| /* |
| * Copyright © 2019 Ebrahim Byagowi |
| * |
| * 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. |
| */ |
| |
| #include "hb.hh" |
| |
| #ifndef HB_NO_STYLE |
| #ifdef HB_EXPERIMENTAL_API |
| |
| #include "hb-ot-var-avar-table.hh" |
| #include "hb-ot-var-fvar-table.hh" |
| #include "hb-ot-stat-table.hh" |
| #include "hb-ot-os2-table.hh" |
| #include "hb-ot-head-table.hh" |
| #include "hb-ot-post-table.hh" |
| #include "hb-ot-face.hh" |
| |
| /** |
| * hb_style_tag_t: |
| * @HB_STYLE_TAG_ITALIC: Used to vary between non-italic and italic. |
| * A value of 0 can be interpreted as "Roman" (non-italic); a value of 1 can |
| * be interpreted as (fully) italic. |
| * @HB_STYLE_TAG_OPTICAL_SIZE: Used to vary design to suit different text sizes. |
| * Non-zero. Values can be interpreted as text size, in points. |
| * @HB_STYLE_TAG_SLANT: Used to vary between upright and slanted text. Values |
| * must be greater than -90 and less than +90. Values can be interpreted as |
| * the angle, in counter-clockwise degrees, of oblique slant from whatever the |
| * designer considers to be upright for that font design. |
| * @HB_STYLE_TAG_WIDTH: Used to vary width of text from narrower to wider. |
| * Non-zero. Values can be interpreted as a percentage of whatever the font |
| * designer considers “normal width” for that font design. |
| * @HB_STYLE_TAG_WEIGHT: Used to vary stroke thicknesses or other design details |
| * to give variation from lighter to blacker. Values can be interpreted in direct |
| * comparison to values for usWeightClass in the OS/2 table, |
| * or the CSS font-weight property. |
| * |
| * Defined by https://docs.microsoft.com/en-us/typography/opentype/spec/dvaraxisreg |
| * |
| * Since: EXPERIMENTAL |
| **/ |
| typedef enum { |
| HB_STYLE_TAG_ITALIC = HB_TAG ('i','t','a','l'), |
| HB_STYLE_TAG_OPTICAL_SIZE = HB_TAG ('o','p','s','z'), |
| HB_STYLE_TAG_SLANT = HB_TAG ('s','l','n','t'), |
| HB_STYLE_TAG_WIDTH = HB_TAG ('w','d','t','h'), |
| HB_STYLE_TAG_WEIGHT = HB_TAG ('w','g','h','t'), |
| |
| /*< private >*/ |
| _HB_STYLE_TAG_MAX_VALUE = HB_TAG_MAX_SIGNED /*< skip >*/ |
| } hb_style_tag_t; |
| |
| /** |
| * hb_style_get_value: |
| * @font: a #hb_font_t object. |
| * @style_tag: a style tag. |
| * |
| * Searches variation axes of a hb_font_t object for a specific axis first, |
| * if not set, then tries to get default style values from different |
| * tables of the font. |
| * |
| * Returns: Corresponding axis or default value to a style tag. |
| * |
| * Since: EXPERIMENTAL |
| **/ |
| float |
| hb_style_get_value (hb_font_t *font, hb_tag_t tag) |
| { |
| hb_style_tag_t style_tag = (hb_style_tag_t) tag; |
| hb_face_t *face = font->face; |
| |
| #ifndef HB_NO_VAR |
| hb_ot_var_axis_info_t axis; |
| if (hb_ot_var_find_axis_info (face, style_tag, &axis)) |
| { |
| if (axis.axis_index < font->num_coords) return font->design_coords[axis.axis_index]; |
| /* If a face is variable, fvar's default_value is better than STAT records */ |
| return axis.default_value; |
| } |
| #endif |
| |
| if (style_tag == HB_STYLE_TAG_OPTICAL_SIZE && font->ptem) |
| return font->ptem; |
| |
| /* STAT */ |
| float value; |
| if (face->table.STAT->get_value (style_tag, &value)) |
| return value; |
| |
| switch ((unsigned) style_tag) |
| { |
| case HB_STYLE_TAG_ITALIC: |
| return face->table.OS2->is_italic () || face->table.head->is_italic () ? 1 : 0; |
| case HB_STYLE_TAG_OPTICAL_SIZE: |
| { |
| unsigned int lower, upper; |
| return face->table.OS2->v5 ().get_optical_size (&lower, &upper) |
| ? (float) (lower + upper) / 2.f |
| : 12.f; |
| } |
| case HB_STYLE_TAG_SLANT: |
| return face->table.post->table->italicAngle.to_float (); |
| case HB_STYLE_TAG_WIDTH: |
| return face->table.OS2->has_data () |
| ? face->table.OS2->get_width () |
| : (face->table.head->is_condensed () ? 75 : 100); |
| case HB_STYLE_TAG_WEIGHT: |
| return face->table.OS2->has_data () |
| ? face->table.OS2->usWeightClass |
| : (face->table.head->is_bold () ? 700 : 400); |
| default: |
| return 0; |
| } |
| } |
| |
| #endif |
| #endif |