Edit File: ftmm.h
/***************************************************************************/ /* */ /* ftmm.h */ /* */ /* FreeType Multiple Master font interface (specification). */ /* */ /* Copyright 1996-2018 by */ /* David Turner, Robert Wilhelm, and Werner Lemberg. */ /* */ /* This file is part of the FreeType project, and may only be used, */ /* modified, and distributed under the terms of the FreeType project */ /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ /* this file you indicate that you have read the license and */ /* understand and accept it fully. */ /* */ /***************************************************************************/ #ifndef FTMM_H_ #define FTMM_H_ #include <ft2build.h> #include FT_TYPE1_TABLES_H FT_BEGIN_HEADER /*************************************************************************/ /* */ /* <Section> */ /* multiple_masters */ /* */ /* <Title> */ /* Multiple Masters */ /* */ /* <Abstract> */ /* How to manage Multiple Masters fonts. */ /* */ /* <Description> */ /* The following types and functions are used to manage Multiple */ /* Master fonts, i.e., the selection of specific design instances by */ /* setting design axis coordinates. */ /* */ /* Besides Adobe MM fonts, the interface supports Apple's TrueType GX */ /* and OpenType variation fonts. Some of the routines only work with */ /* Adobe MM fonts, others will work with all three types. They are */ /* similar enough that a consistent interface makes sense. */ /* */ /*************************************************************************/ /*************************************************************************/ /* */ /* <Struct> */ /* FT_MM_Axis */ /* */ /* <Description> */ /* A structure to model a given axis in design space for Multiple */ /* Masters fonts. */ /* */ /* This structure can't be used for TrueType GX or OpenType variation */ /* fonts. */ /* */ /* <Fields> */ /* name :: The axis's name. */ /* */ /* minimum :: The axis's minimum design coordinate. */ /* */ /* maximum :: The axis's maximum design coordinate. */ /* */ typedef struct FT_MM_Axis_ { FT_String* name; FT_Long minimum; FT_Long maximum; } FT_MM_Axis; /*************************************************************************/ /* */ /* <Struct> */ /* FT_Multi_Master */ /* */ /* <Description> */ /* A structure to model the axes and space of a Multiple Masters */ /* font. */ /* */ /* This structure can't be used for TrueType GX or OpenType variation */ /* fonts. */ /* */ /* <Fields> */ /* num_axis :: Number of axes. Cannot exceed~4. */ /* */ /* num_designs :: Number of designs; should be normally 2^num_axis */ /* even though the Type~1 specification strangely */ /* allows for intermediate designs to be present. */ /* This number cannot exceed~16. */ /* */ /* axis :: A table of axis descriptors. */ /* */ typedef struct FT_Multi_Master_ { FT_UInt num_axis; FT_UInt num_designs; FT_MM_Axis axis[T1_MAX_MM_AXIS]; } FT_Multi_Master; /*************************************************************************/ /* */ /* <Struct> */ /* FT_Var_Axis */ /* */ /* <Description> */ /* A structure to model a given axis in design space for Multiple */ /* Masters, TrueType GX, and OpenType variation fonts. */ /* */ /* <Fields> */ /* name :: The axis's name. */ /* Not always meaningful for TrueType GX or OpenType */ /* variation fonts. */ /* */ /* minimum :: The axis's minimum design coordinate. */ /* */ /* def :: The axis's default design coordinate. */ /* FreeType computes meaningful default values for Adobe */ /* MM fonts. */ /* */ /* maximum :: The axis's maximum design coordinate. */ /* */ /* tag :: The axis's tag (the equivalent to `name' for TrueType */ /* GX and OpenType variation fonts). FreeType provides */ /* default values for Adobe MM fonts if possible. */ /* */ /* strid :: The axis name entry in the font's `name' table. This */ /* is another (and often better) version of the `name' */ /* field for TrueType GX or OpenType variation fonts. Not */ /* meaningful for Adobe MM fonts. */ /* */ /* <Note> */ /* The fields `minimum', `def', and `maximum' are 16.16 fractional */ /* values for TrueType GX and OpenType variation fonts. For Adobe MM */ /* fonts, the values are integers. */ /* */ typedef struct FT_Var_Axis_ { FT_String* name; FT_Fixed minimum; FT_Fixed def; FT_Fixed maximum; FT_ULong tag; FT_UInt strid; } FT_Var_Axis; /*************************************************************************/ /* */ /* <Struct> */ /* FT_Var_Named_Style */ /* */ /* <Description> */ /* A structure to model a named instance in a TrueType GX or OpenType */ /* variation font. */ /* */ /* This structure can't be used for Adobe MM fonts. */ /* */ /* <Fields> */ /* coords :: The design coordinates for this instance. */ /* This is an array with one entry for each axis. */ /* */ /* strid :: The entry in `name' table identifying this instance. */ /* */ /* psid :: The entry in `name' table identifying a PostScript name */ /* for this instance. Value 0xFFFF indicates a missing */ /* entry. */ /* */ typedef struct FT_Var_Named_Style_ { FT_Fixed* coords; FT_UInt strid; FT_UInt psid; /* since 2.7.1 */ } FT_Var_Named_Style; /*************************************************************************/ /* */ /* <Struct> */ /* FT_MM_Var */ /* */ /* <Description> */ /* A structure to model the axes and space of an Adobe MM, TrueType */ /* GX, or OpenType variation font. */ /* */ /* Some fields are specific to one format and not to the others. */ /* */ /* <Fields> */ /* num_axis :: The number of axes. The maximum value is~4 for */ /* Adobe MM fonts; no limit in TrueType GX or */ /* OpenType variation fonts. */ /* */ /* num_designs :: The number of designs; should be normally */ /* 2^num_axis for Adobe MM fonts. Not meaningful */ /* for TrueType GX or OpenType variation fonts */ /* (where every glyph could have a different */ /* number of designs). */ /* */ /* num_namedstyles :: The number of named styles; a `named style' is */ /* a tuple of design coordinates that has a string */ /* ID (in the `name' table) associated with it. */ /* The font can tell the user that, for example, */ /* [Weight=1.5,Width=1.1] is `Bold'. Another name */ /* for `named style' is `named instance'. */ /* */ /* For Adobe Multiple Masters fonts, this value is */ /* always zero because the format does not support */ /* named styles. */ /* */ /* axis :: An axis descriptor table. */ /* TrueType GX and OpenType variation fonts */ /* contain slightly more data than Adobe MM fonts. */ /* Memory management of this pointer is done */ /* internally by FreeType. */ /* */ /* namedstyle :: A named style (instance) table. */ /* Only meaningful for TrueType GX and OpenType */ /* variation fonts. Memory management of this */ /* pointer is done internally by FreeType. */ /* */ typedef struct FT_MM_Var_ { FT_UInt num_axis; FT_UInt num_designs; FT_UInt num_namedstyles; FT_Var_Axis* axis; FT_Var_Named_Style* namedstyle; } FT_MM_Var; /*************************************************************************/ /* */ /* <Function> */ /* FT_Get_Multi_Master */ /* */ /* <Description> */ /* Retrieve a variation descriptor of a given Adobe MM font. */ /* */ /* This function can't be used with TrueType GX or OpenType variation */ /* fonts. */ /* */ /* <Input> */ /* face :: A handle to the source face. */ /* */ /* <Output> */ /* amaster :: The Multiple Masters descriptor. */ /* */ /* <Return> */ /* FreeType error code. 0~means success. */ /* */ FT_EXPORT( FT_Error ) FT_Get_Multi_Master( FT_Face face, FT_Multi_Master *amaster ); /*************************************************************************/ /* */ /* <Function> */ /* FT_Get_MM_Var */ /* */ /* <Description> */ /* Retrieve a variation descriptor for a given font. */ /* */ /* This function works with all supported variation formats. */ /* */ /* <Input> */ /* face :: A handle to the source face. */ /* */ /* <Output> */ /* amaster :: The variation descriptor. */ /* Allocates a data structure, which the user must */ /* deallocate with a call to @FT_Done_MM_Var after use. */ /* */ /* <Return> */ /* FreeType error code. 0~means success. */ /* */ FT_EXPORT( FT_Error ) FT_Get_MM_Var( FT_Face face, FT_MM_Var* *amaster ); /*************************************************************************/ /* */ /* <Function> */ /* FT_Done_MM_Var */ /* */ /* <Description> */ /* Free the memory allocated by @FT_Get_MM_Var. */ /* */ /* <Input> */ /* library :: A handle of the face's parent library object that was */ /* used in the call to @FT_Get_MM_Var to create `amaster'. */ /* */ /* <Return> */ /* FreeType error code. 0~means success. */ /* */ FT_EXPORT( FT_Error ) FT_Done_MM_Var( FT_Library library, FT_MM_Var *amaster ); /*************************************************************************/ /* */ /* <Function> */ /* FT_Set_MM_Design_Coordinates */ /* */ /* <Description> */ /* For Adobe MM fonts, choose