Struct kas_theme::RasterConfig

pub struct RasterConfig {
    pub mode: u8,
    pub scale_steps: u8,
    pub subpixel_threshold: u8,
    pub subpixel_steps: u8,
}

Font raster settings

These are not used by the theme, but passed through to the rendering backend.

Fields

mode: u8

scale_steps: u8

Scale multiplier for fixed-precision

This should be an integer n >= 1, e.g. n = 4 provides four sub-pixel steps of precision. It is also required that n * h < (1 << 24) where h is the text height in pixels.

subpixel_threshold: u8

Subpixel positioning threshold

Text with height h less than this threshold will use sub-pixel positioning, which should make letter spacing more accurate for small fonts (though exact behaviour depends on the font; it may be worse). This may make rendering worse by breaking pixel alignment.

Note: this feature may not be available, depending on the backend and the mode.

See also sub-pixel positioning steps.

subpixel_steps: u8

Subpixel steps

The number of sub-pixel positioning steps to use. 1 is the minimum and equivalent to no sub-pixel positioning. 16 is the maximum.

Note that since this applies to horizontal and vertical positioning, the maximum number of rastered glyphs is multiplied by the square of this value, though this maxmimum may not be reached in practice. Since this feature is usually only used for small fonts this likely acceptable.

Trait Implementations

impl Clone for RasterConfig

fn clone(&self) -> RasterConfig

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for RasterConfig

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

Formats the value using the given formatter.

impl Default for RasterConfig

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for RasterConfig

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error> where
    __D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl PartialEq<RasterConfig> for RasterConfig

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl Serialize for RasterConfig

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 RasterConfig