general/freetype2
2
0
Fork 0
mirror of git://git.sv.nongnu.org/freetype/freetype2.git synced 2026-01-19 04:52:09 +00:00
Code Issues Projects Releases Wiki Activity

[doc] Use 'Adobe MM', 'TrueType GX', and 'OpenType Font Variations'.

Browse Source
This commit is contained in:
Werner Lemberg
2025-06-28 20:25:29 +02:00
parent 61bacf3dae
commit 636aede94b
3 changed files with 77 additions and 78 deletions
Download Patch File Download Diff File Expand all files Collapse all files

56
include/freetype/freetype.h
View File

@@ -1068,12 +1068,12 @@ FT_BEGIN_HEADER
* the face in the font file (starting with value~0). They are set
* to~0 if there is only one face in the font file.
*
* [Since 2.6.1] Bits 16-30 are relevant to GX and OpenType variation
* fonts only, holding the named instance index for the current face
* index (starting with value~1; value~0 indicates font access without
* a named instance). For non-variation fonts, bits 16-30 are ignored.
* If we have the third named instance of face~4, say, `face_index` is
* set to 0x00030004.
* [Since 2.6.1] Bits 16-30 are relevant to TrueType GX and OpenType
* Font Variations only, holding the named instance index for the
* current face index (starting with value~1; value~0 indicates font
* access without a named instance). For non-variation fonts, bits
* 16-30 are ignored. If we have the third named instance of face~4,
* say, `face_index` is set to 0x00030004.
*
* Bit 31 is always zero (that is, `face_index` is always a positive
* value).
@@ -1092,10 +1092,10 @@ FT_BEGIN_HEADER
* the face; see @FT_STYLE_FLAG_XXX for the details.
*
* [Since 2.6.1] Bits 16-30 hold the number of named instances
* available for the current face if we have a GX or OpenType variation
* (sub)font. Bit 31 is always zero (that is, `style_flags` is always
* a positive value). Note that a variation font has always at least
* one named instance, namely the default instance.
* available for the current face if we have a TrueType GX or OpenType
* Font Variation. Bit 31 is always zero (that is, `style_flags` is
* always a positive value). Note that a variation font has always at
* least one named instance, namely the default instance.
*
* num_glyphs ::
* The number of glyphs in the face. If the face is scalable and has
@@ -1159,7 +1159,7 @@ FT_BEGIN_HEADER
* Note that the bounding box might be off by (at least) one pixel for
* hinted fonts. See @FT_Size_Metrics for further discussion.
*
* Note that the bounding box does not vary in OpenType variation fonts
* Note that the bounding box does not vary in OpenType Font Variations
* and should only be used in relation to the default instance.
*
* units_per_EM ::
@@ -1218,7 +1218,7 @@ FT_BEGIN_HEADER
* Fields may be changed after a call to @FT_Attach_File or
* @FT_Attach_Stream.
*
* For an OpenType variation font, the values of the following fields can
* For OpenType Font Variations, the values of the following fields can
* change after a call to @FT_Set_Var_Design_Coordinates (and friends) if
* the font contains an 'MVAR' table: `ascender`, `descender`, `height`,
* `underline_position`, and `underline_thickness`.
@@ -1336,7 +1336,7 @@ FT_BEGIN_HEADER
* FT_FACE_FLAG_MULTIPLE_MASTERS ::
* The face contains multiple masters and is capable of interpolating
* between them. Supported formats are Adobe MM, TrueType GX, and
* OpenType variation fonts.
* OpenType Font Variations.
*
* See section @multiple_masters for API details.
*
@@ -1609,7 +1609,7 @@ FT_BEGIN_HEADER
*
* @description:
* A macro that returns true whenever a face object is a named instance
* of a GX or OpenType variation font.
* of a TrueType GX or OpenType Font Variations.
*
* [Since 2.9] Changing the design coordinates with
* @FT_Set_Var_Design_Coordinates or @FT_Set_Var_Blend_Coordinates does
@@ -2147,7 +2147,7 @@ FT_BEGIN_HEADER
* freed.
*
* [Since 2.10.1] If @FT_LOAD_NO_SCALE is set, outline coordinates of
* OpenType variation fonts for a selected instance are internally
* OpenType Font Variations for a selected instance are internally
* handled as 26.6 fractional font units but returned as (rounded)
* integers, as expected. To get unrounded font units, don't use
* @FT_LOAD_NO_SCALE but load the glyph with @FT_LOAD_NO_HINTING and
@@ -2640,14 +2640,14 @@ FT_BEGIN_HEADER
* the face in the font file (starting with value~0). Set it to~0 if
* there is only one face in the font file.
*
* [Since 2.6.1] Bits 16-30 are relevant to GX and OpenType variation
* fonts only, specifying the named instance index for the current face
* index (starting with value~1; value~0 makes FreeType ignore named
* instances). For non-variation fonts, bits 16-30 are ignored.
* Assuming that you want to access the third named instance in face~4,
* `face_index` should be set to 0x00030004. If you want to access
* face~4 without variation handling, simply set `face_index` to
* value~4.
* [Since 2.6.1] Bits 16-30 are relevant to TrueType GX and OpenType
* Font Variations only, specifying the named instance index for the
* current face index (starting with value~1; value~0 makes FreeType
* ignore named instances). For non-variation fonts, bits 16-30 are
* ignored. Assuming that you want to access the third named instance
* in face~4, `face_index` should be set to 0x00030004. If you want
* to access face~4 without variation handling, simply set
* `face_index` to value~4.
*
* `FT_Open_Face` and its siblings can be used to quickly check whether
* the font format of a given font resource is supported by FreeType.
@@ -2914,11 +2914,11 @@ FT_BEGIN_HEADER
* of the available glyphs at a given ppem value is available. FreeType
* silently uses outlines if there is no bitmap for a given glyph index.
*
* For GX and OpenType variation fonts, a bitmap strike makes sense only
* if the default instance is active (that is, no glyph variation takes
* place); otherwise, FreeType simply ignores bitmap strikes. The same
* is true for all named instances that are different from the default
* instance.
* For TrueType GX and OpenType Font Variations, a bitmap strike makes
* sense only if the default instance is active (that is, no glyph
* variation takes place); otherwise, FreeType simply ignores bitmap
* strikes. The same is true for all named instances that are different
* from the default instance.
*
* Don't use this function if you are using the FreeType cache API.
*/