an interpolated font design through */ /* design coordinates. */ /* */ /* This function can't be used with TrueType GX or OpenType variation */ /* fonts. */ /* */ /* <InOut> */ /* face :: A handle to the source face. */ /* */ /* <Input> */ /* num_coords :: The number of available design coordinates. If it */ /* is larger than the number of axes, ignore the excess */ /* values. If it is smaller than the number of axes, */ /* use default values for the remaining axes. */ /* */ /* coords :: An array of design coordinates. */ /* */ /* <Return> */ /* FreeType error code. 0~means success. */ /* */ /* <Note> */ /* [Since 2.8.1] To reset all axes to the default values, call the */ /* function with `num_coords' set to zero and `coords' set to NULL. */ /* */ /* [Since 2.9] If `num_coords' is larger than zero, this function */ /* sets the @FT_FACE_FLAG_VARIATION bit in @FT_Face's `face_flags' */ /* field (i.e., @FT_IS_VARIATION will return true). If `num_coords' */ /* is zero, this bit flag gets unset. */ /* */ FT_EXPORT( FT_Error ) FT_Set_MM_Design_Coordinates( FT_Face face, FT_UInt num_coords, FT_Long* coords ); /*************************************************************************/ /* */ /* <Function> */ /* FT_Set_Var_Design_Coordinates */ /* */ /* <Description> */ /* Choose an interpolated font design through design coordinates. */ /* */ /* This function works with all supported variation formats. */ /* */ /* <InOut> */ /* face :: A handle to the source face. */ /* */ /* <Input> */ /* num_coords :: The number of available design coordinates. If it */ /* is larger than the number of axes, ignore the excess */ /* values. If it is smaller than the number of axes, */ /* use default values for the remaining axes. */ /* */ /* coords :: An array of design coordinates. */ /* */ /* <Return> */ /* FreeType error code. 0~means success. */ /* */ /* <Note> */ /* [Since 2.8.1] To reset all axes to the default values, call the */ /* function with `num_coords' set to zero and `coords' set to NULL. */ /* [Since 2.9] `Default values' means the currently selected named */ /* instance (or the base font if no named instance is selected). */ /* */ /* [Since 2.9] If `num_coords' is larger than zero, this function */ /* sets the @FT_FACE_FLAG_VARIATION bit in @FT_Face's `face_flags' */ /* field (i.e., @FT_IS_VARIATION will return true). If `num_coords' */ /* is zero, this bit flag gets unset. */ /* */ FT_EXPORT( FT_Error ) FT_Set_Var_Design_Coordinates( FT_Face face, FT_UInt num_coords, FT_Fixed* coords ); /*************************************************************************/ /* */ /* <Function> */ /* FT_Get_Var_Design_Coordinates */ /* */ /* <Description> */ /* Get the design coordinates of the currently selected interpolated */ /* font. */ /* */ /* This function works with all supported variation formats. */ /* */ /* <Input> */ /* face :: A handle to the source face. */ /* */ /* num_coords :: The number of design coordinates to retrieve. If it */ /* is larger than the number of axes, set the excess */ /* values to~0. */ /* */ /* <Output> */ /* coords :: The design coordinates array. */ /* */ /* <Return> */ /* FreeType error code. 0~means success. */ /* */ /* <Since> */ /* 2.7.1 */ /* */ FT_EXPORT( FT_Error ) FT_Get_Var_Design_Coordinates( FT_Face face, FT_UInt num_coords, FT_Fixed* coords ); /*************************************************************************/ /* */ /* <Function> */ /* FT_Set_MM_Blend_Coordinates */ /* */ /* <Description> */ /* Choose an interpolated font design through normalized blend */ /* coordinates. */ /* */ /* This function works with all supported variation formats. */ /* */ /* <InOut> */ /* face :: A handle to the source face. */ /* */ /* <Input> */ /* num_coords :: The number of available design coordinates. If it */ /* is larger than the number of axes, ignore the excess */ /* values. If it is smaller than the number of axes, */ /* use default values for the remaining axes. */ /* */ /* coords :: The design coordinates array (each element must be */ /* between 0 and 1.0 for Adobe MM fonts, and between */ /* -1.0 and 1.0 for TrueType GX and OpenType variation */ /* fonts). */ /* */ /* <Return> */ /* FreeType error code. 0~means success. */ /* */ /* <Note> */ /* [Since 2.8.1] To reset all axes to the default values, call the */ /* function with `num_coords' set to zero and `coords' set to NULL. */ /* [Since 2.9] `Default values' means the currently