harfbuzz/src/hb-ot-var-fvar-table.hh

340 lines
10 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
*/
#ifndef HB_OT_VAR_FVAR_TABLE_HH
#define HB_OT_VAR_FVAR_TABLE_HH
#include "hb-open-type.hh"
/*
* fvar -- Font Variations
* https://docs.microsoft.com/en-us/typography/opentype/spec/fvar
*/
#define HB_OT_TAG_fvar HB_TAG('f','v','a','r')
namespace OT {
struct InstanceRecord
{
friend struct fvar;
hb_array_t<const Fixed> get_coordinates (unsigned int axis_count) const
{ return coordinatesZ.as_array (axis_count); }
bool sanitize (hb_sanitize_context_t *c, unsigned int axis_count) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this) &&
c->check_array (coordinatesZ.arrayZ, axis_count));
}
protected:
NameID subfamilyNameID;/* The name ID for entries in the 'name' table
* that provide subfamily names for this instance. */
HBUINT16 flags; /* Reserved for future use — set to 0. */
UnsizedArrayOf<Fixed>
coordinatesZ; /* The coordinates array for this instance. */
//NameID postScriptNameIDX;/*Optional. The name ID for entries in the 'name'
// * table that provide PostScript names for this
// * instance. */
public:
DEFINE_SIZE_UNBOUNDED (4);
};
struct AxisRecord
{
enum
{
AXIS_FLAG_HIDDEN = 0x0001,
};
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this));
}
public:
Tag axisTag; /* Tag identifying the design variation for the axis. */
Fixed minValue; /* The minimum coordinate value for the axis. */
Fixed defaultValue; /* The default coordinate value for the axis. */
Fixed maxValue; /* The maximum coordinate value for the axis. */
HBUINT16 flags; /* Axis flags. */
NameID axisNameID; /* The name ID for entries in the 'name' table that
* provide a display name for this axis. */
public:
DEFINE_SIZE_STATIC (20);
};
struct fvar
{
static constexpr hb_tag_t tableTag = HB_OT_TAG_fvar;
bool has_data () const { return version.to_int (); }
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (version.sanitize (c) &&
likely (version.major == 1) &&
c->check_struct (this) &&
axisSize == 20 && /* Assumed in our code. */
instanceSize >= axisCount * 4 + 4 &&
get_axes ().sanitize (c) &&
c->check_range (get_instance (0), instanceCount, instanceSize));
}
unsigned int get_axis_count () const { return axisCount; }
#ifndef HB_DISABLE_DEPRECATED
void get_axis_deprecated (unsigned int axis_index,
hb_ot_var_axis_t *info) const
{
const AxisRecord &axis = get_axes ()[axis_index];
info->tag = axis.axisTag;
info->name_id = axis.axisNameID;
info->default_value = axis.defaultValue / 65536.f;
/* Ensure order, to simplify client math. */
info->min_value = hb_min (info->default_value, axis.minValue / 65536.f);
info->max_value = hb_max (info->default_value, axis.maxValue / 65536.f);
}
#endif
void get_axis_info (unsigned int axis_index,
hb_ot_var_axis_info_t *info) const
{
const AxisRecord &axis = get_axes ()[axis_index];
info->axis_index = axis_index;
info->tag = axis.axisTag;
info->name_id = axis.axisNameID;
info->flags = (hb_ot_var_axis_flags_t) (unsigned int) axis.flags;
info->default_value = axis.defaultValue / 65536.f;
/* Ensure order, to simplify client math. */
info->min_value = hb_min (info->default_value, axis.minValue / 65536.f);
info->max_value = hb_max (info->default_value, axis.maxValue / 65536.f);
info->reserved = 0;
}
#ifndef HB_DISABLE_DEPRECATED
unsigned int get_axes_deprecated (unsigned int start_offset,
unsigned int *axes_count /* IN/OUT */,
hb_ot_var_axis_t *axes_array /* OUT */) const
{
if (axes_count)
{
/* TODO Rewrite as hb_array_t<>::sub-array() */
unsigned int count = axisCount;
start_offset = hb_min (start_offset, count);
count -= start_offset;
axes_array += start_offset;
count = hb_min (count, *axes_count);
*axes_count = count;
for (unsigned int i = 0; i < count; i++)
get_axis_deprecated (start_offset + i, axes_array + i);
}
return axisCount;
}
#endif
unsigned int get_axis_infos (unsigned int start_offset,
unsigned int *axes_count /* IN/OUT */,
hb_ot_var_axis_info_t *axes_array /* OUT */) const
{
if (axes_count)
{
/* TODO Rewrite as hb_array_t<>::sub-array() */
unsigned int count = axisCount;
start_offset = hb_min (start_offset, count);
count -= start_offset;
axes_array += start_offset;
count = hb_min (count, *axes_count);
