Set up the cross-fade animation

Cargo.toml

@@ -9,6 +9,8 @@ members = [
     "config",
     "config-derive",
     "coordinates",
+    "cyberpunk",
+    "cyberpunk-slideshow",
     "cyberpunk-splash",
     "dashboard",
     "emseries",

cyberpunk-slideshow/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "cyberpunk-slideshow"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+async-std = "1.13.0"
+cairo-rs    = "0.18"
+cyberpunk   = { path = "../cyberpunk" }
+gio         = "0.18"
+glib        = "0.18"
+gtk         = { version = "0.7", package = "gtk4" }
+serde       = { version = "1.0.210", features = ["derive"] }
+serde_yml   = "0.0.12"

cyberpunk-slideshow/script.yml

@@ -0,0 +1,18 @@
+- text: The distinguishing thing about magic is that it includes some kind of personal element. The person who is performing the magic is relevant to the magic. -- Ted Chang, Marie Brennan
+  position: top
+  transition:
+    secs: 1
+    nanos: 0
+
+- text: Any sufficiently advanced technology is indistinguishable from magic. -- Arthur C. Clark.
+  position: middle
+  transition:
+    secs: 1
+    nanos: 0
+
+- text: Science is our Magic.
+  position: middle
+  transition:
+    secs: 1
+    nanos: 0
+

