From: Keith Packard Date: Sat, 1 Mar 2003 02:23:52 +0000 (+0000) Subject: Reformat documentation into sgml for docbook, split into user/devel guides X-Git-Tag: fc-2_1_91~14 X-Git-Url: https://git.wh0rd.org/?a=commitdiff_plain;h=584ac89a017d30fb337de3d4c038ae2a5b51b3d1;p=fontconfig.git Reformat documentation into sgml for docbook, split into user/devel guides --- diff --git a/doc/fontconfig-devel.sgml b/doc/fontconfig-devel.sgml new file mode 100644 index 0000000..f5d958f --- /dev/null +++ b/doc/fontconfig-devel.sgml @@ -0,0 +1,1257 @@ + + +
+ + Fontconfig Developers Guide + Fontconfig + KeithPackard + krp + +NAME + + fontconfig - Font configuration and customization library + + +SYNOPSIS + + #include <fontconfig/fontconfig.h> + #include <fontconfig/fcfreetype.h> + + +DESCRIPTION + +Fontconfig is a library designed to provide system-wide font configuration, +customization and application access. + + +FUNCTIONAL OVERVIEW + +Fontconfig contains two essential modules, the configuration module which +builds an internal configuration from XML files and the matching module +which accepts font patterns and returns the nearest matching font. + + FONT CONFIGURATION + +The configuration module consists of the FcConfig datatype, libexpat and +FcConfigParse which walks over an XML tree and ammends a configuration with +data found within. From an external perspective, configuration of the +library consists of generating a valid XML tree and feeding that to +FcConfigParse. The only other mechanism provided to applications for +changing the running configuration is to add fonts and directories to the +list of application-provided font files. + +The intent is to make font configurations relatively static, and shared by +as many applications as possible. It is hoped that this will lead to more +stable font selection when passing names from one application to another. +XML was chosen as a configuration file format because it provides a format +which is easy for external agents to edit while retaining the correct +structure and syntax. + +Font configuration is separate from font matching; applications needing to +do their own matching can access the available fonts from the library and +perform private matching. The intent is to permit applications to pick and +choose appropriate functionality from the library instead of forcing them to +choose between this library and a private configuration mechanism. The hope +is that this will ensure that configuration of fonts for all applications +can be centralized in one place. Centralizing font configuration will +simplify and regularize font installation and customization. + + + + FONT PROPERTIES + +While font patterns may contain essentially any properties, there are some +well known properties with associated types. Fontconfig uses some of these +properties for font matching and font completion. Others are provided as a +convenience for the applications rendering mechanism. + + + Property Definitions + + + + + + + + Property + CPP Symbol + Type + Description + + + +familyFC_FAMILYStringFont family name +styleFC_STYLEStringFont style. Overrides weight and slant +slantFC_SLANTIntItalic, oblique or roman +weightFC_WEIGHTIntLight, medium, demibold, bold or black +sizeFC_SIZEDoublePoint size +aspectFC_ASPECTDoubleStretches glyphs horizontally before hinting +pixelsizeFC_PIXEL_SIZEDoublePixel size +spacingFC_SPACINGIntProportional, monospace or charcell +foundryFC_FOUNDRYStringFont foundry name +antialiasFC_ANTIALIASBoolWhether glyphs can be antialiased +hintingFC_HINTINGBoolWhether the rasterizer should use hinting +verticallayoutFC_VERTICAL_LAYOUTBoolUse vertical layout +autohintFC_AUTOHINTBoolUse autohinter instead of normal hinter +globaladvanceFC_GLOBAL_ADVANCEBoolUse font global advance data +fileFC_FILEStringThe filename holding the font +indexFC_INDEXIntThe index of the font within the file +ftfaceFC_FT_FACEFT_FaceUse the specified FreeType face object +rasterizerFC_RASTERIZERStringWhich rasterizer is in use +outlineFC_OUTLINEBoolWhether the glyphs are outlines +scalableFC_SCALABLEBoolWhether glyphs can be scaled +scaleFC_SCALEDoubleScale factor for point->pixel conversions +dpiFC_DPIDoubleTarget dots per inch +rgbaFC_RGBAIntunknown, rgb, bgr, vrgb, vbgr, none - subpixel geometry +minspaceFC_MINSPACEBoolEliminate leading from line spacing +charsetFC_CHARSETCharSetUnicode chars encoded by the font +langFC_LANGStringList of RFC-3066-style languages this font supports + + +
+ +DATATYPES + +Fontconfig uses abstract datatypes to hide internal implementation details +for most data structures. A few structures are exposed where appropriate. + + FcChar8, FcChar16, FcChar32, FcBool + +These are primitive datatypes; the FcChar* types hold precisely the number +of bits stated (if supported by the C implementation). FcBool holds +one of two CPP symbols: FcFalse or FcTrue. + + + FcMatrix + +An FcMatrix holds an affine transformation, usually used to reshape glyphs. +A small set of matrix operations are provided to manipulate these. + + typedef struct _FcMatrix { + double xx, xy, yx, yy; + } FcMatrix; + + + + + FcCharSet + +An FcCharSet is an abstract type that holds the set of encoded unicode chars +in a font. Operations to build and compare these sets are provided. + + + + FcType + +Tags the kind of data stored in an FcValue. + + + FcValue + +An FcValue object holds a single value with one of a number of different +types. The 'type' tag indicates which member is valid. + + typedef struct _FcValue { + FcType type; + union { + const FcChar8 *s; + int i; + FcBool b; + double d; + const FcMatrix *m; + const FcCharSet *c; + } u; + } FcValue; + + + FcValue Members + + + Type + Union member + Datatype + + +FcTypeVoid(none)(none) +FcTypeIntegeriint +FcTypeDoubleddouble +FcTypeStringschar * +FcTypeBoolbb +FcTypeMatrixmFcMatrix * +FcTypeCharSetcFcCharSet * + + +
+ + FcPattern + +holds a set of names with associated value lists; each name refers to a +property of a font. FcPatterns are used as inputs to the matching code as +well as holding information about specific fonts. Each property can hold +one or more values; conventionally all of the same type, although the +interface doesn't demand that. + + + FcFontSet + + + typedef struct _FcFontSet { + int nfont; + int sfont; + FcPattern **fonts; + } FcFontSet; + +An FcFontSet contains a list of FcPatterns. Internally fontconfig uses this +data structure to hold sets of fonts. Externally, fontconfig returns the +results of listing fonts in this format. 