Struct Glyph 

pub struct Glyph { /* private fields */ }

Represents a single glyph (character) in a font.

Contains the character’s bitmap data and rendering metrics. Glyphs store both allocated dimensions (for layout) and actual bitmap dimensions (for rendering).

Bitmap Data

The data field contains 8-bit grayscale pixel data in row-major order:

• Each byte represents one pixel’s intensity/alpha (0-255)
• Total size is width × height bytes
• Empty glyphs (spaces, etc.) may have zero-sized data

Dimensions

Two sets of dimensions are stored:

• Allocated (alloc_width, alloc_height): Space reserved for layout
• Actual (width, height): Size of the bitmap data

Allocated height can be negative for characters with descenders (e.g., ‘g’, ‘y’).

Implementations

impl Glyph

pub fn code(&self) -> &u16

Glyph code/index in the font.

This is the internal glyph identifier used by the font file format.

pub fn character(&self) -> &u16

Unicode character code this glyph represents.

Maps to the Unicode character value (0-65535 range for BMP). This is the character that will be displayed when this glyph is rendered.

pub fn alloc_height(&self) -> &i8

Allocated height in the font layout (can be negative).

This is the vertical space reserved for the glyph in text layout. Negative values indicate descenders (parts of characters below the baseline). For example, lowercase ‘g’ or ‘y’ typically have negative allocated heights.

pub fn alloc_width(&self) -> &u8

Allocated width in the font layout.

This is the horizontal advance width - how far to move the cursor after rendering this glyph. May differ from the actual bitmap width.

pub fn width(&self) -> &u8

Actual bitmap width in pixels.

The width of the glyph’s pixel data. The data field contains width × height bytes of bitmap information.

pub fn height(&self) -> &u8

Actual bitmap height in pixels.

The height of the glyph’s pixel data. The data field contains width × height bytes of bitmap information.

pub fn kerning(&self) -> &u32

Kerning adjustment value.

Used for pair-wise spacing adjustments between specific character combinations. The exact interpretation depends on the kerning data in the font.

pub fn data(&self) -> &Vec<u8>

8-bit grayscale bitmap data.

Contains the glyph’s pixel data in row-major order:

• Size: width × height bytes
• Format: One byte per pixel (0 = transparent, 255 = opaque)
• Empty for characters with no visual representation (e.g., spaces)

Example Layout

For a 3×2 glyph, data is stored as:

[row0_col0, row0_col1, row0_col2, row1_col0, row1_col1, row1_col2]

impl Glyph

pub fn code_mut(&mut self) -> &mut u16

Glyph code/index in the font.

This is the internal glyph identifier used by the font file format.

pub fn character_mut(&mut self) -> &mut u16

Unicode character code this glyph represents.

Maps to the Unicode character value (0-65535 range for BMP). This is the character that will be displayed when this glyph is rendered.

pub fn alloc_height_mut(&mut self) -> &mut i8

Allocated height in the font layout (can be negative).

This is the vertical space reserved for the glyph in text layout. Negative values indicate descenders (parts of characters below the baseline). For example, lowercase ‘g’ or ‘y’ typically have negative allocated heights.

pub fn alloc_width_mut(&mut self) -> &mut u8

Allocated width in the font layout.

This is the horizontal advance width - how far to move the cursor after rendering this glyph. May differ from the actual bitmap width.

pub fn width_mut(&mut self) -> &mut u8

Actual bitmap width in pixels.

The width of the glyph’s pixel data. The data field contains width × height bytes of bitmap information.

pub fn height_mut(&mut self) -> &mut u8

Actual bitmap height in pixels.

The height of the glyph’s pixel data. The data field contains width × height bytes of bitmap information.

pub fn kerning_mut(&mut self) -> &mut u32

Kerning adjustment value.

Used for pair-wise spacing adjustments between specific character combinations. The exact interpretation depends on the kerning data in the font.

pub fn data_mut(&mut self) -> &mut Vec<u8>

8-bit grayscale bitmap data.

Contains the glyph’s pixel data in row-major order:

• Size: width × height bytes
• Format: One byte per pixel (0 = transparent, 255 = opaque)
• Empty for characters with no visual representation (e.g., spaces)

Example Layout

For a 3×2 glyph, data is stored as:

[row0_col0, row0_col1, row0_col2, row1_col0, row1_col1, row1_col2]

impl Glyph

pub fn set_code(&mut self, val: u16) -> &mut Self

Glyph code/index in the font.

This is the internal glyph identifier used by the font file format.

pub fn set_character(&mut self, val: u16) -> &mut Self

Unicode character code this glyph represents.

Maps to the Unicode character value (0-65535 range for BMP). This is the character that will be displayed when this glyph is rendered.

pub fn set_alloc_height(&mut self, val: i8) -> &mut Self

Allocated height in the font layout (can be negative).

This is the vertical space reserved for the glyph in text layout. Negative values indicate descenders (parts of characters below the baseline). For example, lowercase ‘g’ or ‘y’ typically have negative allocated heights.

pub fn set_alloc_width(&mut self, val: u8) -> &mut Self

Allocated width in the font layout.

This is the horizontal advance width - how far to move the cursor after rendering this glyph. May differ from the actual bitmap width.

pub fn set_width(&mut self, val: u8) -> &mut Self

Actual bitmap width in pixels.

The width of the glyph’s pixel data. The data field contains width × height bytes of bitmap information.

pub fn set_height(&mut self, val: u8) -> &mut Self

Actual bitmap height in pixels.

The height of the glyph’s pixel data. The data field contains width × height bytes of bitmap information.

pub fn set_kerning(&mut self, val: u32) -> &mut Self

Kerning adjustment value.

Used for pair-wise spacing adjustments between specific character combinations. The exact interpretation depends on the kerning data in the font.

pub fn set_data(&mut self, val: Vec<u8>) -> &mut Self

8-bit grayscale bitmap data.

Contains the glyph’s pixel data in row-major order:

• Size: width × height bytes
• Format: One byte per pixel (0 = transparent, 255 = opaque)
• Empty for characters with no visual representation (e.g., spaces)

Example Layout

For a 3×2 glyph, data is stored as:

[row0_col0, row0_col1, row0_col2, row1_col0, row1_col1, row1_col2]

Trait Implementations

impl Clone for Glyph

fn clone(&self) -> Glyph

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Glyph

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Glyph

fn default() -> Glyph

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Glyph

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for Glyph

fn eq(&self, other: &Glyph) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for Glyph

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Glyph