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-private.hh" 33 34 35 namespace OT { 36 37 38 /* 39 * head -- Font Header 40 */ 41 42 #define HB_OT_TAG_head HB_TAG('h','e','a','d') 43 44 struct head 45 { 46 static const hb_tag_t tableTag = HB_OT_TAG_head; 47 get_upemOT::head48 inline unsigned int get_upem (void) const 49 { 50 unsigned int upem = unitsPerEm; 51 /* If no valid head table found, assume 1000, which matches typical Type1 usage. */ 52 return 16 <= upem && upem <= 16384 ? upem : 1000; 53 } 54 sanitizeOT::head55 inline bool sanitize (hb_sanitize_context_t *c) const 56 { 57 TRACE_SANITIZE (this); 58 return_trace (c->check_struct (this) && 59 version.major == 1 && 60 magicNumber == 0x5F0F3CF5u); 61 } 62 63 protected: 64 FixedVersion<>version; /* Version of the head table--currently 65 * 0x00010000u for version 1.0. */ 66 FixedVersion<>fontRevision; /* Set by font manufacturer. */ 67 ULONG checkSumAdjustment; /* To compute: set it to 0, sum the 68 * entire font as ULONG, then store 69 * 0xB1B0AFBAu - sum. */ 70 ULONG magicNumber; /* Set to 0x5F0F3CF5u. */ 71 USHORT flags; /* Bit 0: Baseline for font at y=0; 72 * Bit 1: Left sidebearing point at x=0; 73 * Bit 2: Instructions may depend on point size; 74 * Bit 3: Force ppem to integer values for all 75 * internal scaler math; may use fractional 76 * ppem sizes if this bit is clear; 77 * Bit 4: Instructions may alter advance width 78 * (the advance widths might not scale linearly); 79 80 * Bits 5-10: These should be set according to 81 * Apple's specification. However, they are not 82 * implemented in OpenType. 83 * Bit 5: This bit should be set in fonts that are 84 * intended to e laid out vertically, and in 85 * which the glyphs have been drawn such that an 86 * x-coordinate of 0 corresponds to the desired 87 * vertical baseline. 88 * Bit 6: This bit must be set to zero. 89 * Bit 7: This bit should be set if the font 90 * requires layout for correct linguistic 91 * rendering (e.g. Arabic fonts). 92 * Bit 8: This bit should be set for a GX font 93 * which has one or more metamorphosis effects 94 * designated as happening by default. 95 * Bit 9: This bit should be set if the font 96 * contains any strong right-to-left glyphs. 97 * Bit 10: This bit should be set if the font 98 * contains Indic-style rearrangement effects. 99 100 * Bit 11: Font data is 'lossless,' as a result 101 * of having been compressed and decompressed 102 * with the Agfa MicroType Express engine. 103 * Bit 12: Font converted (produce compatible metrics) 104 * Bit 13: Font optimized for ClearType™. 105 * Note, fonts that rely on embedded bitmaps (EBDT) 106 * for rendering should not be considered optimized 107 * for ClearType, and therefore should keep this bit 108 * cleared. 109 * Bit 14: Last Resort font. If set, indicates that 110 * the glyphs encoded in the cmap subtables are simply 111 * generic symbolic representations of code point 112 * ranges and don’t truly represent support for those 113 * code points. If unset, indicates that the glyphs 114 * encoded in the cmap subtables represent proper 115 * support for those code points. 116 * Bit 15: Reserved, set to 0. */ 117 USHORT unitsPerEm; /* Valid range is from 16 to 16384. This value 118 * should be a power of 2 for fonts that have 119 * TrueType outlines. */ 120 LONGDATETIME created; /* Number of seconds since 12:00 midnight, 121 January 1, 1904. 64-bit integer */ 122 LONGDATETIME modified; /* Number of seconds since 12:00 midnight, 123 January 1, 1904. 64-bit integer */ 124 SHORT xMin; /* For all glyph bounding boxes. */ 125 SHORT yMin; /* For all glyph bounding boxes. */ 126 SHORT xMax; /* For all glyph bounding boxes. */ 127 SHORT yMax; /* For all glyph bounding boxes. */ 128 USHORT macStyle; /* Bit 0: Bold (if set to 1); 129 * Bit 1: Italic (if set to 1) 130 * Bit 2: Underline (if set to 1) 131 * Bit 3: Outline (if set to 1) 132 * Bit 4: Shadow (if set to 1) 133 * Bit 5: Condensed (if set to 1) 134 * Bit 6: Extended (if set to 1) 135 * Bits 7-15: Reserved (set to 0). */ 136 USHORT lowestRecPPEM; /* Smallest readable size in pixels. */ 137 SHORT fontDirectionHint; /* Deprecated (Set to 2). 138 * 0: Fully mixed directional glyphs; 139 * 1: Only strongly left to right; 140 * 2: Like 1 but also contains neutrals; 141 * -1: Only strongly right to left; 142 * -2: Like -1 but also contains neutrals. */ 143 public: 144 SHORT indexToLocFormat; /* 0 for short offsets, 1 for long. */ 145 SHORT glyphDataFormat; /* 0 for current format. */ 146 147 DEFINE_SIZE_STATIC (54); 148 }; 149 150 151 } /* namespace OT */ 152 153 154 #endif /* HB_OT_HEAD_TABLE_HH */ 155