'nfont' holds the number of +patterns in the 'fonts' array; 'sfont' is used to indicate the size of that +array. + + + + FcStrSet, FcStrList + +FcStrSet holds a list of strings that can be appended to and enumerated. +Its unique characteristic is that the enumeration works even while strings +are appended during enumeration. FcStrList is used during enumeration to +safely and correctly walk the list of strings even while that list is edited +in the middle of enumeration. + + + + FcObjectSet + + + typedef struct _FcObjectSet { + int nobject; + int sobject; + const char **objects; + } FcObjectSet; + +holds a set of names and is used to specify which fields from fonts are +placed in the the list of returned patterns when listing fonts. + + + + FcObjectType + + + typedef struct _FcObjectType { + const char *object; + FcType type; + } FcObjectType; + +marks the type of a pattern element generated when parsing font names. +Applications can add new object types so that font names may contain the new +elements. + + + + FcConstant + + + typedef struct _FcConstant { + const FcChar8 *name; + const char *object; + int value; + } FcConstant; + +Provides for symbolic constants for new pattern elements. When 'name' is +seen in a font name, an 'object' element is created with value 'value'. + + + + FcBlanks + +holds a list of Unicode chars which are expected to be blank; unexpectedly +blank chars are assumed to be invalid and are elided from the charset +associated with the font. + + + + FcFileCache + +holds the per-user cache information for use while loading the font +database. This is built automatically for the current configuration when +that is loaded. Applications must always pass '0' when one is requested. + + + + FcConfig + +holds a complete configuration of the library; there is one default +configuration, other can be constructed from XML data structures. All +public entry points that need global data can take an optional FcConfig* +argument; passing 0 uses the default configuration. FcConfig objects hold two +sets of fonts, the first contains those specified by the configuration, the +second set holds those added by the application at run-time. Interfaces +that need to reference a particulat set use one of the FcSetName enumerated +values. + + + + FcSetName + +Specifies one of the two sets of fonts available in a configuration; +FcSetSystem for those fonts specified in the configuration and +FcSetApplication which holds fonts provided by the application. + + + + FcResult + +Used as a return type for functions manipulating FcPattern objects. + + FcResult Values + + + Result Code + Meaning + + +FcResultMatchObject exists with the specified ID +FcResultNoMatchObject doesn't exist at all +FcResultTypeMismatchObject exists, but the type doesn't match +FcResultNoIdObject exists, but has fewer values than specified + + +
+ + + + FcAtomic + +Used for locking access to config files. Provides a safe way to update +configuration files. + + + +FUNCTIONS + +Functions are grouped by the main datatype involved + + FcMatrix + +FcMatrix structures hold an affine transformation in matrix form. + + FcMatrixInit +#define FcMatrixInit(m) ((m)->xx = (m)->yy = 1, (m)->xy = (m)->yx = 0) + +Initializes a matrix to the identify transformation. + + FcMatrixCopy +FcMatrix *FcMatrixCopy (const FcMatrix *mat) + +Allocates a new FcMatrix and copies 'mat' into it. + + FcMatrixEqual +FcBool FcMatrixEqual (const FcMatrix *mat1, const FcMatrix *mat2) + +Returns FcTrue if 'mat1' and 'mat2' are equal, else FcFalse. + + FcMatrixMultiply +void FcMatrixMultiply (FcMatrix *result, const FcMatrix *a, const FcMatrix *b) + +Multiplies 'a' and 'b' together, placing the result in 'result'. 'result' +may refer to the sam matrix as either 'a' or 'b'. + + FcMatrixRotate +void FcMatrixRotate (FcMatrix *m, double c, double s) + +If 'c' is cos(angle) and 's' is sin(angle), FcMatrixRotate rotates the +matrix by 'angle'. + + FcMatrixScale +void FcMatrixScale (FcMatrix *m, double sx, double sy) + +Scales 'm' by 'sx' in the horizontal dimension and 'sy' in the +vertical dimension. + + FcMatrixShear +void FcMatrixShear (FcMatrix *m, double sh, double sv) + +Shears 'm' by 'sh' in the horizontal direction and 'sv' in the +vertical direction. + + + FcCharSet + +An FcCharSet is a boolean array indicating a set of unicode chars. Those +associated with a font are marked constant and cannot be edited. +FcCharSets may be reference counted internally to reduce memory consumption; +this may be visible to applications as the result of FcCharSetCopy may +return it's argument, and that CharSet may remain unmodifiable. + + FcCharSetCreate +FcCharSet *FcCharSetCreate (void) + +Creates an empty FcCharSet object. + + FcCharSetDestroy +void FcCharSetDestroy (FcCharSet *fcs) + +Frees an FcCharSet object. + + FcCharSetAddChar +FcBool FcCharSetAddChar (FcCharSet *fcs, FcChar32 ucs4) + +Adds a single unicode char to the set, returning FcFalse on +failure, either as a result of a constant set or from running out of memory. + + FcCharSetCopy +FcCharSet *FcCharSetCopy (FcCharSet *src) + +Makes a copy of 'src'; note that this may not actually do anything more than +increment the reference count on 'src'. + + FcCharSetEqual +FcBool FcCharSetEqual (const FcCharSet *a, const FcCharSet *b) + +Returns whether 'a' and 'b' contain the same set of unicode chars. + + FcCharSetIntersect +FcCharSet *FcCharSetIntersect (const FcCharSet *a, const FcCharSet *b) + +Returns a set including only those chars found in both 'a' and 'b'. + + FcCharSetUnion +FcCharSet *FcCharSetUnion (const FcCharSet *a, const FcCharSet *b); + +Returns a set including only those chars found in either 'a' or 'b'. + + FcCharSetSubtract +FcCharSet *FcCharSetSubtract (const FcCharSet *a, const FcCharSet *b) + +Returns a set including only those chars found in 'a' but not 'b'. + + FcCharSetHasChar +FcBool FcCharSetHasChar (const FcCharSet *fcs, FcChar32 ucs4) + +Returns whether 'fcs' contains the char 'ucs4'. + + FcCharSetCount +FcChar32 FcCharSetCount (const FcCharSet *a) + +Returns the total number of unicode chars in 'a'. + + FcCharSetIntersectCount +FcChar32 FcCharSetIntersectCount (const FcCharSet *a, const FcCharSet *b) + +Returns the number of chars that are in both 'a' and 'b'. + + FcCharSetSubtractCount +FcChar32 FcCharSetSubtractCount (const FcCharSet *a, const FcCharSet *b) + +Returns the number of chars that are in 'a' but not in 'b'. + + FcCharSetIsSubset +FcBool FcCharSetIsSubset (const FcCharSet *a, const FcCharSet *b) + +Returns whether 'a' is a subset of 'b'. + + FcCharSetFirstPage +FcChar32 FcCharSetFirstPage (const FcCharSet *a, FcChar32 [FC_CHARSET_MAP_SIZE], FcChar32 *next) + +Builds an array of bits marking the first page of Unicode coverage of 'a'. +Returns the base of the array. 'next' contains the next page in the font. + + FcCharSetNextPage +FcChar32 FcCharSetNextPage (const FcCharSet *a, FcChar32 [FC_CHARSET_MAP_SIZE], FcChar32 *next) + +Builds an array of bits marking the Unicode coverage of 'a' for page '*next'. +Returns the base of the array. 'next' contains the next page in the font. + + + FcValue + +FcValue is a structure containing a type tag and a union of all possible +datatypes. The tag is an enum of type +FcType +and is intended to provide a measure of run-time +typechecking, although that depends on careful programming. + + FcValueDestroy +void FcValueDestroy (FcValue v) + +Frees any memory referenced by `v'. Values of type FcTypeString, +FcTypeMatrix and FcTypeCharSet reference memory, the other types do not. + + FcValueSave +FcValue FcValueSave (FcValue v) + +Returns a copy of `v' duplicating any object referenced by it so that `v' +may be safely destroyed without harming the new value. + + + FcPattern + +An FcPattern is an opaque type that holds both patterns to match against the +available fonts, as well as the information about each font. + + FcPatternCreate +FcPattern *FcPatternCreate (void) + +Creates a pattern with no properties; used to build patterns from scratch. + + FcPatternDestroy +void FcPatternDestroy (FcPattern *p) + +Destroys a pattern, in the process destroying all related values. + + FcPatternEqual +FcBool FcPatternEqual (const FcPattern *pa, const FcPattern *pb); + +Returns whether 'pa' and 'pb' are exactly alike. + + FcPatternEqualSubset +FcBool FcPatternEqualSubset (const FcPattern *pa, const