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//! RustType is a pure Rust alternative to libraries like FreeType. //! //! The current capabilities of RustType: //! //! * Reading TrueType formatted fonts and font collections. This includes `*.ttf` as well as a subset //! of `*.otf` font files. //! * Retrieving glyph shapes and commonly used properties for a font and its glyphs. //! * Laying out glyphs horizontally using horizontal and vertical metrics, and glyph-pair-specific kerning. //! * Rasterising glyphs with sub-pixel positioning using an accurate analytical algorithm //! (not based on sampling). //! * Managing a font cache on the GPU with the `gpu_cache` module. This keeps recently used glyph renderings //! in a dynamic cache in GPU memory to minimise texture uploads per-frame. It also allows you keep the draw //! call count for text very low, as all glyphs are kept in one GPU texture. //! //! Notable things that RustType does not support *yet*: //! //! * OpenType formatted fonts that are not just TrueType fonts (OpenType is a superset of TrueType). Notably //! there is no support yet for cubic Bezier curves used in glyphs. //! * Font hinting. //! * Ligatures of any kind. //! * Some less common TrueType sub-formats. //! * Right-to-left and vertical text layout. //! //! # Getting Started //! //! Add the following to your Cargo.toml: //! //! ```toml //! [dependencies] //! rusttype = "0.2.1" //! ``` //! //! To hit the ground running with RustType, look at the `simple.rs` example supplied with the crate. It //! demonstrates loading a font file, rasterising an arbitrary string, and displaying the result as ASCII art. //! If you prefer to just look at the documentation, the entry point for loading fonts is `FontCollection`, //! from which you can access individual fonts, then their glyphs. //! //! # Glyphs //! //! The glyph API uses wrapper structs to augment a glyph with //! information such as scaling and positioning, making relevant methods that make use of this information //! available as appropriate. For example, given a `Glyph` `glyph` obtained directly from a `Font`: //! //! ```no_run //! # use rusttype::*; //! # let glyph: Glyph<'static> = unimplemented!(); //! // One of the few things you can do with an unsized, positionless glyph is get its id. //! let id = glyph.id(); //! let glyph = glyph.scaled(Scale::uniform(10.0)); //! // Now glyph is a ScaledGlyph, you can do more with it, as well as what you can do with Glyph. //! // For example, you can access the correctly scaled horizontal metrics for the glyph. //! let h_metrics = glyph.h_metrics(); //! let glyph = glyph.positioned(point(5.0, 3.0)); //! // Now glyph is a PositionedGlyph, and you can do even more with it, e.g. drawing. //! glyph.draw(|x, y, v| {}); // In this case the pixel values are not used. //! ``` //! //! # Unicode terminology //! //! This crate uses terminology for computerised typography as specified by the Unicode standard. If you are //! not sure of the differences between a code point, a character, and a glyph, you may want to check the //! [official Unicode glossary](http://unicode.org/glossary/), or alternatively, here's my take on it from a //! practical perspective: //! //! * A character is what you would conventionally call a single symbol, independent of its appearance or //! representation in a particular font. Examples include `a`, `A`, `ä`, `å`, `1`, `*`, `Ω`, etc. //! * A Unicode code point is the particular number that the Unicode standard associates with a particular //! character. //! Note however that code points also exist for things not conventionally thought of as characters by //! themselves, but can be combined to form characters, such as diacritics like accents. These //! "characters" are known in Unicode as "combining characters". //! E.g., a diaeresis (`¨`) has the code point U+0308. If this code point follows the code point U+0055 //! (the letter `u`), this sequence represents the character `ü`. Note that there is