; x < outWidth; ++x)
                {
                    for (int y = 0; y < outHeight; ++y)
                    {
                        index                     = px + x + ((y + py) * blendWidth);
                        index2                    = x + (y * outWidth);
                        blendImage[2 * index + 1] = copyBitmap[index2];
                    }
                }
            }

            outRect.size.width  = (float)blendWidth;
            outRect.size.height = (float)blendHeight;
            outWidth            = blendWidth;
            outHeight           = blendHeight;

            delete[] outlineBitmap;
            delete[] copyBitmap;
            ret = blendImage;
        }

        return ret;
    } while (0);

    outRect.size.width  = 0;
    outRect.size.height = 0;
    xAdvance            = 0;

    return nullptr;
}

unsigned char* FontFreeType::getGlyphBitmapWithOutline(unsigned int glyphIndex, FT_BBox& bbox)
{
    unsigned char* ret = nullptr;
    if (FT_Load_Glyph(_fontFace, glyphIndex, FT_LOAD_NO_BITMAP) == 0)
    {
        if (_fontFace->glyph->format == FT_GLYPH_FORMAT_OUTLINE)
        {
            FT_Glyph glyph;
            if (FT_Get_Glyph(_fontFace->glyph, &glyph) == 0)
            {
                FT_Glyph_StrokeBorder(&glyph, _stroker, 0, 1);
                if (glyph->format == FT_GLYPH_FORMAT_OUTLINE)
                {
                    FT_Outline* outline = &reinterpret_cast<FT_OutlineGlyph>(glyph)->outline;
                    FT_Glyph_Get_CBox(glyph, FT_GLYPH_BBOX_GRIDFIT, &bbox);
                    int32_t width = (bbox.xMax - bbox.xMin) >> 6;
                    int32_t rows  = (bbox.yMax - bbox.yMin) >> 6;

                    FT_Bitmap bmp;
                    bmp.buffer = new (std::nothrow) unsigned char[width * rows];
                    memset(bmp.buffer, 0, width * rows);
                    bmp.width      = (int)width;
                    bmp.rows       = (int)rows;
                    bmp.pitch      = (int)width;
                    bmp.pixel_mode = FT_PIXEL_MODE_GRAY;
                    bmp.num_grays  = 256;

                    FT_Raster_Params params;
                    memset(&params, 0, sizeof(params));
                    params.source = outline;
                    params.target = &bmp;
                    params.flags  = FT_RASTER_FLAG_AA;
                    FT_Outline_Translate(outline, -bbox.xMin, -bbox.yMin);
                    FT_Outline_Render(_FTlibrary, outline, &params);

                    ret = bmp.buffer;
                }
                FT_Done_Glyph(glyph);
            }
        }
    }

    return ret;
}

void FontFreeType::renderCharAt(unsigned char* dest,
                                int posX,
                                int posY,
                                unsigned char* bitmap,
                                int32_t bitmapWidth,
                                int32_t bitmapHeight)
{
    int iX = posX;
    int iY = posY;

    if (_outlineSize > 0)
    {
        unsigned char tempChar;
        for (int32_t y = 0; y < bitmapHeight; ++y)
        {
            int32_t bitmap_y = y * bitmapWidth;

            for (int x = 0; x < bitmapWidth; ++x)
            {
                tempChar                                                 = bitmap[(bitmap_y + x) * 2];
                dest[(iX + (iY * FontAtlas::CacheTextureWidth)) * 2]     = tempChar;
                tempChar                                                 = bitmap[(bitmap_y + x) * 2 + 1];
                dest[(iX + (iY * FontAtlas::CacheTextureWidth)) * 2 + 1] = tempChar;

                iX += 1;
            }

            iX = posX;
            iY += 1;
        }
        delete[] bitmap;
    }
    else
    {
        for (int32_t y = 0; y < bitmapHeight; ++y)
        {
            int32_t bitmap_y = y * bitmapWidth;

            for (int x = 0; x < bitmapWidth; ++x)
            {
                unsigned char cTemp = bitmap[bitmap_y + x];

                // the final pixel
                dest[(iX + (iY * FontAtlas::CacheTextureWidth))] = cTemp;

                iX += 1;
            }

            iX = posX;
            iY += 1;
        }
    }
}

void FontFreeType::setGlyphCollection(GlyphCollection glyphs, std::string_view customGlyphs)
{
    _usedGlyphs = glyphs;
    if (glyphs == GlyphCollection::CUSTOM)
    {
        _customGlyphs = customGlyphs;
    }
}

std::string_view FontFreeType::getGlyphCollection() const
{
    std::string_view glyphCollection;
    switch (_usedGlyphs)
    {
        case cocos2d::GlyphCollection::DYNAMIC:
            break;
        case cocos2d::GlyphCollection::NEHE:
            glyphCollection = _glyphNEHE;
            break;
        case cocos2d::GlyphCollection::ASCII:
            glyphCollection = _glyphASCII;
            break;
        case cocos2d::GlyphCollection::CUSTOM:
            glyphCollection = _customGlyphs;
            break;
        default:
            break;
    }

    return glyphCollection;
}

void FontFreeType::releaseFont(const std::string& fontName)
{
    auto item = s_cacheFontData.begin();
    while (s_cacheFontData.end() != item)
    {
        if (item->first.find(fontName) != std::string::npos)
            item = s_cacheFontData.erase(item);
        else
            item++;
    }
}

NS_CC_END