FcPattern *pb, const FcObjectSet *os) + +Returns whether 'pa' and 'pb' have exactly the same values for all of the +objects in 'os'. + + FcPatternHash +FcChar32 FcPatternHash (const FcPattern *p) + +Returns a 32-bit number which is the same for any two patterns which are +exactly alike. + + FcPatternAdd +FcBool FcPatternAdd (FcPattern *p, const char *object, FcValue value, FcBool append) + +Adds a single value to the list of values associated with the property named +`object'. If `append' is FcTrue, the value is added at the end of any +existing list, otherwise it is inserted at the begining. `value' is saved +(with FcValueSave) when inserted into the pattern so that the library +retains no reference to any application-supplied data structure. + + FcPatternAddWeak +FcBool FcPatternAddWeak (FcPattern *p, const char *object, FcValue value, FcBool append) + +FcPatternAddWeak is essentially the same as FcPatternAdd except that any +values added to the list have binding 'weak' instead of 'strong'. + + FcPatternAdd <emphasis>Type</emphasis> +FcBool FcPatternAddInteger (FcPattern *p, const char *object, int i) +FcBool FcPatternAddDouble (FcPattern *p, const char *object, double d) +FcBool FcPatternAddString (FcPattern *p, const char *object, const char *s) +FcBool FcPatternAddMatrix (FcPattern *p, const char *object, const FcMatrix *s) +FcBool FcPatternAddCharSet (FcPattern *p, const char *object, const FcCharSet *c) +FcBool FcPatternAddBool (FcPattern *p, const char *object, FcBool b) + +These are all convenience functions that insert objects of the specified +type into the pattern. Use these in preference to FcPatternAdd as they +will provide compile-time typechecking. These all append values to +any existing list of values. + + FcPatternGet +FcResult FcPatternGet (FcPattern *p, const char *object, int id, FcValue *v) + +Returns in `v' the `id'th value associated with the property `object'. +The value returned is not a copy, but rather refers to the data stored +within the pattern directly. Applications must not free this value. + + FcPatternGet <emphasis>Type</emphasis> +FcResult FcPatternGetInteger (FcPattern *p, const char *object, int n, int *i); +FcResult FcPatternGetDouble (FcPattern *p, const char *object, int n, double *d); +FcResult FcPatternGetString (FcPattern *p, const char *object, int n, char **const s); +FcResult FcPatternGetMatrix (FcPattern *p, const char *object, int n, FcMatrix **s); +FcResult FcPatternGetCharSet (FcPattern *p, const char *object, int n, FcCharSet **c); +FcResult FcPatternGetBool (FcPattern *p, const char *object, int n, FcBool *b); + +These are convenience functions that call FcPatternGet and verify that the +returned data is of the expected type. They return FcResultTypeMismatch if +this is not the case. Note that these (like FcPatternGet) do not make a +copy of any data structure referenced by the return value. Use these +in preference to FcPatternGet to provide compile-time typechecking. + + FcPatternBuild, FcPatternVaBuild +FcPattern *FcPatternBuild (FcPattern *orig, ...); +FcPattern *FcPatternVaBuild (FcPattern *orig, va_list va) + +Builds a pattern using a list of objects, types and values. Each +value to be entered in the pattern is specified with three arguments: + + + +Object name, a string describing the property to be added. + +Object type, one of the FcType enumerated values + +Value, not an FcValue, but the raw type as passed to any of the +FcPatternAdd<type> functions. Must match the type of the second +argument. + + +The argument list is terminated by a null object name, no object type nor +value need be passed for this. The values are added to `pattern', if +`pattern' is null, a new pattern is created. In either case, the pattern is +returned. Example + + +pattern = FcPatternBuild (0, FC_FAMILY, FtTypeString, "Times", (char *) 0); + + +FcPatternVaBuild is used when the arguments are already in the form of a +varargs value. + + FcPatternDel +FcBool FcPatternDel (FcPattern *p, const char *object) + +Deletes all values associated with the property `object', returning +whether the property existed or not. + + FcPatternPrint +void FcPatternPrint (const FcPattern *p) + +Prints an easily readable version of the pattern to stdout. There is +no provision for reparsing data in this format, it's just for diagnostics +and debugging. + + FcDefaultSubstitute +void FcDefaultSubstitute (FcPattern *pattern) + +Supplies default values for underspecified font patterns: + + +Patterns without a specified style or weight are set to Medium + + +Patterns without a specified style or slant are set to Roman + + +Patterns without a specified pixel size are given one computed from any +specified point size (default 12), dpi (default 75) and scale (default 1). + + + + FcNameParse +FcPattern *FcNameParse (const char *name) + +Converts 'name' from the standard text format described above into a pattern. + + FcNameUnparse +FcChar8 *FcNameUnparse (FcPattern *pat) + +Converts the given pattern into the standard text format described above. +The return value is not static, but instead refers to newly allocated memory +which should be freed by the caller. + + + FcFontSet + +An FcFontSet simply holds a list of patterns; these are used to return the +results of listing available fonts. + + FcFontSetCreate +FcFontSet *FcFontSetCreate (void) + +Creates an empty font set. + + FcFontSetDestroy +void FcFontSetDestroy (FcFontSet *s); + +Destroys a font set. Note that this destroys any referenced patterns as +well. + + FcFontSetAdd +FcBool FcFontSetAdd (FcFontSet *s, FcPattern *font) + +Adds a pattern to a font set. Note that the pattern is not copied before +being inserted into the set. + + + FcObjectSet + +An FcObjectSet holds a list of pattern property names; it is used to +indiciate which properties are to be returned in the patterns from +FcFontList. + + FcObjectSetCreate +FcObjectSet *FcObjectSetCreate (void) + +Creates an empty set. + + FcObjectSetAdd +FcBool FcObjectSetAdd (FcObjectSet *os, const char *object) + +Adds a proprety name to the set. + + FcObjectSetDestroy +void FcObjectSetDestroy (FcObjectSet *os) + +Destroys an object set. + + FcObjectSetBuild, FcObjectSetVaBuild +FcObjectSet *FcObjectSetBuild (const char *first, ...) +FcObjectSet *FcObjectSetVaBuild (const char *first, va_list va) + +These build an object set from a null-terminated list of property names. + + + FcObjectType + +Provides for applcation-specified font name object types so that new +pattern elements can be generated from font names. + + FcNameRegisterObjectTypes +FcBool FcNameRegisterObjectTypes (const FcObjectType *types, int ntype) + +Register 'ntype' new object types. + + FcNameUnregisterObjectTypes +FcBool FcNameUnregisterObjectTypes (const FcObjectType *types, int ntype) + +Unregister 'ntype' object types. + + FcNameGetObjectType +const FcObjectType *FcNameGetObjectType (const char *object) + +Return the object type for the pattern element named 'object'. + + + FcConstant + +Provides for application-specified symbolic constants for font names. + + FcNameRegisterConstants +FcBool FcNameRegisterConstants (const FcConstant *consts, int nconsts) + +Register 'nconsts' new symbolic constants. + + FcNameUnregisterConstants +FcBool FcNameUnregisterConstants (const FcConstant *consts, int nconsts) + +Unregister 'nconsts' symbolic constants. + + FcNameGetConstant +const FcConstant *FcNameGetConstant (FcChar8 *string) + +Return the