cegui 减小中文字体缓存

cegui将字码表按每256字分页.一旦遇到新字,将加载该字所在的页,即该页的256字全部加载.常用汉字只有几千字,若你的项目比较在乎显存(如兼容较低端显卡),则还是希望某个字使用到才加载或别的策略减少显存占用.

以下是一些修改.这里只是简单的改为使用到加载.

备忘.

View Code
/***********************************************************************
    filename:     CEGUIFreeTypeFont.h
    created:    3/6/2006
    author:        Andrew Zabolotny

    purpose:    Implementation of the Font class via the FreeType library
*************************************************************************/
/***************************************************************************
 *   Copyright (C) 2004 - 2006 Paul D Turner & The CEGUI Development Team
 *
 *   Permission is hereby granted, free of charge, to any person obtaining
 *   a copy of this software and associated documentation files (the
 *   "Software"), to deal in the Software without restriction, including
 *   without limitation the rights to use, copy, modify, merge, publish,
 *   distribute, sublicense, and/or sell copies of the Software, and to
 *   permit persons to whom the Software is furnished to do so, subject to
 *   the following conditions:
 *
 *   The above copyright notice and this permission notice shall be
 *   included in all copies or substantial portions of the Software.
 *
 *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 *   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 *   IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 *   OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 *   ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 *   OTHER DEALINGS IN THE SOFTWARE.
 ***************************************************************************/
#ifndef _CEGUIFreeTypeFont_h_
#define _CEGUIFreeTypeFont_h_

#include "CEGUIFont.h"
#include "CEGUIImage.h"
#include "CEGUIDataContainer.h"

#include <ft2build.h>
#include FT_FREETYPE_H

// Start of CEGUI namespace section
namespace CEGUI
{
/*!
\brief
    Implementation of the Font class interface using the FreeType library.

    This implementation tries to provide maximal support for any kind of
    fonts supported by FreeType. It has been tested on outline font formats
    like TTF and PS as well as on bitmap font formats like PCF and FON.

    Glyphs are rendered dynamically on demand, so a large font with lots
    of glyphs won't slow application startup time.
*/
class FreeTypeFont : public Font
{
public:
    /*!
    \brief
        Constructor for FreeTypeFont based fonts.

    \param font_name
        The name that the font will use within the CEGUI system.

    \param point_size
        Specifies the point size that the font is to be rendered at.

    \param anti_aliased
        Specifies whether the font should be rendered using anti aliasing.

    \param font_filename
        The filename of an font file that will be used as the source for
        glyph images for this font.

    \param resource_group
        The resource group identifier to use when loading the font file
        specified by \a font_filename.

    \param auto_scaled
        Specifies whether the font imagery should be automatically scaled to
        maintain the same physical size (which is calculated by using the
        native resolution setting).

    \param native_horz_res
        The horizontal native resolution value.  This is only significant when
        auto scaling is enabled.

    \param native_vert_res
        The vertical native resolution value.  This is only significant when
        auto scaling is enabled.

    \param specific_line_spacing
        If specified (non-zero), this will be the line spacing that we will
        report for this font, regardless of what is mentioned in the font file
        itself.
    */
    FreeTypeFont(const String& font_name, const float point_size,
                 const bool anti_aliased, const String& font_filename,
                 const String& resource_group = "",
                 const bool auto_scaled = false,
                 const float native_horz_res = 640.0f,
                 const float native_vert_res = 480.0f,
                 const float specific_line_spacing = 0.0f);

    //! Destructor.
    ~FreeTypeFont();

    //! return the point size of the freetype font.
    float getPointSize() const;

    //! return whether the freetype font is rendered anti-aliased.
    bool isAntiAliased() const;

    //! return the point size of the freetype font.
    void setPointSize(const float point_size);

    //! return whether the freetype font is rendered anti-aliased.
    void setAntiAliased(const bool anti_alaised);

protected:
    /*!
    \brief
        Copy the current glyph data into \a buffer, which has a width of
        \a buf_width pixels (not bytes).

    \param buffer
        Memory buffer large enough to receive the imagery for the currently
        loaded glyph.

    \param buf_width
        Width of \a buffer in pixels (where each pixel is a argb_t).

