//---------------------------------------------------------------------------------------
// This file is part of the Lomse library.
// Copyright (c) 2010-present, Lomse Developers
//
// Licensed under the MIT license.
//
// See LICENSE and NOTICE.md files in the root directory of this source tree.
//---------------------------------------------------------------------------------------

//  This code is based on file agg_font_freetype.cpp from
//  Anti-Grain Geometry version 2.4
//  Anti-Grain Geometry (AGG) is copyright (C) 2002-2005 Maxim Shemanarev
//  (http://www.antigrain.com). AGG 2.4 is distributed as follows:
//    "Permission to copy, use, modify, sell and distribute this software
//    is granted provided this copyright notice appears in all copies.
//    This software is provided "as is" without express or implied
//    warranty, and with no claim as to its suitability for any purpose."
//
//---------------------------------------------------------------------------------------

#include "lomse_font_freetype.h"
#include "lomse_build_options.h"
#include "lomse_basic.h"

#include <stdio.h>
#include "agg_bitset_iterator.h"
#include "agg_renderer_scanline.h"



using namespace agg;

namespace lomse
{

//---------------------------------------------------------------------------------------
// These static code implements the AUTODIN II polynomial
// The variable corresponding to the macro argument "crc" should
// be an unsigned long.
// Original code  by Spencer Garrett <srg@quick.com>
//
// generated using the AUTODIN II polynomial
//   x^32 + x^26 + x^23 + x^22 + x^16 +
//   x^12 + x^11 + x^10 + x^8 + x^7 + x^5 + x^4 + x^2 + x^1 + 1
//

static const unsigned crc32tab[256] =
{
    0x00000000, 0x77073096, 0xee0e612c, 0x990951ba,
    0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
    0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
    0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
    0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
    0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
    0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec,
    0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
    0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
    0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
    0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940,
    0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
    0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116,
    0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
    0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
    0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
    0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a,
    0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
    0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818,
    0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
    0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
    0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
    0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c,
    0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
    0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
    0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
    0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
    0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
    0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086,
    0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
    0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4,
    0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
    0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
    0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
    0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
    0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
    0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe,
    0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
    0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
    0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
    0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252,
    0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
    0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60,
    0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
    0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
    0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
    0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04,
    0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
    0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a,
    0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
    0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
    0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
    0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e,
    0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
    0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
    0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
    0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
    0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
    0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0,
    0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
    0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6,
    0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
    0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
    0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d,
};

//---------------------------------------------------------------------------------------
static unsigned calc_crc32(const unsigned char* buf, unsigned size)
{
    unsigned crc = (unsigned)~0;
    const unsigned char* p;
    unsigned nr = size;

    for (p = buf; nr--; ++p)
    {
        crc = (crc >> 8) ^ crc32tab[(crc ^ *p) & 0xff];
    }
    return ~crc;
}

//---------------------------------------------------------------------------------------
static inline int dbl_to_plain_fx(double d)
{
    return int(d * 65536.0);
}

//---------------------------------------------------------------------------------------
static inline double int26p6_to_dbl(int p)
{
    return double(p) / 64.0;
}

//---------------------------------------------------------------------------------------
static inline int dbl_to_int26p6(double p)
{
    return int(p * 64.0 + 0.5);
}

//---------------------------------------------------------------------------------------
template<class PathStorage>
bool decompose_ft_outline(const FT_Outline& outline, bool flip_y, const trans_affine& mtx,
                          PathStorage& path)
{
    typedef typename PathStorage::value_type value_type;

    FT_Vector   v_last;
    FT_Vector   v_control;
    FT_Vector   v_start;
    double x1, y1, x2, y2, x3, y3;

    FT_Vector*  point;
    FT_Vector*  limit;
    // Freetype version 2.13.3 and later uses unsigned char for tags
#if (FREETYPE_MAJOR > 2) || (FREETYPE_MAJOR == 2 && FREETYPE_MINOR > 13) || \
    (FREETYPE_MAJOR == 2 && FREETYPE_MINOR == 13 && FREETYPE_PATCH >= 3)
    unsigned char*       tags;
#else
    char*       tags;
#endif

    int   n;         // index of contour in outline
    int   first;     // index of first point in contour
    char  tag;       // current point's state

    first = 0;

    for(n = 0; n < outline.n_contours; n++)
    {
        int  last;  // index of last point in contour

        last  = outline.contours[n];
        limit = outline.points + last;

        v_start = outline.points[first];
        v_last  = outline.points[last];

        v_control = v_start;

        point = outline.points + first;
        tags  = outline.tags  + first;
        tag   = FT_CURVE_TAG(tags[0]);

