src/hb-font.cc

/*
 * Copyright (C) 2009  Red Hat, 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
 */

#include "hb-private.h"

#include "hb-font-private.h"
#include "hb-blob-private.h"
#include "hb-open-file-private.hh"

#include "hb-ot-layout-private.hh"

#include <string.h>

HB_BEGIN_DECLS


/*
 * hb_font_funcs_t
 */

static hb_codepoint_t
hb_font_get_glyph_nil (hb_font_t *font HB_UNUSED,
		       hb_face_t *face HB_UNUSED,
		       const void *user_data HB_UNUSED,
		       hb_codepoint_t unicode HB_UNUSED,
		       hb_codepoint_t variation_selector HB_UNUSED)
{ return 0; }

static void
hb_font_get_glyph_advance_nil (hb_font_t *font HB_UNUSED,
			       hb_face_t *face HB_UNUSED,
			       const void *user_data HB_UNUSED,
			       hb_codepoint_t glyph HB_UNUSED,
			       hb_position_t *x_advance HB_UNUSED,
			       hb_position_t *y_advance HB_UNUSED)
{ }

static void
hb_font_get_glyph_extents_nil (hb_font_t *font HB_UNUSED,
			       hb_face_t *face HB_UNUSED,
			       const void *user_data HB_UNUSED,
			       hb_codepoint_t glyph HB_UNUSED,
			       hb_glyph_extents_t *extents HB_UNUSED)
{ }

static hb_bool_t
hb_font_get_contour_point_nil (hb_font_t *font HB_UNUSED,
			       hb_face_t *face HB_UNUSED,
			       const void *user_data HB_UNUSED,
			       unsigned int point_index HB_UNUSED,
			       hb_codepoint_t glyph HB_UNUSED,
			       hb_position_t *x HB_UNUSED,
			       hb_position_t *y HB_UNUSED)
{ return false; }

static hb_position_t
hb_font_get_kerning_nil (hb_font_t *font HB_UNUSED,
			 hb_face_t *face HB_UNUSED,
			 const void *user_data HB_UNUSED,
			 hb_codepoint_t first_glyph HB_UNUSED,
			 hb_codepoint_t second_glyph HB_UNUSED)
{ return 0; }

hb_font_funcs_t _hb_font_funcs_nil = {
  HB_REFERENCE_COUNT_INVALID, /* ref_count */
  TRUE,  /* immutable */
  {
    hb_font_get_glyph_nil,
    hb_font_get_glyph_advance_nil,
    hb_font_get_glyph_extents_nil,
    hb_font_get_contour_point_nil,
    hb_font_get_kerning_nil
  }
};

hb_font_funcs_t *
hb_font_funcs_create (void)
{
  hb_font_funcs_t *ffuncs;

  if (!HB_OBJECT_DO_CREATE (hb_font_funcs_t, ffuncs))
    return &_hb_font_funcs_nil;

  ffuncs->v = _hb_font_funcs_nil.v;

  return ffuncs;
}

hb_font_funcs_t *
hb_font_funcs_reference (hb_font_funcs_t *ffuncs)
{
  HB_OBJECT_DO_REFERENCE (ffuncs);
}

unsigned int
hb_font_funcs_get_reference_count (hb_font_funcs_t *ffuncs)
{
  HB_OBJECT_DO_GET_REFERENCE_COUNT (ffuncs);
}

void
hb_font_funcs_destroy (hb_font_funcs_t *ffuncs)
{
  HB_OBJECT_DO_DESTROY (ffuncs);

  free (ffuncs);
}

hb_font_funcs_t *
hb_font_funcs_copy (hb_font_funcs_t *other_ffuncs)
{
  hb_font_funcs_t *ffuncs;

  if (!HB_OBJECT_DO_CREATE (hb_font_funcs_t, ffuncs))
    return &_hb_font_funcs_nil;

  ffuncs->v = other_ffuncs->v;