    \return
        Nothing.
    */
    void drawGlyphToBuffer(argb_t* buffer, uint buf_width) const;

    // 16位像素格式缓存
    void drawGlyphToBuffer(argb16_t* buffer, uint buf_width) const;

    /*!
    \brief
        Return the required texture size required to store imagery for the
        glyphs from s to e
    \param s
        The first glyph in set
    \param e
        The last glyph in set
    */
    uint getTextureSize(CodepointMap::const_iterator s,
                        CodepointMap::const_iterator e) const;

    //! Register all properties of this class.
    void addFreeTypeFontProperties();
    //! Free all allocated font data.
    void free();

    // overrides of functions in Font base class.
    void rasterise(utf32 start_codepoint, utf32 end_codepoint) const;

    //自定义字体纹理创建
    const FontGlyph* rasteriseEx(utf32 codepoint) const;

    void updateFont();
    void writeXMLToStream_impl (XMLSerializer& xml_stream) const;

    //! If non-zero, the overridden line spacing that we're to report.
    float d_specificLineSpacing;
    //! Point size of font.
    float d_ptSize;
    //! True if the font should be rendered as anti-alaised by freeType.
    bool d_antiAliased;
    //! FreeType-specific font handle
    FT_Face d_fontFace;
    //! Font file data
    RawDataContainer d_fontData;
    //! Type definition for ImagesetVector.
    typedef std::vector<Imageset*> ImagesetVector;
    //! Imagesets that holds the glyphs for this font.
    mutable ImagesetVector d_glyphImages;

    mutable argb_t mem_buffer[FONT_TEXTURE_CUSTOM_SIZE * FONT_TEXTURE_CUSTOM_SIZE];
    mutable uint x_cur;
    mutable uint y_cur;
    mutable bool beNeedNewTex;
    int             unused_holder;
    mutable uint y_line_h;

};

} // End of  CEGUI namespace section

#endif    // end of guard _CEGUIFreeTypeFont_h_
View Code
/***********************************************************************
    filename:   CEGUIFont.cpp
    created:    21/2/2004
    author:     Paul D Turner

    purpose:    Implements FreeTypeFont class
*************************************************************************/
/***************************************************************************
 *   Copyright (C) 2004 - 2006 Paul D Turner & The CEGUI Development Team
 *
 *   Permission is hereby granted, free of charge, to any person obtaining
 *   a copy of this software and associated documentation files (the
 *   "Software"), to deal in the Software without restriction, including
 *   without limitation the rights to use, copy, modify, merge, publish,
 *   distribute, sublicense, and/or sell copies of the Software, and to
 *   permit persons to whom the Software is furnished to do so, subject to
 *   the following conditions:
 *
 *   The above copyright notice and this permission notice shall be
 *   included in all copies or substantial portions of the Software.
 *
 *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 *   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 *   IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 *   OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 *   ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 *   OTHER DEALINGS IN THE SOFTWARE.
 ***************************************************************************/
#include "CEGUIFreeTypeFont.h"
#include "CEGUIExceptions.h"
#include "CEGUITexture.h"
#include "CEGUIImageset.h"
#include "CEGUIImagesetManager.h"
#include "CEGUILogger.h"
#include "CEGUIPropertyHelper.h"
#include "CEGUIFont_xmlHandler.h"
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>

#ifdef _MSC_VER
#define snprintf _snprintf
#endif


namespace CEGUI
{
//----------------------------------------------------------------------------//
// Pixels to put between glyphs
#define INTER_GLYPH_PAD_SPACE 2
// A multiplication coefficient to convert FT_Pos values into normal floats
#define FT_POS_COEF  (1.0/64.0)

//----------------------------------------------------------------------------//
// Font objects usage count
static int ft_usage_count = 0;
// A handle to the FreeType library
static FT_Library ft_lib;

//----------------------------------------------------------------------------//
#undef __FTERRORS_H__
#define FT_ERRORDEF( e, v, s ) s,
#define FT_ERROR_START_LIST static const char* ft_errors[] = {
#define FT_ERROR_END_LIST 0};
#include FT_ERRORS_H