cyberpunk-slideshow/src/main.rs

@@ -0,0 +1,396 @@
+use std::{
+    cell::RefCell,
+    collections::HashMap,
+    fs::File,
+    io::Read,
+    ops::Index,
+    path::Path,
+    rc::Rc,
+    time::{Duration, Instant},
+};
+
+use cairo::Context;
+use cyberpunk::{AsymLine, AsymLineCutout, GlowPen, Pen, Text};
+use glib::{GString, Object};
+use gtk::{
+    glib::{self, Propagation},
+    prelude::*,
+    subclass::prelude::*,
+    EventControllerKey,
+};
+use serde::{Deserialize, Serialize};
+
+const FPS: u64 = 60;
+const PURPLE: (f64, f64, f64) = (0.7, 0., 1.);
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, Hash)]
+#[serde(rename_all = "lowercase")]
+enum Position {
+    Top,
+    Middle,
+    Bottom,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone)]
+struct Step {
+    text: String,
+    position: Position,
+    transition: Duration,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone)]
+struct Script(Vec<Step>);
+
+impl Script {
+    fn from_file(path: &Path) -> Result<Script, serde_yml::Error> {
+        let mut buf: Vec<u8> = Vec::new();
+        let mut f = File::open(path).unwrap();
+        f.read_to_end(&mut buf).unwrap();
+        let script = serde_yml::from_slice(&buf)?;
+        Ok(Self(script))
+    }
+
+    fn iter<'a>(&'a self) -> impl Iterator<Item = &'a Step> {
+        self.0.iter()
+    }
+
+    fn len(&self) -> usize {
+        self.0.len()
+    }
+}
+
+impl Default for Script {
+    fn default() -> Self {
+        Self(vec![])
+    }
+}
+
+impl Index<usize> for Script {
+    type Output = Step;
+
+    fn index(&self, index: usize) -> &Self::Output {
+        &self.0[index]
+    }
+}
+
+struct Region {
+    left: f64,
+    top: f64,
+    width: f64,
+    height: f64,
+}
+
+struct Fade {
+    text: String,
+    position: Position,
+    duration: Duration,
+
+    start_time: Instant,
+}
+
+trait Animation {
+    fn position(&self) -> Position;
+
+    fn tick(&self, now: Instant, context: &Context, region: Region);
+}
+
+impl Animation for Fade {
+    fn position(&self) -> Position {
+        self.position.clone()
+    }
+
+    fn tick(&self, now: Instant, context: &Context, region: Region) {
+        let total_frames = self.duration.as_secs() * FPS;
+        let alpha_rate: f64 = 1. / total_frames as f64;
+
+        let frames = (now - self.start_time).as_secs_f64() * FPS as f64;
+        let alpha = alpha_rate * frames as f64;
+
+        let text_display = Text::new(self.text.clone(), context, 32.);
+        let _ = context.move_to(region.left, region.top + text_display.extents().height());
+        let _ = context.set_source_rgba(PURPLE.0, PURPLE.1, PURPLE.2, alpha);
+        text_display.draw();
+    }
+}
+
+struct CrossFade {
+    old_text: String,
+    new_text: String,
+    position: Position,
+    duration: Duration,
+
+    start_time: Instant,
+}
+
+impl Animation for CrossFade {
+    fn position(&self) -> Position {
+        self.position.clone()
+    }
+
+    fn tick(&self, now: Instant, context: &Context, region: Region) {
+        let total_frames = self.duration.as_secs() * FPS;
+        let alpha_rate: f64 = 1. / total_frames as f64;
+
+        let frames = (now - self.start_time).as_secs_f64() * FPS as f64;
+        let alpha = alpha_rate * frames as f64;
+
+        let text_display = Text::new(self.old_text.clone(), context, 32.);
+        let _ = context.move_to(region.left, region.top + text_display.extents().height());
+        let _ = context.set_source_rgba(PURPLE.0, PURPLE.1, PURPLE.2, 1. - alpha);
+        text_display.draw();
+
+        let text_display = Text::new(self.new_text.clone(), context, 32.);
+        let _ = context.move_to(region.left, region.top + text_display.extents().height());
+        let _ = context.set_source_rgba(PURPLE.0, PURPLE.1, PURPLE.2, alpha);
+        text_display.draw();
+    }
+}
+
+#[derive(Debug)]
+pub struct CyberScreenState {
