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Diffstat (limited to 'gfx/graphite2/include/graphite2/Font.h')
| -rw-r--r-- | gfx/graphite2/include/graphite2/Font.h | 389 |
1 files changed, 389 insertions, 0 deletions
diff --git a/gfx/graphite2/include/graphite2/Font.h b/gfx/graphite2/include/graphite2/Font.h new file mode 100644 index 0000000000..fe569295a5 --- /dev/null +++ b/gfx/graphite2/include/graphite2/Font.h @@ -0,0 +1,389 @@ +/* GRAPHITE2 LICENSING + + Copyright 2010, SIL International + All rights reserved. + + This library is free software; you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as published + by the Free Software Foundation; either version 2.1 of License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should also have received a copy of the GNU Lesser General Public + License along with this library in the file named "LICENSE". + If not, write to the Free Software Foundation, 51 Franklin Street, + Suite 500, Boston, MA 02110-1335, USA or visit their web page on the + internet at http://www.fsf.org/licenses/lgpl.html. + + Alternatively, the contents of this file may be used under the terms + of the Mozilla Public License (http://mozilla.org/MPL) or the GNU + General Public License, as published by the Free Software Foundation, + either version 2 of the License or (at your option) any later version. +*/ +#pragma once + +#include "graphite2/Types.h" + +#define GR2_VERSION_MAJOR 1 +#define GR2_VERSION_MINOR 3 +#define GR2_VERSION_BUGFIX 14 + +#ifdef __cplusplus +extern "C" +{ +#endif + +typedef struct gr_face gr_face; +typedef struct gr_font gr_font; +typedef struct gr_feature_ref gr_feature_ref; +typedef struct gr_feature_val gr_feature_val; + +/** +* Returns version information on this engine +*/ +GR2_API void gr_engine_version(int *nMajor, int *nMinor, int *nBugFix); + +/** +* The Face Options allow the application to require that certain tables are +* read during face construction. This may be of concern if the appFaceHandle +* used in the gr_get_table_fn may change. +* The values can be combined +*/ +enum gr_face_options { + /** No preload, no cmap caching, fail if the graphite tables are invalid */ + gr_face_default = 0, + /** Dumb rendering will be enabled if the graphite tables are invalid. @deprecated Since 1.311 */ + gr_face_dumbRendering = 1, + /** preload glyphs at construction time */ + gr_face_preloadGlyphs = 2, + /** Cache the lookup from code point to glyph ID at construction time */ + gr_face_cacheCmap = 4, + /** Preload everything */ + gr_face_preloadAll = gr_face_preloadGlyphs | gr_face_cacheCmap +}; + +/** Holds information about a particular Graphite silf table that has been loaded */ +struct gr_faceinfo { + gr_uint16 extra_ascent; /**< The extra_ascent in the GDL, in design units */ + gr_uint16 extra_descent; /**< The extra_descent in the GDL, in design units */ + gr_uint16 upem; /**< The design units for the font */ + enum gr_space_contextuals { + gr_space_unknown = 0, /**< no information is known. */ + gr_space_none = 1, /**< the space character never occurs in any rules. */ + gr_space_left_only = 2, /**< the space character only occurs as the first element in a rule. */ + gr_space_right_only = 3, /**< the space character only occurs as the last element in a rule. */ + gr_space_either_only = 4, /**< the space character only occurs as the only element in a rule. */ + gr_space_both = 5, /**< the space character may occur as the first or last element of a rule. */ + gr_space_cross = 6 /**< the space character occurs in a rule not as a first or last element. */ + } space_contextuals; + unsigned int has_bidi_pass : 1; /**< the table specifies that a bidirectional pass should run */ + unsigned int line_ends : 1; /**< there are line end contextuals somewhere */ + unsigned int justifies : 1; /**< there are .justify properties set somewhere on some glyphs */ +}; + +typedef struct gr_faceinfo gr_faceinfo; + +/** type describing function to retrieve font table information + * + * @return a pointer to the table in memory. The pointed to memory must exist as + * long as the gr_face which makes the call. + * @param appFaceHandle is the unique information passed to gr_make_face() + * @param name is a 32bit tag to the table name. + * @param len returned by this function to say how long the table is in memory. + */ +typedef const void *(*gr_get_table_fn)(const void* appFaceHandle, unsigned int name, size_t *len); + +/** type describing function to release any resources allocated by the above get_table table function + * + * @param