//----------------------------------------------------------------------------//
FreeTypeFont::FreeTypeFont(const String& font_name, const float point_size,
                           const bool anti_aliased, const String& font_filename,
                           const String& resource_group, const bool auto_scaled,
                           const float native_horz_res,
                           const float native_vert_res,
                           const float specific_line_spacing) :
    Font(font_name, Font_xmlHandler::FontTypeFreeType, font_filename,
         resource_group, auto_scaled, native_horz_res, native_vert_res),
    d_specificLineSpacing(specific_line_spacing),
    d_ptSize(point_size),
    d_antiAliased(anti_aliased),
    d_fontFace(0)
{
    if (!ft_usage_count++)
        FT_Init_FreeType(&ft_lib);

    x_cur = INTER_GLYPH_PAD_SPACE; 
    y_cur = INTER_GLYPH_PAD_SPACE;
    y_line_h = 0;
    beNeedNewTex = false;

    addFreeTypeFontProperties();

    updateFont();

    char tmp[50];
    snprintf(tmp, sizeof(tmp), "Successfully loaded %d glyphs",
             static_cast<int>(d_cp_map.size()));
    Logger::getSingleton().logEvent(tmp, Informative);
}

//----------------------------------------------------------------------------//
FreeTypeFont::~FreeTypeFont()
{
    free();

    if (!--ft_usage_count)
        FT_Done_FreeType(ft_lib);
}

//----------------------------------------------------------------------------//
uint FreeTypeFont::getTextureSize(CodepointMap::const_iterator s,
                                  CodepointMap::const_iterator e) const
{
    uint texsize = 32; // start with 32x32
    uint max_texsize = System::getSingleton().getRenderer()->getMaxTextureSize();
    uint glyph_count = 0;

    // Compute approximatively the optimal texture size for font
    while (texsize < max_texsize)
    {
        uint x = INTER_GLYPH_PAD_SPACE, y = INTER_GLYPH_PAD_SPACE;
        uint yb = INTER_GLYPH_PAD_SPACE;
        for (CodepointMap::const_iterator c = s; c != e; ++c)
        {
            // skip glyphs that are already rendered
            if (c->second.getImage())
                continue;

            // load glyph metrics (don't render)
            if (FT_Load_Char(d_fontFace, c->first,
                             FT_LOAD_DEFAULT | FT_LOAD_FORCE_AUTOHINT))
                continue;

            uint glyph_w = int (ceil(d_fontFace->glyph->metrics.width * FT_POS_COEF)) +
                           INTER_GLYPH_PAD_SPACE;
            uint glyph_h = int (ceil(d_fontFace->glyph->metrics.height * FT_POS_COEF)) +
                           INTER_GLYPH_PAD_SPACE;

            x += glyph_w;
            if (x > texsize)
            {
                x = INTER_GLYPH_PAD_SPACE;
                y = yb;
            }
            uint yy = y + glyph_h;
            if (yy > texsize)
                goto too_small;

            if (yy > yb)
                yb = yy;

            ++glyph_count;
        }
        // Okay, the texture size is enough for holding our glyphs
        break;

    too_small:
        texsize *= 2;
    }

    return glyph_count ? texsize : 0;
}


/*----------------------------------------------------------------------------
//自定义版本字体纹理生成
----------------------------------------------------------------------------*/

const FontGlyph* FreeTypeFont::rasteriseEx(utf32 codepoint) const
{
    const int MAX_MARGIN = 10;
    CodepointMap::const_iterator pos = d_cp_map.find(codepoint);
    if(pos == d_cp_map.end()) 
        return NULL;
    FontGlyph* glyph = const_cast<FontGlyph*>(&pos->second);

    if( FT_Load_Char(d_fontFace, codepoint, FT_LOAD_DEFAULT | FT_LOAD_FORCE_AUTOHINT))
        return NULL;

    uint texsize = FONT_TEXTURE_CUSTOM_SIZE;
    static int count_imageset_font = 0;

    //第一张纹理尚未被渲染,则创建纹理
    if( ( 0==d_glyphImages.size()))
    {
        Imageset& is_first = ImagesetManager::getSingleton().create(
            d_name + "_auto_glyph_images_" + (int)(codepoint),
            System::getSingleton().getRenderer()->createTexture());
        d_glyphImages.push_back(&is_first);
        memset(mem_buffer, 0, texsize * texsize * sizeof(argb_t));
        beNeedNewTex = false;
    }

