Struct glow_glyph::GlyphBrushBuilder

pub struct GlyphBrushBuilder<F, H = DefaultSectionHasher> { /* private fields */ }

Builder for a GlyphBrush.

Implementations

impl GlyphBrushBuilder<()>

pub fn using_font<F: Font>(font: F) -> GlyphBrushBuilder<F>

Specifies the default font used to render glyphs. Referenced with FontId(0), which is default.

pub fn using_fonts<F: Font>(fonts: Vec<F>) -> GlyphBrushBuilder<F>

impl<F: Font, H: BuildHasher> GlyphBrushBuilder<F, H>

pub fn add_font(&mut self, font_data: F) -> FontId

Adds additional fonts to the one added in using_font. Returns a FontId to reference this font.

pub fn initial_cache_size(self, size: (u32, u32)) -> Self

Initial size of 2D texture used as a gpu cache, pixels (width, height). The GPU cache will dynamically quadruple in size whenever the current size is insufficient.

Defaults to (256, 256)

pub fn draw_cache_scale_tolerance(self, tolerance: f32) -> Self

Sets the maximum allowed difference in scale used for judging whether to reuse an existing glyph in the GPU cache.

Defaults to 0.5

See docs for glyph_brush_draw_cache::DrawCache

pub fn draw_cache_position_tolerance(self, tolerance: f32) -> Self

Sets the maximum allowed difference in subpixel position used for judging whether to reuse an existing glyph in the GPU cache. Anything greater than or equal to 1.0 means “don’t care”.

Defaults to 0.1

See docs for glyph_brush_draw_cache::DrawCache

pub fn draw_cache_align_4x4(self, b: bool) -> Self

Align glyphs in texture cache to 4x4 texel boundaries.

If your backend requires texture updates to be aligned to 4x4 texel boundaries (e.g. WebGL), this should be set to true.

Defaults to false

See docs for glyph_brush_draw_cache::DrawCache

pub fn cache_glyph_positioning(self, cache: bool) -> Self

Sets whether perform the calculation of glyph positioning according to the layout every time, or use a cached result if the input Section and GlyphPositioner are the same hash as a previous call.

Improves performance. Should only disable if using a custom GlyphPositioner that is impure according to it’s inputs, so caching a previous call is not desired. Disabling also disables cache_redraws.

Defaults to true

pub fn cache_redraws(self, cache: bool) -> Self

Sets optimising drawing by reusing the last draw requesting an identical draw queue.

Improves performance. Is disabled if cache_glyph_positioning is disabled.

Defaults to true

pub fn draw_cache_multithread(self, multithread: bool) -> Self

When multiple CPU cores are available spread rasterization work across all cores.

Significantly reduces worst case latency in multicore environments.

Platform-specific behaviour

This option has no effect on wasm32.

pub fn section_hasher<T: BuildHasher>(
    self,
    section_hasher: T
) -> GlyphBrushBuilder<F, T>

Sets the section hasher. GlyphBrush cannot handle absolute section hash collisions so use a good hash algorithm.

This hasher is used to distinguish sections, rather than for hashmap internal use.

Defaults to seahash.

pub fn build(self, gl: &Context) -> GlyphBrush<F, H>

Builds a GlyphBrush in the given glow::Context.

Trait Implementations

impl<F, H> From<GlyphBrushBuilder<F, H>> for GlyphBrushBuilder<F, H>

fn from(inner: GlyphBrushBuilder<F, H>) -> Self

Converts to this type from the input type.