+    script: Script,
+    idx: Option<usize>,
+    top: Option<Step>,
+    middle: Option<Step>,
+    bottom: Option<Step>,
+}
+
+impl Default for CyberScreenState {
+    fn default() -> Self {
+        Self {
+            script: Script(vec![]),
+            idx: None,
+            top: None,
+            middle: None,
+            bottom: None,
+        }
+    }
+}
+
+impl CyberScreenState {
+    fn new(script: Script) -> CyberScreenState {
+        let mut s = CyberScreenState::default();
+        s.script = script;
+        s
+    }
+
+    fn next_page(&mut self) -> Box<dyn Animation> {
+        let idx = match self.idx {
+            None => 0,
+            Some(idx) => {
+                if idx < self.script.len() {
+                    idx + 1
+                } else {
+                    idx
+                }
+            }
+        };
+        self.idx = Some(idx);
+        let step = self.script[idx].clone();
+
+        let (old, new) = match step.position {
+            Position::Top => {
+                let old = self.top.replace(step.clone());
+                (old, step)
+            }
+            Position::Middle => {
+                let old = self.middle.replace(step.clone());
+                (old, step)
+            }
+            Position::Bottom => {
+                let old = self.middle.replace(step.clone());
+                (old, step)
+            }
+        };
+
+        match old {
+            Some(old) => Box::new(CrossFade {
+                old_text: old.text.clone(),
+                new_text: new.text.clone(),
+                position: new.position,
+                duration: new.transition,
+                start_time: Instant::now(),
+            }),
+            None => Box::new(Fade {
+                text: new.text.clone(),
+                position: new.position,
+                duration: new.transition,
+                start_time: Instant::now(),
+            }),
+        }
+    }
+}
+
+#[derive(Default)]
+pub struct CyberScreenPrivate {
+    state: Rc<RefCell<CyberScreenState>>,
+    // For crossfading to work, I have to detect that there is an old animation in a position, and
+    // replace it with the new one.
+    animations: Rc<RefCell<HashMap<Position, Box<dyn Animation>>>>,
+}
+
+#[glib::object_subclass]
+impl ObjectSubclass for CyberScreenPrivate {
+    const NAME: &'static str = "CyberScreen";
+    type Type = CyberScreen;
+    type ParentType = gtk::DrawingArea;
+}
+
+impl ObjectImpl for CyberScreenPrivate {}
+impl WidgetImpl for CyberScreenPrivate {}
+impl DrawingAreaImpl for CyberScreenPrivate {}
+
+impl CyberScreenPrivate {
+    fn set_script(&self, script: Script) {
+        *self.state.borrow_mut() = CyberScreenState::new(script);
+    }
+
+    fn next_page(&self) {
+        let transition = self.state.borrow_mut().next_page();
+        self.animations
+            .borrow_mut()
+            .insert(transition.position(), transition);
+    }
+}
+
+glib::wrapper! {
+    pub struct CyberScreen(ObjectSubclass<CyberScreenPrivate>) @extends gtk::DrawingArea, gtk::Widget;
+}
+
+impl CyberScreen {
+    pub fn new(script: Script) -> Self {
+        let s: Self = Object::builder().build();
+        s.imp().set_script(script);
+
+        s.set_draw_func({
+            let s = s.clone();
+            move |_, context, width, height| {
+                let now = Instant::now();
+                let _ = context.set_source_rgb(0., 0., 0.);
+                let _ = context.paint();
+
+                let pen = GlowPen::new(width, height, 2., 8., (0.7, 0., 1.));
+                /*
+                for i in 0..6 {
+                    pen.move_to(0., height as f64 * i as f64 / 5.);
+                    pen.line_to(width as f64, height as f64 * i as f64 / 5.);
+                }
+                pen.stroke();
+                */
+                let line = AsymLineCutout {
