harfbuzz/src/hb-ot-var.cc
2020-09-24 11:57:46 +02:00

326 lines
9.7 KiB
C++

/*
* Copyright © 2017 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.
*
* Google Author(s): Behdad Esfahbod
*/
#include "hb.hh"
#ifndef HB_NO_VAR
#include "hb-ot-var.h"
#include "hb-ot-var-avar-table.hh"
#include "hb-ot-var-fvar-table.hh"
#include "hb-ot-var-mvar-table.hh"
/**
* SECTION:hb-ot-var
* @title: hb-ot-var
* @short_description: OpenType Font Variations
* @include: hb-ot.h
*
* Functions for fetching information about OpenType Variable Fonts.
**/
/*
* fvar/avar
*/
/**
* hb_ot_var_has_data:
* @face: The #hb_face_t to work on
*
* Tests whether a face includes any OpenType variation data in the `fvar` table.
*
* Return value: true if data found, false otherwise
*
* Since: 1.4.2
**/
hb_bool_t
hb_ot_var_has_data (hb_face_t *face)
{
return face->table.fvar->has_data ();
}
/**
* hb_ot_var_get_axis_count:
* @face: The #hb_face_t to work on
*
* Fetches the number of OpenType variation axes included in the face.
*
* Return value: the number of variation axes defined
*
* Since: 1.4.2
**/
unsigned int
hb_ot_var_get_axis_count (hb_face_t *face)
{
return face->table.fvar->get_axis_count ();
}
#ifndef HB_DISABLE_DEPRECATED
/**
* hb_ot_var_get_axes:
* @face: #hb_face_t to work upon
* @start_offset: offset of the first lookup to retrieve
* @axes_count: (inout) (allow-none): Input = the maximum number of variation axes to return;
* Output = the actual number of variation axes returned (may be zero)
* @axes_array: (out caller-allocates) (array length=axes_count): The array of variation axes found
*
* Fetches a list of all variation axes in the specified face. The list returned will begin
* at the offset provided.
*
* Since: 1.4.2
* Deprecated: 2.2.0: use hb_ot_var_get_axis_infos() instead
**/
unsigned int
hb_ot_var_get_axes (hb_face_t *face,
unsigned int start_offset,
unsigned int *axes_count /* IN/OUT */,
hb_ot_var_axis_t *axes_array /* OUT */)
{
return face->table.fvar->get_axes_deprecated (start_offset, axes_count, axes_array);
}
/**
* hb_ot_var_find_axis:
* @face: #hb_face_t to work upon
* @axis_tag: The #hb_tag_t of the variation axis to query
* @axis_index: The index of the variation axis
* @axis_info: (out): The #hb_ot_var_axis_info_t of the axis tag queried
*
* Fetches the variation-axis information corresponding to the specified axis tag
* in the specified face.
*
* Since: 1.4.2
* Deprecated: 2.2.0 - use hb_ot_var_find_axis_info() instead
**/
hb_bool_t
hb_ot_var_find_axis (hb_face_t *face,
hb_tag_t axis_tag,
unsigned int *axis_index,
hb_ot_var_axis_t *axis_info)
{
return face->table.fvar->find_axis_deprecated (axis_tag, axis_index, axis_info);
}
#endif
/**
* hb_ot_var_get_axis_infos:
* @face: #hb_face_t to work upon
* @start_offset: offset of the first lookup to retrieve
* @axes_count: (inout) (allow-none): Input = the maximum number of variation axes to return;
* Output = the actual number of variation axes returned (may be zero)
* @axes_array: (out caller-allocates) (array length=axes_count): The array of variation axes found
*
* Fetches a list of all variation axes in the specified face. The list returned will begin
* at the offset provided.
*
* Return value: the number of variation axes in the face
*
* Since: 2.2.0
**/
HB_EXTERN unsigned int
hb_ot_var_get_axis_infos (hb_face_t *face,
unsigned int start_offset,
unsigned int *axes_count /* IN/OUT */,
hb_ot_var_axis_info_t *axes_array /* OUT */)
{
return face->table.fvar->get_axis_infos (start_offset, axes_count, axes_array);
}
/**
* hb_ot_var_find_axis_info:
* @face: #hb_face_t to work upon
* @axis_tag: The #hb_tag_t of the variation axis to query
* @axis_info: (out): The #hb_ot_var_axis_info_t of the axis tag queried
*
* Fetches the variation-axis information corresponding to the specified axis tag
* in the specified face.
*
* Return value: true if data found, false otherwise
*
* Since: 2.2.0
**/
HB_EXTERN hb_bool_t
hb_ot_var_find_axis_info (hb_face_t *face,
hb_tag_t axis_tag,
hb_ot_var_axis_info_t *axis_info)
{
return face->table.fvar->find_axis_info (axis_tag, axis_info);
}
/*
* Named instances.