also a //! single codepoint for `ü`, U+00FC. This means that what visually looks like the same string can have //! multiple different Unicode representations. Some fonts will have glyphs (see below) for one sequence of //! codepoints, but not another that has the same meaning. To deal with this problem it is recommended to use //! Unicode normalisation, as provided by, for example, the //! [unicode-normalization](http://crates.io/crates/unicode-normalization) crate, to convert to code point //! sequences that work with the font in question. Typically a font is more likely to support a single code //! point vs. a sequence with the same meaning, so the best normalisation to use is "canonical recomposition", //! known as NFC in the normalisation crate. //! * A glyph is a particular font's shape to draw the character for a particular Unicode code point. This will //! have its own identifying number unique to the font, its ID. #![cfg_attr(feature = "bench", feature(test))] #[cfg(feature = "bench")] extern crate test; #[cfg(test)] extern crate unicode_normalization; extern crate arrayvec; extern crate stb_truetype; extern crate linked_hash_map; mod geometry; mod rasterizer; mod support; pub mod gpu_cache; use std::sync::Arc; pub use geometry::{Rect, Point, point, Vector, vector, Line, Curve}; use stb_truetype as tt; /// A collection of fonts read straight from a font file's data. The data in the collection is not validated. /// This structure may or may not own the font data. #[derive(Clone, Debug)] pub struct FontCollection<'a>(SharedBytes<'a>); /// A single font. This may or may not own the font data. #[derive(Clone)] pub struct Font<'a> { info: tt::FontInfo<SharedBytes<'a>> } /// `SharedBytes` handles the lifetime of font data used in RustType. The data is either a shared /// reference to externally owned data, or managed by reference counting. `SharedBytes` can be /// conveniently used with `From` and `Into`, and dereferences to the contained bytes. #[derive(Clone, Debug)] pub enum SharedBytes<'a> { ByRef(&'a [u8]), ByArc(Arc<Box<[u8]>>) } impl<'a> ::std::ops::Deref for SharedBytes<'a> { type Target = [u8]; fn deref(&self) -> &[u8] { match *self { SharedBytes::ByRef(bytes) => bytes, SharedBytes::ByArc(ref bytes) => &***bytes } } } impl<'a> From<&'a [u8]> for SharedBytes<'a> { fn from(bytes: &'a [u8]) -> SharedBytes<'a> { SharedBytes::ByRef(bytes) } } impl From<Arc<Box<[u8]>>> for SharedBytes<'static> { fn from(bytes: Arc<Box<[u8]>>) -> SharedBytes<'static> { SharedBytes::ByArc(bytes) } } impl From<Box<[u8]>> for SharedBytes<'static> { fn from(bytes: Box<[u8]>) -> SharedBytes<'static> { SharedBytes::ByArc(Arc::new(bytes)) } } impl From<Vec<u8>> for SharedBytes<'static> { fn from(bytes: Vec<u8>) -> SharedBytes<'static> { SharedBytes::ByArc(Arc::new(bytes.into_boxed_slice())) } } /// Represents a Unicode code point. #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)] pub struct Codepoint(pub u32); /// Represents either a Unicode code point, or a glyph identifier for a font. /// /// This is used as input for functions that can accept code points or glyph identifiers. /// /// You typically won't construct this type directly, instead relying on `From` and `Into`. #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)] pub enum CodepointOrGlyphId { Codepoint(Codepoint), GlyphId(GlyphId) } /// Represents a glyph identifier for a particular font. This identifier will not necessarily correspond to /// the correct glyph in a font other than the one that it was obtained from. #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)] pub struct GlyphId(pub u32); /// A single glyph of a font. this may either be a thin wrapper referring to the font and the glyph id, or /// it may be a standalone glyph that owns the data needed by it. /// /// A `Glyph` does not have an inherent scale or position associated with it. To augment a glyph with a /// size, give it a scale using `scaled`. You can then position it using `positioned`. #[derive(Clone)] pub