+                    orientation: gtk::Orientation::Horizontal,
+                    start_x: 25.,
+                    start_y: height as f64 / 7.,
+                    start_length: width as f64 / 3.,
+                    cutout_length: width as f64 / 3. - 25.,
+                    height: 25.,
+                    end_length: width as f64 / 3. - 50.,
+                    invert: false,
+                }.draw(&pen);
+                pen.stroke();
+                let tracery = pen.finish();
+                let _ = context.set_source(tracery);
+                let _ = context.paint();
+
+                let mut animations = s.imp().animations.borrow_mut();
+
+                let lr_margin = 50.;
+                let max_width = width as f64 - lr_margin * 2.;
+                let region_height = height as f64 / 5.;
+
+                if let Some(animation) = animations.get(&Position::Top) {
+                    let y = height as f64 * 1. / 5.;
+                    let region = Region {
+                        left: 20.,
+                        top: y,
+                        height: region_height,
+                        width: max_width,
+                    };
+                    animation.tick(now, context, region);
+                }
+                if let Some(animation) = animations.get(&Position::Middle) {
+                    let y = height as f64 * 2. / 5.;
+                    let region = Region {
+                        left: 20.,
+                        top: y,
+                        height: region_height,
+                        width: max_width,
+                    };
+                    animation.tick(now, context, region);
+                }
+                if let Some(animation) = animations.get(&Position::Bottom) {
+                    let y = height as f64 * 3. / 5.;
+                    let region = Region {
+                        left: 20.,
+                        top: y,
+                        height: region_height,
+                        width: max_width,
+                    };
+                    animation.tick(now, context, region);
+                }
+            }
+        });
+
+        s
+    }
+
+    fn next_page(&self) {
+        println!("next page");
+        self.imp().next_page();
+        self.queue_draw();
+    }
+}
+
+fn main() {
+    let script = Script(vec![Step {
+        text: "The distinguishing thing".to_owned(),
+        position: Position::Top,
+        transition: Duration::from_secs(2),
+    }]);
+
+    println!("{}", serde_yml::to_string(&script).unwrap());
+
+    let script = Script::from_file(Path::new("./script.yml")).unwrap();
+    for element in script.iter() {
+        println!("{:?}", element);
+    }
+
+    let app = gtk::Application::builder()
+        .application_id("com.luminescent-dreams.cyberpunk-slideshow")
+        .build();
+
+    app.connect_activate(move |app| {
+        let screen = CyberScreen::new(script.clone());
+
+        let events = EventControllerKey::new();
+
+        events.connect_key_released({
+            let screen = screen.clone();
+            move |_, key, _, _| {
+                if key.name() == Some(GString::from("Right")) {
+                    screen.next_page();
+                }
+            }
+        });
+
+        let window = gtk::ApplicationWindow::new(app);
+        window.add_controller(events);
+
+        window.set_child(Some(&screen));
+        window.set_width_request(800);
+        window.set_height_request(600);
+        window.present();
+
+        let _ = glib::spawn_future_local({
+            let screen = screen.clone();
+            async move {
+                loop {
+                    screen.queue_draw();
+                    async_std::task::sleep(Duration::from_millis(1000 / FPS)).await;
+                }
+            }
+        });
+    });
+
+    app.run();
+}