appFaceHandle is the unique information passed to gr_make_face() + * @param pointer to table memory returned by get_table. + */ +typedef void (*gr_release_table_fn)(const void* appFaceHandle, const void *table_buffer); + +/** struct housing function pointers to manage font table buffers for the graphite engine. */ +struct gr_face_ops +{ + /** size in bytes of this structure */ + size_t size; + /** a pointer to a function to request a table from the client. */ + gr_get_table_fn get_table; + /** is a pointer to a function to notify the client the a table can be released. + * This can be NULL to signify that the client does not wish to do any release handling. */ + gr_release_table_fn release_table; +}; +typedef struct gr_face_ops gr_face_ops; + +/** Create a gr_face object given application information and a table functions. + * + * @return gr_face or NULL if the font fails to load for some reason. + * @param appFaceHandle This is application specific information that is passed + * to the getTable function. The appFaceHandle must stay + * alive as long as the gr_face is alive. + * @param face_ops Pointer to face specific callback structure for table + * management. Must stay alive for the duration of the + * call only. + * @param faceOptions Bitfield describing various options. See enum gr_face_options for details. + */ +GR2_API gr_face* gr_make_face_with_ops(const void* appFaceHandle/*non-NULL*/, const gr_face_ops *face_ops, unsigned int faceOptions); + +/** @deprecated Since v1.2.0 in favour of gr_make_face_with_ops. + * Create a gr_face object given application information and a getTable function. + * + * @return gr_face or NULL if the font fails to load for some reason. + * @param appFaceHandle This is application specific information that is passed + * to the getTable function. The appFaceHandle must stay + * alive as long as the gr_face is alive. + * @param getTable Callback function to get table data. + * @param faceOptions Bitfield describing various options. See enum gr_face_options for details. + */ +GR2_DEPRECATED_API gr_face* gr_make_face(const void* appFaceHandle/*non-NULL*/, gr_get_table_fn getTable, unsigned int faceOptions); + +/** @deprecated Since 1.3.7 this function is now an alias for gr_make_face_with_ops(). + * + * Create a gr_face object given application information, with subsegmental caching support + * + * @return gr_face or NULL if the font fails to load. + * @param appFaceHandle is a pointer to application specific information that is passed to getTable. + * This may not be NULL and must stay alive as long as the gr_face is alive. + * @param face_ops Pointer to face specific callback structure for table management. Must stay + * alive for the duration of the call only. + * @param segCacheMaxSize Unused. + * @param faceOptions Bitfield of values from enum gr_face_options + */ +GR2_DEPRECATED_API gr_face* gr_make_face_with_seg_cache_and_ops(const void* appFaceHandle, const gr_face_ops *face_ops, unsigned int segCacheMaxSize, unsigned int faceOptions); + +/** @deprecated Since 1.3.7 this function is now an alias for gr_make_face(). + * + * Create a gr_face object given application information, with subsegmental caching support. + * This function is deprecated as of v1.2.0 in favour of gr_make_face_with_seg_cache_and_ops. + * + * @return gr_face or NULL if the font fails to load. + * @param appFaceHandle is a pointer to application specific information that is passed to getTable. + * This may not be NULL and must stay alive as long as the gr_face is alive. + * @param getTable The function graphite calls to access font table data + * @param segCacheMaxSize How large the segment cache is. + * @param faceOptions Bitfield of values from enum gr_face_options + */ +GR2_DEPRECATED_API gr_face* gr_make_face_with_seg_cache(const void* appFaceHandle, gr_get_table_fn getTable, unsigned int segCacheMaxSize, unsigned int faceOptions); + +/** Convert a tag in a string into a gr_uint32 + * + * @return gr_uint32 tag, zero padded + * @param str a nul terminated string of which at most the first 4 characters are read + */ +GR2_API gr_uint32 gr_str_to_tag(const char *str); + +/** Convert a gr_uint32 tag into a string + * + * @param tag contains the tag to convert + * @param str is a pointer to a char array of at least size 4 bytes. The first 4 bytes of this array + * will be overwritten by this function. No nul is appended. + */ +GR2_API void gr_tag_to_str(gr_uint32 tag, char *str); + +/** Get feature values for a given language or default + * + * @return a copy of the default feature