        // A contour cannot start with a cubic control point!
        if(tag == FT_CURVE_TAG_CUBIC) return false;

        // check first point to determine origin
        if( tag == FT_CURVE_TAG_CONIC)
        {
            // first point is conic control.  Yes, this happens.
            if(FT_CURVE_TAG(outline.tags[last]) == FT_CURVE_TAG_ON)
            {
                // start at last point if it is on the curve
                v_start = v_last;
                limit--;
            }
            else
            {
                // if both first and last points are conic,
                // start at their middle and record its position
                // for closure
                v_start.x = (v_start.x + v_last.x) / 2;
                v_start.y = (v_start.y + v_last.y) / 2;

                //v_last = v_start;
            }
            point--;
            tags--;
        }

        x1 = int26p6_to_dbl(v_start.x);
        y1 = int26p6_to_dbl(v_start.y);
        if(flip_y) y1 = -y1;
        mtx.transform(&x1, &y1);
        path.move_to(value_type(dbl_to_int26p6(x1)),
                        value_type(dbl_to_int26p6(y1)));

        while(point < limit)
        {
            point++;
            tags++;

            tag = FT_CURVE_TAG(tags[0]);
            switch(tag)
            {
                case FT_CURVE_TAG_ON:  // emit a single line_to
                {
                    x1 = int26p6_to_dbl(point->x);
                    y1 = int26p6_to_dbl(point->y);
                    if(flip_y) y1 = -y1;
                    mtx.transform(&x1, &y1);
                    path.line_to(value_type(dbl_to_int26p6(x1)),
                                    value_type(dbl_to_int26p6(y1)));
                    //path.line_to(conv(point->x), flip_y ? -conv(point->y) : conv(point->y));
                    continue;
                }

                case FT_CURVE_TAG_CONIC:  // consume conic arcs
                {
                    v_control.x = point->x;
                    v_control.y = point->y;

                Do_Conic:
                    if(point < limit)
                    {
                        FT_Vector vec;
                        FT_Vector v_middle;

                        point++;
                        tags++;
                        tag = FT_CURVE_TAG(tags[0]);

                        vec.x = point->x;
                        vec.y = point->y;

                        if(tag == FT_CURVE_TAG_ON)
                        {
                            x1 = int26p6_to_dbl(v_control.x);
                            y1 = int26p6_to_dbl(v_control.y);
                            x2 = int26p6_to_dbl(vec.x);
                            y2 = int26p6_to_dbl(vec.y);
                            if(flip_y) { y1 = -y1; y2 = -y2; }
                            mtx.transform(&x1, &y1);
                            mtx.transform(&x2, &y2);
                            path.curve3(value_type(dbl_to_int26p6(x1)),
                                        value_type(dbl_to_int26p6(y1)),
                                        value_type(dbl_to_int26p6(x2)),
                                        value_type(dbl_to_int26p6(y2)));
                            continue;
                        }

                        if(tag != FT_CURVE_TAG_CONIC) return false;

                        v_middle.x = (v_control.x + vec.x) / 2;
                        v_middle.y = (v_control.y + vec.y) / 2;

                        x1 = int26p6_to_dbl(v_control.x);
                        y1 = int26p6_to_dbl(v_control.y);
                        x2 = int26p6_to_dbl(v_middle.x);
                        y2 = int26p6_to_dbl(v_middle.y);
                        if(flip_y) { y1 = -y1; y2 = -y2; }
                        mtx.transform(&x1, &y1);
                        mtx.transform(&x2, &y2);
                        path.curve3(value_type(dbl_to_int26p6(x1)),
                                    value_type(dbl_to_int26p6(y1)),
                                    value_type(dbl_to_int26p6(x2)),
                                    value_type(dbl_to_int26p6(y2)));

                        //path.curve3(conv(v_control.x),
                        //            flip_y ? -conv(v_control.y) : conv(v_control.y),
                        //            conv(v_middle.x),
                        //            flip_y ? -conv(v_middle.y) : conv(v_middle.y));