    {
        Imageset* is = d_glyphImages.back();
        // Render the glyph
        if (FT_Load_Char(d_fontFace, codepoint, FT_LOAD_RENDER | FT_LOAD_FORCE_AUTOHINT |
            (d_antiAliased ? FT_LOAD_TARGET_NORMAL : FT_LOAD_TARGET_MONO)))
        {
            std::stringstream err;
            err << "Font::loadFreetypeGlyph - Failed to load glyph for codepoint: ";
            err << static_cast<unsigned int>(codepoint);
            err << ".  Will use an empty image for this glyph!";
            Logger::getSingleton().logEvent(err.str(), Errors);

            // Create a 'null' image for this glyph so we do not seg later
            Rect area(0, 0, 0, 0);
            Point offset(0, 0);
            String name;
            name += codepoint;
            is->defineImage(name, area, offset);
            glyph->setImage(&(is->getImage(name)));
        }
        else
        {
            uint glyph_w = d_fontFace->glyph->bitmap.width + INTER_GLYPH_PAD_SPACE;
            uint glyph_h = d_fontFace->glyph->bitmap.rows + INTER_GLYPH_PAD_SPACE;
            if(glyph_h > y_line_h)
                y_line_h = glyph_h;

            uint x_next = x_cur + glyph_w;
            uint y_next = y_cur + y_line_h;
            if(y_next + MAX_MARGIN > texsize)//高度超出纹理,换页
            {
                y_cur = INTER_GLYPH_PAD_SPACE;
                x_cur = INTER_GLYPH_PAD_SPACE;
                x_next = x_cur + glyph_w ;
                y_line_h = glyph_h;
                beNeedNewTex = true;
            }
            else if(x_next + MAX_MARGIN > texsize)//需换行
            {
                x_cur = INTER_GLYPH_PAD_SPACE;
                y_cur = y_next;
                x_next = x_cur + glyph_w ;
                y_line_h = 0;
            }

            //若换页,创建纹理
            if(beNeedNewTex == true) 
            {
                is = &ImagesetManager::getSingleton().create(
                    d_name + "_auto_glyph_images_"+codepoint,
                    System::getSingleton().getRenderer()->createTexture());
                d_glyphImages.push_back(is);
                memset(mem_buffer, 0, texsize * texsize * sizeof(argb_t));
                beNeedNewTex = false;
            }
            
            drawGlyphToBuffer(mem_buffer + (y_cur * texsize) + x_cur, texsize);

            // Create a new image in the imageset
            Rect area(static_cast<float>(x_cur),
                static_cast<float>(y_cur),
                static_cast<float>(x_cur + glyph_w - INTER_GLYPH_PAD_SPACE),
                static_cast<float>(y_cur + glyph_h - INTER_GLYPH_PAD_SPACE));

            Point offset(d_fontFace->glyph->metrics.horiBearingX * static_cast<float>(FT_POS_COEF),
                -d_fontFace->glyph->metrics.horiBearingY * static_cast<float>(FT_POS_COEF));

            String name;
            name += codepoint;
            is->defineImage(name, area, offset);
            glyph->setImage(&(is->getImage(name)));

            // Advance to next position
            x_cur = x_next;
        }
        // Copy our memory buffer into the texture
        is->getTexture()->loadFromMemory(mem_buffer, Size(texsize, texsize), Texture::PF_RGBA);
    }
    return glyph;
}

//----------------------------------------------------------------------------//
void FreeTypeFont::rasterise(utf32 start_codepoint, utf32 end_codepoint) const
{
    CodepointMap::const_iterator s = d_cp_map.lower_bound(start_codepoint);
    if (s == d_cp_map.end())
        return;

    CodepointMap::const_iterator orig_s = s;
    CodepointMap::const_iterator e = d_cp_map.upper_bound(end_codepoint);
    while (true)
    {
        // Create a new Imageset for glyphs
        uint texsize = getTextureSize(s, e);
        // If all glyphs were already rendered, do nothing
        if (!texsize)
            break;

        Imageset& is = ImagesetManager::getSingleton().create(
            d_name + "_auto_glyph_images_" + int (s->first),
            System::getSingleton().getRenderer()->createTexture());
        d_glyphImages.push_back(&is);

