/*

 * Copyright © 2009  Red Hat, Inc.

 * Copyright © 2011  Google, Inc.

 *

 *  This is part of HarfBuzz, a text shaping library.

 *

 * Permission is hereby granted, without written agreement and without

 * license or royalty fees, to use, copy, modify, and distribute this

 * software and its documentation for any purpose, provided that the

 * above copyright notice and the following two paragraphs appear in

 * all copies of this software.

 *

 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR

 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES

 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN

 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH

 * DAMAGE.

 *

 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,

 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS

 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO

 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

 *

 * Red Hat Author(s): Behdad Esfahbod

 * Google Author(s): Behdad Esfahbod

 */

#ifndef HB_FONT_PRIVATE_HH

#define HB_FONT_PRIVATE_HH

#include "hb-private.hh"

#include "hb-object-private.hh"

#include "hb-face-private.hh"

#include "hb-shaper-private.hh"

/*

 * hb_font_funcs_t

 */

#define HB_FONT_FUNCS_IMPLEMENT_CALLBACKS \

  HB_FONT_FUNC_IMPLEMENT (font_h_extents) \

  HB_FONT_FUNC_IMPLEMENT (font_v_extents) \

  HB_FONT_FUNC_IMPLEMENT (nominal_glyph) \

  HB_FONT_FUNC_IMPLEMENT (variation_glyph) \

  HB_FONT_FUNC_IMPLEMENT (glyph_h_advance) \

  HB_FONT_FUNC_IMPLEMENT (glyph_v_advance) \

  HB_FONT_FUNC_IMPLEMENT (glyph_h_origin) \

  HB_FONT_FUNC_IMPLEMENT (glyph_v_origin) \

  HB_FONT_FUNC_IMPLEMENT (glyph_h_kerning) \

  HB_FONT_FUNC_IMPLEMENT (glyph_v_kerning) \

  HB_FONT_FUNC_IMPLEMENT (glyph_extents) \

  HB_FONT_FUNC_IMPLEMENT (glyph_contour_point) \

  HB_FONT_FUNC_IMPLEMENT (glyph_name) \

  HB_FONT_FUNC_IMPLEMENT (glyph_from_name) \

  /* ^--- Add new callbacks here */

struct hb_font_funcs_t {

  hb_object_header_t header;

  ASSERT_POD ();

  hb_bool_t immutable;

  struct {

#define HB_FONT_FUNC_IMPLEMENT(name) void *name;

    HB_FONT_FUNCS_IMPLEMENT_CALLBACKS

#undef HB_FONT_FUNC_IMPLEMENT

  } user_data;

  struct {

#define HB_FONT_FUNC_IMPLEMENT(name) hb_destroy_func_t name;

    HB_FONT_FUNCS_IMPLEMENT_CALLBACKS

#undef HB_FONT_FUNC_IMPLEMENT

  } destroy;

  /* Don't access these directly.  Call font->get_*() instead. */

  union get_t {

    struct get_funcs_t {

#define HB_FONT_FUNC_IMPLEMENT(name) hb_font_get_##name##_func_t name;

      HB_FONT_FUNCS_IMPLEMENT_CALLBACKS

#undef HB_FONT_FUNC_IMPLEMENT

    } f;

    void (*array[VAR]) (void);

  } get;

};

/*

 * hb_font_t

 */

struct hb_font_t {

  hb_object_header_t header;

  ASSERT_POD ();

  hb_bool_t immutable;

  hb_font_t *parent;

  hb_face_t *face;

  int x_scale;

  int y_scale;

  unsigned int x_ppem;

  unsigned int y_ppem;

  /* Font variation coordinates. */

  unsigned int num_coords;

  int *coords;

  hb_font_funcs_t   *klass;

  void              *user_data;

  hb_destroy_func_t  destroy;

  struct hb_shaper_data_t shaper_data;

  /* Convert from font-space to user-space */

  inline int dir_scale (hb_direction_t direction)

  { return HB_DIRECTION_IS_VERTICAL(direction) ? y_scale : x_scale; }

  inline hb_position_t em_scale_x (int16_t v) { return em_scale (v, x_scale); }

  inline hb_position_t em_scale_y (int16_t v) { return em_scale (v, y_scale); }

  inline hb_position_t em_scalef_x (float v) { return em_scalef (v, this->x_scale); }

  inline hb_position_t em_scalef_y (float v) { return em_scalef (v, this->y_scale); }

  inline hb_position_t em_scale_dir (int16_t v, hb_direction_t direction)