                        v_control = vec;
                        goto Do_Conic;
                    }

                    x1 = int26p6_to_dbl(v_control.x);
                    y1 = int26p6_to_dbl(v_control.y);
                    x2 = int26p6_to_dbl(v_start.x);
                    y2 = int26p6_to_dbl(v_start.y);
                    if(flip_y) { y1 = -y1; y2 = -y2; }
                    mtx.transform(&x1, &y1);
                    mtx.transform(&x2, &y2);
                    path.curve3(value_type(dbl_to_int26p6(x1)),
                                value_type(dbl_to_int26p6(y1)),
                                value_type(dbl_to_int26p6(x2)),
                                value_type(dbl_to_int26p6(y2)));

                    //path.curve3(conv(v_control.x),
                    //            flip_y ? -conv(v_control.y) : conv(v_control.y),
                    //            conv(v_start.x),
                    //            flip_y ? -conv(v_start.y) : conv(v_start.y));
                    goto Close;
                }

                default:  // FT_CURVE_TAG_CUBIC
                {
                    FT_Vector vec1, vec2;

                    if(point + 1 > limit || FT_CURVE_TAG(tags[1]) != FT_CURVE_TAG_CUBIC)
                    {
                        return false;
                    }

                    vec1.x = point[0].x;
                    vec1.y = point[0].y;
                    vec2.x = point[1].x;
                    vec2.y = point[1].y;

                    point += 2;
                    tags  += 2;

                    if(point <= limit)
                    {
                        FT_Vector vec;

                        vec.x = point->x;
                        vec.y = point->y;

                        x1 = int26p6_to_dbl(vec1.x);
                        y1 = int26p6_to_dbl(vec1.y);
                        x2 = int26p6_to_dbl(vec2.x);
                        y2 = int26p6_to_dbl(vec2.y);
                        x3 = int26p6_to_dbl(vec.x);
                        y3 = int26p6_to_dbl(vec.y);
                        if(flip_y) { y1 = -y1; y2 = -y2; y3 = -y3; }
                        mtx.transform(&x1, &y1);
                        mtx.transform(&x2, &y2);
                        mtx.transform(&x3, &y3);
                        path.curve4(value_type(dbl_to_int26p6(x1)),
                                    value_type(dbl_to_int26p6(y1)),
                                    value_type(dbl_to_int26p6(x2)),
                                    value_type(dbl_to_int26p6(y2)),
                                    value_type(dbl_to_int26p6(x3)),
                                    value_type(dbl_to_int26p6(y3)));

                        //path.curve4(conv(vec1.x),
                        //            flip_y ? -conv(vec1.y) : conv(vec1.y),
                        //            conv(vec2.x),
                        //            flip_y ? -conv(vec2.y) : conv(vec2.y),
                        //            conv(vec.x),
                        //            flip_y ? -conv(vec.y) : conv(vec.y));
                        continue;
                    }

                    x1 = int26p6_to_dbl(vec1.x);
                    y1 = int26p6_to_dbl(vec1.y);
                    x2 = int26p6_to_dbl(vec2.x);
                    y2 = int26p6_to_dbl(vec2.y);
                    x3 = int26p6_to_dbl(v_start.x);
                    y3 = int26p6_to_dbl(v_start.y);
                    if(flip_y) { y1 = -y1; y2 = -y2; y3 = -y3; }
                    mtx.transform(&x1, &y1);
                    mtx.transform(&x2, &y2);
                    mtx.transform(&x3, &y3);
                    path.curve4(value_type(dbl_to_int26p6(x1)),
                                value_type(dbl_to_int26p6(y1)),
                                value_type(dbl_to_int26p6(x2)),
                                value_type(dbl_to_int26p6(y2)),
                                value_type(dbl_to_int26p6(x3)),
                                value_type(dbl_to_int26p6(y3)));

                    //path.curve4(conv(vec1.x),
                    //            flip_y ? -conv(vec1.y) : conv(vec1.y),
                    //            conv(vec2.x),
                    //            flip_y ? -conv(vec2.y) : conv(vec2.y),
                    //            conv(v_start.x),
                    //            flip_y ? -conv(v_start.y) : conv(v_start.y));
                    goto Close;
                }
            }
        }

        path.close_polygon();