values for a given language. The application must call + * gr_featureval_destroy() to free this object when done. + * @param pFace The font face to get feature values from + * @param langname The language tag to get feature values for. If there is no such language or + * langname is 0, the default feature values for the font are returned. + * langname is right 0 padded and assumes lowercase. Thus the en langauge + * would be 0x656E0000. Langname may also be space padded, thus 0x656E2020. + */ +GR2_API gr_feature_val* gr_face_featureval_for_lang(const gr_face* pFace, gr_uint32 langname); + +/** Get feature reference for a given feature id from a face + * + * @return a feature reference corresponding to the given id. This data is part of the gr_face and + * will be freed when the face is destroyed. + * @param pFace Font face to get information on. + * @param featId Feature id tag to get reference to. + */ +GR2_API const gr_feature_ref* gr_face_find_fref(const gr_face* pFace, gr_uint32 featId); + +/** Returns number of feature references in a face **/ +GR2_API gr_uint16 gr_face_n_fref(const gr_face* pFace); + +/** Returns feature reference at given index in face **/ +GR2_API const gr_feature_ref* gr_face_fref(const gr_face* pFace, gr_uint16 i); + +/** Return number of languages the face knows about **/ +GR2_API unsigned short gr_face_n_languages(const gr_face* pFace); + +/** Returns a language id corresponding to a language of given index in the face **/ +GR2_API gr_uint32 gr_face_lang_by_index(const gr_face* pFace, gr_uint16 i); + +/** Destroy the given face and free its memory **/ +GR2_API void gr_face_destroy(gr_face *face); + +/** Returns the number of glyphs in the face **/ +GR2_API unsigned short gr_face_n_glyphs(const gr_face* pFace); + +/** Returns a faceinfo for the face and script **/ +GR2_API const gr_faceinfo *gr_face_info(const gr_face *pFace, gr_uint32 script); + +/** Returns whether the font supports a given Unicode character + * + * @return true if the character is supported. + * @param pFace face to test within + * @param usv Unicode Scalar Value of character to test + * @param script Tag of script for selecting which set of pseudo glyphs to test. May be NULL. + */ +GR2_API int gr_face_is_char_supported(const gr_face *pFace, gr_uint32 usv, gr_uint32 script); + +#ifndef GRAPHITE2_NFILEFACE +/** Create gr_face from a font file + * + * @return gr_face that accesses a font file directly. Returns NULL on failure. + * @param filename Full path and filename to font file + * @param faceOptions Bitfile from enum gr_face_options to control face options. + */ +GR2_API gr_face* gr_make_file_face(const char *filename, unsigned int faceOptions); + +/** @deprecated Since 1.3.7. This function is now an alias for gr_make_file_face(). + * + * Create gr_face from a font file, with subsegment caching support. + * + * @return gr_face that accesses a font file directly. Returns NULL on failure. + * @param filename Full path and filename to font file + * @param segCacheMaxSize Specifies how big to make the cache in segments. + * @param faceOptions Bitfield from enum gr_face_options to control face options. + */ +GR2_DEPRECATED_API gr_face* gr_make_file_face_with_seg_cache(const char *filename, unsigned int segCacheMaxSize, unsigned int faceOptions); +#endif // !GRAPHITE2_NFILEFACE + +/** Create a font from a face + * + * @return gr_font Call font_destroy to free this font + * @param ppm Resolution of the font in pixels per em + * @param face Face this font corresponds to. This must stay alive as long as the font is alive. + */ +GR2_API gr_font* gr_make_font(float ppm, const gr_face *face); + +/** query function to find the hinted advance of a glyph + * + * @param appFontHandle is the unique information passed to gr_make_font_with_advance() + * @param glyphid is the glyph to retireve the hinted advance for. + */ +typedef float (*gr_advance_fn)(const void* appFontHandle, gr_uint16 glyphid); + +/** struct housing function pointers to manage font hinted metrics for the + * graphite engine. */ +struct gr_font_ops +{ + /** size of the structure in bytes to allow for future extensibility */ + size_t size; + /** a pointer to a function to retrieve the hinted + * advance width of a glyph which the font cannot + * provide without client assistance. This can be + * NULL to signify no horizontal hinted metrics are necessary. */ + gr_advance_fn glyph_advance_x; + /** a pointer to a function to retrieve the hinted + * advance height of a glyph which the font cannot + * provide without client