luametalatex-c/luaharfbuzz/src/harfbuzz.luadoc
Marcel Fabian Krüger ca93f7224c Initial commit
2021-12-28 10:18:21 +01:00

536 lines
16 KiB
Plaintext
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

-----------
-- Lua bindings to Harfbuzz.
-- * [Wiki](http://github.com/ufytex/luaharfbuzz/wiki)
-- * [Source on Github](https://github.com/ufytex/luaharfbuzz)
-- * [API Coverage Status](https://github.com/ufytex/luaharfbuzz/blob/master/status/done.txt)
--
-- @author Deepak Jois <<deepak.jois@gmail.com>>
-- @copyright 2016
-- @license MIT
-- @module harfbuzz
--- Wraps `hb_version`
-- @function version
--- Wraps `hb_shape`.
-- @param font `Font` to use for shaping
--
-- @param buffer `Buffer` to shape
--
-- @param[opt] options table containing one or more supported options:
--
-- * `direction`: A `Direction` object representing the object.
-- * `script`: A `Script` object representing the script.
-- * `language`: A `Language` object representing the language.
-- * `features`: features to enable, specified as either of the following.
-- - comma-separated list of features. See [feature string syntax reference](https://github.com/ufytex/luaharfbuzz/wiki/Feature-Strings)
-- - table of `Feature` objects
-- @function shape
--- Lua wrapper for `hb_blob_t` type
-- @type Blob
--- Wraps `hb_blob_create`.
-- Initializes a new `hb_blob_t`.
-- @param data lua string containing binary or character data.
-- @function Blob.new
--- Wraps `hb_blob_create_from_file`.
-- Initializes a new `hb_blob_t`.
-- @param filename lua string.
-- @function Blob.new_from_file
--- Wraps `hb_blob_get_length`.
-- @function Blob:get_length
--- Wraps `hb_blob_get_data`.
-- @function Blob:get_data
--- Lua wrapper for `hb_face_t` type
-- @type Face
--- Wraps `hb_face_create`.
-- Initializes a new `hb_face_t` from a `Blob` object.
-- @param blob `Blob` to read the font from.
-- @param[opt=0] font_index index of font to read.
-- @function Face.new_from_blob
--- Create a new `Face` from a file.
-- Makes a call to `Face:new_from_blob` after creating a `Blob` from the
-- file contents.
-- @param file path to font file.
-- @param[opt=0] font_index index of font to read.
-- @function Face.new
--- Wraps `hb_face_collect_unicodes`.
-- @return table of codepoints supported by the face.
-- @function Face:collect_unicodes
--- Wraps `hb_face_get_glyph_count`.
-- @function Face:get_glyph_count
--- Wraps `hb_face_reference_table`.
-- @param tag `Tag` object of the table.
-- @return `Blob` object for the face table of `tag`.
-- @function Face:get_table
--- Wraps `hb_face_get_table_tags`.
-- @return table of `Tag`s representing face table tags.
-- @function Face:get_table_tags
--- Wraps `hb_face_get_upem`.
-- @function Face:get_upem
--- Wraps `hb_ot_color_has_palettes`.
-- @function Face:ot_color_has_palettes
--- Wraps `hb_ot_color_palette_get_count`.
-- @function Face:ot_color_palette_get_count
--- Wraps `hb_ot_color_palette_get_colors`.
-- @function Face:ot_color_palette_get_colors
--- Wraps `hb_ot_color_has_layers`.
-- @function Face:ot_color_has_layers
--- Wraps `hb_ot_color_glyph_get_layers`.
-- @function Face:ot_color_glyph_get_layers
--- Wraps `hb_ot_color_has_png`.
-- @function Face:ot_color_has_png
--- Wraps `hb_ot_layout_table_get_script_tags`.
-- @function Face:ot_layout_get_script_tags
--- Wraps `hb_ot_layout_script_get_language_tags`.
-- @function Face:ot_layout_get_language_tags
--- Wraps `hb_ot_layout_language_get_feature_tags`.
-- @function Face:ot_layout_get_feature_tags
--- Wraps `hb_ot_layout_table_find_script`.