cyberpunk-splash/Cargo.toml

@@ -8,6 +8,7 @@ license = "GPL-3.0-only"
 
 [dependencies]
 cairo-rs    = { version = "0.18" }
+cyberpunk   = { path = "../cyberpunk" }
 gio         = { version = "0.18" }
 glib        = { version = "0.18" }
 gtk         = { version = "0.7", package = "gtk4" }

cyberpunk-splash/src/main.rs

@@ -419,212 +419,6 @@ impl Splash {
     }
 }
 
-struct AsymLineCutout {
-    orientation: gtk::Orientation,
-    start_x: f64,
-    start_y: f64,
-    start_length: f64,
-    total_length: f64,
-    cutout_length: f64,
-    height: f64,
-    invert: bool,
-}
-
-impl AsymLineCutout {
-    fn draw(&self, pen: &impl Pen) {
-        let dodge = if self.invert {
-            self.height
-        } else {
-            -self.height
-        };
-        match self.orientation {
-            gtk::Orientation::Horizontal => {
-                pen.move_to(self.start_x, self.start_y);
-                pen.line_to(self.start_x + self.start_length, self.start_y);
-                pen.line_to(
-                    self.start_x + self.start_length + self.height,
-                    self.start_y + dodge,
-                );
-                pen.line_to(
-                    self.start_x + self.start_length + self.height + self.cutout_length,
-                    self.start_y + dodge,
-                );
-                pen.line_to(
-                    self.start_x
-                        + self.start_length
-                        + self.height
-                        + self.cutout_length
-                        + (self.height / 2.),
-                    self.start_y + dodge / 2.,
-                );
-                pen.line_to(self.total_length, self.start_y + dodge / 2.);
-            }
-            gtk::Orientation::Vertical => {
-                pen.move_to(self.start_x, self.start_y);
-                pen.line_to(self.start_x, self.start_y + self.start_length);
-                pen.line_to(
-                    self.start_x + dodge,
-                    self.start_y + self.start_length + self.height,
-                );
-                pen.line_to(
-                    self.start_x + dodge,
-                    self.start_y + self.start_length + self.height + self.cutout_length,
-                );
-                pen.line_to(
-                    self.start_x + dodge / 2.,
-                    self.start_y
-                        + self.start_length
-                        + self.height
-                        + self.cutout_length
-                        + (self.height / 2.),
-                );
-                pen.line_to(self.start_x + dodge / 2., self.total_length);
-            }
-            _ => panic!("unknown orientation"),
-        }
-    }
-}
-
-struct AsymLine {
-    orientation: gtk::Orientation,
-    start_x: f64,
-    start_y: f64,
-    start_length: f64,
-    height: f64,
-    total_length: f64,
-    invert: bool,
-}
-
-impl AsymLine {
-    fn draw(&self, pen: &impl Pen) {
-        let dodge = if self.invert {
-            self.height
-        } else {
-            -self.height
-        };
-        match self.orientation {
-            gtk::Orientation::Horizontal => {
-                pen.move_to(self.start_x, self.start_y);
-                pen.line_to(self.start_x + self.start_length, self.start_y);
-                pen.line_to(
-                    self.start_x + self.start_length + self.height,
-                    self.start_y + dodge,
-                );
-                pen.line_to(self.start_x + self.total_length, self.start_y + dodge);
-            }
-            gtk::Orientation::Vertical => {}
-            _ => panic!("unknown orientation"),
-        }
-    }
-}
-
-struct SlashMeter {
-    orientation: gtk::Orientation,
-    start_x: f64,
-    start_y: f64,
-    count: u8,
-    fill_count: u8,
-    height: f64,
-    length: f64,
-}
-
-impl SlashMeter {
-    fn draw(&self, context: &Context) {
-        match self.orientation {
-            gtk::Orientation::Horizontal => {
-                let angle: f64 = 0.8;
-                let run = self.height / angle.tan();
-                let width = self.length / (self.count as f64 * 2.);
-
-                for c in 0..self.count {
-                    context.set_line_width(1.);
-
-                    let start_x = self.start_x + c as f64 * width * 2.;
-                    context.move_to(start_x, self.start_y);
-                    context.line_to(start_x + run, self.start_y - self.height);
-                    context.line_to(start_x + run + width, self.start_y - self.height);
-                    context.line_to(start_x + width, self.start_y);
-                    context.line_to(start_x, self.start_y);
-                    if c < self.fill_count {
-                        let _ = context.fill();
-                    } else {
-                        let _ = context.stroke();
-                    }
-                }
-            }
-            gtk::Orientation::Vertical => {}
-            _ => panic!("unknown orientation"),
-        }
-    }
-}
-
-trait Pen {
-    fn move_to(&self, x: f64, y: f64);
-    fn line_to(&self, x: f64, y: f64);
-    fn stroke(&self);
-
-    fn finish(self) -> Pattern;
-}
-
-struct GlowPen {
-    blur_context: Context,
-    draw_context: Context,
-}
-
-impl GlowPen {
-    fn new(
-        width: i32,
-        height: i32,
-        line_width: f64,
-        blur_line_width: f64,
-        color: (f64, f64, f64),
-    ) -> Self {
-        let blur_context =
-            Context::new(ImageSurface::create(Format::Rgb24, width, height).unwrap()).unwrap();
-        blur_context.set_line_width(blur_line_width);
-        blur_context.set_source_rgba(color.0, color.1, color.2, 0.5);
-        blur_context.push_group();
-        blur_context.set_line_cap(LineCap::Round);
-
-        let draw_context =
-            Context::new(ImageSurface::create(Format::Rgb24, width, height).unwrap()).unwrap();
-        draw_context.set_line_width(line_width);
-        draw_context.set_source_rgb(color.0, color.1, color.2);
-        draw_context.push_group();
-        draw_context.set_line_cap(LineCap::Round);
-
-        Self {
-            blur_context,
-            draw_context,
-        }
-    }
-}
-
-impl Pen for GlowPen {
-    fn move_to(&self, x: f64, y: f64) {
-        self.blur_context.move_to(x, y);
-        self.draw_context.move_to(x, y);
-    }
-
-    fn line_to(&self, x: f64, y: f64) {
-        self.blur_context.line_to(x, y);
-        self.draw_context.line_to(x, y);
-    }
-
-    fn stroke(&self) {
-        self.blur_context.stroke().expect("to draw the blur line");
-        self.draw_context
-            .stroke()
-            .expect("to draw the regular line");
-    }
-
-    fn finish(self) -> Pattern {
-        let foreground = self.draw_context.pop_group().unwrap();
-        self.blur_context.set_source(foreground).unwrap();
-        self.blur_context.paint().unwrap();
-        self.blur_context.pop_group().unwrap()
-    }
-}
 
 fn main() {
     let app = gtk::Application::builder()

cyberpunk/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "cyberpunk"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+cairo-rs    = { version = "0.18" }
+gio         = { version = "0.18" }
+glib        = { version = "0.18" }
+gtk         = { version = "0.7", package = "gtk4" }

