1 /* 2 * Copyright © 2010 Red Hat, Inc. 3 * Copyright © 2012 Google, Inc. 4 * 5 * This is part of HarfBuzz, a text shaping library. 6 * 7 * Permission is hereby granted, without written agreement and without 8 * license or royalty fees, to use, copy, modify, and distribute this 9 * software and its documentation for any purpose, provided that the 10 * above copyright notice and the following two paragraphs appear in 11 * all copies of this software. 12 * 13 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR 14 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES 15 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN 16 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH 17 * DAMAGE. 18 * 19 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, 20 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 21 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS 22 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO 23 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. 24 * 25 * Red Hat Author(s): Behdad Esfahbod 26 * Google Author(s): Behdad Esfahbod 27 */ 28 29 #ifndef HB_OT_HEAD_TABLE_HH 30 #define HB_OT_HEAD_TABLE_HH 31 32 #include "hb-open-type.hh" 33 34 /* 35 * head -- Font Header 36 * https://docs.microsoft.com/en-us/typography/opentype/spec/head 37 */ 38 #define HB_OT_TAG_head HB_TAG('h','e','a','d') 39 40 41 namespace OT { 42 43 44 struct head 45 { 46 friend struct OffsetTable; 47 48 static constexpr hb_tag_t tableTag = HB_OT_TAG_head; 49 get_upemOT::head50 unsigned int get_upem () const 51 { 52 unsigned int upem = unitsPerEm; 53 /* If no valid head table found, assume 1000, which matches typical Type1 usage. */ 54 return 16 <= upem && upem <= 16384 ? upem : 1000; 55 } 56 57 enum mac_style_flag_t { 58 BOLD = 1u<<0, 59 ITALIC = 1u<<1, 60 UNDERLINE = 1u<<2, 61 OUTLINE = 1u<<3, 62 SHADOW = 1u<<4, 63 CONDENSED = 1u<<5 64 }; 65 is_boldOT::head66 bool is_bold () const { return macStyle & BOLD; } is_italicOT::head67 bool is_italic () const { return macStyle & ITALIC; } is_condensedOT::head68 bool is_condensed () const { return macStyle & CONDENSED; } 69 sanitizeOT::head70 bool sanitize (hb_sanitize_context_t *c) const 71 { 72 TRACE_SANITIZE (this); 73 return_trace (c->check_struct (this) && 74 version.major == 1 && 75 magicNumber == 0x5F0F3CF5u); 76 } 77 78 protected: 79 FixedVersion<>version; /* Version of the head table--currently 80 * 0x00010000u for version 1.0. */ 81 FixedVersion<>fontRevision; /* Set by font manufacturer. */ 82 HBUINT32 checkSumAdjustment; /* To compute: set it to 0, sum the 83 * entire font as HBUINT32, then store 84 * 0xB1B0AFBAu - sum. */ 85 HBUINT32 magicNumber; /* Set to 0x5F0F3CF5u. */ 86 HBUINT16 flags; /* Bit 0: Baseline for font at y=0; 87 * Bit 1: Left sidebearing point at x=0; 88 * Bit 2: Instructions may depend on point size; 89 * Bit 3: Force ppem to integer values for all 90 * internal scaler math; may use fractional 91 * ppem sizes if this bit is clear; 92 * Bit 4: Instructions may alter advance width 93 * (the advance widths might not scale linearly); 94 * Bits 5-10: These should be set according to 95 * Apple's specification. However, they are not 96 * implemented in OpenType. 97 * Bit 5: This bit should be set in fonts that are 98 * intended to e laid out vertically, and in 99 * which the glyphs have been drawn such that an 100 * x-coordinate of 0 corresponds to the desired 101 * vertical baseline. 102 * Bit 6: This bit must be set to zero. 103 * Bit 7: This bit should be set if the font 104 * requires layout for correct linguistic 105 * rendering (e.g. Arabic fonts). 106 * Bit 8: This bit should be set for a GX font 107 * which has one or more metamorphosis effects 108 * designated as happening by default. 109 * Bit 9: This bit should be set if the font 110 * contains any strong right-to-left glyphs. 111 * Bit 10: This bit should be set if the font 112 * contains Indic-style rearrangement effects. 113 * Bit 11: Font data is 'lossless,' as a result 114 * of having been compressed and decompressed 115 * with the Agfa MicroType Express engine. 116 * Bit 12: Font converted (produce compatible metrics) 117 * Bit 13: Font optimized for ClearType™. 118 * Note, fonts that rely on embedded bitmaps (EBDT) 119 * for rendering should not be considered optimized 120 * for ClearType, and therefore should keep this bit 121 * cleared. 122 * Bit 14: Last Resort font. If set, indicates that 123 * the glyphs encoded in the cmap subtables are simply 124 * generic symbolic representations of code point 125 * ranges and don’t truly represent support for those 126 * code points. If unset, indicates that the glyphs 127 * encoded in the cmap subtables represent proper 128 * support for those code points. 129 * Bit 15: Reserved, set to 0. */ 130 HBUINT16 unitsPerEm; /* Valid range is from 16 to 16384. This value 131 * should be a power of 2 for fonts that have 132 * TrueType outlines. */ 133 LONGDATETIME created; /* Number of seconds since 12:00 midnight, 134 January 1, 1904. 64-bit integer */ 135 LONGDATETIME modified; /* Number of seconds since 12:00 midnight, 136 January 1, 1904. 64-bit integer */ 137 HBINT16 xMin; /* For all glyph bounding boxes. */ 138 HBINT16 yMin; /* For all glyph bounding boxes. */ 139 HBINT16 xMax; /* For all glyph bounding boxes. */ 140 HBINT16 yMax; /* For all glyph bounding boxes. */ 141 HBUINT16 macStyle; /* Bit 0: Bold (if set to 1); 142 * Bit 1: Italic (if set to 1) 143 * Bit 2: Underline (if set to 1) 144 * Bit 3: Outline (if set to 1) 145 * Bit 4: Shadow (if set to 1) 146 * Bit 5: Condensed (if set to 1) 147 * Bit 6: Extended (if set to 1) 148 * Bits 7-15: Reserved (set to 0). */ 149 HBUINT16 lowestRecPPEM; /* Smallest readable size in pixels. */ 150 HBINT16 fontDirectionHint; /* Deprecated (Set to 2). 151 * 0: Fully mixed directional glyphs; 152 * 1: Only strongly left to right; 153 * 2: Like 1 but also contains neutrals; 154 * -1: Only strongly right to left; 155 * -2: Like -1 but also contains neutrals. */ 156 public: 157 HBUINT16 indexToLocFormat; /* 0 for short offsets, 1 for long. */ 158 HBUINT16 glyphDataFormat; /* 0 for current format. */ 159 160 DEFINE_SIZE_STATIC (54); 161 }; 162 163 164 } /* namespace OT */ 165 166 167 #endif /* HB_OT_HEAD_TABLE_HH */ 168