    Close:
        first = last + 1;
    }

    return true;
}

//---------------------------------------------------------------------------------------
template<class Scanline, class ScanlineStorage>
void decompose_ft_bitmap_mono(const FT_Bitmap& bitmap,
                                int x, int y,
                                bool flip_y,
                                Scanline& sl,
                                ScanlineStorage& storage)
{
    int i;
    const int8u* buf = (const int8u*)bitmap.buffer;
    int pitch = bitmap.pitch;
    sl.reset(x, x + bitmap.width);
    storage.prepare();
    if(flip_y)
    {
        buf += bitmap.pitch * (bitmap.rows - 1);
        y += bitmap.rows;
        pitch = -pitch;
    }
    for(i = 0; i < int(bitmap.rows); i++)
    {
        sl.reset_spans();
        bitset_iterator bits(buf, 0);
        int j;
        for(j = 0; j < int(bitmap.width); j++)
        {
            if(bits.bit()) sl.add_cell(x + j, cover_full);
            ++bits;
        }
        buf += pitch;
        if(sl.num_spans())
        {
            sl.finalize(y - i - 1);
            storage.render(sl);
        }
    }
}

//---------------------------------------------------------------------------------------
template<class Rasterizer, class Scanline, class ScanlineStorage>
void decompose_ft_bitmap_gray8(const FT_Bitmap& bitmap,
                                int x, int y,
                                bool flip_y,
                                Rasterizer& ras,
                                Scanline& sl,
                                ScanlineStorage& storage)
{
    int i, j;
    const int8u* buf = (const int8u*)bitmap.buffer;
    int pitch = bitmap.pitch;
    sl.reset(x, x + bitmap.width);
    storage.prepare();
    if(flip_y)
    {
        buf += bitmap.pitch * (bitmap.rows - 1);
        y += bitmap.rows;
        pitch = -pitch;
    }
    for(i = 0; i < int(bitmap.rows); i++)
    {
        sl.reset_spans();
        const int8u* p = buf;
        for(j = 0; j < int(bitmap.width); j++)
        {
            if(*p) sl.add_cell(x + j, ras.apply_gamma(*p));
            ++p;
        }
        buf += pitch;
        if(sl.num_spans())
        {
            sl.finalize(y - i - 1);
            storage.render(sl);
        }
    }
}



//---------------------------------------------------------------------------------------
// font_engine_freetype_base implementation
//---------------------------------------------------------------------------------------
font_engine_freetype_base::font_engine_freetype_base(bool flag32,
                                                     unsigned max_faces)
    : m_flag32(flag32)
    , m_change_stamp(0)
    , m_last_error(0)
    , m_name(0)
    , m_name_len(256-16-1)
    , m_face_index(0)
    , m_char_map(FT_ENCODING_NONE)
    , m_signature(LOMSE_NEW char [256+256-16])
    , m_height(0)
    , m_width(0)
    , m_hinting(true)
    , m_flip_y(false)
    , m_library_initialized(false)
    , m_library(0)
    , m_faces(LOMSE_NEW FT_Face [max_faces])
    , m_face_names(LOMSE_NEW char* [max_faces])
    , m_num_faces(0)
    , m_max_faces(max_faces)
    , m_cur_face(0)
    , m_resolution(0)
    , m_glyph_rendering(glyph_ren_native_gray8)
    , m_glyph_index(0)
    , m_data_size(0)
    , m_data_type(glyph_data_invalid)
    , m_bounds(1,1,0,0)
    , m_advance_x(0.0)
    , m_advance_y(0.0)

    , m_path16()
    , m_path32()
    , m_curves16(m_path16)
    , m_curves32(m_path32)
    , m_scanline_aa()
    , m_scanline_bin()
    , m_scanlines_aa()
    , m_scanlines_bin()
    , m_rasterizer()
{
    m_curves16.approximation_scale(4.0);
    m_curves32.approximation_scale(4.0);
    m_last_error = FT_Init_FreeType(&m_library);
    if(m_last_error == 0)
        m_library_initialized = true;
}

//---------------------------------------------------------------------------------------
font_engine_freetype_base::~font_engine_freetype_base()
{
    for(unsigned i = 0; i < m_num_faces; ++i)
    {
        delete [] m_face_names[i];
        FT_Done_Face(m_faces[i]);
    }
    delete [] m_face_names;
    delete [] m_faces;
    delete [] m_signature;
    if(m_library_initialized)
        FT_Done_FreeType(m_library);
}

//---------------------------------------------------------------------------------------
void font_engine_freetype_base::resolution(unsigned dpi)
{
    m_resolution = dpi;
    update_char_size();
}

//---------------------------------------------------------------------------------------
int font_engine_freetype_base::find_face(const char* face_name) const
{
    unsigned i;
    for(i = 0; i < m_num_faces; ++i)
    {
        if(strcmp(face_name, m_face_names[i]) == 0) return i;
    }
    return -1;
}