FcConstant structure related to symbolic constant 'string'. + + FcNameConstant +FcBool FcNameConstant (FcChar8 *string, int *result); + +Returns whether a symbolic constant with name 'string' is registered, +placing the value of the constant in 'result' if present. + + + FcBlanks + +An FcBlanks object holds a list of Unicode chars which are expected to +be blank when drawn. When scanning new fonts, any glyphs which are +empty and not in this list will be assumed to be broken and not placed in +the FcCharSet associated with the font. This provides a significantly more +accurate CharSet for applications. + + FcBlanksCreate +FcBlanks *FcBlanksCreate (void) + +Creates an empty FcBlanks object. + + FcBlanksDestroy +void FcBlanksDestroy (FcBlanks *b) + +Destroys an FcBlanks object, freeing any associated memory. + + FcBlanksAdd +FcBool FcBlanksAdd (FcBlanks *b, FcChar32 ucs4) + +Adds a single character to an FcBlanks object, returning FcFalse +if this process ran out of memory. + + FcBlanksIsMember +FcBool FcBlanksIsMember (FcBlanks *b, FcChar32 ucs4) + +Returns whether the specified FcBlanks object contains the indicated Unicode +value. + + + FcConfig + +An FcConfig object holds the internal representation of a configuration. +There is a default configuration which applications may use by passing 0 to +any function using the data within an FcConfig. + + FcConfigCreate +FcConfig *FcConfigCreate (void) + +Creates an empty configuration. + + FcConfigDestroy +void FcConfigDestroy (FcConfig *config) + +Destroys a configuration and any data associated with it. Note that calling +this function with the return from FcConfigGetCurrent will place the library +in an indeterminate state. + + FcConfigSetCurrent +FcBool FcConfigSetCurrent (FcConfig *config) + +Sets the current default configuration to 'config'. Implicitly calls +FcConfigBuildFonts if necessary, returning FcFalse if that call fails. + + FcConfigGetCurrent +FcConfig *FcConfigGetCurrent (void) + +Returns the current default configuration. + + FcConfigUptoDate +FcBool FcConfigUptoDate (FcConfig *config) + +Checks all of the files related to 'config' and returns whether the +in-memory version is in sync with the disk version. + + FcConfigBuildFonts +FcBool FcConfigBuildFonts (FcConfig *config) + +Builds the set of available fonts for the given configuration. Note that +any changes to the configuration after this call have indeterminate effects. +Returns FcFalse if this operation runs out of memory. + + FcConfigGetConfigDirs +FcStrList *FcConfigGetConfigDirs (FcConfig *config) + +Returns the list of font directories specified in the configuration files +for 'config'. Does not include any subdirectories. + + FcConfigGetFontDirs +FcStrList *FcConfigGetFontDirs (FcConfig *config) + +Returns the list of font directories in 'config'. This includes the +configured font directories along with any directories below those in the +filesystem. + + FcConfigGetConfigFiles +FcStrList *FcConfigGetConfigFiles (FcConfig *config) + +Returns the list of known configuration files used to generate 'config'. +Note that this will not include any configuration done with FcConfigParse. + + FcConfigGetCache +char *FcConfigGetCache (FcConfig *config) + +Returns the name of the file used to store per-user font information. + + FcConfigGetFonts +FcFontSet *FcConfigGetFonts (FcConfig *config, FcSetName set) + +Returns one of the two sets of fonts from the configuration as specified +by 'set'. + + FcConfigGetBlanks +FcBlanks *FcConfigGetBlanks (FcConfig *config) + +Returns the FcBlanks object associated with the given configuration, if no +blanks were present in the configuration, this function will return 0. + + FcConfigGetRescanInverval +int FcConfigGetRescanInverval (FcConfig *config) + +Returns the interval between automatic checks of the configuration (in +seconds) specified in 'config'. The configuration is checked during +a call to FcFontList when this interval has passed since the last check. + + FcConfigSetRescanInverval +FcBool FcConfigSetRescanInverval (FcConfig *config, int rescanInterval) + +Sets the rescan interval; returns FcFalse if an error occurred. + + FcConfigAppFontAddFile +FcBool FcConfigAppFontAddFile (FcConfig *config, const char *file) + +Adds an application-specific font to the configuration. + + FcConfigAppFontAddDir +FcBool FcConfigAppFontAddDir (FcConfig *config, const char *dir) + +Scans the specified directory for fonts, adding each one found to the +application-specific set of fonts. + + FcConfigAppFontClear +void FcConfigAppFontClear (FcConfig *config) + +Clears the set of application-specific fonts. + + FcConfigSubstituteWithPat +FcBool FcConfigSubstituteWithPat (FcConfig *config, FcPattern *p, FcPattern *p_pat FcMatchKind kind) + +Performs the sequence of pattern modification operations, if 'kind' is +FcMatchPattern, then those tagged as pattern operations are applied, else +if 'kind' is FcMatchFont, those tagged as font operations are applied and +p_pat is used for <test> elements with target=pattern. + + FcConfigSubstitute +FcBool FcConfigSubstitute (FcConfig *config, FcPattern *p, FcMatchKind kind) + +Calls FcConfigSubstituteWithPat setting p_pat to NULL. + + FcFontMatch +FcPattern *FcFontMatch (FcConfig *config, FcPattern *p, FcResult *result) + +Returns the font in 'config' most close matching 'p'. This function +should be called only after FcConfigSubstitute and FcDefaultSubstitute have +been called for 'p'; otherwise the results will not be correct. + + FcFontSort +FcFontSet *FcFontSort (FcConfig *config, FcPattern *p, FcBool trim, FcCharSet **csp, FcResult *result) + +Returns the list of fonts sorted by closeness to 'p'. If 'trim' is FcTrue, +elements in the list which don't include Unicode coverage not provided by +earlier elements in the list are elided. The union of Unicode coverage of +all of the fonts is returned in 'csp', if 'csp' is not NULL. This function +should be called only after FcConfigSubstitute and FcDefaultSubstitute have +been called for 'p'; otherwise the results will not be correct. + +The returned FcFontSet references FcPattern structures which may be shared +by the return value from multiple FcFontSort calls, applications must not +modify these patterns. Instead, they should be passed, along with 'p' to +FcFontRenderPrepare which combines them into a complete pattern. + +The FcFontSet returned by FcFontSort is destroyed by caling FcFontSetDestroy. + + FcFontRenderPrepare +FcPattern *FcFontRenderPrepare (FcConfig *config, FcPattern *pat, FcPattern *font) + +Creates a new pattern consisting of elements of 'font' not appearing +in 'pat', elements of 'pat' not appearing in 'font' and the best matching +value from 'pat' for elements appearing in both. The result is passed to +FcConfigSubstitute with 'kind' FcMatchFont and then returned. + + FcFontList +FcFontSet *FcFontList (FcConfig *config, FcPattern *p, FcObjectSet *os) + +Selects fonts matching 'p', creates patterns from those fonts containing +only the objects in 'os' and returns the set of unique such patterns. + + FcConfigFilename +char *FcConfigFilename (const char *name) + +Given the specified external entity name, return the associated filename. +This provides applications a way to convert various configuration file +references into filename form. + +A null or empty 'name' indicates that the default configuration file should +be used; which file this references can be overridden with