GlyphCache.h

// SPDX-License-Identifier: MIT OR MPL-2.0 OR LGPL-2.1-or-later OR GPL-2.0-or-later
// Copyright 2012, SIL International, All rights reserved.

#pragma once


#include "graphite2/Font.h"
#include "inc/Main.h"
#include "inc/Position.h"
#include "inc/GlyphFace.h"

namespace graphite2 {

class Face;
class FeatureVal;
class Segment;


struct SlantBox
{
    static const SlantBox empty;

//    SlantBox(float psi = 0., float pdi = 0., float psa = 0., float pda = 0.) : si(psi), di(pdi), sa(psa), da(pda) {};
    float width() const { return sa - si; }
    float height() const { return da - di; }
    float si; // min
    float di; // min
    float sa; // max
    float da; // max
};


struct BBox
{
    BBox(float pxi = 0, float pyi = 0., float pxa = 0., float pya = 0.) : xi(pxi), yi(pyi), xa(pxa), ya(pya) {};
    float width() const { return xa - xi; }
    float height() const { return ya - yi; }
    float xi; // min
    float yi; // min
    float xa; // max
    float ya; // max
};


class GlyphBox
{
    GlyphBox(const GlyphBox &);
    GlyphBox & operator = (const GlyphBox &);

public:
    GlyphBox(uint8 numsubs, unsigned short bitmap, Rect *slanted) : _num(numsubs), _bitmap(bitmap), _slant(*slanted) {};

    void addSubBox(int subindex, int boundary, Rect *val) { _subs[subindex * 2 + boundary] = *val; }
    Rect &subVal(int subindex, int boundary) { return _subs[subindex * 2 + boundary]; }
    const Rect &slant() const { return _slant; }
    uint8 num() const { return _num; }
    const Rect *subs() const { return _subs; }

private:
    uint8   _num;
    unsigned short  _bitmap;
    Rect    _slant;
    Rect    _subs[1];
};

class GlyphCache
{
    class Loader;

    GlyphCache(const GlyphCache&);
    GlyphCache& operator=(const GlyphCache&);

public:
    GlyphCache(const Face & face, const uint32 face_options);
    ~GlyphCache();

    unsigned short  numGlyphs() const throw();
    unsigned short  numAttrs() const throw();
    unsigned short  unitsPerEm() const throw();

    const GlyphFace *glyph(unsigned short glyphid) const;      //result may be changed by subsequent call with a different glyphid
    const GlyphFace *glyphSafe(unsigned short glyphid) const;
    float            getBoundingMetric(unsigned short glyphid, uint8 metric) const;
    uint8            numSubBounds(unsigned short glyphid) const;
    float            getSubBoundingMetric(unsigned short glyphid, uint8 subindex, uint8 metric) const;
    const Rect &     slant(unsigned short glyphid) const { return _boxes[glyphid] ? _boxes[glyphid]->slant() : _empty_slant_box; }
    const SlantBox & getBoundingSlantBox(unsigned short glyphid) const;
    const BBox &     getBoundingBBox(unsigned short glyphid) const;
    const SlantBox & getSubBoundingSlantBox(unsigned short glyphid, uint8 subindex) const;
    const BBox &     getSubBoundingBBox(unsigned short glyphid, uint8 subindex) const;
    bool             check(unsigned short glyphid) const;
    bool             hasBoxes() const { return _boxes != 0; }

    CLASS_NEW_DELETE;

private:
    const Rect            _empty_slant_box;
    const Loader        * _glyph_loader;
    const GlyphFace *   * _glyphs;
    GlyphBox        *   * _boxes;
    unsigned short        _num_glyphs,
                          _num_attrs,
                          _upem;
};

inline
unsigned short GlyphCache::numGlyphs() const throw()
{
    return _num_glyphs;
}

inline
unsigned short GlyphCache::numAttrs() const throw()
{
    return _num_attrs;
}

inline
unsigned short  GlyphCache::unitsPerEm() const throw()
{
    return _upem;
}

inline
bool GlyphCache::check(unsigned short glyphid) const
{
    return _boxes && glyphid < _num_glyphs;
}

inline
const GlyphFace *GlyphCache::glyphSafe(unsigned short glyphid) const
{
    return glyphid < _num_glyphs ? glyph(glyphid) : NULL;
}

inline
float GlyphCache::getBoundingMetric(unsigned short glyphid, uint8 metric) const
{
    if (glyphid >= _num_glyphs) return 0.;
    switch (metric) {
        case 0: return (float)(glyph(glyphid)->theBBox().bl.x);                          // x_min
        case 1: return (float)(glyph(glyphid)->theBBox().bl.y);                          // y_min
        case 2: return (float)(glyph(glyphid)->theBBox().tr.x);                          // x_max
        case 3: return (float)(glyph(glyphid)->theBBox().tr.y);                          // y_max
        case 4: return (float)(_boxes[glyphid] ? _boxes[glyphid]->slant().bl.x : 0.f);    // sum_min
        case 5: return (float)(_boxes[glyphid] ? _boxes[glyphid]->slant().bl.y : 0.f);    // diff_min
        case 6: return (float)(_boxes[glyphid] ? _boxes[glyphid]->slant().tr.x : 0.f);    // sum_max
        case 7: return (float)(_boxes[glyphid] ? _boxes[glyphid]->slant().tr.y : 0.f);    // diff_max
        default: return 0.;
    }
}

inline const SlantBox &GlyphCache::getBoundingSlantBox(unsigned short glyphid) const
{
    return _boxes[glyphid] ? *(SlantBox *)(&(_boxes[glyphid]->slant())) : SlantBox::empty;
}

inline const BBox &GlyphCache::getBoundingBBox(unsigned short glyphid) const
{
    return *(BBox *)(&(glyph(glyphid)->theBBox()));
}

inline
float GlyphCache::getSubBoundingMetric(unsigned short glyphid, uint8 subindex, uint8 metric) const
{
    GlyphBox *b = _boxes[glyphid];
    if (b == NULL || subindex >= b->num()) return 0;

    switch (metric) {
        case 0: return b->subVal(subindex, 0).bl.x;
        case 1: return b->subVal(subindex, 0).bl.y;
        case 2: return b->subVal(subindex, 0).tr.x;
        case 3: return b->subVal(subindex, 0).tr.y;
        case 4: return b->subVal(subindex, 1).bl.x;
        case 5: return b->subVal(subindex, 1).bl.y;
        case 6: return b->subVal(subindex, 1).tr.x;
        case 7: return b->subVal(subindex, 1).tr.y;
        default: return 0.;
    }
}

inline const SlantBox &GlyphCache::getSubBoundingSlantBox(unsigned short glyphid, uint8 subindex) const
{
    GlyphBox *b = _boxes[glyphid];
    return *(SlantBox *)(b->subs() + 2 * subindex + 1);
}

inline const BBox &GlyphCache::getSubBoundingBBox(unsigned short glyphid, uint8 subindex) const
{
    GlyphBox *b = _boxes[glyphid];
    return *(BBox *)(b->subs() + 2 * subindex);
}

inline
uint8 GlyphCache::numSubBounds(unsigned short glyphid) const
{
    return _boxes[glyphid] ? _boxes[glyphid]->num() : 0;
}

} // namespace graphite2