hb-style.h (3340B)
1 /* 2 * Copyright © 2019 Ebrahim Byagowi 3 * 4 * This is part of HarfBuzz, a text shaping library. 5 * 6 * Permission is hereby granted, without written agreement and without 7 * license or royalty fees, to use, copy, modify, and distribute this 8 * software and its documentation for any purpose, provided that the 9 * above copyright notice and the following two paragraphs appear in 10 * all copies of this software. 11 * 12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR 13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES 14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN 15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH 16 * DAMAGE. 17 * 18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, 19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS 21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO 22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. 23 */ 24 25 #if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR) 26 #error "Include <hb.h> instead." 27 #endif 28 29 #ifndef HB_STYLE_H 30 #define HB_STYLE_H 31 32 #include "hb.h" 33 34 HB_BEGIN_DECLS 35 36 /** 37 * hb_style_tag_t: 38 * @HB_STYLE_TAG_ITALIC: Used to vary between non-italic and italic. 39 * A value of 0 can be interpreted as "Roman" (non-italic); a value of 1 can 40 * be interpreted as (fully) italic. 41 * @HB_STYLE_TAG_OPTICAL_SIZE: Used to vary design to suit different text sizes. 42 * Non-zero. Values can be interpreted as text size, in points. 43 * @HB_STYLE_TAG_SLANT_ANGLE: Used to vary between upright and slanted text. Values 44 * must be greater than -90 and less than +90. Values can be interpreted as 45 * the angle, in counter-clockwise degrees, of oblique slant from whatever the 46 * designer considers to be upright for that font design. Typical right-leaning 47 * Italic fonts have a negative slant angle (typically around -12) 48 * @HB_STYLE_TAG_SLANT_RATIO: same as @HB_STYLE_TAG_SLANT_ANGLE expression as ratio. 49 * Typical right-leaning Italic fonts have a positive slant ratio (typically around 0.2) 50 * @HB_STYLE_TAG_WIDTH: Used to vary width of text from narrower to wider. 51 * Non-zero. Values can be interpreted as a percentage of whatever the font 52 * designer considers “normal width” for that font design. 53 * @HB_STYLE_TAG_WEIGHT: Used to vary stroke thicknesses or other design details 54 * to give variation from lighter to blacker. Values can be interpreted in direct 55 * comparison to values for usWeightClass in the OS/2 table, 56 * or the CSS font-weight property. 57 * 58 * Defined by [OpenType Design-Variation Axis Tag Registry](https://docs.microsoft.com/en-us/typography/opentype/spec/dvaraxisreg). 59 * 60 * Since: 3.0.0 61 **/ 62 typedef enum 63 { 64 HB_STYLE_TAG_ITALIC = HB_TAG ('i','t','a','l'), 65 HB_STYLE_TAG_OPTICAL_SIZE = HB_TAG ('o','p','s','z'), 66 HB_STYLE_TAG_SLANT_ANGLE = HB_TAG ('s','l','n','t'), 67 HB_STYLE_TAG_SLANT_RATIO = HB_TAG ('S','l','n','t'), 68 HB_STYLE_TAG_WIDTH = HB_TAG ('w','d','t','h'), 69 HB_STYLE_TAG_WEIGHT = HB_TAG ('w','g','h','t'), 70 71 /*< private >*/ 72 _HB_STYLE_TAG_MAX_VALUE = HB_TAG_MAX_SIGNED /*< skip >*/ 73 } hb_style_tag_t; 74 75 76 HB_EXTERN float 77 hb_style_get_value (hb_font_t *font, hb_style_tag_t style_tag); 78 79 HB_END_DECLS 80 81 #endif /* HB_STYLE_H */