the +FC_CONFIG_FILE environment variable. Next, if the name starts with '~', it +refers to a file in the current users home directory. Otherwise if the name +doesn't start with '/', it refers to a file in the default configuration +directory; the built-in default directory can be overridden with the +FC_CONFIG_DIR environment variable. + + + Initialization + +These functions provide some control over how the library is initialized. + + FcInitLoadConfig +FcConfig *FcInitLoadConfig (void) + +Loads the default configuration file and returns the resulting configuration. +Does not load any font information. + + FcInitLoadConfigAndFonts +FcConfig *FcInitLoadConfigAndFonts (void) + +Loads the default configuration file and builds information about the +available fonts. Returns the resulting configuration. + + FcInit +FcBool FcInit (void) + +Loads the default configuration file and the fonts referenced therein and +sets the default configuration to that result. Returns whether this +process succeeded or not. If the default configuration has already +been loaded, this routine does nothing and returns FcTrue. + + FcGetVersion +int FcGetVersion (void) + +Returns the version number of the library. + + FcInitReinitialize +FcBool FcInitReinitialize (void) + +Forces the default configuration file to be reloaded and resets the default +configuration. + + FcInitBringUptoDate +FcBool FcInitBringUptoDate (void) + +Checks the rescan interval in the default configuration, checking the +configuration if the interval has passed and reloading the configuration if +when any changes are detected. + + + FcAtomic + +These functions provide a safe way to update config files, allowing ongoing +reading of the old config file while locked for writing and ensuring that a +consistent and complete version of the config file is always available. + + FcAtomicCreate +FcAtomic * FcAtomicCreate (const FcChar8 *file) + +Creates a data structure containing data needed to control access to 'file'. +Writing is done to a separate file. Once that file is complete, the original +configuration file is atomically replaced so that reading process always see +a consistent and complete file without the need to lock for reading. + + FcAtomicLock +FcBool FcAtomicLock (FcAtomic *atomic) + +Attempts to lock the file referenced by 'atomic'. Returns FcFalse if the +file is locked by another process, else returns FcTrue and leaves the file +locked. + + FcAtomicNewFile +FcChar8 *FcAtomicNewFile (FcAtomic *atomic) + +Returns the filename for writing a new version of the file referenced +by 'atomic'. + + FcAtomicOrigFile +FcChar8 *FcAtomicOrigFile (FcAtomic *atomic) + +Returns the file refernced by 'atomic'. + + FcAtomicReplaceOrig +FcBool FcAtomicReplaceOrig (FcAtomic *atomic) + +Replaces the original file referenced by 'atomic' with the new file. + + FcAtomicDeleteNew +void FcAtomicDeleteNew (FcAtomic *atomic) + +Deletes the new file. + + FcAtomicUnlock +void FcAtomicUnlock (FcAtomic *atomic) + +Unlocks the file. + + FcAtomicDestroy +void FcAtomicDestroy (FcAtomic *atomic) + +Destroys 'atomic'. + + + FreeType specific functions + + +#include <fontconfig/fcfreetype.h> + +While the fontconfig library doesn't insist that FreeType be used as the +rasterization mechanism for fonts, it does provide some convenience +functions. + + FcFreeTypeCharIndex +FT_UInt FcFreeTypeCharIndex (FT_Face face, FcChar32 ucs4) + +Maps a Unicode char to a glyph index. This function uses information from +several possible underlying encoding tables to work around broken fonts. +As a result, this function isn't designed to be used in performance +sensitive areas; results from this function are intended to be cached by +higher level functions. + + FcFreeTypeCharSet +FcCharSet *FcFreeTypeCharSet (FT_Face face, FcBlanks *blanks) Scans a + +FreeType face and returns the set of encoded Unicode chars. This scans +several encoding tables to build as complete a list as possible. +If 'blanks' is not 0, the glyphs in the font are examined and any blank glyphs +not in 'blanks' are not placed in the returned FcCharSet. + + FcFreeTypeQuery +FcPattern *FcFreeTypeQuery (const char *file, int id, FcBlanks *blanks, int *count) + +Constructs a pattern representing the 'id'th font in 'file'. The number +of fonts in 'file' is returned in 'count'. + + + XML specific functions + FcConfigParseAndLoad +FcBool FcConfigParseAndLoad (FcConfig *config, const FcChar8 *file, FcBool complain) + +Walks the configuration in 'file' and constructs the internal representation +in 'config'. Any include files referenced from within 'file' will be loaded +with FcConfigLoad and also parsed. If 'complain' is FcFalse, no warning +will be displayed if 'file' does not exist. + + + File and Directory routines + FcFileScan +FcBool FcFileScan (FcFontSet *set, FcStrSet *dirs, FcFileCache *cache, FcBlanks *blanks, const char *file, FcBool force) + +Scans a single file and adds all fonts found to 'set'. If 'force' is FcTrue, +then the file is scanned even if associated information is found in 'cache'. +If 'file' is a directory, it is added to 'dirs'. + + FcDirScan +FcBool FcDirScan (FcFontSet *set, FcStrSet *dirs, FcFileCache *cache, FcBlanks *blanks, const char *dir, FcBool force) + +Scans an entire directory and adds all fonts found to 'set'. If 'force' is +FcTrue, then the directory and all files within it are scanned even if +information is present in the per-directory cache file or 'cache'. Any +subdirectories found are added to 'dirs'. + + FcDirSave +FcBool FcDirSave (FcFontSet *set, FcStrSet *dirs, const char *dir) + +Creates the per-directory cache file for 'dir' and populates it with the +fonts in 'set' and subdirectories in 'dirs'. + + FcDirCacheValid +FcBool FcDirCacheValid (const FcChar8 *cache_file) + +Returns FcTrue if 'cache_file' is no older than the directory containing it, +else FcFalse. + + + FcStrSet and FcStrList + +A data structure for enumerating strings, used to list directories while +scanning the configuration as directories are added while scanning. + + FcStrSetCreate +FcStrSet *FcStrSetCreate (void) + +Create an empty set. + + FcStrSetMember +FcBool FcStrSetMember (FcStrSet *set, const FcChar8 *s) + +Returns whether 's' is a member of 'set'. + + FcStrSetAdd +FcBool FcStrSetAdd (FcStrSet *set, const FcChar8 *s) + +Adds a copy of 's' to 'set'. + + FcStrSetAddFilename +FcBool FcStrSetAddFilename (FcStrSet *set, const FcChar8 *s) + +Adds a copy 's' to 'set', The copy is created with FcStrCopyFilename +so that leading '~' values are replaced with the value of the HOME +environment variable. + + FcStrSetDel +FcBool FcStrSetDel (FcStrSet *set, const FcChar8 *s) + +Removes 's' from 'set', returning FcTrue if 's' was a member else FcFalse. + + FcStrSetDestroy +void FcStrSetDestroy (FcStrSet *set) + +Destroys 'set'. + + FcStrListCreate +FcStrList *FcStrListCreate (FcStrSet *set) + +Creates an enumerator to list the strings in 'set'. + + FcStrListNext +FcChar8 *FcStrListNext (FcStrList *list) + +Returns the next string in 'set'. + + FcStrListDone +void FcStrListDone (FcStrList *list) + +Destroys the enumerator 'list'. + + + String utilities + FcUtf8ToUcs4 + +int FcUtf8ToUcs4 (FcChar8 *src, FcChar32 *dst, int len) + + +Converts the next Unicode char from 'src' into 'dst' and returns the number +of bytes containing the char. 