| /**************************************************************************** |
| * |
| * 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 */ |