91
include/freetype/ftmm.h
View File

@@ -2,7 +2,7 @@
*
* ftmm.h
*
* FreeType Multiple Master font interface (specification).
* FreeType variation font interface (specification).
*
* Copyright (C) 1996-2024 by
* David Turner, Robert Wilhelm, and Werner Lemberg.
@@ -48,12 +48,12 @@ FT_BEGIN_HEADER
* 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
* OpenType Font Variations. 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.
*
* For Adobe MM fonts, macro @FT_IS_SFNT returns false. For GX and
* OpenType variation fonts, it returns true.
* For Adobe MM fonts, macro @FT_IS_SFNT returns false. For TrueType GX
* and OpenType Font Variations, it returns true.
*
*/
@@ -64,14 +64,14 @@ FT_BEGIN_HEADER
* T1_MAX_MM_XXX
*
* @description:
* Multiple Masters limits as defined in their specifications.
* Adobe MM font limits as defined in their specifications.
*
* @values:
* T1_MAX_MM_AXIS ::
* The maximum number of Multiple Masters axes.
* The maximum number of Adobe MM font axes.
*
* T1_MAX_MM_DESIGNS ::
* The maximum number of Multiple Masters designs.
* The maximum number of Adobe MM font designs.
*
* T1_MAX_MM_MAP_POINTS ::
* The maximum number of elements in a design map.
@@ -88,11 +88,10 @@ FT_BEGIN_HEADER
* FT_MM_Axis
*
* @description:
* A structure to model a given axis in design space for Multiple Masters
* fonts.
* A structure to model a given axis in design space for Adobe MM fonts.
*
* This structure can't be used for TrueType GX or OpenType variation
* fonts.
* This structure can't be used for TrueType GX or OpenType Font
* Variations.
*
* @fields:
* name ::
@@ -119,10 +118,10 @@ FT_BEGIN_HEADER
* FT_Multi_Master
*
* @description:
* A structure to model the axes and space of a Multiple Masters font.
* A structure to model the axes and space of an Adobe MM font.
*
* This structure can't be used for TrueType GX or OpenType variation
* fonts.
* This structure can't be used for TrueType GX or OpenType Font
* Variations.
*
* @fields:
* num_axis ::
@@ -151,13 +150,13 @@ FT_BEGIN_HEADER
* FT_Var_Axis
*
* @description:
* A structure to model a given axis in design space for Multiple
* Masters, TrueType GX, and OpenType variation fonts.
* A structure to model a given axis in design space for Adobe MM fonts,
* TrueType GX, and OpenType Font Variations.
*
* @fields:
* name ::
* The axis's name. Not always meaningful for TrueType GX or OpenType
* variation fonts.
* Font Variations.
*
* minimum ::
* The axis's minimum design coordinate.
@@ -171,17 +170,17 @@ FT_BEGIN_HEADER
*
* tag ::
* The axis's tag (the equivalent to 'name' for TrueType GX and
* OpenType variation fonts). FreeType provides default values for
* OpenType Font Variations). 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.
* OpenType Font Variations. 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
* for TrueType GX and OpenType Font Variations. For Adobe MM fonts, the
* values are whole numbers (i.e., the fractional part is zero).
*/
typedef struct FT_Var_Axis_
@@ -205,7 +204,7 @@ FT_BEGIN_HEADER
*
* @description:
* A structure to model a named instance in a TrueType GX or OpenType
* variation font.
* Font Variations.
*
* This structure can't be used for Adobe MM fonts.
*
@@ -237,18 +236,18 @@ FT_BEGIN_HEADER
*
* @description:
* A structure to model the axes and space of an Adobe MM, TrueType GX,
* or OpenType variation font.
* or OpenType Font Variations.
*
* 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.
