freetype2/include/freetype/ftmm.h

462 lines
28 KiB
C

/***************************************************************************/
/* */
/* ftmm.h */
/* */
/* FreeType Multiple Master font interface (specification). */
/* */
/* Copyright 1996-2016 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. */
/* */
/* George Williams has extended this interface to make it work with */
/* both Type~1 Multiple Masters fonts and GX distortable (var) */
/* fonts. Some of these routines only work with MM fonts, others */
/* will work with both types. They are similar enough that a */
/* consistent interface makes sense. */
/* */
/*************************************************************************/
/*************************************************************************/
/* */
/* <Struct> */
/* FT_MM_Axis */
/* */
/* <Description> */
/* A simple structure used to model a given axis in design space for */
/* Multiple Masters fonts. */
/* */
/* This structure can't be used for GX var 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 used to model the axes and space of a Multiple Masters */
/* font. */
/* */
/* This structure can't be used for GX var 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 simple structure used to model a given axis in design space for */
/* Multiple Masters and GX var fonts. */
/* */
/* <Fields> */
/* name :: The axis's name. */
/* Not always meaningful for GX. */
/* */
/* minimum :: The axis's minimum design coordinate. */
/* */
/* def :: The axis's default design coordinate. */
/* FreeType computes meaningful default values for MM; it */
/* is then an integer value, not in 16.16 format. */
/* */
/* maximum :: The axis's maximum design coordinate. */
/* */
/* tag :: The axis's tag (the GX equivalent to `name'). */
/* FreeType provides default values for MM if possible. */
/* */
/* strid :: The entry in `name' table (another GX version of */
/* `name'). */
/* Not meaningful for MM. */
/* */
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 simple structure used to model a named style in a GX var font. */
/* */
/* This structure can't be used for MM fonts. */
/* */
/* <Fields> */
/* coords :: The design coordinates for this style. */
/* This is an array with one entry for each axis. */
/* */
/* strid :: The entry in `name' table identifying this style. */
/* */
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 used to model the axes and space of a Multiple Masters */
/* or GX var distortable font. */
/* */
/* Some fields are specific to one format and not to the other. */
/* */
/* <Fields> */
/* num_axis :: The number of axes. The maximum value is~4 for */
/* MM; no limit in GX. */
/* */
/* num_designs :: The number of designs; should be normally */
/* 2^num_axis for MM fonts. Not meaningful for GX */
/* (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'. */
/* */
/* For Type 1 Multiple Masters fonts, this value */
/* is always zero because the format does not */
/* support named styles. */
/* */
/* axis :: An axis descriptor table. */
/* GX fonts contain slightly more data than MM. */
/* Memory management of this pointer is done */
/* internally by FreeType. */
/* */
/* namedstyle :: A named style table. */
/* Only meaningful with GX. */
/* 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 the Multiple Master descriptor of a given font. */
/* */
/* This function can't be used with GX 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 the Multiple Master/GX var descriptor of a given font. */
/* */
/* <Input> */
/* face :: A handle to the source face. */
/* */
/* <Output> */
/* amaster :: The Multiple Masters/GX var descriptor. */
/* Allocates a data structure, which the user must */
/* deallocate with `free' 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_Set_MM_Design_Coordinates */
/* */
/* <Description> */
/* For Multiple Masters fonts, choose an interpolated font design */
/* through design coordinates. */
/* */
/* This function can't be used with GX 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. */
/* */
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> */
/* For Multiple Master or GX Var fonts, choose an interpolated font */
/* design through design coordinates. */
/* */
/* <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. */
/* */
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> */
/* For Multiple Master and GX Var fonts, get the design coordinates */
/* of the currently selected interpolated font. */
/* */
/* <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. */
/* */
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> */
/* For Multiple Masters and GX var fonts, choose an interpolated font */
/* design through normalized blend coordinates. */
/* */
/* <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 MM fonts, and between -1.0 and */
/* 1.0 for GX var fonts). */
/* */
/* <Return> */
/* FreeType error code. 0~means success. */
/* */
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> */
/* For Multiple Masters and GX var fonts, get the normalized blend */
/* coordinates of the currently selected interpolated font. */
/* */
/* <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 MM fonts, and to~0 */
/* for GX var fonts. */
/* */
/* <Output> */
/* coords :: The normalized blend coordinates array. */
/* */
/* <Return> */
/* FreeType error code. 0~means success. */
/* */
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. */
/* */
FT_EXPORT( FT_Error )
FT_Get_Var_Blend_Coordinates( FT_Face face,
FT_UInt num_coords,
FT_Fixed* coords );
/* */
FT_END_HEADER
#endif /* FTMM_H_ */
/* END */