//---------------------------------------------------------------------------------------
double font_engine_freetype_base::ascender() const
{
    if(m_cur_face)
    {
        return m_cur_face->ascender * height() / m_cur_face->height;
    }
    return 0.0;
}

//---------------------------------------------------------------------------------------
double font_engine_freetype_base::descender() const
{
    if(m_cur_face)
    {
        return m_cur_face->descender * height() / m_cur_face->height;
    }
    return 0.0;
}

//---------------------------------------------------------------------------------------
bool font_engine_freetype_base::select_font(const std::string& font_name,
                                            unsigned face_index,
                                            glyph_rendering ren_type,
                                            const char* font_mem,
                                            const long font_mem_size)
{
    if(!m_library_initialized)
        return false;

    m_last_error = 0;

    int idx = find_face(font_name.c_str());
    if(idx >= 0)
    {
        m_cur_face = m_faces[idx];
        m_name = m_face_names[idx];
    }
    else
        load_font_file(font_name, face_index, font_mem, font_mem_size);

    if(m_last_error == 0)
    {
        determine_rendering_mode(ren_type);
        update_signature();
    }
    return m_last_error == 0;
}

//---------------------------------------------------------------------------------------
void font_engine_freetype_base::load_font_file(const std::string& font_name,
                                               unsigned face_index,
                                               const char* font_mem,
                                               const long font_mem_size)
{
    if(m_num_faces >= m_max_faces)
    {
        delete [] m_face_names[0];
        FT_Done_Face(m_faces[0]);
        memmove(m_faces,
                m_faces + 1,
                (m_max_faces - 1) * sizeof(FT_Face));
        memmove(m_face_names,
                m_face_names + 1,
                (m_max_faces - 1) * sizeof(char*));
        m_num_faces = m_max_faces - 1;
    }

    if (font_mem && font_mem_size)
    {
        m_last_error = FT_New_Memory_Face(m_library,
                                            (const FT_Byte*)font_mem,
                                            font_mem_size,
                                            face_index,
                                            &m_faces[m_num_faces]);
    }
    else
    {
        m_last_error = FT_New_Face(m_library,
                                    font_name.c_str(),
                                    face_index,
                                    &m_faces[m_num_faces]);
    }

    //For error codes have a look into file include/freetype/fterrdef.h;
    if(m_last_error == 0)
    {
        m_face_names[m_num_faces] = LOMSE_NEW char [font_name.size() + 1];
        strcpy(m_face_names[m_num_faces], font_name.c_str());
        m_cur_face = m_faces[m_num_faces];
        m_name     = m_face_names[m_num_faces];
        ++m_num_faces;
    }
    else
    {
        m_face_names[m_num_faces] = 0;
        m_cur_face = 0;
        m_name = 0;
    }
}

//---------------------------------------------------------------------------------------
void font_engine_freetype_base::determine_rendering_mode(glyph_rendering ren_type)
{
    switch(ren_type)
    {
        case glyph_ren_native_mono:
            m_glyph_rendering = glyph_ren_native_mono;
            break;

        case glyph_ren_native_gray8:
            m_glyph_rendering = glyph_ren_native_gray8;
            break;

        case glyph_ren_outline:
            if(FT_IS_SCALABLE(m_cur_face))
                m_glyph_rendering = glyph_ren_outline;
            else
                m_glyph_rendering = glyph_ren_native_gray8;
            break;

        case glyph_ren_agg_mono:
            if(FT_IS_SCALABLE(m_cur_face))
                m_glyph_rendering = glyph_ren_agg_mono;
            else
                m_glyph_rendering = glyph_ren_native_mono;
            break;

        case glyph_ren_agg_gray8:
            if(FT_IS_SCALABLE(m_cur_face))
                m_glyph_rendering = glyph_ren_agg_gray8;
            else
                m_glyph_rendering = glyph_ren_native_gray8;
            break;
    }
}

//---------------------------------------------------------------------------------------
bool font_engine_freetype_base::attach(const char* file_name)
{
    if(m_cur_face)
    {
        m_last_error = FT_Attach_File(m_cur_face, file_name);
        return m_last_error == 0;
    }
    return false;
}

//---------------------------------------------------------------------------------------
unsigned font_engine_freetype_base::num_faces() const
{
    if(m_cur_face)
    {
        return m_cur_face->num_faces;
    }
    return 0;
}