-- @function Face:ot_layout_find_script
--- Wraps `hb_ot_layout_script_find_language`.
-- @function Face:ot_layout_find_language
--- Wraps `hb_ot_layout_language_find_feature`.
-- @function Face:ot_layout_find_feature
--- Lua wrapper for `hb_font_t` type
-- @type Font
--- Wraps `hb_font_create`, and sets up some defaults for scale and shaping functions.
-- Initializes a new `hb_font_t` from a `Face` object. Sets the default scale
-- to the faces upem value, and sets the font shaping functions by
-- calling `hb_ot_font_set_funcs` on it.
-- @param face `Face` object.
-- @function Font.new
--- Wraps `hb_font_get_scale`.
-- @return two values for the x-scale and y-scale of the font.
-- @function Font:get_scale
--- Wraps `hb_font_set_scale`.
-- @param x_scale desired x-scale of font.
-- @param y_scale desired y-scale of font.
-- @function Font:set_scale
--- Wraps `hb_font_get_h_extents`.
-- @return font extents table for horizontal direction, contains the following
-- or `nil` if HarfBuzz fails to load font extents:
--
-- * `ascender`: typographic ascender.
-- * `descender`: typographic descender.
-- * `line_gap`: line spacing gap.
-- @function Font:get_h_extents
--- Wraps `hb_font_get_v_extents`.
-- @return font extents table for vertical direction, similar to
-- `Font:get_h_extents`, or `nil` if HarfBuzz fails to load font extents:
-- @function Font:get_v_extents
--- Wraps `hb_font_get_glyph_extents`.
-- @param glyph index inside the font.
-- @return extents table contains the following or `nil` if HarfBuzz fails to
-- load glyph extents:
--
-- * `x_bearing`: left side of glyph from origin.
-- * `y_bearing`: top side of glyph from origin.
-- * `width`: distance from left to right side.
-- * `height`: distance from top to bottom side.
-- @function Font:get_glyph_extents
--- Wraps `hb_font_get_glyph_name`.
-- @param glyph index inside the font.
-- @return name of the glyph or nil.
-- @function Font:get_glyph_name
--- Wraps `hb_font_get_glyph_from_name`.
-- @param name of the glyph.
-- @return glyph index inside the font or nil.
-- @function Font:get_glyph_from_name
--- Wraps `hb_font_get_glyph_h_advance`.
-- @param glyph index inside the font.
-- @return advance glyph advance of the glyph in horizontal direction.
-- @function Font:get_glyph_h_advance
--- Wraps `hb_font_get_glyph_v_advance`.
-- @param glyph index inside the font.
-- @return advance glyph advance of the glyph in vertical direction.
-- @function Font:get_glyph_v_advance
--- Wraps `hb_font_get_nominal_glyph`.
-- @param codepoint.
-- @return glyph index or `nil` if `codepoint` is not supported by the font.
-- @function Font:get_nominal_glyph
--- Wraps `hb_ot_color_glyph_get_png`.
-- @function Font:ot_color_glyph_get_png
--- Lua wrapper for `hb_buffer_t` type.
-- @type Buffer
--- Wraps `hb_buffer_create`.
-- @function Buffer.new
--- Wraps `hb_buffer_add_utf8`.
-- @param text UTF8 encoded string.
-- @param[opt=0] item_offset 0-indexed offset in `text`, from where to start adding.
-- @param[opt=-1] item_length length to add from `item_offset`. `-1` adds till end of `text`.
-- @function Buffer:add_utf8
--- Wraps `hb_buffer_add_codepoints`.
-- @param text table with codepoints as lua numbers.
-- @param[opt=0] item_offset 0-indexed offset in `text`, from where to start adding.
-- @param[opt=-1] item_length length to add from `item_offset`. `-1` adds till end of&nbsp;`text`.
-- @function Buffer:add_codepoints
--- Wraps `hb_buffer_set_direction`.
-- @param dir A `Direction` object.
-- @function Buffer:set_direction
--- Wraps `hb_buffer_get_direction`.
-- @return A `Direction` object.
-- @function Buffer:get_direction
--- Wraps `hb_buffer_set_script`.
-- @param script A `Script` object.