* limit in TrueType GX or OpenType Font Variations.
*
* 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
* fonts. Not meaningful for TrueType GX or OpenType Font Variations
* (where every glyph could have a different number of designs).
*
* num_namedstyles ::
@@ -258,17 +257,17 @@ FT_BEGIN_HEADER
* [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.
* For Adobe MM 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
* An axis descriptor table. TrueType GX and OpenType Font Variations
* 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
* OpenType Font Variations. Memory management of this pointer is done
* internally by FreeType.
*/
typedef struct FT_MM_Var_
@@ -290,8 +289,8 @@ FT_BEGIN_HEADER
* @description:
* Retrieve a variation descriptor of a given Adobe MM font.
*
* This function can't be used with TrueType GX or OpenType variation
* fonts.
* This function can't be used with TrueType GX or OpenType Font
* Variations.
*
* @input:
* face ::
@@ -299,7 +298,7 @@ FT_BEGIN_HEADER
*
* @output:
* amaster ::
* The Multiple Masters descriptor.
* The Adobe MM font's variation descriptor.
*
* @return:
* FreeType error code. 0~means success.
@@ -366,8 +365,8 @@ FT_BEGIN_HEADER
* 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.
* This function can't be used with TrueType GX or OpenType Font
* Variations.
*
* @inout:
* face ::
@@ -428,7 +427,7 @@ FT_BEGIN_HEADER
*
* @note:
* The design coordinates are 16.16 fractional values for TrueType GX and
* OpenType variation fonts. For Adobe MM fonts, the values are supposed
* OpenType Font Variations. For Adobe MM fonts, the values are supposed
* to be whole numbers (i.e., the fractional part is zero).
*
* [Since 2.8.1] To reset all axes to the default values, call the
@@ -481,7 +480,7 @@ FT_BEGIN_HEADER
*
* @note:
* The design coordinates are 16.16 fractional values for TrueType GX and
* OpenType variation fonts. For Adobe MM fonts, the values are whole
* OpenType Font Variations. For Adobe MM fonts, the values are whole
* numbers (i.e., the fractional part is zero).
*
* @since:
@@ -517,7 +516,7 @@ FT_BEGIN_HEADER
* coords ::
* The design coordinates array. Each element is a 16.16 fractional
* value and 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.
* -1.0 and 1.0 for TrueType GX and OpenType Font Variations.
*
* @return:
* FreeType error code. 0~means success.
@@ -563,8 +562,8 @@ FT_BEGIN_HEADER
* 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.
* Adobe MM fonts, and to~0 for TrueType GX and OpenType Font
* Variations.
*
* @output:
* coords ::
@@ -622,8 +621,8 @@ FT_BEGIN_HEADER
* 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.
* This function can't be used with TrueType GX or OpenType Font
* Variations.
*
* @inout:
* face ::
@@ -642,8 +641,8 @@ FT_BEGIN_HEADER
* 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~elements.
* Adobe MM fonts limit the number of designs, and thus the length of
* the weight vector to 16~elements.
*
* If `len` is larger than zero, this function sets the
* @FT_FACE_FLAG_VARIATION bit in @FT_Face's `face_flags` field (i.e.,
@@ -671,8 +670,8 @@ FT_BEGIN_HEADER
* @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.
* This function can't be used with TrueType GX or OpenType Font
* Variations.
*
* @inout:
* face ::
@@ -695,8 +694,8 @@ FT_BEGIN_HEADER
* 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.
* Adobe MM fonts limit the number of designs, and thus the length of
* the WeightVector to~16.
*
* @since:
* 2.10