cyberpunk/src/lib.rs

@@ -0,0 +1,272 @@
+use cairo::{
+    Context, FontSlant, FontWeight, Format, ImageSurface, LineCap, Pattern,
+    TextExtents,
+};
+
+pub struct AsymLineCutout {
+    pub orientation: gtk::Orientation,
+    pub start_x: f64,
+    pub start_y: f64,
+    pub start_length: f64,
+    pub cutout_length: f64,
+    pub end_length: f64,
+    pub height: f64,
+    pub invert: bool,
+}
+
+impl AsymLineCutout {
+    pub fn draw(&self, pen: &impl Pen) {
+        let dodge = if self.invert {
+            self.height
+        } else {
+            -self.height
+        };
+        match self.orientation {
+            gtk::Orientation::Horizontal => {
+                pen.move_to(self.start_x, self.start_y);
+                pen.line_to(self.start_x + self.start_length, self.start_y);
+                pen.line_to(
+                    self.start_x + self.start_length + self.height,
+                    self.start_y + dodge,
+                );
+                pen.line_to(
+                    self.start_x + self.start_length + self.height + self.cutout_length,
+                    self.start_y + dodge,
+                );
+                pen.line_to(
+                    self.start_x
+                        + self.start_length
+                        + self.height
+                        + self.cutout_length
+                        + (self.height / 2.),
+                    self.start_y + dodge / 2.,
+                );
+                pen.line_to(
+                    self.start_x
+                        + self.start_length
+                        + self.height
+                        + self.cutout_length
+                        + (self.height / 2.)
+                        + self.end_length,
+                    self.start_y + dodge / 2.,
+                );
+            }
+            gtk::Orientation::Vertical => {
+                pen.move_to(self.start_x, self.start_y);
+                pen.line_to(self.start_x, self.start_y + self.start_length);
+                pen.line_to(
+                    self.start_x + dodge,
+                    self.start_y + self.start_length + self.height,
+                );
+                pen.line_to(
+                    self.start_x + dodge,
+                    self.start_y + self.start_length + self.height + self.cutout_length,
+                );
+                pen.line_to(
+                    self.start_x + dodge / 2.,
+                    self.start_y
+                        + self.start_length
+                        + self.height
+                        + self.cutout_length
+                        + (self.height / 2.),
+                );
+                pen.line_to(
+                    self.start_x + dodge / 2.,
+                    self.start_y
+                        + self.start_length
+                        + self.height
+                        + self.cutout_length
+                        + (self.height / 2.)
+                        + self.end_length,
+                );
+            }
+            _ => panic!("unknown orientation"),
+        }
+    }
+}
+
+// Represents an asymetrical line that starts at one location, then a 45-degree angle and then
+// another line afterwards.
+pub struct AsymLine {
+    // Will this be drawn left-to-right or up-to-down?
+    pub orientation: gtk::Orientation,
+
+    // Starting address
+    pub start_x: f64,
+    pub start_y: f64,
+
+    // Length of the first segment
+    pub start_length: f64,
+
+    // Height to dodge over to the next section
+    pub height: f64,
+
+    // Total length of the entire line.
+    pub end_length: f64,
+
+    // When normal, the angle dodge is upwards. When inverted, the angle dodge is downwards.
+    pub invert: bool,
+}
+
+impl AsymLine {
+    pub fn draw(&self, pen: &impl Pen) {
+        let dodge = if self.invert {
+            self.height
+        } else {
+            -self.height
+        };
+        match self.orientation {
+            gtk::Orientation::Horizontal => {
+                pen.move_to(self.start_x, self.start_y);
+                pen.line_to(self.start_x + self.start_length, self.start_y);
+                pen.line_to(
+                    self.start_x + self.start_length + self.height,
+                    self.start_y + dodge,
+                );
+                pen.line_to(
+                    self.start_x + self.start_length + self.height + self.end_length,