  { return em_scale (v, dir_scale (direction)); }

  /* Convert from parent-font user-space to our user-space */

  inline hb_position_t parent_scale_x_distance (hb_position_t v) {

    if (unlikely (parent && parent->x_scale != x_scale))

      return (hb_position_t) (v * (int64_t) this->x_scale / this->parent->x_scale);

    return v;

  }

  inline hb_position_t parent_scale_y_distance (hb_position_t v) {

    if (unlikely (parent && parent->y_scale != y_scale))

      return (hb_position_t) (v * (int64_t) this->y_scale / this->parent->y_scale);

    return v;

  }

  inline hb_position_t parent_scale_x_position (hb_position_t v) {

    return parent_scale_x_distance (v);

  }

  inline hb_position_t parent_scale_y_position (hb_position_t v) {

    return parent_scale_y_distance (v);

  }

  inline void parent_scale_distance (hb_position_t *x, hb_position_t *y) {

    *x = parent_scale_x_distance (*x);

    *y = parent_scale_y_distance (*y);

  }

  inline void parent_scale_position (hb_position_t *x, hb_position_t *y) {

    *x = parent_scale_x_position (*x);

    *y = parent_scale_y_position (*y);

  }

  /* Public getters */

  HB_INTERNAL bool has_func (unsigned int i);

  /* has_* ... */

#define HB_FONT_FUNC_IMPLEMENT(name) \

  bool \

  has_##name##_func (void) \

  { \

    hb_font_funcs_t *funcs = this->klass; \

    unsigned int i = offsetof (hb_font_funcs_t::get_t::get_funcs_t, name) / sizeof (funcs->get.array[0]); \

    return has_func (i); \

  }

  HB_FONT_FUNCS_IMPLEMENT_CALLBACKS

#undef HB_FONT_FUNC_IMPLEMENT

  inline hb_bool_t get_font_h_extents (hb_font_extents_t *extents)

  {

    memset (extents, 0, sizeof (*extents));

    return klass->get.f.font_h_extents (this, user_data,

                                        extents,

                                        klass->user_data.font_h_extents);

  }

  inline hb_bool_t get_font_v_extents (hb_font_extents_t *extents)

  {

    memset (extents, 0, sizeof (*extents));

    return klass->get.f.font_v_extents (this, user_data,

                                        extents,

                                        klass->user_data.font_v_extents);

  }

  inline bool has_glyph (hb_codepoint_t unicode)

  {

    hb_codepoint_t glyph;

    return get_nominal_glyph (unicode, &glyph);

  }

  inline hb_bool_t get_nominal_glyph (hb_codepoint_t unicode,

                                      hb_codepoint_t *glyph)

  {

    *glyph = 0;

    return klass->get.f.nominal_glyph (this, user_data,

                                       unicode, glyph,

                                       klass->user_data.nominal_glyph);

  }

  inline hb_bool_t get_variation_glyph (hb_codepoint_t unicode, hb_codepoint_t variation_selector,

                                        hb_codepoint_t *glyph)

  {

    *glyph = 0;

    return klass->get.f.variation_glyph (this, user_data,

                                         unicode, variation_selector, glyph,

                                         klass->user_data.variation_glyph);

  }

  inline hb_position_t get_glyph_h_advance (hb_codepoint_t glyph)

  {

    return klass->get.f.glyph_h_advance (this, user_data,

                                         glyph,

                                         klass->user_data.glyph_h_advance);

  }

  inline hb_position_t get_glyph_v_advance (hb_codepoint_t glyph)

  {

    return klass->get.f.glyph_v_advance (this, user_data,

                                         glyph,

                                         klass->user_data.glyph_v_advance);

  }

  inline hb_bool_t get_glyph_h_origin (hb_codepoint_t glyph,

                                       hb_position_t *x, hb_position_t *y)

  {

    *x = *y = 0;

    return klass->get.f.glyph_h_origin (this, user_data,

                                        glyph, x, y,

                                        klass->user_data.glyph_h_origin);

  }

  inline hb_bool_t get_glyph_v_origin (hb_codepoint_t glyph,

                                       hb_position_t *x, hb_position_t *y)

  {

    *x = *y = 0;

    return klass->get.f.glyph_v_origin (this, user_data,

                                        glyph, x, y,

                                        klass->user_data.glyph_v_origin);

  }

  inline hb_position_t get_glyph_h_kerning (hb_codepoint_t left_glyph, hb_codepoint_t right_glyph)