//---------------------------------------------------------------------------------------
bool font_engine_freetype_base::char_map(FT_Encoding UNUSED(char_map))
{
    if(m_cur_face)
    {
        m_last_error = FT_Select_Charmap(m_cur_face, m_char_map);
        if(m_last_error == 0)
        {
            update_signature();
            return true;
        }
    }
    return false;
}

//---------------------------------------------------------------------------------------
bool font_engine_freetype_base::height(double h)
{
    //set font size (for current face) in points
    m_height = int(h * 64.0);
    if(m_cur_face)
    {
        update_char_size();
        return true;
    }
    return false;
}

//---------------------------------------------------------------------------------------
bool font_engine_freetype_base::width(double w)
{
    //set font size (for current face) in points
    m_width = int(w * 64.0);
    if(m_cur_face)
    {
        update_char_size();
        return true;
    }
    return false;
}

//---------------------------------------------------------------------------------------
void font_engine_freetype_base::hinting(bool h)
{
    //set hintig  (for current face)
    m_hinting = h;
    if(m_cur_face)
    {
        update_signature();
    }
}

//---------------------------------------------------------------------------------------
void font_engine_freetype_base::flip_y(bool f)
{
    // set filp  (for current face)
    m_flip_y = f;
    if(m_cur_face)
    {
        update_signature();
    }
}

//---------------------------------------------------------------------------------------
void font_engine_freetype_base::transform(const trans_affine& affine)
{
    //set affine transform  (for current face)
    m_affine = affine;
    if(m_cur_face)
    {
        update_signature();
    }
}

//---------------------------------------------------------------------------------------
void font_engine_freetype_base::update_signature()
{
    if(m_cur_face && m_name)
    {
        unsigned name_len = unsigned( strlen(m_name) );
        if(name_len > m_name_len)
        {
            delete [] m_signature;
            m_signature = LOMSE_NEW char [name_len + 32 + 256];
            m_name_len = name_len + 32 - 1;
        }

        unsigned gamma_hash = 0;
        if(m_glyph_rendering == glyph_ren_native_gray8 ||
            m_glyph_rendering == glyph_ren_agg_mono ||
            m_glyph_rendering == glyph_ren_agg_gray8)
        {
            unsigned char gamma_table[rasterizer_scanline_aa<>::aa_scale];
            unsigned i;
            for(i = 0; i < rasterizer_scanline_aa<>::aa_scale; ++i)
            {
                gamma_table[i] = m_rasterizer.apply_gamma(i);
            }
            gamma_hash = calc_crc32(gamma_table, sizeof(gamma_table));
        }

        sprintf(m_signature,
                "%s,%u,%d,%d,%d:%dx%d,%d,%d,%08X",
                m_name,
                m_char_map,
                m_face_index,
                int(m_glyph_rendering),
                m_resolution,
                m_height,
                m_width,
                int(m_hinting),
                int(m_flip_y),
                gamma_hash);
        if(m_glyph_rendering == glyph_ren_outline ||
            m_glyph_rendering == glyph_ren_agg_mono ||
            m_glyph_rendering == glyph_ren_agg_gray8)
        {
            double mtx[6];
            char buf[100];
            m_affine.store_to(mtx);
            sprintf(buf, ",%08X%08X%08X%08X%08X%08X",
                dbl_to_plain_fx(mtx[0]),
                dbl_to_plain_fx(mtx[1]),
                dbl_to_plain_fx(mtx[2]),
                dbl_to_plain_fx(mtx[3]),
                dbl_to_plain_fx(mtx[4]),
                dbl_to_plain_fx(mtx[5]));
            strcat(m_signature, buf);
        }
        ++m_change_stamp;
    }
}

//---------------------------------------------------------------------------------------
void font_engine_freetype_base::update_char_size()
{
    if(m_cur_face)
    {
        if(m_resolution)
        {
            FT_Set_Char_Size(m_cur_face,
                             m_width,       // char_width in 1/64th of points
                             m_height,      // char_height in 1/64th of points
                             m_resolution,  // horizontal device resolution in dpi
                             m_resolution); // vertical device resolution in dpi
        }
        else
        {
            FT_Set_Pixel_Sizes(m_cur_face,
                               m_width >> 6,    // pixel_width
                               m_height >> 6);  // pixel_height
        }
        update_signature();
    }
}

