Trait font_kit::loader::Loader[−][src]

pub trait Loader: Clone + Sized {
    type NativeFont;
    fn from_bytes(
        font_data: Arc<Vec<u8>>, 
        font_index: u32
    ) -> Result<Self, FontLoadingError>;

    fn from_file(
        file: &mut File, 
        font_index: u32
    ) -> Result<Self, FontLoadingError>;

    unsafe fn from_native_font(native_font: Self::NativeFont) -> Self;

    fn analyze_bytes(
        font_data: Arc<Vec<u8>>
    ) -> Result<FileType, FontLoadingError>;

    fn analyze_file(file: &mut File) -> Result<FileType, FontLoadingError>;

    fn native_font(&self) -> Self::NativeFont;

    fn postscript_name(&self) -> Option<String>;

    fn full_name(&self) -> String;

    fn family_name(&self) -> String;

    fn is_monospace(&self) -> bool;

    fn properties(&self) -> Properties;

    fn glyph_count(&self) -> u32;

    fn glyph_for_char(&self, character: char) -> Option<u32>;

    fn outline<B>(
        &self, 
        glyph_id: u32, 
        hinting_mode: HintingOptions, 
        path_builder: &mut B
    ) -> Result<(), GlyphLoadingError>
    where
        B: PathBuilder;

    fn typographic_bounds(
        &self, 
        glyph_id: u32
    ) -> Result<Rect<f32>, GlyphLoadingError>;

    fn advance(&self, glyph_id: u32) -> Result<Vector2D<f32>, GlyphLoadingError>;

    fn origin(&self, glyph_id: u32) -> Result<Point2D<f32>, GlyphLoadingError>;

    fn metrics(&self) -> Metrics;

    fn copy_font_data(&self) -> Option<Arc<Vec<u8>>>;

    fn supports_hinting_options(
        &self, 
        hinting_options: HintingOptions, 
        for_rasterization: bool
    ) -> bool;

    fn rasterize_glyph(
        &self, 
        canvas: &mut Canvas, 
        glyph_id: u32, 
        point_size: f32, 
        origin: &Point2D<f32>, 
        hinting_options: HintingOptions, 
        rasterization_options: RasterizationOptions
    ) -> Result<(), GlyphLoadingError>;

    fn from_path<P>(path: P, font_index: u32) -> Result<Self, FontLoadingError>
    where
        P: AsRef<Path>,
    { ... }

    fn from_handle(handle: &Handle) -> Result<Self, FontLoadingError> { ... }

    fn analyze_path<P>(path: P) -> Result<FileType, FontLoadingError>
    where
        P: AsRef<Path>,
    { ... }

    fn handle(&self) -> Option<Handle> { ... }

    fn raster_bounds(
        &self, 
        glyph_id: u32, 
        point_size: f32, 
        origin: &Point2D<f32>, 
        _: HintingOptions, 
        _: RasterizationOptions
    ) -> Result<Rect<i32>, GlyphLoadingError> { ... }
}

Provides a common interface to the platform-specific API that loads, parses, and rasterizes fonts.

Associated Types

The handle that the API natively uses to represent a font.

Required Methods

Loads a font from raw font data (the contents of a .ttf/.otf/etc. file).

If the data represents a collection (.ttc/.otc/etc.), font_index specifies the index of the font to load from it. If the data represents a single font, pass 0 for font_index.

Loads a font from a .ttf/.otf/etc. file.

If the file is a collection (.ttc/.otc/etc.), font_index specifies the index of the font to load from it. If the file represents a single font, pass 0 for font_index.

Creates a font from a native API handle.

Determines whether a blob of raw font data represents a supported font, and, if so, what type of font it is.

Determines whether a file represents a supported font, and, if so, what type of font it is.

Returns the wrapped native font handle.

Returns the PostScript name of the font. This should be globally unique.

Returns the full name of the font (also known as "display name" on macOS).

Returns the name of the font family.

Returns true if and only if the font is monospace (fixed-width).

Returns the values of various font properties, corresponding to those defined in CSS.

Returns the number of glyphs in the font.

Glyph IDs range from 0 inclusive to this value exclusive.

Returns the usual glyph ID for a Unicode character.

Be careful with this function; typographically correct character-to-glyph mapping must be done using a shaper such as HarfBuzz. This function is only useful for best-effort simple use cases like "what does character X look like on its own".

Sends the vector path for a glyph to a path builder.

If hinting_mode is not None, this function performs grid-fitting as requested before sending the hinding outlines to the builder.

TODO(pcwalton): What should we do for bitmap glyphs?

Returns the boundaries of a glyph in font units.

Returns the distance from the origin of the glyph with the given ID to the next, in font units.

Returns the amount that the given glyph should be displaced from the origin.

Retrieves various metrics that apply to the entire font.

Attempts to return the raw font data (contents of the font file).

If this font is a member of a collection, this function returns the data for the entire collection.

Returns true if and only if the font loader can perform hinting in the requested way.

Some APIs support only rasterizing glyphs with hinting, not retriving hinted outlines. If for_rasterization is false, this function returns true if and only if the loader supports retrieval of hinted outlines. If for_rasterization is true, this function returns true if and only if the loader supports rasterizing hinted glyphs.

Rasterizes a glyph to a canvas with the given size and origin.

Format conversion will be performed if the canvas format does not match the rasterization options. For example, if bilevel (black and white) rendering is requested to an RGBA surface, this function will automatically convert the 1-bit raster image to the 32-bit format of the canvas. Note that this may result in a performance penalty, depending on the loader.

If hinting_options is not None, the requested grid fitting is performed.

Provided Methods

Loads a font from the path to a .ttf/.otf/etc. file.

If the file is a collection (.ttc/.otc/etc.), font_index specifies the index of the font to load from it. If the file represents a single font, pass 0 for font_index.

Loads the font pointed to by a handle.

Determines whether a path points to a supported font, and, if so, what type of font it is.

Returns a handle to this font, if possible.

This is useful if you want to open the font with a different loader.

Returns the pixel boundaries that the glyph will take up when rendered using this loader's rasterizer at the given size and origin.

Implementors