-- @function Buffer:set_script
--- Wraps `hb_buffer_get_script`.
-- @return A `Script` object.
-- @function Buffer:get_script
--- Wraps `hb_buffer_set_language`.
-- @param lang A `Language` object
-- @function Buffer:set_language
--- Wraps `hb_buffer_get_language`.
-- @return A `Language` object
-- @function Buffer:get_language
--- Wraps `hb_buffer_reverse`.
-- @function Buffer:reverse
--- Wraps `hb_buffer_get_length`.
-- @function Buffer:get_length
--- Wraps `hb_buffer_get_cluster_level`.
-- @return see [Cluster Levels](#Cluster_Levels)
-- @function Buffer:get_cluster_level
--- Wraps `hb_buffer_set_cluster_level`.
-- @param level see [Cluster Levels](#Cluster_Levels)
-- @function Buffer:set_cluster_level
--- Wraps `hb_buffer_guess_segment_properties`.
-- @function Buffer:guess_segment_properties
--- Helper method to get shaped glyph data.
-- Calls `hb_buffer_get_glyph_infos`, `hb_buffer_get_glyph_positions` and
-- `hb_glyph_info_get_glyph_flags`, and assembles the data into a Lua table.
-- @return table containing data for each glyph, in a nested table. Each nested
-- table contains the following:
--
-- * `x_advance`: horizontal advance.
-- * `y_advance`: vertical advance.
-- * `x_offset`: horizontal displacement.
-- * `y_offset`: vertical displacement.
-- * `cluster`: glyph cluster index within input.
-- * `codepoint`: glyph index inside the font _(this field name is a bit misleading, but thats what Harfbuzz uses)_.
-- * `flags`: glyph flags
-- @function Buffer:get_glyphs
--- Cluster Levels.
-- See [Harfbuzz docs](http://behdad.github.io/harfbuzz/clusters.html) for more details
-- about what each of these levels mean.
-- @section
--- Wraps `HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES`.
-- @field Buffer.CLUSTER_LEVEL_MONOTONE_GRAPHEMES
--- Wraps `HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS`.
-- @field Buffer.CLUSTER_LEVEL_MONOTONE_CHARACTERS
--- Wraps `HB_BUFFER_CLUSTER_LEVEL_CHARACTERS`.
-- @field Buffer.CLUSTER_LEVEL_CHARACTERS
--- Wraps `HB_BUFFER_CLUSTER_LEVEL_DEFAULT`.
-- @field Buffer.CLUSTER_LEVEL_DEFAULT
--- Wraps `HB_GLYPH_FLAG_UNSAFE_TO_BREAK`.
-- @field Buffer.GLYPH_FLAG_UNSAFE_TO_BREAK
--- Wraps `HB_GLYPH_FLAG_DEFINED`.
-- @field Buffer.GLYPH_FLAG_DEFINED
--- Lua wrapper for `hb_feature_t` type
-- @type Feature
--- Wraps `hb_feature_from_string`
-- @param feature_string See [feature string syntax reference](https://github.com/ufytex/luaharfbuzz/wiki/Feature-Strings)
-- @function Feature.new
--- Wraps `hb_feature_to_string`.
-- Enables nice output with `tostring(…)`.
-- @function Feature:__tostring
--- Lua wrapper for `hb_tag_t` type.
-- @type Tag
--- Wraps `hb_tag_from_string`.
-- @param string to be converted to a `Tag` object.
-- @return a `Tag` object.
-- @function Tag.new
--- Wraps `hb_tag_to_string`. Enable nice output with `tostring(…)`.
-- @return Returns a string representation for the tag object.
-- @function Tag:__to_string
--- Enables equality comparisions with `==` between two tags.
-- @return `true` or `false` depending on whether the two tags are equal.
-- @function Tag:__eq
--- Lua wrapper for `hb_script_t` type.
-- @type Script
--- Wraps `hb_script_from_string`.
-- @param script 4-letter script code according to the [ISO 15924 standard](http://www.unicode.org/iso15924/iso15924-num.html).
-- @return a `Script` object.
