135 lines
3.8 KiB
C++
135 lines
3.8 KiB
C++
/*
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* Copyright © 2019 Ebrahim Byagowi
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*
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* This is part of HarfBuzz, a text shaping library.
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*
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* Permission is hereby granted, without written agreement and without
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* license or royalty fees, to use, copy, modify, and distribute this
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* software and its documentation for any purpose, provided that the
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* above copyright notice and the following two paragraphs appear in
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* all copies of this software.
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*
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* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
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* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
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* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
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* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
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* DAMAGE.
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*
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* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
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* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
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* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
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* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
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* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
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*/
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#include "hb.hh"
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#ifndef HB_NO_STYLE
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#include "hb-ot-var-avar-table.hh"
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#include "hb-ot-var-fvar-table.hh"
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#include "hb-ot-stat-table.hh"
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#include "hb-ot-os2-table.hh"
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#include "hb-ot-head-table.hh"
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#include "hb-ot-post-table.hh"
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#include "hb-ot-face.hh"
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/**
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* SECTION:hb-style
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* @title: hb-style
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* @short_description: Font Styles
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* @include: hb.h
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*
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* Functions for fetching style information from fonts.
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**/
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static inline float
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_hb_angle_to_ratio (float a)
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{
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return tanf (a * float (-M_PI / 180.));
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}
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static inline float
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_hb_ratio_to_angle (float r)
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{
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return atanf (r) * float (-180. / M_PI);
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}
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/**
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* hb_style_get_value:
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* @font: a #hb_font_t object.
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* @style_tag: a style tag.
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*
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* Searches variation axes of a #hb_font_t object for a specific axis first,
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* if not set, then tries to get default style values from different
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* tables of the font.
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*
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* Returns: Corresponding axis or default value to a style tag.
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*
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* Since: 3.0.0
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**/
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float
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hb_style_get_value (hb_font_t *font, hb_style_tag_t style_tag)
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{
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if (unlikely (style_tag == HB_STYLE_TAG_SLANT_RATIO))
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return _hb_angle_to_ratio (hb_style_get_value (font, HB_STYLE_TAG_SLANT_ANGLE));
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hb_face_t *face = font->face;
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#ifndef HB_NO_VAR
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hb_ot_var_axis_info_t axis;
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if (hb_ot_var_find_axis_info (face, style_tag, &axis))
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{
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if (axis.axis_index < font->num_coords) return font->design_coords[axis.axis_index];
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/* If a face is variable, fvar's default_value is better than STAT records */
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return axis.default_value;
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}
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#endif
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if (style_tag == HB_STYLE_TAG_OPTICAL_SIZE && font->ptem)
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return font->ptem;
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/* STAT */
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float value;
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if (face->table.STAT->get_value (style_tag, &value))
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return value;
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switch ((unsigned) style_tag)
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{
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case HB_STYLE_TAG_ITALIC:
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return face->table.OS2->is_italic () || face->table.head->is_italic () ? 1 : 0;
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case HB_STYLE_TAG_OPTICAL_SIZE:
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{
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unsigned int lower, design, upper;
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return face->table.OS2->v5 ().get_optical_size (&lower, &upper)
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? (float) (lower + upper) / 2.f
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: hb_ot_layout_get_size_params (face, &design, nullptr, nullptr, nullptr, nullptr)
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? design / 10.f
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: 12.f;
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}
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case HB_STYLE_TAG_SLANT_ANGLE:
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{
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float angle = face->table.post->table->italicAngle.to_float ();
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if (font->slant)
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angle = _hb_ratio_to_angle (font->slant + _hb_angle_to_ratio (angle));
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return angle;
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}
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case HB_STYLE_TAG_WIDTH:
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return face->table.OS2->has_data ()
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? face->table.OS2->get_width ()
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: (face->table.head->is_condensed () ? 75 :
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face->table.head->is_expanded () ? 125 :
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100);
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case HB_STYLE_TAG_WEIGHT:
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return face->table.OS2->has_data ()
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? face->table.OS2->usWeightClass
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: (face->table.head->is_bold () ? 700 : 400);
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default:
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return 0;
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}
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}
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#endif
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