// SPDX-License-Identifier: GPL-2.0-or-later
/** @file
 * TODO: insert short description here
 *//*
 * Authors: see git history
 *
 * Copyright (C) 2018 Authors
 * Released under GNU GPL v2+, read the file 'COPYING' for more information.
 */
#ifndef SEEN_LIBNRTYPE_FONT_INSTANCE_H
#define SEEN_LIBNRTYPE_FONT_INSTANCE_H

#include <map>

#include <pango/pango-types.h>
#include <pango/pango-font.h>

#include <2geom/d2.h>

#include "FontFactory.h"
#include "font-style.h"
#include "OpenTypeUtil.h"

namespace Inkscape { class Pixbuf; }

class font_factory;
struct font_glyph;

// the font_instance are the template of several raster_font; they provide metrics and outlines
// that are drawn by the raster_font, so the raster_font needs info relative to the way the
// font need to be drawn. note that fontsize is a scale factor in the transform matrix
// of the style
class font_instance {
public:
    // the real source of the font
    PangoFont*            pFont = nullptr;
    // depending on the rendering backend, different temporary data

    // that's the font's fingerprint; this particular PangoFontDescription gives the entry at which this font_instance
    // resides in the font_factory loadedFaces unordered_map
    PangoFontDescription* descr = nullptr;
    // refcount
    int                   refCount = 0;
    // font_factory owning this font_instance
    font_factory*         parent = nullptr;

    // common glyph definitions for all the rasterfonts
    std::map<int, int>    id_to_no;
    int                   nbGlyph = 0;
    int                   maxGlyph = 0;

    font_glyph*           glyphs = nullptr;

    // font is loaded with GSUB in 2 pass
    bool    fulloaded = false;

    // Map of OpenType tables found in font.
    std::map<Glib::ustring, OTSubstitution> openTypeTables;

    // Maps for font variations.
    std::map<Glib::ustring, OTVarAxis> openTypeVarAxes;      // Axes with ranges

    // Map of SVG in OpenType glyphs
    std::map<int, SVGTableEntry> openTypeSVGGlyphs;

    // Does OpenType font contain SVG glyphs?
    bool   fontHasSVG = false;

    font_instance();
    virtual ~font_instance();

    void                 Ref();
    void                 Unref();

    bool                 IsOutlineFont(); // utility
    void                 InstallFace(PangoFont* iFace); // utility; should reset the pFont field if loading failed
    // in case the PangoFont is a bitmap font, for example. that way, the calling function
    // will be able to check the validity of the font before installing it in loadedFaces
    void                 InitTheFace(bool loadgsub = false);

    int                  MapUnicodeChar(gunichar c); // calls the relevant unicode->glyph index function
    void                 LoadGlyph(int glyph_id);    // the main backend-dependent function
    // loads the given glyph's info

    // nota: all coordinates returned by these functions are on a [0..1] scale; you need to multiply
    // by the fontsize to get the real sizes

    // Return 2geom pathvector for glyph. Deallocated when font instance dies.
    Geom::PathVector*    PathVector(int glyph_id);

    // Return font has SVG OpenType enties.
    bool                 FontHasSVG() { return fontHasSVG; };

    // Return pixbuf of SVG glyph or nullptr if no SVG glyph exists.
    Inkscape::Pixbuf*    PixBuf(int glyph_id);


    // Horizontal advance if 'vertical' is false, vertical advance if true.
    double               Advance(int glyph_id, bool vertical);

    double               GetTypoAscent()  { return _ascent; }
    double               GetTypoDescent() { return _descent; }
    double               GetXHeight()     { return _xheight; }
    double               GetMaxAscent()   { return _ascent_max; }
    double               GetMaxDescent()  { return _descent_max; }
    const double*        GetBaselines()   { return _baselines; }
    int                  GetDesignUnits() { return _design_units; }

    bool                 FontMetrics(double &ascent, double &descent, double &leading);
    bool                 FontDecoration(double &underline_position, double &underline_thickness,
                                        double &linethrough_position, double &linethrough_thickness);
    bool                 FontSlope(double &run, double &rise);
                                // for generating slanted cursors for oblique fonts
    Geom::OptRect        BBox(int glyph_id);

private:
    void                 FreeTheFace();
    // Find ascent, descent, x-height, and baselines.
    void                 FindFontMetrics();

    // Temp: make public
public:
#ifdef USE_PANGO_WIN32
    HFONT                 theFace = nullptr;
#else
    // we need to keep around an rw copy of the (read-only) hb font to extract the freetype face
    hb_font_t*            hb_font_copy = nullptr;
    FT_Face               theFace = nullptr;
                // it's a pointer in fact; no worries to ref/unref it, pango does its magic
                // as long as pFont is valid, theFace is too
#endif

private:
    // Font metrics in em-box units
    double  _ascent;       // Typographic ascent.
    double  _descent;      // Typographic descent.
    double  _xheight;      // x-height of font.
    double  _ascent_max;   // Maximum ascent of all glyphs in font.
    double  _descent_max;  // Maximum descent of all glyphs in font.
    int     _design_units; // Design units, (units per em, typically 1000 or 2048).

    // Baselines
    double _baselines[SP_CSS_BASELINE_SIZE];
};


#endif /* !SEEN_LIBNRTYPE_FONT_INSTANCE_H */

/*
  Local Variables:
  mode:c++
  c-file-style:"stroustrup"
  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
  indent-tabs-mode:nil
  fill-column:99
  End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :