| 1 | /***************************************************************************/ |
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| 2 | /* */ |
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| 3 | /* ftgasp.h */ |
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| 4 | /* */ |
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| 5 | /* Access of TrueType's `gasp' table (specification). */ |
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| 6 | /* */ |
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| 7 | /* Copyright 2007, 2008 by */ |
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| 8 | /* David Turner, Robert Wilhelm, and Werner Lemberg. */ |
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| 9 | /* */ |
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| 10 | /* This file is part of the FreeType project, and may only be used, */ |
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| 11 | /* modified, and distributed under the terms of the FreeType project */ |
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| 12 | /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ |
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| 13 | /* this file you indicate that you have read the license and */ |
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| 14 | /* understand and accept it fully. */ |
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| 15 | /* */ |
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| 16 | /***************************************************************************/ |
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| 17 | |
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| 18 | |
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| 19 | #ifndef _FT_GASP_H_ |
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| 20 | #define _FT_GASP_H_ |
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| 21 | |
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| 22 | #include <ft2build.h> |
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| 23 | #include FT_FREETYPE_H |
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| 24 | |
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| 25 | #ifdef FREETYPE_H |
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| 26 | #error "freetype.h of FreeType 1 has been loaded!" |
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| 27 | #error "Please fix the directory search order for header files" |
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| 28 | #error "so that freetype.h of FreeType 2 is found first." |
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| 29 | #endif |
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| 30 | |
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| 31 | |
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| 32 | /*************************************************************************** |
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| 33 | * |
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| 34 | * @section: |
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| 35 | * gasp_table |
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| 36 | * |
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| 37 | * @title: |
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| 38 | * Gasp Table |
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| 39 | * |
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| 40 | * @abstract: |
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| 41 | * Retrieving TrueType `gasp' table entries. |
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| 42 | * |
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| 43 | * @description: |
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| 44 | * The function @FT_Get_Gasp can be used to query a TrueType or OpenType |
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| 45 | * font for specific entries in its `gasp' table, if any. This is |
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| 46 | * mainly useful when implementing native TrueType hinting with the |
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| 47 | * bytecode interpreter to duplicate the Windows text rendering results. |
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| 48 | */ |
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| 49 | |
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| 50 | /************************************************************************* |
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| 51 | * |
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| 52 | * @enum: |
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| 53 | * FT_GASP_XXX |
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| 54 | * |
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| 55 | * @description: |
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| 56 | * A list of values and/or bit-flags returned by the @FT_Get_Gasp |
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| 57 | * function. |
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| 58 | * |
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| 59 | * @values: |
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| 60 | * FT_GASP_NO_TABLE :: |
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| 61 | * This special value means that there is no GASP table in this face. |
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| 62 | * It is up to the client to decide what to do. |
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| 63 | * |
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| 64 | * FT_GASP_DO_GRIDFIT :: |
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| 65 | * Grid-fitting and hinting should be performed at the specified ppem. |
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| 66 | * This *really* means TrueType bytecode interpretation. |
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| 67 | * |
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| 68 | * FT_GASP_DO_GRAY :: |
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| 69 | * Anti-aliased rendering should be performed at the specified ppem. |
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| 70 | * |
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| 71 | * FT_GASP_SYMMETRIC_SMOOTHING :: |
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| 72 | * Smoothing along multiple axes must be used with ClearType. |
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| 73 | * |
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| 74 | * FT_GASP_SYMMETRIC_GRIDFIT :: |
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| 75 | * Grid-fitting must be used with ClearType's symmetric smoothing. |
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| 76 | * |
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| 77 | * @note: |
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| 78 | * `ClearType' is Microsoft's implementation of LCD rendering, partly |
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| 79 | * protected by patents. |
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| 80 | * |
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| 81 | * @since: |
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| 82 | * 2.3.0 |
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| 83 | */ |
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| 84 | #define FT_GASP_NO_TABLE -1 |
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| 85 | #define FT_GASP_DO_GRIDFIT 0x01 |
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| 86 | #define FT_GASP_DO_GRAY 0x02 |
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| 87 | #define FT_GASP_SYMMETRIC_SMOOTHING 0x08 |
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| 88 | #define FT_GASP_SYMMETRIC_GRIDFIT 0x10 |
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| 89 | |
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| 90 | |
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| 91 | /************************************************************************* |
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| 92 | * |
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| 93 | * @func: |
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| 94 | * FT_Get_Gasp |
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| 95 | * |
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| 96 | * @description: |
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| 97 | * Read the `gasp' table from a TrueType or OpenType font file and |
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| 98 | * return the entry corresponding to a given character pixel size. |
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| 99 | * |
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| 100 | * @input: |
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| 101 | * face :: The source face handle. |
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| 102 | * ppem :: The vertical character pixel size. |
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| 103 | * |
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| 104 | * @return: |
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| 105 | * Bit flags (see @FT_GASP_XXX), or @FT_GASP_NO_TABLE if there is no |
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| 106 | * `gasp' table in the face. |
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| 107 | * |
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| 108 | * @since: |
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| 109 | * 2.3.0 |
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| 110 | */ |
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| 111 | FT_EXPORT( FT_Int ) |
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| 112 | FT_Get_Gasp( FT_Face face, |
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| 113 | FT_UInt ppem ); |
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| 114 | |
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| 115 | /* */ |
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| 116 | |
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| 117 | #endif /* _FT_GASP_H_ */ |
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| 118 | |
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| 119 | |
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| 120 | /* END */ |
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