| /**************************************************************************** |
| * |
| * ftmm.h |
| * |
| * FreeType Multiple Master font interface (specification). |
| * |
| * Copyright (C) 1996-2021 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 <freetype/t1tables.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 ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Set_MM_WeightVector |
| * |
| * @description: |
| * For Adobe MM fonts, choose an interpolated font design by directly |
| * setting the weight vector. |
| * |
| * This function can't be used with TrueType GX or OpenType variation |
| * fonts. |
| * |
| * @inout: |
| * face :: |
| * A handle to the source face. |
| * |
| * @input: |
| * len :: |
| * The length of the weight vector array. If it is larger than the |
| * number of designs, the extra values are ignored. If it is less than |
| * the number of designs, the remaining values are set to zero. |
| * |
| * weightvector :: |
| * An array representing the weight vector. |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| * |
| * @note: |
| * Adobe Multiple Master fonts limit the number of designs, and thus the |
| * length of the weight vector to~16. |
| * |
| * If `len` is zero and `weightvector` is `NULL`, the weight vector array |
| * is reset to the default values. |
| * |
| * The Adobe documentation also states that the values in the |
| * WeightVector array must total 1.0 +/-~0.001. In practice this does |
| * not seem to be enforced, so is not enforced here, either. |
| * |
| * @since: |
| * 2.10 |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_Set_MM_WeightVector( FT_Face face, |
| FT_UInt len, |
| FT_Fixed* weightvector ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Get_MM_WeightVector |
| * |
| * @description: |
| * For Adobe MM fonts, retrieve the current weight vector of the font. |
| * |
| * This function can't be used with TrueType GX or OpenType variation |
| * fonts. |
| * |
| * @inout: |
| * face :: |
| * A handle to the source face. |
| * |
| * len :: |
| * A pointer to the size of the array to be filled. If the size of the |
| * array is less than the number of designs, `FT_Err_Invalid_Argument` |
| * is returned, and `len` is set to the required size (the number of |
| * designs). If the size of the array is greater than the number of |
| * designs, the remaining entries are set to~0. On successful |
| * completion, `len` is set to the number of designs (i.e., the number |
| * of values written to the array). |
| * |
| * @output: |
| * weightvector :: |
| * An array to be filled. |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| * |
| * @note: |
| * Adobe Multiple Master fonts limit the number of designs, and thus the |
| * length of the WeightVector to~16. |
| * |
| * @since: |
| * 2.10 |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_Get_MM_WeightVector( FT_Face face, |
| FT_UInt* len, |
| FT_Fixed* weightvector ); |
| |
| |
| /************************************************************************** |
| * |
| * @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 */ |