+                    self.start_y + dodge,
+                );
+            }
+            gtk::Orientation::Vertical => {}
+            _ => panic!("unknown orientation"),
+        }
+    }
+}
+
+struct SlashMeter {
+    orientation: gtk::Orientation,
+    start_x: f64,
+    start_y: f64,
+    count: u8,
+    fill_count: u8,
+    height: f64,
+    length: f64,
+}
+
+impl SlashMeter {
+    fn draw(&self, context: &Context) {
+        match self.orientation {
+            gtk::Orientation::Horizontal => {
+                let angle: f64 = 0.8;
+                let run = self.height / angle.tan();
+                let width = self.length / (self.count as f64 * 2.);
+
+                for c in 0..self.count {
+                    context.set_line_width(1.);
+
+                    let start_x = self.start_x + c as f64 * width * 2.;
+                    context.move_to(start_x, self.start_y);
+                    context.line_to(start_x + run, self.start_y - self.height);
+                    context.line_to(start_x + run + width, self.start_y - self.height);
+                    context.line_to(start_x + width, self.start_y);
+                    context.line_to(start_x, self.start_y);
+                    if c < self.fill_count {
+                        let _ = context.fill();
+                    } else {
+                        let _ = context.stroke();
+                    }
+                }
+            }
+            gtk::Orientation::Vertical => {}
+            _ => panic!("unknown orientation"),
+        }
+    }
+}
+
+/// Represents a pen for drawing a pattern. This is good for complex patterns that may require
+/// multiple identical steps.
+pub trait Pen {
+    /// Move the pen to a location.
+    fn move_to(&self, x: f64, y: f64);
+
+    /// Draw a line from the current location to the specified destination.
+    fn line_to(&self, x: f64, y: f64);
+
+    /// Instantiate the line.
+    fn stroke(&self);
+
+    /// Convert all of the drawing into a pattern that can be painted to a drawing context.
+    fn finish(self) -> Pattern;
+}
+
+pub struct GlowPen {
+    blur_context: Context,
+    draw_context: Context,
+}
+
+impl GlowPen {
+    pub fn new(
+        width: i32,
+        height: i32,
+        line_width: f64,
+        blur_line_width: f64,
+        color: (f64, f64, f64),
+    ) -> Self {
+        let blur_context =
+            Context::new(ImageSurface::create(Format::Rgb24, width, height).unwrap()).unwrap();
+        blur_context.set_line_width(blur_line_width);
+        blur_context.set_source_rgba(color.0, color.1, color.2, 0.5);
+        blur_context.push_group();
+        blur_context.set_line_cap(LineCap::Round);
+
+        let draw_context =
+            Context::new(ImageSurface::create(Format::Rgb24, width, height).unwrap()).unwrap();
+        draw_context.set_line_width(line_width);
+        draw_context.set_source_rgb(color.0, color.1, color.2);
+        draw_context.push_group();
+        draw_context.set_line_cap(LineCap::Round);
+
+        Self {
+            blur_context,
+            draw_context,
+        }
+    }
+}
+
+impl Pen for GlowPen {
+    fn move_to(&self, x: f64, y: f64) {
+        self.blur_context.move_to(x, y);
+        self.draw_context.move_to(x, y);
+    }
+
+    fn line_to(&self, x: f64, y: f64) {
+        self.blur_context.line_to(x, y);
+        self.draw_context.line_to(x, y);
+    }
+
+    fn stroke(&self) {
+        self.blur_context.stroke().expect("to draw the blur line");
+        self.draw_context
+            .stroke()
+            .expect("to draw the regular line");
+    }
+
+    fn finish(self) -> Pattern {
+        let foreground = self.draw_context.pop_group().unwrap();
+        self.blur_context.set_source(foreground).unwrap();
+        self.blur_context.paint().unwrap();
+        self.blur_context.pop_group().unwrap()
+    }
+}
+
+pub struct Text<'a> {
+    content: String,
+    context: &'a Context,
+}
+
+impl<'a> Text<'a> {
+    pub fn new(content: String, context: &'a Context, size: f64) -> Self {
+        context.select_font_face("Alegreya Sans SC", FontSlant::Normal, FontWeight::Bold);
+        context.set_font_size(size);
+        Self { content, context }
+    }
+
+    pub fn extents(&self) -> TextExtents {
+        self.context.text_extents(&self.content).unwrap()
+    }
+
+    pub fn draw(&self) {
+        let _ = self.context.show_text(&self.content);
+    }
+}