struct Glyph<'a> { inner: GlyphInner<'a> } #[derive(Clone)] enum GlyphInner<'a> { Proxy(&'a Font<'a>, u32), Shared(Arc<SharedGlyphData>) } #[derive(Debug)] struct SharedGlyphData { id: u32, extents: Option<Rect<i32>>, scale_for_1_pixel: f32, unit_h_metrics: HMetrics, shape: Option<Vec<tt::Vertex>> } /// The "horizontal metrics" of a glyph. This is useful for calculating the horizontal offset of a glyph /// from the previous one in a string when laying a string out horizontally. #[derive(Copy, Clone, Debug, PartialEq, PartialOrd)] pub struct HMetrics { /// The horizontal offset that the origin of the next glyph should be from the origin of this glyph. pub advance_width: f32, /// The horizontal offset between the origin of this glyph and the leftmost edge/point of the glyph. pub left_side_bearing: f32 } #[derive(Copy, Clone, Debug, PartialEq, PartialOrd)] /// The "vertical metrics" of a font at a particular scale. This is useful for calculating the amount of /// vertical space to give a line of text, and for computing the vertical offset between successive lines. pub struct VMetrics { /// The highest point that any glyph in the font extends to above the baseline. Typically positive. pub ascent: f32, /// The lowest point that any glyph in the font extends to below the baseline. Typically negative. pub descent: f32, /// The gap to leave between the descent of one line and the ascent of the next. This is of /// course only a guideline given by the font's designers. pub line_gap: f32 } /// A glyph augmented with scaling information. You can query such a glyph for information that depends /// on the scale of the glyph. #[derive(Clone)] pub struct ScaledGlyph<'a> { g: Glyph<'a>, api_scale: Scale, scale: Vector<f32> } /// A glyph augmented with positioning and scaling information. You can query such a glyph for information /// that depends on the scale and position of the glyph. #[derive(Clone)] pub struct PositionedGlyph<'a> { sg: ScaledGlyph<'a>, position: Point<f32>, bb: Option<Rect<i32>> } /// Defines the size of a rendered face of a font, in pixels, horizontally and vertically. A vertical /// scale of `y` pixels means that the distance betwen the ascent and descent lines (see `VMetrics`) of the /// face will be `y` pixels. If `x` and `y` are equal the scaling is uniform. Non-uniform scaling by a factor /// *f* in the horizontal direction is achieved by setting `x` equal to *f* times `y`. #[derive(Copy, Clone, PartialEq, PartialOrd, Debug)] pub struct Scale { /// Horizontal scale, in pixels. pub x: f32, /// Vertical scale, in pixels. pub y: f32 } impl Scale { /// Uniform scaling, equivalent to `Scale { x: s, y: s }`. pub fn uniform(s: f32) -> Scale { Scale { x: s, y: s } } } impl From<char> for Codepoint { fn from(c: char) -> Codepoint { Codepoint(c as u32) } } impl From<Codepoint> for CodepointOrGlyphId { fn from(c: Codepoint) -> CodepointOrGlyphId { CodepointOrGlyphId::Codepoint(c) } } impl From<GlyphId> for CodepointOrGlyphId { fn from(g: GlyphId) -> CodepointOrGlyphId { CodepointOrGlyphId::GlyphId(g) } } impl From<char> for CodepointOrGlyphId { fn from(c: char) -> CodepointOrGlyphId { Codepoint(c as u32).into() } } impl<'a> FontCollection<'a> { /// Constructs a font collection from an array of bytes, typically loaded from a font file. /// This array may be owned (e.g. `Vec<u8>`), or borrowed (`&[u8]`). /// As long as `From<T>` is implemented for `Bytes` for some type `T`, `T` can be used as input. pub fn from_bytes<B: Into<SharedBytes<'a>>>(bytes: B) -> FontCollection<'a> { FontCollection(bytes.into()) } /// In the common case that a font collection consists of only one font, this function /// consumes this font collection and turns it into a font. If this is not the case, /// or the font is not valid (read: not supported by this library), `None` is returned. pub fn into_font(self) -> Option<Font<'a>> { if tt::is_font(&self.0) && tt::get_font_offset_for_index(&self.0, 1).is_none() { tt::FontInfo::new(self.0, 