selected named */ /* instance (or the base font if no named instance is selected). */ /* */ /* [Since 2.9] If `num_coords' is larger than zero, this function */ /* sets the @FT_FACE_FLAG_VARIATION bit in @FT_Face's `face_flags' */ /* field (i.e., @FT_IS_VARIATION will return true). If `num_coords' */ /* is zero, this bit flag gets unset. */ /* */ FT_EXPORT( FT_Error ) FT_Set_MM_Blend_Coordinates( FT_Face face, FT_UInt num_coords, FT_Fixed* coords ); /*************************************************************************/ /* */ /* <Function> */ /* FT_Get_MM_Blend_Coordinates */ /* */ /* <Description> */ /* Get the normalized blend coordinates of the currently selected */ /* interpolated font. */ /* */ /* This function works with all supported variation formats. */ /* */ /* <Input> */ /* face :: A handle to the source face. */ /* */ /* num_coords :: The number of normalized blend coordinates to */ /* retrieve. If it is larger than the number of axes, */ /* set the excess values to~0.5 for Adobe MM fonts, and */ /* to~0 for TrueType GX and OpenType variation fonts. */ /* */ /* <Output> */ /* coords :: The normalized blend coordinates array. */ /* */ /* <Return> */ /* FreeType error code. 0~means success. */ /* */ /* <Since> */ /* 2.7.1 */ /* */ FT_EXPORT( FT_Error ) FT_Get_MM_Blend_Coordinates( FT_Face face, FT_UInt num_coords, FT_Fixed* coords ); /*************************************************************************/ /* */ /* <Function> */ /* FT_Set_Var_Blend_Coordinates */ /* */ /* <Description> */ /* This is another name of @FT_Set_MM_Blend_Coordinates. */ /* */ FT_EXPORT( FT_Error ) FT_Set_Var_Blend_Coordinates( FT_Face face, FT_UInt num_coords, FT_Fixed* coords ); /*************************************************************************/ /* */ /* <Function> */ /* FT_Get_Var_Blend_Coordinates */ /* */ /* <Description> */ /* This is another name of @FT_Get_MM_Blend_Coordinates. */ /* */ /* <Since> */ /* 2.7.1 */ /* */ FT_EXPORT( FT_Error ) FT_Get_Var_Blend_Coordinates( FT_Face face, FT_UInt num_coords, FT_Fixed* coords ); /*************************************************************************/ /* */ /* <Enum> */ /* FT_VAR_AXIS_FLAG_XXX */ /* */ /* <Description> */ /* A list of bit flags used in the return value of */ /* @FT_Get_Var_Axis_Flags. */ /* */ /* <Values> */ /* FT_VAR_AXIS_FLAG_HIDDEN :: */ /* The variation axis should not be exposed to user interfaces. */ /* */ /* <Since> */ /* 2.8.1 */ /* */ #define FT_VAR_AXIS_FLAG_HIDDEN 1 /*************************************************************************/ /* */ /* <Function> */ /* FT_Get_Var_Axis_Flags */ /* */ /* <Description> */ /* Get the `flags' field of an OpenType Variation Axis Record. */ /* */ /* Not meaningful for Adobe MM fonts (`*flags' is always zero). */ /* */ /* <Input> */ /* master :: The variation descriptor. */ /* */ /* axis_index :: The index of the requested variation axis. */ /* */ /* <Output> */ /* flags :: The `flags' field. See @FT_VAR_AXIS_FLAG_XXX for */ /* possible values. */ /* */ /* <Return> */ /* FreeType error code. 0~means success. */ /* */ /* <Since> */ /* 2.8.1 */ /* */ FT_EXPORT( FT_Error ) FT_Get_Var_Axis_Flags( FT_MM_Var* master, FT_UInt axis_index, FT_UInt* flags ); /*************************************************************************/ /* */ /* <Function> */ /* FT_Set_Named_Instance */ /* */ /* <Description> */ /* Set or change the current named instance. */ /* */ /* <Input> */ /* face :: A handle to the source face. */ /* */ /* instance_index :: The index of the requested instance, starting */ /* with value 1. If set to value 0, FreeType */ /* switches to font access without a named */ /* instance. */ /* */ /* <Return> */ /* FreeType error code. 0~means success. */ /* */ /* <Note> */ /* The function uses the value of `instance_index' to set bits 16-30 */ /* of the face's `face_index' field. It also resets any variation */ /* applied to the font, and the @FT_FACE_FLAG_VARIATION bit of the */ /* face's `face_flags' field gets reset to zero (i.e., */ /* @FT_IS_VARIATION will return false). */ /* */ /* For Adobe MM fonts (which don't have named instances) this */ /* function simply resets the current face to the default instance. */ /* */ /* <Since> */ /* 2.9 */ /* */ FT_EXPORT( FT_Error ) FT_Set_Named_Instance( FT_Face face, FT_UInt instance_index ); /* */ FT_END_HEADER #endif /* FTMM_H_ */ /* END */
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