  {

    return klass->get.f.glyph_h_kerning (this, user_data,

                                         left_glyph, right_glyph,

                                         klass->user_data.glyph_h_kerning);

  }

  inline hb_position_t get_glyph_v_kerning (hb_codepoint_t top_glyph, hb_codepoint_t bottom_glyph)

  {

    return klass->get.f.glyph_v_kerning (this, user_data,

                                         top_glyph, bottom_glyph,

                                         klass->user_data.glyph_v_kerning);

  }

  inline hb_bool_t get_glyph_extents (hb_codepoint_t glyph,

                                      hb_glyph_extents_t *extents)

  {

    memset (extents, 0, sizeof (*extents));

    return klass->get.f.glyph_extents (this, user_data,

                                       glyph,

                                       extents,

                                       klass->user_data.glyph_extents);

  }

  inline hb_bool_t get_glyph_contour_point (hb_codepoint_t glyph, unsigned int point_index,

                                            hb_position_t *x, hb_position_t *y)

  {

    *x = *y = 0;

    return klass->get.f.glyph_contour_point (this, user_data,

                                             glyph, point_index,

                                             x, y,

                                             klass->user_data.glyph_contour_point);

  }

  inline hb_bool_t get_glyph_name (hb_codepoint_t glyph,

                                   char *name, unsigned int size)

  {

    if (size) *name = '\0';

    return klass->get.f.glyph_name (this, user_data,

                                    glyph,

                                    name, size,

                                    klass->user_data.glyph_name);

  }

  inline hb_bool_t get_glyph_from_name (const char *name, int len, /* -1 means nul-terminated */

                                        hb_codepoint_t *glyph)

  {

    *glyph = 0;

    if (len == -1) len = strlen (name);

    return klass->get.f.glyph_from_name (this, user_data,

                                         name, len,

                                         glyph,

                                         klass->user_data.glyph_from_name);

  }

  /* A bit higher-level, and with fallback */

  inline void get_h_extents_with_fallback (hb_font_extents_t *extents)

  {

    if (!get_font_h_extents (extents))

    {

      extents->ascender = y_scale * .8;

      extents->descender = extents->ascender - y_scale;

      extents->line_gap = 0;

    }

  }

  inline void get_v_extents_with_fallback (hb_font_extents_t *extents)

  {

    if (!get_font_v_extents (extents))

    {

      extents->ascender = x_scale / 2;

      extents->descender = extents->ascender - x_scale;

      extents->line_gap = 0;

    }

  }

  inline void get_extents_for_direction (hb_direction_t direction,

                                         hb_font_extents_t *extents)

  {

    if (likely (HB_DIRECTION_IS_HORIZONTAL (direction)))

      get_h_extents_with_fallback (extents);

    else

      get_v_extents_with_fallback (extents);

  }

  inline void get_glyph_advance_for_direction (hb_codepoint_t glyph,

                                               hb_direction_t direction,

                                               hb_position_t *x, hb_position_t *y)

  {

    if (likely (HB_DIRECTION_IS_HORIZONTAL (direction))) {

      *x = get_glyph_h_advance (glyph);

      *y = 0;

    } else {

      *x = 0;

      *y = get_glyph_v_advance (glyph);

    }

  }

  inline void guess_v_origin_minus_h_origin (hb_codepoint_t glyph,

                                             hb_position_t *x, hb_position_t *y)

  {

    *x = get_glyph_h_advance (glyph) / 2;

    /* TODO cache this somehow?! */

    hb_font_extents_t extents;

    get_h_extents_with_fallback (&extents);

    *y = extents.ascender;

  }

  inline void get_glyph_h_origin_with_fallback (hb_codepoint_t glyph,

                                                hb_position_t *x, hb_position_t *y)

  {

    if (!get_glyph_h_origin (glyph, x, y) &&

         get_glyph_v_origin (glyph, x, y))

    {

      hb_position_t dx, dy;

      guess_v_origin_minus_h_origin (glyph, &dx, &dy);

      *x -= dx; *y -= dy;

    }

  }

  inline void get_glyph_v_origin_with_fallback (hb_codepoint_t glyph,

                                                hb_position_t *x, hb_position_t *y)

  {

    if (!get_glyph_v_origin (glyph, x, y) &&

         get_glyph_h_origin (glyph, x, y))

    {

      hb_position_t dx, dy;

      guess_v_origin_minus_h_origin (glyph, &dx, &dy);

      *x += dx; *y += dy;