-- @function Script.new
--- Wraps `hb_script_from_iso15924_tag`
-- @param tag a `Tag` object representing a [ISO 15924 script](http://www.unicode.org/iso15924/iso15924-num.html).
-- @function Script.from_iso15924_tag
--- Wraps `hb_script_to_iso15924_tag`.
-- @return a `Tag` object representing the script.
-- @function Script:to_iso15924_tag
--- Enable nice output with `tostring(…)`
-- @return Returns a 4-letter [ISO 15924 script code](http://www.unicode.org/iso15924/iso15924-num.html) for the script object.
-- @function Script:__to_string
--- Enables equality comparisions with `==` between two scripts.
-- @return `true` or `false` depending on whether the two scripts are equal.
-- @function Script:__eq
--- Predefined Script Codes.
-- Predefined directions that correspond to their original definitions in Harfbuzz.
-- @section
--- Wraps `HB_SCRIPT_COMMON`.
-- @field Script.COMMON
--- Wraps `HB_SCRIPT_INHERITED`.
-- @field Script.INHERITED
--- Wraps `HB_SCRIPT_UNKNOWN`.
-- @field Script.UNKNOWN
--- Wraps `HB_SCRIPT_INVALID`.
-- @field Script.INVALID
--- Lua wrapper for `hb_direction_t` type.
-- @type Direction
--- Wraps `hb_direction_from_string`.
-- @param dir can be one of `ltr`, `rtl`, `ttb`, `btt` or `invalid`.
-- @return a `Direction` object.
-- @function Direction.new
--- Wraps `hb_direction_to_string`. Enable nice output with `tostring(…)`.
-- @return Returns a string representation for direction.
-- @function Direction:__to_string
--- Enables equality comparisions with `==` between two directions.
-- @return `true` or `false` depending on whether the two tags are equal.
-- @function Direction:__eq
--- Wraps `HB_DIRECTION_IS_VALID`.
-- @return a boolean value
-- @function Direction:is_valid
--- Wraps `HB_DIRECTION_IS_HORIZONTAL`.
-- @return a boolean value
-- @function Direction:is_horizontal
--- Wraps `HB_DIRECTION_IS_VERTICAL`.
-- @return a boolean value
-- @function Direction:is_vertical
--- Wraps `HB_DIRECTION_IS_FORWARD`.
-- @return a boolean value
-- @function Direction:is_forward
--- Wraps `HB_DIRECTION_IS_BACKWARD`.
-- @return a boolean value
-- @function Direction:is_backward
--- Predefined directions.
-- Predefined directions that correspond to their original definitions in Harfbuzz.
-- @section
--- Wraps `HB_DIRECTION_LTR`.
-- @field Direction.LTR
--- Wraps `HB_DIRECTION_RTL`.
-- @field Direction.RTL
--- Wraps `HB_DIRECTION_TTB`.
-- @field Direction.TTB
--- Wraps `HB_DIRECTION_LTR`.
-- @field Direction.BTT
--- Lua wrapper for `hb_language_t` type.
-- @type Language
--- Wraps `hb_language_from_string`.
-- @param lang [three-letter language tag](http://www.microsoft.com/typography/otspec/languagetags.htm) to be converted to a `Language` object.
-- @return a `Language` object.
-- @function Language.new
--- Wraps `hb_language_to_string`. Enable nice output with `tostring(…)`.
-- @return Returns a string representation for the language object.
-- @function Language:__to_string
--- Enables equality comparisions with `==` between two languages.
-- @return `true` or `false` depending on whether the two languages are equal.
-- @function Language:__eq
--- Predefined languages.
-- Predefined languages that correspond to their original definitions in Harfbuzz.
-- @section
--- Wraps `HB_LANGUAGE_INVALID`.
-- @field Language.INVALID
--- Unicode functions.
-- @section
--- Wraps `hb_unicode_script`
-- @param char Unicode codepoint
-- @return a `Script` object.
-- @function unicode.script
--- Predefined Name IDs.
-- Predefined OpenType 'name' table name identifier.