  return ffuncs;
}

void
hb_font_funcs_make_immutable (hb_font_funcs_t *ffuncs)
{
  if (HB_OBJECT_IS_INERT (ffuncs))
    return;

  ffuncs->immutable = TRUE;
}

hb_bool_t
hb_font_funcs_is_immutable (hb_font_funcs_t *ffuncs)
{
  return ffuncs->immutable;
}


void
hb_font_funcs_set_glyph_func (hb_font_funcs_t *ffuncs,
			      hb_font_get_glyph_func_t glyph_func)
{
  if (ffuncs->immutable)
    return;

  ffuncs->v.get_glyph = glyph_func ? glyph_func : hb_font_get_glyph_nil;
}

void
hb_font_funcs_set_glyph_advance_func (hb_font_funcs_t *ffuncs,
				      hb_font_get_glyph_advance_func_t glyph_advance_func)
{
  if (ffuncs->immutable)
    return;

  ffuncs->v.get_glyph_advance = glyph_advance_func ? glyph_advance_func : hb_font_get_glyph_advance_nil;
}

void
hb_font_funcs_set_glyph_extents_func (hb_font_funcs_t *ffuncs,
				      hb_font_get_glyph_extents_func_t glyph_extents_func)
{
  if (ffuncs->immutable)
    return;

  ffuncs->v.get_glyph_extents = glyph_extents_func ? glyph_extents_func : hb_font_get_glyph_extents_nil;
}

void
hb_font_funcs_set_contour_point_func (hb_font_funcs_t *ffuncs,
				      hb_font_get_contour_point_func_t contour_point_func)
{
  if (ffuncs->immutable)
    return;

  ffuncs->v.get_contour_point = contour_point_func ? contour_point_func : hb_font_get_contour_point_nil;
}

void
hb_font_funcs_set_kerning_func (hb_font_funcs_t *ffuncs,
				hb_font_get_kerning_func_t kerning_func)
{
  if (ffuncs->immutable)
    return;

  ffuncs->v.get_kerning = kerning_func ? kerning_func : hb_font_get_kerning_nil;
}


hb_font_get_glyph_func_t
hb_font_funcs_get_glyph_func (hb_font_funcs_t *ffuncs)
{
  return ffuncs->v.get_glyph;
}

hb_font_get_glyph_advance_func_t
hb_font_funcs_get_glyph_advance_func (hb_font_funcs_t *ffuncs)
{
  return ffuncs->v.get_glyph_advance;
}

hb_font_get_glyph_extents_func_t
hb_font_funcs_get_glyph_extents_func (hb_font_funcs_t *ffuncs)
{
  return ffuncs->v.get_glyph_extents;
}

hb_font_get_contour_point_func_t
hb_font_funcs_get_contour_point_func (hb_font_funcs_t *ffuncs)
{
  return ffuncs->v.get_contour_point;
}

hb_font_get_kerning_func_t
hb_font_funcs_get_kerning_func (hb_font_funcs_t *ffuncs)
{
  return ffuncs->v.get_kerning;
}



hb_codepoint_t
hb_font_get_glyph (hb_font_t *font, hb_face_t *face,
		   hb_codepoint_t unicode, hb_codepoint_t variation_selector)
{
  return font->klass->v.get_glyph (font, face, font->user_data,
				   unicode, variation_selector);
}

void
hb_font_get_glyph_advance (hb_font_t *font, hb_face_t *face,
			   hb_codepoint_t glyph,
			   hb_position_t *x_advance, hb_position_t *y_advance)
{
  *x_advance = *y_advance = 0;
  return font->klass->v.get_glyph_advance (font, face, font->user_data,
					   glyph, x_advance, y_advance);
}

void
hb_font_get_glyph_extents (hb_font_t *font, hb_face_t *face,
			   hb_codepoint_t glyph, hb_glyph_extents_t *extents)
{
  memset (extents, 0, sizeof (*extents));
  return font->klass->v.get_glyph_extents (font, face, font->user_data,
					   glyph, extents);
}

hb_bool_t
hb_font_get_contour_point (hb_font_t *font, hb_face_t *face,
			   unsigned int point_index,
			   hb_codepoint_t glyph, hb_position_t *x, hb_position_t *y)
{
  *x = 0; *y = 0;
  return font->klass->v.get_contour_point (font, face, font->user_data,
					   point_index,
					   glyph, x, y);
}

hb_position_t
hb_font_get_kerning (hb_font_t *font, hb_face_t *face,
		     hb_codepoint_t first_glyph, hb_codepoint_t second_glyph)
{
  return font->klass->v.get_kerning (font, face, font->user_data,
				     first_glyph, second_glyph);
}


