1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317
//! Functions and types relating to text rendering. // Without this, we'd have conditionally compile a ton more stuff to // avoid warnings when fonts are disabled: #![cfg_attr(not(feature = "font_ttf"), allow(unused))] mod cache; mod packer; #[cfg(feature = "font_ttf")] mod vector; use std::cell::RefCell; use std::fmt::{self, Debug, Formatter}; use std::path::Path; use std::rc::Rc; use crate::error::Result; use crate::graphics::text::cache::{FontCache, TextGeometry}; use crate::graphics::{self, DrawParams, Rectangle}; use crate::Context; #[cfg(feature = "font_ttf")] pub use crate::graphics::text::vector::VectorFontBuilder; use super::FilterMode; /// A font with an associated size, cached on the GPU. /// /// # Performance /// /// Creating a `Font` is a relatively expensive operation. If you can, store them in your `State` /// struct rather than recreating them each frame. /// /// Cloning a `Font` is a very cheap operation, as the underlying data is shared between the /// original instance and the clone via [reference-counting](https://doc.rust-lang.org/std/rc/struct.Rc.html). /// This does mean, however, that updating a `Font` (for example, changing its filter mode) will also /// update any other clones of that `Font`. /// /// # Examples /// /// The [`text`](https://github.com/17cupsofcoffee/tetra/blob/main/examples/text.rs) /// example demonstrates how to load a font and then draw some text. #[derive(Clone)] pub struct Font { data: Rc<RefCell<FontCache>>, } impl Font { /// Creates a `Font` from a vector font file, with the given size. /// /// TrueType and OpenType fonts are supported. /// /// If you want to load multiple sizes of the same font, you can use a /// [`VectorFontBuilder`] to avoid loading/parsing the file multiple times. /// /// # Errors /// /// * [`TetraError::FailedToLoadAsset`](crate::TetraError::FailedToLoadAsset) will be returned /// if the file could not be loaded. /// * [`TetraError::InvalidFont`](crate::TetraError::InvalidFont) will be returned if the font /// data was invalid. /// * [`TetraError::PlatformError`](crate::TetraError::PlatformError) will be returned if the GPU cache for the font /// could not be created. #[cfg(feature = "font_ttf")] pub fn vector<P>(ctx: &mut Context, path: P, size: f32) -> Result<Font> where P: AsRef<Path>, { VectorFontBuilder::new(path)?.with_size(ctx, size) } /// Creates a `Font` from a slice of binary data. /// /// TrueType and OpenType fonts are supported. /// /// This is useful in combination with [`include_bytes`](std::include_bytes), as it /// allows you to include your font data directly in the binary. /// /// If you want to load multiple sizes of the same font, you can use a /// [`VectorFontBuilder`] to avoid parsing the data multiple times. /// /// # Errors /// /// * [`TetraError::InvalidFont`](crate::TetraError::InvalidFont) will be returned if the font /// data was invalid. /// * [`TetraError::PlatformError`](crate::TetraError::PlatformError) will be returned if the GPU cache for the font /// could not be created. #[cfg(feature = "font_ttf")] pub fn from_vector_file_data( ctx: &mut Context, data: &'static [u8], size: f32, ) -> Result<Font> { VectorFontBuilder::from_file_data(data)?.with_size(ctx, size) } /// Returns the filter mode of the font. pub fn filter_mode(&self) -> FilterMode { self.data.borrow().filter_mode() } /// Sets the filter mode of the font. /// /// Note that changing the filter mode of a font will affect all [`Text`] objects /// that use that font, including existing ones. This is due to the fact that /// each font has a shared texture atlas. pub fn set_filter_mode(&mut self, ctx: &mut Context, filter_mode: FilterMode) { self.data.borrow_mut().set_filter_mode(ctx, filter_mode); } } impl Debug for Font { fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result { f.debug_struct("Font").finish() } } /// A piece of text that can be rendered. /// /// # Performance /// /// The layout of the text is cached after the first time it is calculated, making subsequent /// rendering of the text much faster. /// /// Cloning a `Text` is a fairly expensive operation, as it creates an entirely new copy of the /// object with its own cache. /// /// # Examples /// /// The [`text`](https://github.com/17cupsofcoffee/tetra/blob/main/examples/text.rs) /// example demonstrates how to load a font