//---------------------------------------------------------------------------------------
bool font_engine_freetype_base::prepare_glyph(unsigned glyph_code)
{
    m_glyph_index = FT_Get_Char_Index(m_cur_face, glyph_code);
    if (m_glyph_index == 0)
        return false;   //missing glyph
    m_last_error = FT_Load_Glyph(m_cur_face,
                                    m_glyph_index,
                                    m_hinting ? FT_LOAD_DEFAULT : FT_LOAD_NO_HINTING);
    if(m_last_error == 0)
    {
        switch(m_glyph_rendering)
        {
        case glyph_ren_native_mono:
            m_last_error = FT_Render_Glyph(m_cur_face->glyph, FT_RENDER_MODE_MONO);
            if(m_last_error == 0)
            {
                decompose_ft_bitmap_mono(m_cur_face->glyph->bitmap,
                                            m_cur_face->glyph->bitmap_left,
                                            m_flip_y ? -m_cur_face->glyph->bitmap_top :
                                                        m_cur_face->glyph->bitmap_top,
                                            m_flip_y,
                                            m_scanline_bin,
                                            m_scanlines_bin);
                m_bounds.x1 = m_scanlines_bin.min_x();
                m_bounds.y1 = m_scanlines_bin.min_y();
                m_bounds.x2 = m_scanlines_bin.max_x() + 1;
                m_bounds.y2 = m_scanlines_bin.max_y() + 1;
                m_data_size = m_scanlines_bin.byte_size();
                m_data_type = glyph_data_mono;
                m_advance_x = int26p6_to_dbl(m_cur_face->glyph->advance.x);
                m_advance_y = int26p6_to_dbl(m_cur_face->glyph->advance.y);
                return true;
            }
            break;


        case glyph_ren_native_gray8:
            m_last_error = FT_Render_Glyph(m_cur_face->glyph, FT_RENDER_MODE_NORMAL);
            if(m_last_error == 0)
            {
                decompose_ft_bitmap_gray8(m_cur_face->glyph->bitmap,
                                            m_cur_face->glyph->bitmap_left,
                                            m_flip_y ? -m_cur_face->glyph->bitmap_top :
                                                        m_cur_face->glyph->bitmap_top,
                                            m_flip_y,
                                            m_rasterizer,
                                            m_scanline_aa,
                                            m_scanlines_aa);
                m_bounds.x1 = m_scanlines_aa.min_x();
                m_bounds.y1 = m_scanlines_aa.min_y();
                m_bounds.x2 = m_scanlines_aa.max_x() + 1;
                m_bounds.y2 = m_scanlines_aa.max_y() + 1;
                m_data_size = m_scanlines_aa.byte_size();
                m_data_type = glyph_data_gray8;
                m_advance_x = int26p6_to_dbl(m_cur_face->glyph->advance.x);
                m_advance_y = int26p6_to_dbl(m_cur_face->glyph->advance.y);
                return true;
            }
            break;


        case glyph_ren_outline:
            if(m_last_error == 0)
            {
                if(m_flag32)
                {
                    m_path32.remove_all();
                    if(decompose_ft_outline(m_cur_face->glyph->outline,
                                            m_flip_y,
                                            m_affine,
                                            m_path32))
                    {
                        rect_d bnd  = m_path32.bounding_rect();
                        m_data_size = m_path32.byte_size();
                        m_data_type = glyph_data_outline;
                        m_bounds.x1 = int(floor(bnd.x1));
                        m_bounds.y1 = int(floor(bnd.y1));
                        m_bounds.x2 = int(ceil(bnd.x2));
                        m_bounds.y2 = int(ceil(bnd.y2));
                        m_advance_x = int26p6_to_dbl(m_cur_face->glyph->advance.x);
                        m_advance_y = int26p6_to_dbl(m_cur_face->glyph->advance.y);
                        m_affine.transform(&m_advance_x, &m_advance_y);
                        return true;
                    }
                }
                else
                {
                    m_path16.remove_all();
                    if(decompose_ft_outline(m_cur_face->glyph->outline,
                                            m_flip_y,
                                            m_affine,
                                            m_path16))
                    {
                        rect_d bnd  = m_path16.bounding_rect();
                        m_data_size = m_path16.byte_size();
                        m_data_type = glyph_data_outline;
                        m_bounds.x1 = int(floor(bnd.x1));
                        m_bounds.y1 = int(floor(bnd.y1));
                        m_bounds.x2 = int(ceil(bnd.x2));
                        m_bounds.y2 = int(ceil(bnd.y2));
                        m_advance_x = int26p6_to_dbl(m_cur_face->glyph->advance.x);
                        m_advance_y = int26p6_to_dbl(m_cur_face->glyph->advance.y);
                        m_affine.transform(&m_advance_x, &m_advance_y);
                        return true;
                    }
                }
            }
            return false;