'src' nust be at least 'len' bytes long. + + + FcUcs4ToUtf8 +int FcUcs4ToUtf8 (FcChar32 src, FcChar8 dst[FC_UTF8_MAX_LEN]) + +Converts the Unicode char from 'src' into 'dst' and returns the +number of bytes needed to encode the char. + + FcUtf8Len +FcBool FcUtf8Len (FcChar8 *src, int len, int *nchar, int *wchar) + +Counts the number of Unicode chars in 'len' bytes of 'src'. Places that +count in 'nchar'. 'wchar' contains 1, 2 or 4 depending on the number of +bytes needed to hold the largest unicode char counted. The return value +indicates whether 'src' is a well-formed UTF8 string. + + FcUtf16ToUcs4 +int FcUtf16ToUcs4 (FcChar8 *src, FcEndian endian, FcChar32 *dst, int len) + +Converts the next Unicode char from 'src' into 'dst' and returns the +number of bytes containing the char. 'src' must be at least 'len' bytes +long. Bytes of 'src' are combined into 16-bit units according to 'endian'. + + FcUtf16Len +FcBool FcUtf16Len (FcChar8 *src, FcEndian endian, int len, int *nchar, int *wchar) + +Counts the number of Unicode chars in 'len' bytes of 'src'. Bytes of 'src' +are combined into 16-bit units according to 'endian'. Places that +count in 'nchar'. 'wchar' contains 1, 2 or 4 depending on the number of +bytes needed to hold the largest unicode char counted. The return value +indicates whether 'string' is a well-formed UTF16 string. + + FcStrCopy +FcChar8 *FcStrCopy (const FcChar8 *s) + +Allocates memory, copies 's' and returns the resulting buffer. Yes, this +is 'strdup', but that function isn't available on every platform. + + FcStrCopyFilename +FcChar8 *FcStrCopyFilename (const FcChar8 *s) + +Just like FcStrCopy except that it converts any leading '~' characters +in 's' to the value of the HOME environment variable. + + FcStrCmpIgnoreCase +int FcStrCmpIgnoreCase (const char *s1, const char *s2) + +Returns the usual <0, 0, >0 result of comparing 's1' and 's2'. This test +is case-insensitive in the ASCII range and will operate properly with UTF8 +encoded strings, although it does not check for well formed strings. + + FcStrDirname +FcChar8 *FcStrDirname (const FcChar8 *file) + +Returns the directory containing 'file'. + + FcStrBasename +FcChar8 *FcStrBasename (const FcChar8 *file) + +Returns the filename of 'file' stripped of any leading directory names. + + + +
diff --git a/doc/fontconfig-user.sgml b/doc/fontconfig-user.sgml new file mode 100644 index 0000000..f243f6d --- /dev/null +++ b/doc/fontconfig-user.sgml @@ -0,0 +1,559 @@ + + +
+ + Fontconfig Users Guide + Fontconfig + KeithPackard + krp + +NAME + + fontconfig - Font configuration and customization library + + +DESCRIPTION + +Fontconfig is a library designed to provide system-wide font configuration, +customization and application access. + + +FUNCTIONAL OVERVIEW + +Fontconfig contains two essential modules, the configuration module which +builds an internal configuration from XML files and the matching module +which accepts font patterns and returns the nearest matching font. + + FONT CONFIGURATION + +The configuration module consists of the FcConfig datatype, libexpat and +FcConfigParse which walks over an XML tree and ammends a configuration with +data found within. From an external perspective, configuration of the +library consists of generating a valid XML tree and feeding that to +FcConfigParse. The only other mechanism provided to applications for +changing the running configuration is to add fonts and directories to the +list of application-provided font files. + +The intent is to make font configurations relatively static, and shared by +as many applications as possible. It is hoped that this will lead to more +stable font selection when passing names from one application to another. +XML was chosen as a configuration file format because it provides a format +which is easy for external agents to edit while retaining the correct +structure and syntax. + +Font configuration is separate from font matching; applications needing to +do their own matching can access the available fonts from the library and +perform private matching. The intent is to permit applications to pick and +choose appropriate functionality from the library instead of forcing them to +choose between this library and a private configuration mechanism. The hope +is that this will ensure that configuration of fonts for all applications +can be centralized in one place. Centralizing font configuration will +simplify and regularize font installation and customization. + + + + FONT PROPERTIES + +While font patterns may contain essentially any properties, there are some +well known properties with associated types. Fontconfig uses some of these +properties for font matching and font completion. Others are provided as a +convenience for the applications rendering mechanism. + + + Property Definitions + + + + + + + Property + Type + Description + + + +familyStringFont family name +styleStringFont style. Overrides weight and slant +slantIntItalic, oblique or roman +weightIntLight, medium, demibold, bold or black +sizeDoublePoint size +aspectDoubleStretches glyphs horizontally before hinting +pixelsizeDoublePixel size +spacingIntProportional, monospace or charcell +foundryStringFont foundry name +antialiasBoolWhether glyphs can be antialiased +hintingBoolWhether the rasterizer should use hinting +verticallayoutBoolUse vertical layout +autohintBoolUse autohinter instead of normal hinter +globaladvanceBoolUse font global advance data +fileStringThe filename holding the font +indexIntThe index of the font within the file +ftfaceFT_FaceUse the specified FreeType face object +rasterizerStringWhich rasterizer is in use +outlineBoolWhether the glyphs are outlines +scalableBoolWhether glyphs can be scaled +scaleDoubleScale factor for point->pixel conversions +dpiDoubleTarget dots per inch +rgbaIntunknown, rgb, bgr, vrgb, vbgr, none - subpixel geometry +minspaceBoolEliminate leading from line spacing +charsetCharSetUnicode chars encoded by the font +langStringList of RFC-3066-style languages this font supports + + +
+ + + FONT MATCHING + +Fontconfig performs matching by measuring the distance from a provided +pattern to all of the available fonts in the system. The closest matching +font is selected. This ensures that a font will always be returned, but +doesn't ensure that it is anything like the requested pattern. + +Font matching starts with an application constructed pattern. The desired +attributes of the resulting font are collected together in a pattern. Each +property of the pattern can contain one or more values; these are listed in +priority order; matches earlier in the list are considered "closer" than +matches later in the list. + +The initial pattern is modified by applying the list of editing instructions +specific to patterns found in the configuration; each consists of a match +predicate and a set of editing operations. They are executed in the order +they appeared in the configuration. Each match causes the associated +sequence of editing operations to be applied. + +After the pattern has been edited, a sequence of default substitutions are +performed to canonicalize the set of available properties; this avoids the +need for the lower layers to constantly provide default values for various +font properties during rendering. + +The canonical font pattern is finally matched against all available fonts. +The distance from the pattern to the font is measured for each of several +properties: foundry, charset, family, lang, spacing, pixelsize, style, +slant, weight, antialias, rasterizer and