and then draw some text. #[derive(Debug, Clone)] pub struct Text { content: String, font: Font, max_width: Option<f32>, geometry: Option<TextGeometry>, } impl Text { /// Creates a new `Text`, with the given content and font. pub fn new<C>(content: C, font: Font) -> Text where C: Into<String>, { Text { content: content.into(), font, max_width: None, geometry: None, } } /// Creates a new wrapped `Text`, with the given content, font /// and maximum width. /// /// If a word is too long to fit, it may extend beyond the max width - use /// [`get_bounds`](Text::get_bounds) if you need to find the actual bounds /// of the text. pub fn wrapped<C>(content: C, font: Font, max_width: f32) -> Text where C: Into<String>, { Text { content: content.into(), font, max_width: Some(max_width), geometry: None, } } /// Draws the text to the screen (or to a canvas, if one is enabled). pub fn draw<P>(&mut self, ctx: &mut Context, params: P) where P: Into<DrawParams>, { self.update_geometry(ctx); let params = params.into(); let data = self.font.data.borrow(); graphics::set_texture(ctx, data.texture()); let geometry = self .geometry .as_ref() .expect("geometry should have been generated"); for quad in &geometry.quads { graphics::push_quad( ctx, quad.position.x, quad.position.y, quad.position.right(), quad.position.bottom(), quad.uv.x, quad.uv.y, quad.uv.right(), quad.uv.bottom(), ¶ms, ); } } /// Returns a reference to the content of the text. pub fn content(&self) -> &str { &self.content } /// Sets the content of the text. /// /// Calling this function will cause a re-layout of the text the next time it /// is rendered. pub fn set_content<C>(&mut self, content: C) where C: Into<String>, { self.geometry.take(); self.content = content.into(); } /// Gets the font of the text. pub fn font(&self) -> &Font { &self.font } /// Sets the font of the text. /// /// Calling this function will cause a re-layout of the text the next time it /// is rendered. pub fn set_font(&mut self, font: Font) { self.geometry.take(); self.font = font; } /// Gets the maximum width of the text, if one is set. /// /// If a word is too long to fit, it may extend beyond this width - use /// [`get_bounds`](Text::get_bounds) if you need to find the actual bounds /// of the text. pub fn max_width(&self) -> Option<f32> { self.max_width } /// Sets the maximum width of the text. /// /// If `Some` is passed, word-wrapping will be enabled. If `None` is passed, /// it will be disabled. /// /// If a word is too long to fit, it may extend beyond this width - use /// [`get_bounds`](Text::get_bounds) if you need to find the actual bounds /// of the text. /// /// Calling this function will cause a re-layout of the text the next time it /// is rendered. pub fn set_max_width(&mut self, max_width: Option<f32>) { self.geometry.take(); self.max_width = max_width; } /// Appends the given character to the end of the text. /// /// Calling this function will cause a re-layout of the text the next time it /// is rendered. pub fn push(&mut self, ch: char) { self.geometry.take(); self.content.push(ch); } /// Appends the given string slice to the end of the text. /// /// Calling this function will cause a re-layout of the text the next time it /// is rendered. pub fn push_str(&mut self, string: &str) { self.geometry.take(); self.content.push_str(string); } /// Removes the last character from the text and returns it. /// /// Returns [`None`] if the text is empty. /// /// Calling this function will cause a re-layout of the text the next time it /// is rendered. pub fn pop(&mut self) -> Option<char> { self.geometry.take(); self.content.pop() } /// Get the outer bounds of the text when rendered to the screen. /// /// If the text's layout needs calculating, this method will do so. /// /// Note that this method will not take into account the positioning applied to the text via [`DrawParams`]. pub fn get_bounds(&mut self, ctx: &mut Context) -> Option<Rectangle> { self.update_geometry(ctx); self.geometry .as_ref() .expect("geometry should have been generated") .bounds } fn update_geometry(&mut self, ctx: &mut Context) { let mut data = self.font.data.borrow_mut(); let needs_render = match &self.geometry { None => true, Some(g) => g.resize_count != data.resize_count(), }; if needs_render { let new_geometry = data.render(&mut ctx.device, &self.content, self.max_width); self.geometry = Some(new_geometry); } } }