/*
 * hb_face_t
 */

static hb_face_t _hb_face_nil = {
  HB_REFERENCE_COUNT_INVALID, /* ref_count */

  NULL, /* get_table */
  NULL, /* destroy */
  NULL, /* user_data */

  NULL, /* head_blob */
  NULL, /* head_table */

  NULL  /* ot_layout */
};


hb_face_t *
hb_face_create_for_tables (hb_get_table_func_t  get_table,
			   hb_destroy_func_t    destroy,
			   void                *user_data)
{
  hb_face_t *face;

  if (!HB_OBJECT_DO_CREATE (hb_face_t, face)) {
    if (destroy)
      destroy (user_data);
    return &_hb_face_nil;
  }

  face->get_table = get_table;
  face->destroy = destroy;
  face->user_data = user_data;

  face->ot_layout = _hb_ot_layout_new (face);

  face->head_blob = Sanitizer<head>::sanitize (hb_face_get_table (face, HB_OT_TAG_head));
  face->head_table = Sanitizer<head>::lock_instance (face->head_blob);

  return face;
}


typedef struct _hb_face_for_data_closure_t {
  hb_blob_t *blob;
  unsigned int  index;
} hb_face_for_data_closure_t;

static hb_face_for_data_closure_t *
_hb_face_for_data_closure_create (hb_blob_t *blob, unsigned int index)
{
  hb_face_for_data_closure_t *closure;

  closure = (hb_face_for_data_closure_t *) malloc (sizeof (hb_face_for_data_closure_t));
  if (unlikely (!closure))
    return NULL;

  closure->blob = blob;
  closure->index = index;

  return closure;
}

static void
_hb_face_for_data_closure_destroy (hb_face_for_data_closure_t *closure)
{
  hb_blob_destroy (closure->blob);
  free (closure);
}

static hb_blob_t *
_hb_face_for_data_get_table (hb_tag_t tag, void *user_data)
{
  hb_face_for_data_closure_t *data = (hb_face_for_data_closure_t *) user_data;

  const OpenTypeFontFile &ot_file = *Sanitizer<OpenTypeFontFile>::lock_instance (data->blob);
  const OpenTypeFontFace &ot_face = ot_file.get_face (data->index);

  const OpenTypeTable &table = ot_face.get_table_by_tag (tag);

  hb_blob_t *blob = hb_blob_create_sub_blob (data->blob, table.offset, table.length);

  hb_blob_unlock (data->blob);

  return blob;
}

hb_face_t *
hb_face_create_for_data (hb_blob_t    *blob,
			 unsigned int  index)
{
  hb_face_for_data_closure_t *closure = _hb_face_for_data_closure_create (Sanitizer<OpenTypeFontFile>::sanitize (hb_blob_reference (blob)), index);

  if (unlikely (!closure))
    return &_hb_face_nil;

  return hb_face_create_for_tables (_hb_face_for_data_get_table,
				    (hb_destroy_func_t) _hb_face_for_data_closure_destroy,
				    closure);
}


hb_face_t *
hb_face_reference (hb_face_t *face)
{
  HB_OBJECT_DO_REFERENCE (face);
}

unsigned int
hb_face_get_reference_count (hb_face_t *face)
{
  HB_OBJECT_DO_GET_REFERENCE_COUNT (face);
}

void
hb_face_destroy (hb_face_t *face)
{
  HB_OBJECT_DO_DESTROY (face);