outline. This list is in priority +order -- results of comparing earlier elements of this list weigh more +heavily than later elements. + +There is one special case to this rule; family names are split into two +bindings; strong and weak. Strong family names are given greater precedence +in the match than lang elements while weak family names are given lower +precedence than lang elements. This permits the document language to drive +font selection when any document specified font is unavailable. + +The pattern representing that font is augmented to include any properties +found in the pattern but not found in the font itself; this permits the +application to pass rendering instructions or any other data through the +matching system. Finally, the list of editing instructions specific to +fonts found in the configuration are applied to the pattern. This modified +pattern is returned to the application. + +The return value contains sufficient information to locate and rasterize the +font, including the file name, pixel size and other rendering data. As +none of the information involved pertains to the FreeType library, +applications are free to use any rasterization engine or even to take +the identified font file and access it directly. + +The match/edit sequences in the configuration are performed in two passes +because there are essentially two different operations necessary -- the +first is to modify how fonts are selected; aliasing families and adding +suitable defaults. The second is to modify how the selected fonts are +rasterized. Those must apply to the selected font, not the original pattern +as false matches will often occur. + + + FONT NAMES + +Fontconfig provides a textual representation for patterns that the library +can both accept and generate. The representation is in three parts, first a +list of family names, second a list of point sizes and finally a list of +additional properties: + + + <families>-<point sizes>:<name1>=<values1>:<name2>=<values2>... + + +Values in a list are separated with commas. The name needn't include either +families or point sizes; they can be elided. In addition, there are +symbolic constants that simultaneously indicate both a name and a value. +Here are some examples: + + + Sample Font Names + + + Name + Meaning + + +Times-1212 point Times Roman +Times-12:bold12 point Times Bold +Courier:italicCourier Italic in the default size +Monospace:matrix=1 .1 0 1The users preferred monospace font +with artificial obliquing + + +
+ + +LANG TAGS + +Each font in the database contains a list of languages it supports. This is +computed by comparing the Unicode coverage of the font with the orthography +of each language. Languages are tagged using an RFC-3066 compatible naming +and occur in two parts -- the ISO639 language tag followed a hyphen and then +by the ISO 3166 country code. The hyphen and country code may be elided. + +Fontconfig has orthographies for several languages built into the library. +No provision has been made for adding new ones aside from rebuilding the +library. It currently supports 122 of the 139 languages named in ISO 639-1, +141 of the languages with two-letter codes from ISO 639-2 and another 30 +languages with only three-letter codes. + + +CONFIGURATION FILE FORMAT + +Configuration files for fontconfig are stored in XML format; this +format makes external configuration tools easier to write and ensures that +they will generate syntactically correct configuration files. As XML +files are plain text, they can also be manipulated by the expert user using +a text editor. + +The fontconfig document type definition resides in the external entity +"fonts.dtd"; this is normally stored in the default font configuration +directory (/etc/fonts). Each configuration file should contain the +following structure: + + <?xml version="1.0"?> + <!DOCTYPE fontconfig SYSTEM "fonts.dtd"> + <fontconfig> + ... + </fontconfig> + + + <fontconfig> +This is the top level element for a font configuration and can contain +<dir>, <cache>, <include>, <match> and <alias> elements in any order. + + <dir> +This element contains a directory name which will be scanned for font files +to include in the set of available fonts. + + <cache> +This element contains a file name for the per-user cache of font +information. If it starts with '~', it refers to a file in the users +home directory. This file is used to hold information about fonts that +isn't present in the per-directory cache files. It is automatically +maintained by the fontconfig library. The default for this file +is ``~/.fonts.cache-<version>'', where <version> is the font configuration +file version number (currently 1). + + <include ignore_missing="no"> +This element contains the name of an additional configuration file. When +the XML datatype is traversed by FcConfigParse, the contents of the file +will also be incorporated into the configuration by passing the filename to +FcConfigLoadAndParse. If 'ignore_missing' is set to "yes" instead of the +default "no", a missing file will elicit no warning message from the library. + + <config> +This element provides a place to consolodate additional configuration +information. <config> can contain <blank> and <rescan> elements in any +order. + + <blank> +Fonts often include "broken" glyphs which appear in the encoding but are +drawn as blanks on the screen. Within the <blank> element, place each +Unicode characters which is supposed to be blank in an <int> element. +Characters outside of this set which are drawn as blank will be elided from +the set of characters supported by the font. + + <rescan> +The <rescan> element holds an <int> element which indicates the default +interval between automatic checks for font configuration changes. +Fontconfig will validate all of the configuration files and directories and +automatically rebuild the internal datastructures when this interval passes. + + <match target="pattern"> +This element holds first a (possibly empty) list of <test> elements and then +a (possibly empty) list of <edit> elements. Patterns which match all of the +tests are subjected to all the edits. If 'target' is set to "font" instead +of the default "pattern", then this element applies to the font name +resulting from a match rather than a font pattern to be matched. + + <test qual="any" name="property" compare="eq"> +This element contains a single value which is compared with the pattern +property "property" (substitute any of the property names seen +above). 'compare' can be one of "eq", "not_eq", "less", "less_eq", "more", or +"more_eq". 'qual' may either be the default, "any", in which case the match +succeeds if any value associated with the property matches the test value, or +"all", in which case all of the values associated with the property must +match the test value. + + <edit name="property" mode="assign" binding="weak"> +This element contains a list of expression elements (any of the value or +operator elements). The expression elements are evaluated at run-time and +modify the property "property". The modification depends on whether +"property" was matched by one of the associated <test> elements, if so, the +modification may affect the first matched value. Any values inserted into +the property are given the indicated binding. 'mode' is one of: + + Edit Element Modes + + + + Mode + Operation With Match + Operation Without Match + + + +"assign"Replace matching valueReplace all values +"assign_replace"Replace all valuesReplace all values +"prepend"Insert before matching valueInsert at head of list +"prepend_first"Insert at head of listInsert at head of list +"append"Append after matching valueAppend at end of list +"append_last"Append at end of listAppend at end of list + + +
