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 Tag = HB_OT_TAG_head; 47 48 inline unsigned int get_upem (void) const { 49 unsigned int upem = unitsPerEm; 50 /* If no valid head table found, assume 1000, which matches typical Type1 usage. */ 51 return 16 <= upem && upem <= 16384 ? upem : 1000; 52 } 53 54 inline bool sanitize (hb_sanitize_context_t *c) { 55 TRACE_SANITIZE (this); 56 return TRACE_RETURN (c->check_struct (this) && likely (version.major == 1)); 57 } 58 59 protected: 60 FixedVersion version; /* Version of the head table--currently 61 * 0x00010000 for version 1.0. */ 62 FixedVersion fontRevision; /* Set by font manufacturer. */ 63 ULONG checkSumAdjustment; /* To compute: set it to 0, sum the 64 * entire font as ULONG, then store 65 * 0xB1B0AFBA - sum. */ 66 ULONG magicNumber; /* Set to 0x5F0F3CF5. */ 67 USHORT flags; /* Bit 0: Baseline for font at y=0; 68 * Bit 1: Left sidebearing point at x=0; 69 * Bit 2: Instructions may depend on point size; 70 * Bit 3: Force ppem to integer values for all 71 * internal scaler math; may use fractional 72 * ppem sizes if this bit is clear; 73 * Bit 4: Instructions may alter advance width 74 * (the advance widths might not scale linearly); 75 76 * Bits 5-10: These should be set according to 77 * Apple's specification. However, they are not 78 * implemented in OpenType. 79 * Bit 5: This bit should be set in fonts that are 80 * intended to e laid out vertically, and in 81 * which the glyphs have been drawn such that an 82 * x-coordinate of 0 corresponds to the desired 83 * vertical baseline. 84 * Bit 6: This bit must be set to zero. 85 * Bit 7: This bit should be set if the font 86 * requires layout for correct linguistic 87 * rendering (e.g. Arabic fonts). 88 * Bit 8: This bit should be set for a GX font 89 * which has one or more metamorphosis effects 90 * designated as happening by default. 91 * Bit 9: This bit should be set if the font 92 * contains any strong right-to-left glyphs. 93 * Bit 10: This bit should be set if the font 94 * contains Indic-style rearrangement effects. 95 96 * Bit 11: Font data is 'lossless,' as a result 97 * of having been compressed and decompressed 98 * with the Agfa MicroType Express engine. 99 * Bit 12: Font converted (produce compatible metrics) 100 * Bit 13: Font optimized for ClearType. 101 * Note, fonts that rely on embedded bitmaps (EBDT) 102 * for rendering should not be considered optimized 103 * for ClearType, and therefore should keep this bit 104 * cleared. 105 * Bit 14: Last Resort font. If set, indicates that 106 * the glyphs encoded in the cmap subtables are simply 107 * generic symbolic representations of code point 108 * ranges and dont truly represent support for those 109 * code points. If unset, indicates that the glyphs 110 * encoded in the cmap subtables represent proper 111 * support for those code points. 112 * Bit 15: Reserved, set to 0. */ 113 USHORT unitsPerEm; /* Valid range is from 16 to 16384. This value 114 * should be a power of 2 for fonts that have 115 * TrueType outlines. */ 116 LONGDATETIME created; /* Number of seconds since 12:00 midnight, 117 January 1, 1904. 64-bit integer */ 118 LONGDATETIME modified; /* Number of seconds since 12:00 midnight, 119 January 1, 1904. 64-bit integer */ 120 SHORT xMin; /* For all glyph bounding boxes. */ 121 SHORT yMin; /* For all glyph bounding boxes. */ 122 SHORT xMax; /* For all glyph bounding boxes. */ 123 SHORT yMax; /* For all glyph bounding boxes. */ 124 USHORT macStyle; /* Bit 0: Bold (if set to 1); 125 * Bit 1: Italic (if set to 1) 126 * Bit 2: Underline (if set to 1) 127 * Bit 3: Outline (if set to 1) 128 * Bit 4: Shadow (if set to 1) 129 * Bit 5: Condensed (if set to 1) 130 * Bit 6: Extended (if set to 1) 131 * Bits 7-15: Reserved (set to 0). */ 132 USHORT lowestRecPPEM; /* Smallest readable size in pixels. */ 133 SHORT fontDirectionHint; /* Deprecated (Set to 2). 134 * 0: Fully mixed directional glyphs; 135 * 1: Only strongly left to right; 136 * 2: Like 1 but also contains neutrals; 137 * -1: Only strongly right to left; 138 * -2: Like -1 but also contains neutrals. */ 139 SHORT indexToLocFormat; /* 0 for short offsets, 1 for long. */ 140 SHORT glyphDataFormat; /* 0 for current format. */ 141 public: 142 DEFINE_SIZE_STATIC (54); 143 }; 144 145 146 } /* namespace OT */ 147 148 149 #endif /* HB_OT_HEAD_TABLE_HH */ 150