0).map( |info| Font { info: info }) } else { None } } /// Gets the font at index `i` in the font collection, if it exists and is valid. /// The produced font borrows the font data that is either borrowed or owned by this font collection. pub fn font_at(&self, i: usize) -> Option<Font<'a>> { tt::get_font_offset_for_index(&self.0, i as i32) .and_then(|o| tt::FontInfo::new(self.0.clone(), o as usize)) .map(|info| Font { info: info }) } /// Converts `self` into an `Iterator` yielding each `Font` that exists within the collection. pub fn into_fonts(self) -> IntoFontsIter<'a> { IntoFontsIter { collection: self, next_index: 0, } } } pub struct IntoFontsIter<'a> { next_index: usize, collection: FontCollection<'a>, } impl<'a> Iterator for IntoFontsIter<'a> { type Item = Font<'a>; fn next(&mut self) -> Option<Self::Item> { self.collection.font_at(self.next_index).map(|font| { self.next_index += 1; font }) } } impl<'a> Font<'a> { /// The "vertical metrics" for this font at a given scale. These metrics are shared by all of the glyphs /// in the font. /// See `VMetrics` for more detail. pub fn v_metrics(&self, scale: Scale) -> VMetrics { let vm = self.info.get_v_metrics(); let scale = self.info.scale_for_pixel_height(scale.y); VMetrics { ascent: vm.ascent as f32 * scale, descent: vm.descent as f32 * scale, line_gap: vm.line_gap as f32 * scale } } /// The number of glyphs present in this font. Glyph identifiers for this font will always be in the range /// `0..self.glyph_count()` pub fn glyph_count(&self) -> usize { self.info.get_num_glyphs() as usize } /// Returns the corresponding glyph for a Unicode code point or a glyph id for this font. /// If id corresponds to a glyph identifier, the identifier must be valid (smaller than `self.glyph_count()`), /// otherwise `None` is returned. /// /// Note that code points without corresponding glyphs in this font map to the "undef" glyph, glyph 0. pub fn glyph<C: Into<CodepointOrGlyphId>>(&self, id: C) -> Option<Glyph> { let gid = match id.into() { CodepointOrGlyphId::Codepoint(Codepoint(c)) => self.info.find_glyph_index(c), CodepointOrGlyphId::GlyphId(GlyphId(gid)) => gid }; Some(Glyph::new(GlyphInner::Proxy(self, gid))) } /// A convenience function. /// /// Returns an iterator that produces the glyphs corresponding to the code points or glyph ids produced /// by the given iterator `itr`. /// /// This is equivalent in behaviour to `itr.map(|c| font.glyph(c).unwrap())`. pub fn glyphs_for<I: Iterator>(&self, itr: I) -> GlyphIter<I> where I::Item: Into<CodepointOrGlyphId> { GlyphIter { font: self, itr: itr } } /// A convenience function for laying out glyphs for a string horizontally. It does not take control /// characters like line breaks into account, as treatment of these is likely to depend on the application. /// /// Note that this function does not perform Unicode normalisation. Composite characters (such as ö /// constructed from two code points, ¨ and o), will not be normalised to single code points. So if a font /// does not contain a glyph for each separate code point, but does contain one for the normalised single /// code point (which is common), the desired glyph will not be produced, despite being present in the font. /// Deal with this by performing Unicode normalisation on the input string before passing it to `layout`. /// The crate [unicode-normalization](http://crates.io/crates/unicode-normalization) is perfect for this /// purpose. /// /// Calling this function is equivalent to a longer sequence of operations involving `glyphs_for`, e.g. /// /// ```no_run /// # use rusttype::*; /// # let (scale, start) = (Scale::uniform(0.0), point(0.0, 0.0)); /// # let font: Font = unimplemented!(); /// font.layout("Hello World!", scale, start) /// # ; /// ``` /// /// produces an iterator with behaviour equivalent to the following: /// /// ```no_run /// # use rusttype::*; /// # let (scale, start) = (Scale::uniform(0.0), point(0.0, 0.0)); /// # let font: Font = unimplemented!