+ + <int>, <double>, <string>, <bool> +These elements hold a single value of the indicated type. <bool> elements +hold either true or false. + + <matrix> +This element holds the four <double> elements of an affine +transformation. + + <name> +Holds a property name. Evaluates to the first value from the property of +the font, not the pattern. + + <const> +Holds the name of a constant; these are always integers and serve as +symbolic names for common font values: + + Symbolic Constants + + + + Constant + Property + CPP Symbol + + + +lightweight +mediumweight +demiboldweight +boldweight +blackweight +romanslant +italicslant +obliqueslant +proportionalspacing +monospacing +charcellspacing +unknownrgba +rgbrgba +bgrrgba +vrgbrgba +vbgrrgba +nonergba + + +
+ <or>, + <and>, + <plus>, + <minus>, + <times>, + <divide> +These elements perform the specified operation on a list of expression +elements. <or> and <and> are boolean, not bitwise. + <eq>, + <not_eq>, + <less>, + <less_eq>, + <more>, + <more_eq> +These elements compare two values, producing a boolean result. + + <not> +Inverts the boolean sense of its one expression element + + <if> +This element takes three expression elements; if the value of the first is +true, it produces the value of the second, otherwise it produces the value +of the third. + + <alias> +Alias elements provide a shorthand notation for the set of common match +operations needed to substitute one font family for another. They contain a +<family> element followed by optional <prefer>, <accept> and <default> +elements. Fonts matching the <family> element are edited to prepend the +list of <prefer>ed families before the matching <family>, append the +<accept>able familys after the matching <family> and append the <default> +families to the end of the family list. + + <family> +Holds a single font family name + + <prefer>, <accept>, <default> +These hold a list of <family> elements to be used by the <alias> element. +</article> + + +EXAMPLE CONFIGURATION FILE + System configuration file + +This is an example of a system-wide configuration file + + +<?xml version="1.0"?> +<!DOCTYPE fontconfig SYSTEM "fonts.dtd"> +<!-- /etc/fonts/fonts.conf file to configure system font access --> +<fontconfig> +<!-- + Find fonts in these directories +--> +<dir>/usr/X11R6/lib/X11/fonts/truetype</dir> +<dir>/usr/X11R6/lib/X11/fonts/Type1</dir> + +<!-- + Accept deprecated 'mono' alias, replacing it with 'monospace' +--> +<match target="pattern"> + <test qual="any" name="family"><string>mono</string></test> + <edit name="family" mode="assign"><string>monospace</string></edit> +</match> + +<!-- + Names not including any well known alias are given 'sans' +--> +<match target="pattern"> + <test qual="all" name="family" mode="not_eq">sans</test> + <test qual="all" name="family" mode="not_eq">serif</test> + <test qual="all" name="family" mode="not_eq">monospace</test> + <edit name="family" mode="append_last"><string>sans</string></edit> +</match> + +<!-- + Load per-user customization file, but don't complain + if it doesn't exist +--> +<include ignore_missing="yes">~/.fonts.conf</include> + +<!-- + Alias well known font names to available TrueType fonts. + These substitute TrueType faces for similar Type1 + faces to improve screen appearance. +--> +<alias> + <family>Times</family> + <prefer><family>Times New Roman</family></prefer> + <default><family>serif</family></default> +</alias> +<alias> + <family>Helvetica</family> + <prefer><family>Verdana</family></prefer> + <default><family>sans</family></default> +</alias> +<alias> + <family>Courier</family> + <prefer><family>Courier New</family></prefer> + <default><family>monospace</family></default> +</alias> + +<!-- + Provide required aliases for standard names + Do these after the users configuration file so that + any aliases there are used preferentially +--> +<alias> + <family>serif</family> + <prefer><family>Times New Roman</family></prefer> +</alias> +<alias> + <family>sans</family> + <prefer><family>Verdana</family></prefer> +</alias> +<alias> + <family>monospace</family> + <prefer><family>Andale Mono</family></prefer> +</alias> +</fontconfig> + + User configuration file + +This is an example of a per-user configuration file that lives in +~/.fonts.conf + + +<?xml version="1.0"?> +<!DOCTYPE fontconfig SYSTEM "fonts.dtd"> +<!-- ~/.fonts.conf for per-user font configuration --> +<fontconfig> + +<!-- + Private font directory +--> +<dir>~/misc/fonts</dir> + +<!-- + use rgb sub-pixel ordering to improve glyph appearance on + LCD screens. Changes affecting rendering, but not matching + should always use target="font". +--> +<match target="font"> + <edit name="rgba" mode="assign"><const>rgb</const></edit> +</match> +</fontconfig> + + +FILES + +fonts.conf +contains configuration information for the fontconfig library +consisting of directories to look at for font information as well as +instructions on editing program specified font patterns before attempting to +match the available fonts. It is in xml format. + + +fonts.dtd +is a DTD that describes the format of the configuration files. + + +~/.fonts.conf +is the conventional location for per-user font configuration, although the +actual location is specified in the global fonts.conf file. + + + ~/.fonts.cache-* +is the conventional repository of font information that isn't found in the +per-directory caches. This file is automatically maintained by fontconfig. + + +
diff --git a/doc/fontconfig.tex b/doc/fontconfig.tex deleted file mode 100644 index 2e60a51..0000000 --- a/doc/fontconfig.tex +++ /dev/null @@ -1,55 +0,0 @@ -\documentclass[10pt]{article} -\usepackage{latexsym} -\usepackage{epsfig} -\usepackage{times} - -\begin{document} -\date{} -\title{The Fontconfig Library:\\ -Architecture and Users Guide} -\author{Keith Packard\\ -{\em XFree86 Core Team}\\ -keithp@keithp.com} -\maketitle -\thispagestyle{empty} - -\abstract - -The Fontconfig library provides for central administration and configuration -of fonts in a POSIX system. All font consumers can share a common database -of fonts and use common matching rules for font names. The set of available -fonts can be configured for each user and a set of configurable matching -rules allow for customizing the selection of fonts and configuring various -parameters related to rasterizing of those fonts for display in a variety of -media. The Fontconfig library is designed to co-exist peacefully with -existing font configuration and rasterization mechanisms; while it uses the -FreeType library to discover characteristics of available fonts, there -is no requirement to use FreeType for rasterization. - -\section {Introduction} - -\section {Configuration Files} - -\section {Application Interface} - -\subsection {Datatypes} - -\subsection {Font Set Interface} - -\subsection {Font Patterns} - -\subsection {Listing Available Fonts} - -\subsection {Using Font Names} - -\subsection {Manipulating Matrices} - -\subsection {UTF-8 Helper Functions} - -\section {Font Sub-System Interface} - -\subsection {Extending Font Names} - -\subsection {Executing Configuration Rules} - -\end{document}