  _hb_ot_layout_free (face->ot_layout);

  hb_blob_unlock (face->head_blob);
  hb_blob_destroy (face->head_blob);

  if (face->destroy)
    face->destroy (face->user_data);

  free (face);
}

hb_blob_t *
hb_face_get_table (hb_face_t *face,
		   hb_tag_t   tag)
{
  hb_blob_t *blob;

  if (unlikely (!face || !face->get_table))
    return &_hb_blob_nil;

  blob = face->get_table (tag, face->user_data);

  return blob;
}

unsigned int
hb_face_get_upem (hb_face_t *face)
{
  return (face->head_table ? face->head_table : &Null(head))->get_upem ();
}


/*
 * hb_font_t
 */

static hb_font_t _hb_font_nil = {
  HB_REFERENCE_COUNT_INVALID, /* ref_count */

  0, /* x_scale */
  0, /* y_scale */

  0, /* x_ppem */
  0, /* y_ppem */

  NULL, /* klass */
  NULL, /* destroy */
  NULL  /* user_data */
};

hb_font_t *
hb_font_create (void)
{
  hb_font_t *font;

  if (!HB_OBJECT_DO_CREATE (hb_font_t, font))
    return &_hb_font_nil;

  font->klass = &_hb_font_funcs_nil;

  return font;
}

hb_font_t *
hb_font_reference (hb_font_t *font)
{
  HB_OBJECT_DO_REFERENCE (font);
}

unsigned int
hb_font_get_reference_count (hb_font_t *font)
{
  HB_OBJECT_DO_GET_REFERENCE_COUNT (font);
}

void
hb_font_destroy (hb_font_t *font)
{
  HB_OBJECT_DO_DESTROY (font);

  hb_font_funcs_destroy (font->klass);
  if (font->destroy)
    font->destroy (font->user_data);

  free (font);
}

void
hb_font_set_funcs (hb_font_t         *font,
		   hb_font_funcs_t   *klass,
		   hb_destroy_func_t  destroy,
		   void              *user_data)
{
  if (HB_OBJECT_IS_INERT (font))
    return;

  if (font->destroy)
    font->destroy (font->user_data);

  if (!klass)
    klass = &_hb_font_funcs_nil;

  hb_font_funcs_reference (klass);
  hb_font_funcs_destroy (font->klass);
  font->klass = klass;
  font->destroy = destroy;
  font->user_data = user_data;
}

void
hb_font_unset_funcs (hb_font_t          *font,
		     hb_font_funcs_t   **klass,
		     hb_destroy_func_t  *destroy,
		     void              **user_data)
{
  /* None of the input arguments can be NULL. */

  *klass = font->klass;
  *destroy = font->destroy;
  *user_data = font->user_data;

  if (HB_OBJECT_IS_INERT (font))
    return;

  font->klass = NULL;
  font->destroy = NULL;
  font->user_data = NULL;
}

void
hb_font_set_scale (hb_font_t *font,
		   unsigned int x_scale,
		   unsigned int y_scale)
{
  if (HB_OBJECT_IS_INERT (font))
    return;

  font->x_scale = x_scale;
  font->y_scale = y_scale;
}

void
hb_font_get_scale (hb_font_t *font,
		   unsigned int *x_scale,
		   unsigned int *y_scale)
{
  if (x_scale) *x_scale = font->x_scale;
  if (y_scale) *y_scale = font->y_scale;
}

void
hb_font_set_ppem (hb_font_t *font,
		  unsigned int x_ppem,
		  unsigned int y_ppem)
{
  if (HB_OBJECT_IS_INERT (font))
    return;

  font->x_ppem = x_ppem;
  font->y_ppem = y_ppem;
}

void
hb_font_get_ppem (hb_font_t *font,
		  unsigned int *x_ppem,
		  unsigned int *y_ppem)
{
  if (x_ppem) *x_ppem = font->x_ppem;
  if (y_ppem) *y_ppem = font->y_ppem;
}


HB_END_DECLS