diff options
Diffstat (limited to '')
| -rw-r--r-- | Cargo.toml | 1 | ||||
| -rw-r--r-- | examples/pure/arc/Cargo.toml | 9 | ||||
| -rw-r--r-- | examples/pure/arc/README.md | 14 | ||||
| -rw-r--r-- | examples/pure/arc/src/main.rs | 124 | ||||
| -rw-r--r-- | graphics/src/widget/canvas/path/builder.rs | 53 | ||||
| -rw-r--r-- | style/src/theme/palette.rs | 10 |
6 files changed, 199 insertions, 12 deletions
@@ -90,6 +90,7 @@ members = [ "examples/tour", "examples/url_handler", "examples/websocket", + "examples/pure/arc", "examples/pure/component", "examples/pure/counter", "examples/pure/game_of_life", diff --git a/examples/pure/arc/Cargo.toml b/examples/pure/arc/Cargo.toml new file mode 100644 index 00000000..22113cf1 --- /dev/null +++ b/examples/pure/arc/Cargo.toml @@ -0,0 +1,9 @@ +[package] +name = "arc" +version = "0.1.0" +authors = ["ThatsNoMoon <git@thatsnomoon.dev>"] +edition = "2021" +publish = false + +[dependencies] +iced = { path = "../../..", features = ["pure", "canvas", "tokio", "debug"] } diff --git a/examples/pure/arc/README.md b/examples/pure/arc/README.md new file mode 100644 index 00000000..303253da --- /dev/null +++ b/examples/pure/arc/README.md @@ -0,0 +1,14 @@ +## Arc + +An application that uses the `Canvas` widget to draw a rotating arc. + +This is a simple demo for https://github.com/iced-rs/iced/pull/1358. + +The __[`main`]__ file contains all the code of the example. + +You can run it with `cargo run`: +``` +cargo run --package arc +``` + +[`main`]: src/main.rs diff --git a/examples/pure/arc/src/main.rs b/examples/pure/arc/src/main.rs new file mode 100644 index 00000000..df0e1e8a --- /dev/null +++ b/examples/pure/arc/src/main.rs @@ -0,0 +1,124 @@ +use std::{f32::consts::PI, time::Instant}; + +use iced::executor; +use iced::pure::widget::canvas::{ + self, Cache, Canvas, Cursor, Geometry, Path, Stroke, +}; +use iced::pure::{Application, Element}; +use iced::{Command, Length, Point, Rectangle, Settings, Subscription, Theme}; + +pub fn main() -> iced::Result { + Arc::run(Settings { + antialiasing: true, + ..Settings::default() + }) +} + +struct Arc { + start: Instant, + cache: Cache, +} + +#[derive(Debug, Clone, Copy)] +enum Message { + Tick, +} + +impl Application for Arc { + type Executor = executor::Default; + type Message = Message; + type Theme = Theme; + type Flags = (); + + fn new(_flags: ()) -> (Self, Command<Message>) { + ( + Arc { + start: Instant::now(), + cache: Default::default(), + }, + Command::none(), + ) + } + + fn title(&self) -> String { + String::from("Arc - Iced") + } + + fn update(&mut self, _: Message) -> Command<Message> { + self.cache.clear(); + + Command::none() + } + + fn subscription(&self) -> Subscription<Message> { + iced::time::every(std::time::Duration::from_millis(10)) + .map(|_| Message::Tick) + } + + fn view(&self) -> Element<Message> { + Canvas::new(self) + .width(Length::Fill) + .height(Length::Fill) + .into() + } + + fn theme(&self) -> Theme { + Theme::Dark + } +} + +impl<Message> canvas::Program<Message> for Arc { + type State = (); + + fn draw( + &self, + _state: &Self::State, + theme: &Theme, + bounds: Rectangle, + _cursor: Cursor, + ) -> Vec<Geometry> { + let geometry = self.cache.draw(bounds.size(), |frame| { + let palette = theme.palette(); + + let center = frame.center(); + let radius = frame.width().min(frame.height()) / 5.0; + + let start = Point::new(center.x, center.y - radius); + + let angle = (self.start.elapsed().as_millis() % 10_000) as f32 + / 10_000.0 + * 2.0 + * PI; + + let end = Point::new( + center.x + radius * angle.cos(), + center.y + radius * angle.sin(), + ); + + let circles = Path::new(|b| { + b.circle(start, 10.0); + b.move_to(end); + b.circle(end, 10.0); + }); + + frame.fill(&circles, palette.text); + + let path = Path::new(|b| { + b.move_to(start); + b.arc_to(center, end, 50.0); + b.line_to(end); + }); + + frame.stroke( + &path, + Stroke { + color: palette.text, + width: 10.0, + ..Stroke::default() + }, + ); + }); + + vec![geometry] + } +} diff --git a/graphics/src/widget/canvas/path/builder.rs b/graphics/src/widget/canvas/path/builder.rs index 05316d8a..88acf544 100644 --- a/graphics/src/widget/canvas/path/builder.rs +++ b/graphics/src/widget/canvas/path/builder.rs @@ -42,22 +42,61 @@ impl Builder { /// Adds a circular arc to the [`Path`] with the given control points and /// radius. /// - /// The arc is connected to the previous point by a straight line, if - /// necessary. + /// This essentially draws a straight line segment from the current + /// position to `a`, but fits a circular arc of `radius` tangent to that + /// segment and tangent to the line between `a` and `b`. + /// + /// With another `.line_to(b)`, the result will be a path connecting the + /// starting point and `b` with straight line segments towards `a` and a + /// circular arc smoothing out the corner at `a`. + /// + /// See [the HTML5 specification of `arcTo`](https://html.spec.whatwg.org/multipage/canvas.html#building-paths:dom-context-2d-arcto) + /// for more details and examples. pub fn arc_to(&mut self, a: Point, b: Point, radius: f32) { use lyon::{math, path}; - let a = math::Point::new(a.x, a.y); + let start = self.raw.current_position(); + let mid = math::Point::new(a.x, a.y); + let end = math::Point::new(b.x, b.y); + + if start == mid || mid == end || radius == 0.0 { + let _ = self.raw.line_to(mid); + return; + } + + let double_area = start.x * (mid.y - end.y) + + mid.x * (end.y - start.y) + + end.x * (start.y - mid.y); - if self.raw.current_position() != a { - let _ = self.raw.line_to(a); + if double_area == 0.0 { + let _ = self.raw.line_to(mid); + return; } + let to_start = (start - mid).normalize(); + let to_end = (end - mid).normalize(); + + let inner_angle = to_start.dot(to_end).acos(); + + let origin_angle = inner_angle / 2.0; + + let origin_adjacent = radius / origin_angle.tan(); + + let arc_start = mid + to_start * origin_adjacent; + let arc_end = mid + to_end * origin_adjacent; + + let sweep = to_start.cross(to_end) < 0.0; + + let _ = self.raw.line_to(arc_start); + self.raw.arc_to( math::Vector::new(radius, radius), math::Angle::radians(0.0), - path::ArcFlags::default(), - math::Point::new(b.x, b.y), + path::ArcFlags { + large_arc: false, + sweep, + }, + arc_end, ); } diff --git a/style/src/theme/palette.rs b/style/src/theme/palette.rs index cb8bb6e6..81aa9cc7 100644 --- a/style/src/theme/palette.rs +++ b/style/src/theme/palette.rs @@ -5,11 +5,11 @@ use palette::{FromColor, Hsl, Mix, RelativeContrast, Srgb}; #[derive(Debug, Clone, Copy, PartialEq)] pub struct Palette { - background: Color, - text: Color, - primary: Color, - success: Color, - danger: Color, + pub background: Color, + pub text: Color, + pub primary: Color, + pub success: Color, + pub danger: Color, } impl Palette { |