        // Create a memory buffer where we will render our glyphs
        argb_t *mem_buffer = new argb_t [texsize * texsize];
        memset(mem_buffer, 0, texsize * texsize * sizeof(argb_t));

        // Go ahead, line by line, top-left to bottom-right
        uint x = INTER_GLYPH_PAD_SPACE, y = INTER_GLYPH_PAD_SPACE;
        uint yb = INTER_GLYPH_PAD_SPACE;

        // Set to true when we finish rendering all glyphs we were asked to
        bool finished = false;
        // Set to false when we reach d_cp_map.end() and we start going backward
        bool forward = true;

        /* To conserve texture space we will render more glyphs than asked,
        * but never less than asked. First we render all glyphs from s to e
        * and after that we render glyphs until we reach d_cp_map.end(),
        * and if there's still free texture space we will go backward
        * from s until we hit d_cp_map.begin().
        */
        while (s != d_cp_map.end())
        {
            // Check if we finished rendering all the required glyphs
            finished |= (s == e);

            // Check if glyph already rendered
            if (!s->second.getImage())
            {
                // Render the glyph
                if (FT_Load_Char(d_fontFace, s->first, FT_LOAD_RENDER | FT_LOAD_FORCE_AUTOHINT |
                    (d_antiAliased ? FT_LOAD_TARGET_NORMAL : FT_LOAD_TARGET_MONO)))
                {
                    std::stringstream err;
                    err << "Font::loadFreetypeGlyph - Failed to load glyph for codepoint: ";
                    err << static_cast<unsigned int>(s->first);
                    err << ".  Will use an empty image for this glyph!";
                    Logger::getSingleton().logEvent(err.str(), Errors);

                    // Create a 'null' image for this glyph so we do not seg later
                    Rect area(0, 0, 0, 0);
                    Point offset(0, 0);
                    String name;
                    name += s->first;
                    is.defineImage(name, area, offset);
                    ((FontGlyph &)s->second).setImage(&is.getImage(name));
                }
                else
                {
                    uint glyph_w = d_fontFace->glyph->bitmap.width + INTER_GLYPH_PAD_SPACE;
                    uint glyph_h = d_fontFace->glyph->bitmap.rows + INTER_GLYPH_PAD_SPACE;

                    // Check if glyph right margin does not exceed texture size
                    uint x_next = x + glyph_w;
                    if (x_next > texsize)
                    {
                        x = INTER_GLYPH_PAD_SPACE;
                        x_next = x + glyph_w;
                        y = yb;
                    }

                    // Check if glyph bottom margine does not exceed texture size
                    uint y_bot = y + glyph_h;
                    if (y_bot > texsize)
                        break;

                    // Copy rendered glyph to memory buffer in RGBA format
                    drawGlyphToBuffer(mem_buffer + (y * texsize) + x, texsize);

                    // Create a new image in the imageset
                    Rect area(static_cast<float>(x),
                        static_cast<float>(y),
                        static_cast<float>(x + glyph_w - INTER_GLYPH_PAD_SPACE),
                        static_cast<float>(y + glyph_h - INTER_GLYPH_PAD_SPACE));

                    Point offset(d_fontFace->glyph->metrics.horiBearingX * static_cast<float>(FT_POS_COEF),
                        -d_fontFace->glyph->metrics.horiBearingY * static_cast<float>(FT_POS_COEF));

                    String name;
                    name += s->first;
                    is.defineImage(name, area, offset);
                    ((FontGlyph &)s->second).setImage(&is.getImage(name));

                    // Advance to next position
                    x = x_next;
                    if (y_bot > yb)
                    {
                        yb = y_bot;
                    }
                }
            }

            // Go to next glyph, if we are going forward
            if (forward)
                if (++s == d_cp_map.end())
                {
                    finished = true;
                    forward = false;
                    s = orig_s;
                }
                // Go to previous glyph, if we are going backward
                if (!forward)
                    if ((s == d_cp_map.begin()) || (--s == d_cp_map.begin()))
                        break;
        }

