kc3-lang/harfbuzz/src/hb-font-private.hh

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• Hash : 188ee6e5
  Author :
  Date : 2018-01-10T05:13:47
  

  Calculate anchor positions in float, then round
  
  Hoping to reduce rounding error, to make tests happier...
  No luck.
  

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• src/hb-font-private.hh

• /*
   * 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;
  
    float ptem;
  
    /* 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 float em_fscale_x (int16_t v) { return em_fscale (v, x_scale); }
    inline float em_fscale_y (int16_t v) { return em_fscale (v, 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);
  
      /* Straight glyph index. */
      if (hb_codepoint_parse (s, len, 10, glyph))
        return true;
  
      if (len > 3)
      {
        /* gidDDD syntax for glyph indices. */
        if (0 == strncmp (s, "gid", 3) &&
  	  hb_codepoint_parse (s + 3, len - 3, 10, glyph))
  	return true;
  
        /* uniUUUU and other Unicode character indices. */
        hb_codepoint_t unichar;
        if (0 == strncmp (s, "uni", 3) &&
  	  hb_codepoint_parse (s + 3, len - 3, 16, &unichar) &&
  	  get_nominal_glyph (unichar, glyph))
  	return true;
      }
  
      return false;
    }
  
    inline hb_position_t em_scale (int16_t v, int scale)
    {
      int upem = face->get_upem ();
      int64_t scaled = v * (int64_t) scale;
      scaled += scaled >= 0 ? upem/2 : -upem/2; /* Round. */
      return (hb_position_t) (scaled / upem);
    }
    inline hb_position_t em_scalef (float v, int scale)
    {
      return (hb_position_t) round (v * scale / face->get_upem ());
    }
    inline float em_fscale (int16_t v, int scale)
    {
      return (float) v * scale / face->get_upem ();
    }
  };
  
  #define HB_SHAPER_DATA_CREATE_FUNC_EXTRA_ARGS
  #define HB_SHAPER_IMPLEMENT(shaper) HB_SHAPER_DATA_PROTOTYPE(shaper, font);
  #include "hb-shaper-list.hh"
  #undef HB_SHAPER_IMPLEMENT
  #undef HB_SHAPER_DATA_CREATE_FUNC_EXTRA_ARGS
  
  
  #endif /* HB_FONT_PRIVATE_HH */
  

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