(); /// font.glyphs_for("Hello World!".chars()) /// .scan((None, 0.0), |&mut (mut last, mut x), g| { /// let g = g.scaled(scale); /// let w = g.h_metrics().advance_width /// + last.map(|last| font.pair_kerning(scale, last, g.id())).unwrap_or(0.0); /// let next = g.positioned(start + vector(x, 0.0)); /// last = Some(next.id()); /// x += w; /// Some(next) /// }) /// # ; /// ``` pub fn layout<'b, 'c>(&'b self, s: &'c str, scale: Scale, start: Point<f32>) -> LayoutIter<'b, 'c> { LayoutIter { font: self, chars: s.chars(), caret: 0.0, scale: scale, start: start, last_glyph: None } } /// Returns additional kerning to apply as well as that given by HMetrics for a particular pair of glyphs. pub fn pair_kerning<A, B>(&self, scale: Scale, first: A, second: B) -> f32 where A: Into<CodepointOrGlyphId>, B: Into<CodepointOrGlyphId> { let (first, second) = (self.glyph(first).unwrap(), self.glyph(second).unwrap()); let factor = self.info.scale_for_pixel_height(scale.y) * (scale.x / scale.y); let kern = self.info.get_glyph_kern_advance(first.id().0, second.id().0); factor * kern as f32 } } #[derive(Clone)] pub struct GlyphIter<'a, I: Iterator> where I::Item: Into<CodepointOrGlyphId> { font: &'a Font<'a>, itr: I } impl<'a, I: Iterator> Iterator for GlyphIter<'a, I> where I::Item: Into<CodepointOrGlyphId> { type Item = Glyph<'a>; fn next(&mut self) -> Option<Glyph<'a>> { self.itr.next().map(|c| self.font.glyph(c).unwrap()) } } #[derive(Clone)] pub struct LayoutIter<'a, 'b> { font: &'a Font<'a>, chars: ::std::str::Chars<'b>, caret: f32, scale: Scale, start: Point<f32>, last_glyph: Option<GlyphId> } impl<'a, 'b> Iterator for LayoutIter<'a, 'b> { type Item = PositionedGlyph<'a>; fn next(&mut self) -> Option<PositionedGlyph<'a>> { self.chars.next().map(|c| { let g = self.font.glyph(c).unwrap().scaled(self.scale); if let Some(last) = self.last_glyph { self.caret += self.font.pair_kerning(self.scale, last, g.id()); } let g = g.positioned(point(self.start.x + self.caret, self.start.y)); self.caret += g.sg.h_metrics().advance_width; self.last_glyph = Some(g.id()); g }) } } impl<'a> Glyph<'a> { fn new(inner: GlyphInner) -> Glyph { Glyph { inner: inner } } /// The font to which this glyph belongs. If the glyph is a standalone glyph that owns its resources, /// it no longer has a reference to the font which it was created from (using `standalone()`). In which /// case, `None` is returned. pub fn font(&self) -> Option<&Font<'a>> { match self.inner { GlyphInner::Proxy(f, _) => Some(f), GlyphInner::Shared(_) => None } } /// The glyph identifier for this glyph. pub fn id(&self) -> GlyphId { match self.inner { GlyphInner::Proxy(_, id) => GlyphId(id), GlyphInner::Shared(ref data) => GlyphId(data.id), } } /// Augments this glyph with scaling information, making methods that depend on the scale of the glyph /// available. pub fn scaled(self, scale: Scale) -> ScaledGlyph<'a> { let (scale_x, scale_y) = match self.inner { GlyphInner::Proxy(font, _) => { let scale_y = font.info.scale_for_pixel_height(scale.y); let scale_x = scale_y * scale.x / scale.y; (scale_x, scale_y) } GlyphInner::Shared(ref data) => { let scale_y = data.scale_for_1_pixel * scale.y; let scale_x = scale_y * scale.x / scale.y; (scale_x, scale_y) } }; ScaledGlyph { g: self, api_scale: scale, scale: vector(scale_x, scale_y) } } /// Turns a `Glyph<'a>` into a `Glyph<'static>`. This produces a glyph that owns its resources, /// extracted from the font. This glyph can outlive the font that it comes from. /// /// Calling `standalone()` on a standalone glyph shares the resources, and is equivalent to `clone()`. pub fn standalone(&self) -> Glyph<'static> { match self.inner { GlyphInner::Proxy(font, id) => Glyph::new(GlyphInner::Shared(Arc::new(SharedGlyphData { id: id, scale_for_1_pixel: font.info.scale_for_pixel_height(1.0), unit_h_metrics: { let hm = font.info.get_glyph_h_metrics(id); HMetrics { advance_width: hm.advance_width as f32, left_side_bearing: hm.left_side_bearing as f32 } }, extents: font.info.get_glyph_box(id).map(|bb| Rect { min: point(bb.x0 as i32, -(bb.y1 as i32)), max: point(bb.x1 as i32, -(bb.y0 as i32)) }), shape: font.info.get_glyph_shape(id) }))), GlyphInner::Shared(ref data) => Glyph::new(GlyphInner::Shared(data.clone())) } } } /// Part of a `Contour`, either a `Line` or a `Curve`. #[derive(Copy, Clone, Debug)] pub enum Segment { Line(Line), Curve(Curve) } /// A closed loop consisting of a sequence of `Segment`s. #[derive(Clone, Debug)] pub struct Contour { pub segments: Vec<Segment> } impl<'a> ScaledGlyph<'a> { /// The glyph identifier for this glyph. pub fn id(&self) -> GlyphId { self.g.id() } /// The font to which this glyph belongs. If the glyph is a standalone glyph that owns its resources, /// it no longer has a reference to the font which it was created from (using `standalone()`). In which /// case, `None` is returned. pub fn font(&self) -> Option<&Font<'a>> { self.g.font() } /// A reference to this glyph without the scaling pub fn into_unscaled(self) -> Glyph<'a> { self.g } /// Removes the scaling from this glyph pub fn unscaled(&self) -> &Glyph<'a> { &self.g } /// Augments this glyph with positioning information, making methods that depend on the position of the /// glyph available. pub fn positioned(self, p: Point<f32>) -> PositionedGlyph<'a> { let bb = match self.g.inner { GlyphInner::Proxy(font, id) => { font.info.get_glyph_bitmap_box_subpixel(id, self.scale.x, self.scale.y, p.x, p.y) .map(|bb| Rect { min: point(bb.x0, bb.y0), max: point(bb.x1, bb.y1) }) } GlyphInner::Shared(ref data) => { data.extents.map(|bb| Rect { min: point((bb.min.x as f32 * self.scale.x + p.x).floor() as i32, (bb.min.y as f32 * self.scale.y + p.y).floor() as i32), max: point((bb.max.x as f32 * self.scale.x + p.x).ceil() as i32, (bb.max.y as f32 * self.scale.y + p.y).ceil() as i32) }) } }; PositionedGlyph { sg: self, position: p, bb: bb } } pub fn scale(&self) -> Scale { self.api_scale } /// Retrieves the "horizontal metrics" of this glyph. See `HMetrics` for more detail. pub fn h_metrics(&self) -> HMetrics { match self.g.inner { GlyphInner::Proxy(font, id) => { let hm = font.info.get_glyph_h_metrics(id); HMetrics { advance_width: hm.advance_width as f32 * self.scale.x, left_side_bearing: hm.left_side_bearing as f32 * self.scale.x } } GlyphInner::Shared(ref data) => { HMetrics { advance_width: data.unit_h_metrics.advance_width * self.scale.x, left_side_bearing: data.unit_h_metrics.left_side_bearing * self.scale.y } } } } fn shape_with_offset(&self, offset: Point<f32>) -> Option<Vec<Contour>> { use stb_truetype::VertexType; use std::mem::replace; match self.g.inner { GlyphInner::Proxy(font, id) => font.info.get_glyph_shape(id), GlyphInner::Shared(ref data) => data.shape.clone() }.map(|shape| { let mut result = Vec::new(); let mut current = Vec::new(); let mut last = point(0.0, 0.0); for v in shape { let end = point(v.x as f32 * self.scale.x + offset.x, v.y as f32 * self.scale.y + offset.y); match v.vertex_type() { VertexType::MoveTo if result.len() != 0 => { result.push(Contour { segments: replace(&mut current, Vec::new()) }) } VertexType::LineTo => { current.push(Segment::Line(Line { p: [last, end] })) } VertexType::CurveTo => { let control = point(v.cx as f32 * self.scale.x + offset.x, v.cy as f32 * self.scale.y + offset.y); current.push(Segment::Curve(Curve { p: [last, control, end] })) } _ => () } last = end; } if current.len() > 0 { result.push(Contour { segments: replace(&mut current, Vec::new()) }); } result }) } /// Produces a list of the contours that make up the shape of this glyph. Each contour consists of /// a sequence of segments. Each segment is either a straight `Line` or a `Curve`. /// /// The winding of the produced contours is clockwise for closed shapes, anticlockwise for holes. pub fn shape(&self) -> Option<Vec<Contour>> { self.shape_with_offset(point(0.0, 0.0)) } /// The bounding box of the shape of this glyph, not to be confused with `pixel_bounding_box`, the /// conservative pixel-boundary bounding box. The coordinates are