        // Copy our memory buffer into the texture and free it
        is.getTexture()->loadFromMemory(mem_buffer, Size(texsize, texsize), Texture::PF_RGBA);
        delete [] mem_buffer;

        if (finished)
            break;
    }
}


//----------------------------------------------------------------------------//
void FreeTypeFont::drawGlyphToBuffer(argb_t *buffer, uint buf_width) const
{
    FT_Bitmap *glyph_bitmap = &d_fontFace->glyph->bitmap;

    for (int i = 0; i < glyph_bitmap->rows; ++i)
    {
        uchar *src = glyph_bitmap->buffer + (i * glyph_bitmap->pitch);
        switch (glyph_bitmap->pixel_mode)
        {
        case FT_PIXEL_MODE_GRAY:
        {
            uchar *dst = reinterpret_cast<uchar*>(buffer);
            for (int j = 0; j < glyph_bitmap->width; ++j)
            {
                // RGBA
                *dst++ = 0xFF;
                *dst++ = 0xFF;
                *dst++ = 0xFF;
                *dst++ = *src++;
            }
        }
        break;

        case FT_PIXEL_MODE_MONO:
            for (int j = 0; j < glyph_bitmap->width; ++j)
                buffer [j] = (src [j / 8] & (0x80 >> (j & 7))) ? 0xFFFFFFFF : 0x00000000;
            break;

        default:
            CEGUI_THROW(InvalidRequestException("Font::drawGlyphToBuffer: "
                "The glyph could not be drawn because the pixel mode is "
                "unsupported."));
            break;
        }

        buffer += buf_width;
    }
}

//----------------------------------------------------------------------------//
void FreeTypeFont::drawGlyphToBuffer(argb16_t* buffer, uint buf_width) const
{

}

//----------------------------------------------------------------------------//
void FreeTypeFont::free()
{
#ifdef FONT_TEXUTRE_CUSTOM_CREATE
    memset(mem_buffer, 0, FONT_TEXTURE_CUSTOM_SIZE * FONT_TEXTURE_CUSTOM_SIZE * sizeof(argb_t));
#endif

    if (!d_fontFace)
        return;

    d_cp_map.clear();

    for (size_t i = 0; i < d_glyphImages.size(); i++)
        ImagesetManager::getSingleton().destroy(d_glyphImages [i]->getName());
    d_glyphImages.clear();

    FT_Done_Face(d_fontFace);
    d_fontFace = 0;
    System::getSingleton().getResourceProvider()->unloadRawDataContainer(d_fontData);
}

//----------------------------------------------------------------------------//
void FreeTypeFont::updateFont()
{
    free();

    System::getSingleton().getResourceProvider()->loadRawDataContainer(
        d_filename, d_fontData, d_resourceGroup.empty() ?
            getDefaultResourceGroup() : d_resourceGroup);

    FT_Error error;

    // create face using input font
    if ((error = FT_New_Memory_Face(ft_lib, d_fontData.getDataPtr(),
                           static_cast<FT_Long>(d_fontData.getSize()), 0,
                           &d_fontFace)) != 0)
        CEGUI_THROW(GenericException("FreeTypeFont::updateFont: Failed to "
            "create face from font file '" + d_filename + "' error was: " +
            ((error < FT_Err_Max) ? ft_errors[error] : "unknown error")));

    // check that default Unicode character map is available
    if (!d_fontFace->charmap)
    {
        FT_Done_Face(d_fontFace);
        d_fontFace = 0;
        CEGUI_THROW(GenericException("FreeTypeFont::updateFont: "
            "The font '" + d_name + "' does not have a Unicode charmap, and "
            "cannot be used."));
    }

    uint horzdpi = System::getSingleton().getRenderer()->getDisplayDPI().d_x;
    uint vertdpi = System::getSingleton().getRenderer()->getDisplayDPI().d_y;

    float hps = d_ptSize * 64;
    float vps = d_ptSize * 64;
    if (d_autoScale)
    {
        hps *= d_horzScaling;
        vps *= d_vertScaling;
    }