-- @section
--- Wraps `HB_OT_NAME_ID_COPYRIGHT`
-- @field ot.NAME_ID_COPYRIGHT
--- Wraps `HB_OT_NAME_ID_FONT_FAMILY`
-- @field ot.NAME_ID_FONT_FAMILY
--- Wraps `HB_OT_NAME_ID_FONT_SUBFAMILY`
-- @field ot.NAME_ID_FONT_SUBFAMILY
--- Wraps `HB_OT_NAME_ID_UNIQUE_ID`
-- @field ot.NAME_ID_UNIQUE_ID
--- Wraps `HB_OT_NAME_ID_FULL_NAME`
-- @field ot.NAME_ID_FULL_NAME
--- Wraps `HB_OT_NAME_ID_VERSION_STRING`
-- @field ot.NAME_ID_VERSION_STRING
--- Wraps `HB_OT_NAME_ID_POSTSCRIPT_NAME`
-- @field ot.NAME_ID_POSTSCRIPT_NAME
--- Wraps `HB_OT_NAME_ID_TRADEMARK`
-- @field ot.NAME_ID_TRADEMARK
--- Wraps `HB_OT_NAME_ID_MANUFACTURER`
-- @field ot.NAME_ID_MANUFACTURER
--- Wraps `HB_OT_NAME_ID_DESIGNER`
-- @field ot.NAME_ID_DESIGNER
--- Wraps `HB_OT_NAME_ID_DESCRIPTION`
-- @field ot.NAME_ID_DESCRIPTION
--- Wraps `HB_OT_NAME_ID_VENDOR_URL`
-- @field ot.NAME_ID_VENDOR_URL
--- Wraps `HB_OT_NAME_ID_DESIGNER_URL`
-- @field ot.NAME_ID_DESIGNER_URL
--- Wraps `HB_OT_NAME_ID_LICENSE`
-- @field ot.NAME_ID_LICENSE
--- Wraps `HB_OT_NAME_ID_LICENSE_URL`
-- @field ot.NAME_ID_LICENSE_URL
--- Wraps `HB_OT_NAME_ID_TYPOGRAPHIC_FAMILY`
-- @field ot.NAME_ID_TYPOGRAPHIC_FAMILY
--- Wraps `HB_OT_NAME_ID_TYPOGRAPHIC_SUBFAMILY`
-- @field ot.NAME_ID_TYPOGRAPHIC_SUBFAMILY
--- Wraps `HB_OT_NAME_ID_MAC_FULL_NAME`
-- @field ot.NAME_ID_MAC_FULL_NAME
--- Wraps `HB_OT_NAME_ID_SAMPLE_TEXT`
-- @field ot.NAME_ID_SAMPLE_TEXT
--- Wraps `HB_OT_NAME_ID_CID_FINDFONT_NAME`
-- @field ot.NAME_ID_CID_FINDFONT_NAME
--- Wraps `HB_OT_NAME_ID_WWS_FAMILY`
-- @field ot.NAME_ID_WWS_FAMILY
--- Wraps `HB_OT_NAME_ID_WWS_SUBFAMILY`
-- @field ot.NAME_ID_WWS_SUBFAMILY
--- Wraps `HB_OT_NAME_ID_LIGHT_BACKGROUND`
-- @field ot.NAME_ID_LIGHT_BACKGROUND
--- Wraps `HB_OT_NAME_ID_DARK_BACKGROUND`
-- @field ot.NAME_ID_DARK_BACKGROUND
--- Wraps `HB_OT_NAME_ID_VARIATIONS_PS_PREFIX`
-- @field ot.NAME_ID_VARIATIONS_PS_PREFIX
--- Wraps `HB_OT_NAME_ID_INVALID`
-- @field ot.NAME_ID_INVALID
--- Wraps `HB_OT_LAYOUT_NO_SCRIPT_INDEX`
-- @field ot.LAYOUT_NO_SCRIPT_INDEX
--- Wraps `HB_OT_LAYOUT_NO_FEATURE_INDEX`
-- @field ot.LAYOUT_NO_FEATURE_INDEX
--- Wraps `HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX`
-- @field ot.LAYOUT_DEFAULT_LANGUAGE_INDEX
--- Wraps `HB_OT_LAYOUT_NO_VARIATIONS_INDEX`
-- @field ot.LAYOUT_NO_VARIATIONS_INDEX