relative to the glyph's origin. pub fn exact_bounding_box(&self) -> Option<Rect<f32>> { match self.g.inner { GlyphInner::Proxy(font, id) => font.info.get_glyph_box(id).map(|bb| { Rect { min: point(bb.x0 as f32 * self.scale.x, -bb.y1 as f32 * self.scale.y), max: point(bb.x1 as f32 * self.scale.x, -bb.y0 as f32 * self.scale.y) } }), GlyphInner::Shared(ref data) => data.extents.map(|bb| Rect { min: point(bb.min.x as f32 * self.scale.x, bb.min.y as f32 * self.scale.y), max: point(bb.max.x as f32 * self.scale.x, bb.max.y as f32 * self.scale.y) }) } } /// Constructs a glyph that owns its data from this glyph. This is similar to `Glyph::standalone`. See /// that function for more details. pub fn standalone(&self) -> ScaledGlyph<'static> { ScaledGlyph { g: self.g.standalone(), api_scale: self.api_scale, scale: self.scale } } } impl<'a> PositionedGlyph<'a> { /// The glyph identifier for this glyph. pub fn id(&self) -> GlyphId { self.sg.id() } /// The font to which this glyph belongs. If the glyph is a standalone glyph that owns its resources, /// it no longer has a reference to the font which it was created from (using `standalone()`). In which /// case, `None` is returned. pub fn font(&self) -> Option<&Font<'a>> { self.sg.font() } /// A reference to this glyph without positioning pub fn unpositioned(&self) -> &ScaledGlyph<'a> { &self.sg } /// Removes the positioning from this glyph pub fn into_unpositioned(self) -> ScaledGlyph<'a> { self.sg } /// The conservative pixel-boundary bounding box for this glyph. This is the smallest rectangle /// aligned to pixel boundaries that encloses the shape of this glyph at this position. pub fn pixel_bounding_box(&self) -> Option<Rect<i32>> { self.bb } /// Similar to `ScaledGlyph::shape()`, but with the position of the glyph taken into account. pub fn shape(&self) -> Option<Vec<Contour>> { self.sg.shape_with_offset(self.position) } pub fn scale(&self) -> Scale { self.sg.api_scale } pub fn position(&self) -> Point<f32> { self.position } /// Rasterises this glyph. For each pixel in the rect given by `pixel_bounding_box()`, `o` is called: /// /// ```ignore /// o(x, y, v) /// ``` /// /// where `x` and `y` are the coordinates of the pixel relative to the `min` coordinates of the bounding box, /// and `v` is the analytically calculated coverage of the pixel by the shape of the glyph. /// Calls to `o` proceed in horizontal scanline order, similar to this pseudo-code: /// /// ```ignore /// let bb = glyph.pixel_bounding_box(); /// for y in 0..bb.height() { /// for x in 0..bb.width() { /// o(x, y, calc_coverage(&glyph, x, y)); /// } /// } /// ``` pub fn draw<O: FnMut(u32, u32, f32)>(&self, o: O) { use geometry::{Line, Curve}; use stb_truetype::VertexType; let shape = match self.sg.g.inner { GlyphInner::Proxy(font, id) => font.info.get_glyph_shape(id).unwrap_or_else(|| Vec::new()), GlyphInner::Shared(ref data) => data.shape.clone().unwrap_or_else(|| Vec::new()) }; let bb = if let Some(bb) = self.bb.as_ref() { bb } else { return }; let offset = vector(bb.min.x as f32, bb.min.y as f32); let mut lines = Vec::new(); let mut curves = Vec::new(); let mut last = point(0.0, 0.0); for v in shape { let end = point(v.x as f32 * self.sg.scale.x + self.position.x, -v.y as f32 * self.sg.scale.y + self.position.y) - offset; match v.vertex_type() { VertexType::LineTo => { lines.push(Line { p: [last, end] }) } VertexType::CurveTo => { let control = point(v.cx as f32 * self.sg.scale.x + self.position.x, -v.cy as f32 * self.sg.scale.y + self.position.y) - offset; curves.push(Curve { p: [last, control, end] }) } VertexType::MoveTo => {} } last = end; } rasterizer::rasterize(&lines, &curves, (bb.max.x - bb.min.x) as u32, (bb.max.y - bb.min.y) as u32, o); } /// Constructs a glyph that owns its data from this glyph. This is similar to `Glyph::standalone`. See /// that function for more details. pub fn standalone(&self) -> PositionedGlyph<'static> { PositionedGlyph { sg: self.sg.standalone(), bb: self.bb, position: self.position } } }