assistance. This can be + * NULL to signify no horizontal hinted metrics are necessary. */ + gr_advance_fn glyph_advance_y; +}; +typedef struct gr_font_ops gr_font_ops; + +/** Creates a font with hinted advance width query functions + * + * @return gr_font to be destroyed via font_destroy + * @param ppm size of font in pixels per em + * @param appFontHandle font specific information that must stay alive as long + * as the font does + * @param font_ops pointer font specific callback structure for hinted metrics. + * Need only stay alive for the duration of the call. + * @param face the face this font corresponds to. Must stay alive as long as + * the font does. + */ +GR2_API gr_font* gr_make_font_with_ops(float ppm, const void* appFontHandle, const gr_font_ops * font_ops, const gr_face *face); + +/** Creates a font with hinted advance width query function. + * This function is deprecated. Use gr_make_font_with_ops instead. + * + * @return gr_font to be destroyed via font_destroy + * @param ppm size of font in pixels per em + * @param appFontHandle font specific information that must stay alive as long + * as the font does + * @param getAdvance callback function reference that returns horizontal advance in pixels for a glyph. + * @param face the face this font corresponds to. Must stay alive as long as + * the font does. + */ +GR2_API gr_font* gr_make_font_with_advance_fn(float ppm, const void* appFontHandle, gr_advance_fn getAdvance, const gr_face *face); + +/** Free a font **/ +GR2_API void gr_font_destroy(gr_font *font); + +/** get a feature value + * + * @return value of specific feature or 0 if any problems. + * @param pfeatureref gr_feature_ref to the feature + * @param feats gr_feature_val containing all the values + */ +GR2_API gr_uint16 gr_fref_feature_value(const gr_feature_ref* pfeatureref, const gr_feature_val* feats); + +/** set a feature value + * + * @return false if there were any problems (value out of range, etc.) + * @param pfeatureref gr_feature_ref to the feature + * @param val value to set the feature to + * @param pDest the gr_feature_val containing all the values for all the features + */ +GR2_API int gr_fref_set_feature_value(const gr_feature_ref* pfeatureref, gr_uint16 val, gr_feature_val* pDest); + +/** Returns the id tag for a gr_feature_ref **/ +GR2_API gr_uint32 gr_fref_id(const gr_feature_ref* pfeatureref); + +/** Returns number of values a feature may take, given a gr_feature_ref **/ +GR2_API gr_uint16 gr_fref_n_values(const gr_feature_ref* pfeatureref); + +/** Returns the value associated with a particular value in a feature + * + * @return value + * @param pfeatureref gr_feature_ref of the feature of interest + * @param settingno Index up to the return value of gr_fref_n_values() of the value + */ +GR2_API gr_int16 gr_fref_value(const gr_feature_ref* pfeatureref, gr_uint16 settingno); + +/** Returns a string of the UI name of a feature + * + * @return string of the UI name, in the encoding form requested. Call gr_label_destroy() after use. + * @param pfeatureref gr_feature_ref of the feature + * @param langId This is a pointer since the face may not support a string in the requested + * language. The actual language of the string is returned in langId + * @param utf Encoding form for the string + * @param length Used to return the length of the string returned in bytes. + */ +GR2_API void* gr_fref_label(const gr_feature_ref* pfeatureref, gr_uint16 *langId, enum gr_encform utf, gr_uint32 *length); + +/** Return a UI string for a possible value of a feature + * + * @return string of the UI name, in the encoding form requested. nul terminated. Call gr_label_destroy() + * after use. + * @param pfeatureref gr_feature_ref of the feature + * @param settingno Value setting index + * @param langId This is a pointer to the requested language. The requested language id is + * replaced by the actual language id of the string returned. + * @param utf Encoding form for the string + * @param length Returns the length of the string returned in bytes. + */ +GR2_API void* gr_fref_value_label(const gr_feature_ref* pfeatureref, gr_uint16 settingno/*rather than a value*/, gr_uint16 *langId, enum gr_encform utf, gr_uint32 *length); + +/** Destroy a previously returned label string **/ +GR2_API void gr_label_destroy(void * label); + +/** Copies a gr_feature_val **/ +GR2_API gr_feature_val* gr_featureval_clone(const gr_feature_val* pfeatures); + +/** Destroys a gr_feature_val **/ +GR2_API void gr_featureval_destroy(gr_feature_val *pfeatures); + +#ifdef __cplusplus +} +#endif |