    if (FT_Set_Char_Size(d_fontFace, FT_F26Dot6(hps), FT_F26Dot6(vps), horzdpi, vertdpi))
    {
        // For bitmap fonts we can render only at specific point sizes.
        // Try to find nearest point size and use it, if that is possible
        float ptSize_72 = (d_ptSize * 72.0f) / vertdpi;
        float best_delta = 99999;
        float best_size = 0;
        for (int i = 0; i < d_fontFace->num_fixed_sizes; i++)
        {
            float size = d_fontFace->available_sizes [i].size * float(FT_POS_COEF);
            float delta = fabs(size - ptSize_72);
            if (delta < best_delta)
            {
                best_delta = delta;
                best_size = size;
            }
        }

        if ((best_size <= 0) ||
                FT_Set_Char_Size(d_fontFace, 0, FT_F26Dot6(best_size * 64), 0, 0))
        {
            char size [20];
            snprintf(size, sizeof(size), "%g", d_ptSize);
            CEGUI_THROW(GenericException("FreeTypeFont::load - The font '" + d_name + "' cannot be rasterised at a size of " + size + " points, and cannot be used."));
        }
    }

    if (d_fontFace->face_flags & FT_FACE_FLAG_SCALABLE)
    {
        //float x_scale = d_fontFace->size->metrics.x_scale * FT_POS_COEF * (1.0/65536.0);
        float y_scale = d_fontFace->size->metrics.y_scale * float(FT_POS_COEF) * (1.0f / 65536.0f);
        d_ascender = d_fontFace->ascender * y_scale;
        d_descender = d_fontFace->descender * y_scale;
        d_height = d_fontFace->height * y_scale;
    }
    else
    {
        d_ascender = d_fontFace->size->metrics.ascender * float(FT_POS_COEF);
        d_descender = d_fontFace->size->metrics.descender * float(FT_POS_COEF);
        d_height = d_fontFace->size->metrics.height * float(FT_POS_COEF);
    }

    if (d_specificLineSpacing > 0.0f)
    {
        d_height = d_specificLineSpacing;
    }

    // Create an empty FontGlyph structure for every glyph of the font
    FT_UInt gindex;
    FT_ULong codepoint = FT_Get_First_Char(d_fontFace, &gindex);
    FT_ULong max_codepoint = codepoint;
    while (gindex)
    {
        if (max_codepoint < codepoint)
            max_codepoint = codepoint;

        // load-up required glyph metrics (don't render)
        if (FT_Load_Char(d_fontFace, codepoint,
                         FT_LOAD_DEFAULT | FT_LOAD_FORCE_AUTOHINT))
            continue; // glyph error

        float adv = d_fontFace->glyph->metrics.horiAdvance * float(FT_POS_COEF);

        // create a new empty FontGlyph with given character code
        d_cp_map[codepoint] = FontGlyph(adv);

        // proceed to next glyph
        codepoint = FT_Get_Next_Char(d_fontFace, codepoint, &gindex);
    }

    setMaxCodepoint(max_codepoint);
}

//----------------------------------------------------------------------------//
void FreeTypeFont::writeXMLToStream_impl(XMLSerializer& xml_stream) const
{
    xml_stream.attribute(Font_xmlHandler::FontSizeAttribute,
                         PropertyHelper::floatToString(d_ptSize));
    if (!d_antiAliased)
        xml_stream.attribute(Font_xmlHandler::FontAntiAliasedAttribute, "False");

    if (d_specificLineSpacing > 0.0f)
        xml_stream.attribute(Font_xmlHandler::FontLineSpacingAttribute,
                             PropertyHelper::floatToString(d_specificLineSpacing));
}

//----------------------------------------------------------------------------//
float FreeTypeFont::getPointSize() const
{
    return d_ptSize;
}

//----------------------------------------------------------------------------//
bool FreeTypeFont::isAntiAliased() const
{
    return d_antiAliased;
}

//----------------------------------------------------------------------------//
void FreeTypeFont::setPointSize(const float point_size)
{
    if (point_size == d_ptSize)
        return;

    d_ptSize = point_size;
    updateFont();
}

//----------------------------------------------------------------------------//
void FreeTypeFont::setAntiAliased(const bool anti_alaised)
{
    if (anti_alaised == d_antiAliased)
        return;

    d_antiAliased = anti_alaised;
    updateFont();
}

//----------------------------------------------------------------------------//

} // End of  CEGUI namespace section
原文地址:https://www.cnblogs.com/flytrace/p/2942542.html