8
include/freetype/tttables.h
View File

@@ -192,7 +192,7 @@ FT_BEGIN_HEADER
* A pointer into the 'hmtx' table.
*
* @note:
* For an OpenType variation font, the values of the following fields can
* For OpenType Font Variations, the values of the following fields can
* change after a call to @FT_Set_Var_Design_Coordinates (and friends) if
* the font contains an 'MVAR' table: `caret_Slope_Rise`,
* `caret_Slope_Run`, and `caret_Offset`.
@@ -310,7 +310,7 @@ FT_BEGIN_HEADER
* A pointer into the 'vmtx' table.
*
* @note:
* For an OpenType variation font, the values of the following fields can
* For OpenType Font Variations, the values of the following fields can
* change after a call to @FT_Set_Var_Design_Coordinates (and friends) if
* the font contains an 'MVAR' table: `Ascender`, `Descender`,
* `Line_Gap`, `caret_Slope_Rise`, `caret_Slope_Run`, and `caret_Offset`.
@@ -359,7 +359,7 @@ FT_BEGIN_HEADER
* table. In this case, the `version` field is always set to 0xFFFF.
*
* @note:
* For an OpenType variation font, the values of the following fields can
* For OpenType Font Variations, the values of the following fields can
* change after a call to @FT_Set_Var_Design_Coordinates (and friends) if
* the font contains an 'MVAR' table: `sCapHeight`, `sTypoAscender`,
* `sTypoDescender`, `sTypoLineGap`, `sxHeight`, `usWinAscent`,
@@ -442,7 +442,7 @@ FT_BEGIN_HEADER
* them.
*
* @note:
* For an OpenType variation font, the values of the following fields can
* For OpenType Font Variations, the values of the following fields can
* change after a call to @FT_Set_Var_Design_Coordinates (and friends) if
* the font contains an 'MVAR' table: `underlinePosition` and
* `underlineThickness`.