psblues.h (5995B)
1 /**************************************************************************** 2 * 3 * psblues.h 4 * 5 * Adobe's code for handling Blue Zones (specification). 6 * 7 * Copyright 2009-2013 Adobe Systems Incorporated. 8 * 9 * This software, and all works of authorship, whether in source or 10 * object code form as indicated by the copyright notice(s) included 11 * herein (collectively, the "Work") is made available, and may only be 12 * used, modified, and distributed under the FreeType Project License, 13 * LICENSE.TXT. Additionally, subject to the terms and conditions of the 14 * FreeType Project License, each contributor to the Work hereby grants 15 * to any individual or legal entity exercising permissions granted by 16 * the FreeType Project License and this section (hereafter, "You" or 17 * "Your") a perpetual, worldwide, non-exclusive, no-charge, 18 * royalty-free, irrevocable (except as stated in this section) patent 19 * license to make, have made, use, offer to sell, sell, import, and 20 * otherwise transfer the Work, where such license applies only to those 21 * patent claims licensable by such contributor that are necessarily 22 * infringed by their contribution(s) alone or by combination of their 23 * contribution(s) with the Work to which such contribution(s) was 24 * submitted. If You institute patent litigation against any entity 25 * (including a cross-claim or counterclaim in a lawsuit) alleging that 26 * the Work or a contribution incorporated within the Work constitutes 27 * direct or contributory patent infringement, then any patent licenses 28 * granted to You under this License for that Work shall terminate as of 29 * the date such litigation is filed. 30 * 31 * By using, modifying, or distributing the Work you indicate that you 32 * have read and understood the terms and conditions of the 33 * FreeType Project License as well as those provided in this section, 34 * and you accept them fully. 35 * 36 */ 37 38 39 /* 40 * A `CF2_Blues' object stores the blue zones (horizontal alignment 41 * zones) of a font. These are specified in the CFF private dictionary 42 * by `BlueValues', `OtherBlues', `FamilyBlues', and `FamilyOtherBlues'. 43 * Each zone is defined by a top and bottom edge in character space. 44 * Further, each zone is either a top zone or a bottom zone, as recorded 45 * by `bottomZone'. 46 * 47 * The maximum number of `BlueValues' and `FamilyBlues' is 7 each. 48 * However, these are combined to produce a total of 7 zones. 49 * Similarly, the maximum number of `OtherBlues' and `FamilyOtherBlues' 50 * is 5 and these are combined to produce an additional 5 zones. 51 * 52 * Blue zones are used to `capture' hints and force them to a common 53 * alignment point. This alignment is recorded in device space in 54 * `dsFlatEdge'. Except for this value, a `CF2_Blues' object could be 55 * constructed independently of scaling. Construction may occur once 56 * the matrix is known. Other features implemented in the Capture 57 * method are overshoot suppression, overshoot enforcement, and Blue 58 * Boost. 59 * 60 * Capture is determined by `BlueValues' and `OtherBlues', but the 61 * alignment point may be adjusted to the scaled flat edge of 62 * `FamilyBlues' or `FamilyOtherBlues'. No alignment is done to the 63 * curved edge of a zone. 64 * 65 */ 66 67 68 #ifndef PSBLUES_H_ 69 #define PSBLUES_H_ 70 71 72 #include "psglue.h" 73 74 75 FT_BEGIN_HEADER 76 77 78 /* 79 * `CF2_Hint' is shared by `cf2hints.h' and 80 * `cf2blues.h', but `cf2blues.h' depends on 81 * `cf2hints.h', so define it here. Note: The typedef is in 82 * `cf2glue.h'. 83 * 84 */ 85 enum 86 { 87 CF2_GhostBottom = 0x1, /* a single bottom edge */ 88 CF2_GhostTop = 0x2, /* a single top edge */ 89 CF2_PairBottom = 0x4, /* the bottom edge of a stem hint */ 90 CF2_PairTop = 0x8, /* the top edge of a stem hint */ 91 CF2_Locked = 0x10, /* this edge has been aligned */ 92 /* by a blue zone */ 93 CF2_Synthetic = 0x20 /* this edge was synthesized */ 94 }; 95 96 97 /* 98 * Default value for OS/2 typoAscender/Descender when their difference 99 * is not equal to `unitsPerEm'. The default is based on -250 and 1100 100 * in `CF2_Blues', assuming 1000 units per em here. 101 * 102 */ 103 enum 104 { 105 CF2_ICF_Top = cf2_intToFixed( 880 ), 106 CF2_ICF_Bottom = cf2_intToFixed( -120 ) 107 }; 108 109 110 /* 111 * Constant used for hint adjustment and for synthetic em box hint 112 * placement. 113 */ 114 #define CF2_MIN_COUNTER cf2_doubleToFixed( 0.5 ) 115 116 117 /* shared typedef is in cf2glue.h */ 118 struct CF2_HintRec_ 119 { 120 CF2_UInt flags; /* attributes of the edge */ 121 size_t index; /* index in original stem hint array */ 122 /* (if not synthetic) */ 123 CF2_Fixed csCoord; 124 CF2_Fixed dsCoord; 125 CF2_Fixed scale; 126 }; 127 128 129 typedef struct CF2_BlueRec_ 130 { 131 CF2_Fixed csBottomEdge; 132 CF2_Fixed csTopEdge; 133 CF2_Fixed csFlatEdge; /* may be from either local or Family zones */ 134 CF2_Fixed dsFlatEdge; /* top edge of bottom zone or bottom edge */ 135 /* of top zone (rounded) */ 136 FT_Bool bottomZone; 137 138 } CF2_BlueRec; 139 140 141 /* max total blue zones is 12 */ 142 enum 143 { 144 CF2_MAX_BLUES = 7, 145 CF2_MAX_OTHERBLUES = 5 146 }; 147 148 149 typedef struct CF2_BluesRec_ 150 { 151 CF2_Fixed scale; 152 CF2_UInt count; 153 FT_Bool suppressOvershoot; 154 FT_Bool doEmBoxHints; 155 156 CF2_Fixed blueScale; 157 CF2_Fixed blueShift; 158 CF2_Fixed blueFuzz; 159 160 CF2_Fixed boost; 161 162 CF2_HintRec emBoxTopEdge; 163 CF2_HintRec emBoxBottomEdge; 164 165 CF2_BlueRec zone[CF2_MAX_BLUES + CF2_MAX_OTHERBLUES]; 166 167 } CF2_BluesRec, *CF2_Blues; 168 169 170 FT_LOCAL( void ) 171 cf2_blues_init( CF2_Blues blues, 172 CF2_Font font ); 173 FT_LOCAL( FT_Bool ) 174 cf2_blues_capture( const CF2_Blues blues, 175 CF2_Hint bottomHintEdge, 176 CF2_Hint topHintEdge ); 177 178 179 FT_END_HEADER 180 181 182 #endif /* PSBLUES_H_ */ 183 184 185 /* END */