Struct webgl2_glyph::glyph_brush::GlyphBrushBuilder

#[non_exhaustive]
pub struct GlyphBrushBuilder<F = FontArc, H = RandomXxHashBuilder64> {
    pub font_data: Vec<F, Global>,
    pub cache_glyph_positioning: bool,
    pub cache_redraws: bool,
    pub section_hasher: H,
    pub draw_cache_builder: DrawCacheBuilder,
}

Builder for a GlyphBrush.

Example

use glyph_brush::{ab_glyph::FontArc, GlyphBrush, GlyphBrushBuilder};

let dejavu = FontArc::try_from_slice(include_bytes!("../../../fonts/DejaVuSans.ttf")).unwrap();
let mut glyph_brush: GlyphBrush<Vertex> =
    GlyphBrushBuilder::using_font(dejavu).build();

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

font_data: Vec<F, Global>

cache_glyph_positioning: bool

cache_redraws: bool

section_hasher: H

draw_cache_builder: DrawCacheBuilder

Implementations

impl GlyphBrushBuilder<(), RandomXxHashBuilder64>

pub fn using_fonts<F>(
    fonts: Vec<F, Global>
) -> GlyphBrushBuilder<F, RandomXxHashBuilder64> where
    F: Font, 

Create a new builder with multiple fonts.

pub fn using_font<F>(font: F) -> GlyphBrushBuilder<F, RandomXxHashBuilder64> where
    F: Font, 

Create a new builder with multiple fonts.

pub fn without_fonts() -> GlyphBrushBuilder<(), RandomXxHashBuilder64>

Create a new builder without any fonts.

impl<F, H> GlyphBrushBuilder<F, H>

pub fn replace_fonts<F2, V, NF>(self, font_fn: NF) -> GlyphBrushBuilder<F2, H> where
    F2: Font,
    V: Into<Vec<F2, Global>>,
    NF: FnOnce(Vec<F, Global>) -> V, 

Consume all builder fonts a replace with new fonts returned by the input function.

Generally only makes sense when wanting to change fonts after calling GlyphBrush::to_builder.

Example

let two_font_brush: GlyphBrush<Vertex>
    = GlyphBrushBuilder::using_fonts(vec![open_sans, deja_vu_sans]).build();

let one_font_brush: GlyphBrush<FontRef<'static>, Vertex> = two_font_brush
    .to_builder()
    .replace_fonts(|mut fonts| {
        // remove open_sans, leaving just deja_vu as FontId(0)
        fonts.remove(0);
        fonts
    })
    .build();

assert_eq!(one_font_brush.fonts().len(), 1);
assert_eq!(two_font_brush.fonts().len(), 2);

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

pub fn add_font<I>(&mut self, font_data: I) -> FontId where
    I: Into<F>, 

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

pub fn initial_cache_size(self, (u32, u32)) -> GlyphBrushBuilder<F, H>

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
) -> GlyphBrushBuilder<F, H>

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
) -> GlyphBrushBuilder<F, H>

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 multithread(self, multithread: bool) -> GlyphBrushBuilder<F, H>

When multiple CPU cores are available spread draw-cache work across all cores.

Defaults to true.

pub fn draw_cache_align_4x4(self, align: bool) -> GlyphBrushBuilder<F, H>

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) -> GlyphBrushBuilder<F, H>

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_redraws: bool) -> GlyphBrushBuilder<F, H>

Sets optimising vertex drawing by reusing the last draw requesting an identical draw queue. Will result in the usage of BrushAction::ReDraw.

Improves performance. Is disabled if cache_glyph_positioning is disabled.

Defaults to true

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

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 xxHash.

Example

GlyphBrushBuilder::using_font(some_font)
    .section_hasher(SomeOtherBuildHasher::default())
    // ...

pub fn build<V, X>(self) -> GlyphBrush<V, X, F, H>

Builds a GlyphBrush.

If type inference fails try declaring the types V & X. See GlyphBrush generic types.

let glyph_brush = GlyphBrushBuilder::using_font(some_font)
    .build::<Vertex, glyph_brush::Extra>();

pub fn rebuild<V, X>(self, brush: &mut GlyphBrush<V, X, F, H>)

Rebuilds an existing GlyphBrush with this builder’s properties. This will clear all caches and queues.

Example

let mut glyph_brush: GlyphBrush<Vertex> = GlyphBrushBuilder::using_font(sans).build();
assert_eq!(glyph_brush.texture_dimensions(), (256, 256));

// Use a new builder to rebuild the brush with a smaller initial cache size
glyph_brush.to_builder().initial_cache_size((64, 64)).rebuild(&mut glyph_brush);
assert_eq!(glyph_brush.texture_dimensions(), (64, 64));