*axes_count = count;
for (unsigned int i = 0; i < count; i++)
get_axis_info (start_offset + i, axes_array + i);
}
return axisCount;
}
#ifndef HB_DISABLE_DEPRECATED
bool find_axis_deprecated (hb_tag_t tag,
unsigned int *axis_index,
hb_ot_var_axis_t *info) const
{
const AxisRecord *axes = get_axes ();
unsigned int count = get_axis_count ();
for (unsigned int i = 0; i < count; i++)
if (axes[i].axisTag == tag)
{
if (axis_index)
*axis_index = i;
get_axis_deprecated (i, info);
return true;
}
if (axis_index)
*axis_index = HB_OT_VAR_NO_AXIS_INDEX;
return false;
}
#endif
bool find_axis_info (hb_tag_t tag,
hb_ot_var_axis_info_t *info) const
{
const AxisRecord *axes = get_axes ();
unsigned int count = get_axis_count ();
for (unsigned int i = 0; i < count; i++)
if (axes[i].axisTag == tag)
{
get_axis_info (i, info);
return true;
}
return false;
}
int normalize_axis_value (unsigned int axis_index, float v) const
{
hb_ot_var_axis_info_t axis;
get_axis_info (axis_index, &axis);
v = hb_max (hb_min (v, axis.max_value), axis.min_value); /* Clamp. */
if (v == axis.default_value)
return 0;
else if (v < axis.default_value)
v = (v - axis.default_value) / (axis.default_value - axis.min_value);
else
v = (v - axis.default_value) / (axis.max_value - axis.default_value);
return (int) (v * 16384.f + (v >= 0.f ? .5f : -.5f));
}
unsigned int get_instance_count () const { return instanceCount; }
hb_ot_name_id_t get_instance_subfamily_name_id (unsigned int instance_index) const
{
const InstanceRecord *instance = get_instance (instance_index);
if (unlikely (!instance)) return HB_OT_NAME_ID_INVALID;
return instance->subfamilyNameID;
}
hb_ot_name_id_t get_instance_postscript_name_id (unsigned int instance_index) const
{
const InstanceRecord *instance = get_instance (instance_index);
if (unlikely (!instance)) return HB_OT_NAME_ID_INVALID;
if (instanceSize >= axisCount * 4 + 6)
return StructAfter<NameID> (instance->get_coordinates (axisCount));
return HB_OT_NAME_ID_INVALID;
}
unsigned int get_instance_coords (unsigned int instance_index,
unsigned int *coords_length, /* IN/OUT */
float *coords /* OUT */) const
{
const InstanceRecord *instance = get_instance (instance_index);
if (unlikely (!instance))
{
if (coords_length)
*coords_length = 0;
return 0;
}
if (coords_length && *coords_length)
{
hb_array_t<const Fixed> instanceCoords = instance->get_coordinates (axisCount)
.sub_array (0, *coords_length);
for (unsigned int i = 0; i < instanceCoords.length; i++)
coords[i] = instanceCoords.arrayZ[i].to_float ();
}
return axisCount;
}
void collect_name_ids (hb_set_t *nameids) const
{
if (!has_data ()) return;
+ get_axes ()
| hb_map (&AxisRecord::axisNameID)
| hb_sink (nameids)
;
+ hb_range ((unsigned) instanceCount)
| hb_map ([this] (const unsigned _) { return get_instance_subfamily_name_id (_); })
| hb_sink (nameids)
;
+ hb_range ((unsigned) instanceCount)
| hb_map ([this] (const unsigned _) { return get_instance_postscript_name_id (_); })
| hb_sink (nameids)
;
}
protected:
hb_array_t<const AxisRecord> get_axes () const
{ return hb_array (&(this+firstAxis), axisCount); }
const InstanceRecord *get_instance (unsigned int i) const
{
if (unlikely (i >= instanceCount)) return nullptr;
return &StructAtOffset<InstanceRecord> (&StructAfter<InstanceRecord> (get_axes ()),
i * instanceSize);
}
protected:
FixedVersion<>version; /* Version of the fvar table
* initially set to 0x00010000u */
OffsetTo<AxisRecord>
firstAxis; /* Offset in bytes from the beginning of the table
* to the start of the AxisRecord array. */
HBUINT16 reserved; /* This field is permanently reserved. Set to 2. */
HBUINT16 axisCount; /* The number of variation axes in the font (the
* number of records in the axes array). */
HBUINT16 axisSize; /* The size in bytes of each VariationAxisRecord —
* set to 20 (0x0014) for this version. */
HBUINT16 instanceCount; /* The number of named instances defined in the font
* (the number of records in the instances array). */
HBUINT16 instanceSize; /* The size in bytes of each InstanceRecord — set
* to either axisCount * sizeof(Fixed) + 4, or to
* axisCount * sizeof(Fixed) + 6. */
public:
DEFINE_SIZE_STATIC (16);
};
} /* namespace OT */
#endif /* HB_OT_VAR_FVAR_TABLE_HH */