        case glyph_ren_agg_mono:
            if(m_last_error == 0)
            {
                m_rasterizer.reset();
                if(m_flag32)
                {
                    m_path32.remove_all();
                    decompose_ft_outline(m_cur_face->glyph->outline,
                                            m_flip_y,
                                            m_affine,
                                            m_path32);
                    m_rasterizer.add_path(m_curves32);
                }
                else
                {
                    m_path16.remove_all();
                    decompose_ft_outline(m_cur_face->glyph->outline,
                                            m_flip_y,
                                            m_affine,
                                            m_path16);
                    m_rasterizer.add_path(m_curves16);
                }
                m_scanlines_bin.prepare(); // Remove all
                render_scanlines(m_rasterizer, m_scanline_bin, m_scanlines_bin);
                m_bounds.x1 = m_scanlines_bin.min_x();
                m_bounds.y1 = m_scanlines_bin.min_y();
                m_bounds.x2 = m_scanlines_bin.max_x() + 1;
                m_bounds.y2 = m_scanlines_bin.max_y() + 1;
                m_data_size = m_scanlines_bin.byte_size();
                m_data_type = glyph_data_mono;
                m_advance_x = int26p6_to_dbl(m_cur_face->glyph->advance.x);
                m_advance_y = int26p6_to_dbl(m_cur_face->glyph->advance.y);
                m_affine.transform(&m_advance_x, &m_advance_y);
                return true;
            }
            return false;


        case glyph_ren_agg_gray8:
            if(m_last_error == 0)
            {
                m_rasterizer.reset();
                if(m_flag32)
                {
                    m_path32.remove_all();
                    decompose_ft_outline(m_cur_face->glyph->outline,
                                            m_flip_y,
                                            m_affine,
                                            m_path32);
                    m_rasterizer.add_path(m_curves32);
                }
                else
                {
                    m_path16.remove_all();
                    decompose_ft_outline(m_cur_face->glyph->outline,
                                            m_flip_y,
                                            m_affine,
                                            m_path16);
                    m_rasterizer.add_path(m_curves16);
                }
                m_scanlines_aa.prepare(); // Remove all
                render_scanlines(m_rasterizer, m_scanline_aa, m_scanlines_aa);
                m_bounds.x1 = m_scanlines_aa.min_x();
                m_bounds.y1 = m_scanlines_aa.min_y();
                m_bounds.x2 = m_scanlines_aa.max_x() + 1;
                m_bounds.y2 = m_scanlines_aa.max_y() + 1;
                m_data_size = m_scanlines_aa.byte_size();
                m_data_type = glyph_data_gray8;
                m_advance_x = int26p6_to_dbl(m_cur_face->glyph->advance.x);
                m_advance_y = int26p6_to_dbl(m_cur_face->glyph->advance.y);
                m_affine.transform(&m_advance_x, &m_advance_y);
                return true;
            }
            return false;
        }
    }
    return false;
}

//---------------------------------------------------------------------------------------
void font_engine_freetype_base::write_glyph_to(int8u* data) const
{
    if(data && m_data_size)
    {
        switch(m_data_type)
        {
        default: return;
        case glyph_data_mono:    m_scanlines_bin.serialize(data); break;
        case glyph_data_gray8:   m_scanlines_aa.serialize(data);  break;
        case glyph_data_outline:
            if(m_flag32)
            {
                m_path32.serialize(data);
            }
            else
            {
                m_path16.serialize(data);
            }
            break;
        case glyph_data_invalid: break;
        }
    }
}

//---------------------------------------------------------------------------------------
bool font_engine_freetype_base::add_kerning(unsigned first, unsigned second,
                                        double* x, double* y)
{
    if(m_cur_face && first && second && FT_HAS_KERNING(m_cur_face))
    {
        FT_Vector delta;
        FT_Get_Kerning(m_cur_face, first, second, FT_KERNING_DEFAULT, &delta);
        double dx = int26p6_to_dbl(delta.x);
        double dy = int26p6_to_dbl(delta.y);
        if(m_glyph_rendering == glyph_ren_outline
           || m_glyph_rendering == glyph_ren_agg_mono
           || m_glyph_rendering == glyph_ren_agg_gray8)
        {
            m_affine.transform_2x2(&dx, &dy);
        }
        *x += dx;
        *y += dy;

        return true;
    }
    return false;
}


}   //namespace lomse