*/
/**
* hb_ot_var_get_named_instance_count:
* @face: The #hb_face_t to work on
*
* Fetches the number of named instances included in the face.
*
* Return value: the number of named instances defined
*
* Since: 2.2.0
**/
unsigned int
hb_ot_var_get_named_instance_count (hb_face_t *face)
{
return face->table.fvar->get_instance_count ();
}
/**
* hb_ot_var_named_instance_get_subfamily_name_id:
* @face: The #hb_face_t to work on
* @instance_index: The index of the named instance to query
*
* Fetches the `name` table Name ID that provides display names for
* the "Subfamily name" defined for the given named instance in the face.
*
* Return value: the Name ID found for the Subfamily name
*
* Since: 2.2.0
**/
hb_ot_name_id_t
hb_ot_var_named_instance_get_subfamily_name_id (hb_face_t *face,
unsigned int instance_index)
{
return face->table.fvar->get_instance_subfamily_name_id (instance_index);
}
/**
* hb_ot_var_named_instance_get_postscript_name_id:
* @face: The #hb_face_t to work on
* @instance_index: The index of the named instance to query
*
* Fetches the `name` table Name ID that provides display names for
* the "PostScript name" defined for the given named instance in the face.
*
* Return value: the Name ID found for the PostScript name
*
* Since: 2.2.0
**/
hb_ot_name_id_t
hb_ot_var_named_instance_get_postscript_name_id (hb_face_t *face,
unsigned int instance_index)
{
return face->table.fvar->get_instance_postscript_name_id (instance_index);
}
/**
* hb_ot_var_named_instance_get_design_coords:
* @face: The #hb_face_t to work on
* @instance_index: The index of the named instance to query
* @coords_length: (inout) (allow-none): Input = the maximum number of coordinates to return;
* Output = the actual number of coordinates returned (may be zero)
* @coords: (out) (array length=coords_length): The array of coordinates found for the query
*
* Fetches the design-space coordinates corresponding to the given
* named instance in the face.
*
* Return value: the number of variation axes in the face
*
* Since: 2.2.0
**/
unsigned int
hb_ot_var_named_instance_get_design_coords (hb_face_t *face,
unsigned int instance_index,
unsigned int *coords_length, /* IN/OUT */
float *coords /* OUT */)
{
return face->table.fvar->get_instance_coords (instance_index, coords_length, coords);
}
/**
* hb_ot_var_normalize_variations:
* @face: The #hb_face_t to work on
* @variations: The array of variations to normalize
* @variations_length: The number of variations to normalize
* @coords: (out) (array length=coords_length): The array of normalized coordinates
* @coords_length: The length of the coordinate array
*
* Normalizes all of the coordinates in the given list of variation axes.
*
* Since: 1.4.2
**/
void
hb_ot_var_normalize_variations (hb_face_t *face,
const hb_variation_t *variations, /* IN */
unsigned int variations_length,
int *coords, /* OUT */
unsigned int coords_length)
{
for (unsigned int i = 0; i < coords_length; i++)
coords[i] = 0;
const OT::fvar &fvar = *face->table.fvar;
for (unsigned int i = 0; i < variations_length; i++)
{
hb_ot_var_axis_info_t info;
if (hb_ot_var_find_axis_info (face, variations[i].tag, &info) &&
info.axis_index < coords_length)
coords[info.axis_index] = fvar.normalize_axis_value (info.axis_index, variations[i].value);
}
face->table.avar->map_coords (coords, coords_length);
}
/**
* hb_ot_var_normalize_coords:
* @face: The #hb_face_t to work on
* @coords_length: The length of the coordinate array
* @design_coords: The design-space coordinates to normalize
* @normalized_coords: (out): The normalized coordinates
*
* Normalizes the given design-space coordinates. The minimum and maximum
* values for the axis are mapped to the interval [-1,1], with the default
* axis value mapped to 0.
*
* Any additional scaling defined in the face's `avar` table is also
* applied, as described at https://docs.microsoft.com/en-us/typography/opentype/spec/avar
*
* Since: 1.4.2
**/
void
hb_ot_var_normalize_coords (hb_face_t *face,
unsigned int coords_length,
const float *design_coords, /* IN */
int *normalized_coords /* OUT */)
{
const OT::fvar &fvar = *face->table.fvar;
for (unsigned int i = 0; i < coords_length; i++)
normalized_coords[i] = fvar.normalize_axis_value (i, design_coords[i]);
face->table.avar->map_coords (normalized_coords, coords_length);
}
#endif