    }

  }

  inline void get_glyph_origin_for_direction (hb_codepoint_t glyph,

                                              hb_direction_t direction,

                                              hb_position_t *x, hb_position_t *y)

  {

    if (likely (HB_DIRECTION_IS_HORIZONTAL (direction)))

      get_glyph_h_origin_with_fallback (glyph, x, y);

    else

      get_glyph_v_origin_with_fallback (glyph, x, y);

  }

  inline void add_glyph_h_origin (hb_codepoint_t glyph,

                                  hb_position_t *x, hb_position_t *y)

  {

    hb_position_t origin_x, origin_y;

    get_glyph_h_origin_with_fallback (glyph, &origin_x, &origin_y);

    *x += origin_x;

    *y += origin_y;

  }

  inline void add_glyph_v_origin (hb_codepoint_t glyph,

                                  hb_position_t *x, hb_position_t *y)

  {

    hb_position_t origin_x, origin_y;

    get_glyph_v_origin_with_fallback (glyph, &origin_x, &origin_y);

    *x += origin_x;

    *y += origin_y;

  }

  inline void add_glyph_origin_for_direction (hb_codepoint_t glyph,

                                              hb_direction_t direction,

                                              hb_position_t *x, hb_position_t *y)

  {

    hb_position_t origin_x, origin_y;

    get_glyph_origin_for_direction (glyph, direction, &origin_x, &origin_y);

    *x += origin_x;

    *y += origin_y;

  }

  inline void subtract_glyph_h_origin (hb_codepoint_t glyph,

                                       hb_position_t *x, hb_position_t *y)

  {

    hb_position_t origin_x, origin_y;

    get_glyph_h_origin_with_fallback (glyph, &origin_x, &origin_y);

    *x -= origin_x;

    *y -= origin_y;

  }

  inline void subtract_glyph_v_origin (hb_codepoint_t glyph,

                                       hb_position_t *x, hb_position_t *y)

  {

    hb_position_t origin_x, origin_y;

    get_glyph_v_origin_with_fallback (glyph, &origin_x, &origin_y);

    *x -= origin_x;

    *y -= origin_y;

  }

  inline void subtract_glyph_origin_for_direction (hb_codepoint_t glyph,

                                                   hb_direction_t direction,

                                                   hb_position_t *x, hb_position_t *y)

  {

    hb_position_t origin_x, origin_y;

    get_glyph_origin_for_direction (glyph, direction, &origin_x, &origin_y);

    *x -= origin_x;

    *y -= origin_y;

  }

  inline void get_glyph_kerning_for_direction (hb_codepoint_t first_glyph, hb_codepoint_t second_glyph,

                                               hb_direction_t direction,

                                               hb_position_t *x, hb_position_t *y)

  {

    if (likely (HB_DIRECTION_IS_HORIZONTAL (direction))) {

      *x = get_glyph_h_kerning (first_glyph, second_glyph);

      *y = 0;

    } else {

      *x = 0;

      *y = get_glyph_v_kerning (first_glyph, second_glyph);

    }

  }

  inline hb_bool_t get_glyph_extents_for_origin (hb_codepoint_t glyph,

                                                 hb_direction_t direction,

                                                 hb_glyph_extents_t *extents)

  {

    hb_bool_t ret = get_glyph_extents (glyph, extents);

    if (ret)

      subtract_glyph_origin_for_direction (glyph, direction, &extents->x_bearing, &extents->y_bearing);

    return ret;

  }

  inline hb_bool_t get_glyph_contour_point_for_origin (hb_codepoint_t glyph, unsigned int point_index,

                                                       hb_direction_t direction,

                                                       hb_position_t *x, hb_position_t *y)

  {

    hb_bool_t ret = get_glyph_contour_point (glyph, point_index, x, y);

    if (ret)

      subtract_glyph_origin_for_direction (glyph, direction, x, y);

    return ret;

  }

  /* Generates gidDDD if glyph has no name. */

  inline void

  glyph_to_string (hb_codepoint_t glyph,

                   char *s, unsigned int size)

  {

    if (get_glyph_name (glyph, s, size)) return;

    if (size && snprintf (s, size, "gid%u", glyph) < 0)

      *s = '\0';

  }

  /* Parses gidDDD and uniUUUU strings automatically. */

  inline hb_bool_t

  glyph_from_string (const char *s, int len, /* -1 means nul-terminated */

                     hb_codepoint_t *glyph)

  {

    if (get_glyph_from_name (s, len, glyph)) return true;

    if (len == -1) len = strlen (s);