From 221b18d0852b615a3ca3e962d67d1c6c85632383 Mon Sep 17 00:00:00 2001
From: Tangent Wantwight <tangent128@gmail.com>
Date: Thu, 12 Oct 2023 21:09:15 -0400
Subject: [PATCH] Halloween 2023

---
 harrogate/Cargo.toml            |  1 +
 harrogate/src/halloween_2023.rs | 96 +++++++++++++++++++++++++++++++++
 harrogate/src/main.rs           |  4 ++
 3 files changed, 101 insertions(+)
 create mode 100644 harrogate/src/halloween_2023.rs

diff --git a/harrogate/Cargo.toml b/harrogate/Cargo.toml
index 01807bd..2779039 100644
--- a/harrogate/Cargo.toml
+++ b/harrogate/Cargo.toml
@@ -25,6 +25,7 @@ july-4 = ["replace-default"]
 halloween-2020 = ["replace-default"]
 halloween-2021 = ["replace-default"]
 halloween-2022 = ["replace-default"]
+halloween-2023 = ["replace-default"]
 new-years-eve-2020 = ["replace-default"]
 november-2020 = ["replace-default"]
 
diff --git a/harrogate/src/halloween_2023.rs b/harrogate/src/halloween_2023.rs
new file mode 100644
index 0000000..82984b5
--- /dev/null
+++ b/harrogate/src/halloween_2023.rs
@@ -0,0 +1,96 @@
+//! purple-and-orange with chaotically-varying background
+
+use super::delay;
+use house::{Harrogate, PORCH_BACK_LEN, PORCH_FRONT_LEN};
+use lights::{
+    murmurf,
+    rgb::{gray, Rgb},
+    HardwareRgb, Lights,
+};
+
+const BLACK: Rgb = Rgb(0, 0, 0);
+const BG_WAVE_1: Rgb = Rgb(200, 100, 0);
+const BG_WAVE_2: Rgb = Rgb(0, 100, 100);
+const ORANGE: Rgb = Rgb(255, 150, 0);
+const PURPLE: Rgb = Rgb(100, 0, 128);
+
+// tenth of a second
+const TIC: u32 = 4_800_000;
+
+enum Direction {
+    UP,
+    DOWN,
+}
+
+struct Wave {
+    spot: u8,
+    target: u8,
+    direction: Direction,
+}
+
+impl Wave {
+    fn tick(&mut self, rng: &mut u32) {
+        if self.spot == self.target {
+            // target caught, pick new one
+            self.target = (murmurf(rng) % 256) as u8;
+            self.direction = if self.target > self.spot {
+                Direction::UP
+            } else {
+                Direction::DOWN
+            };
+        } else {
+            // chase target brightness
+            self.spot = match self.direction {
+                Direction::UP => self.spot + 1,
+                Direction::DOWN => self.spot - 1,
+            }
+        }
+    }
+
+    fn rgb(&self, color: Rgb) -> Rgb {
+        color * gray(self.spot)
+    }
+}
+
+#[allow(dead_code)]
+#[inline(always)]
+pub fn run(lights: &mut impl Lights<Pixel = HardwareRgb>) -> ! {
+    let mut rng = 0xB00u32;
+    let mut wave1 = Wave {
+        spot: 128,
+        target: 128,
+        direction: Direction::UP,
+    };
+    let mut wave2 = Wave {
+        spot: 128,
+        target: 128,
+        direction: Direction::UP,
+    };
+
+    let mut back_buffer = [BLACK; PORCH_BACK_LEN];
+
+    let mut draw = |back_buffer: &[Rgb]| {
+        let front_pattern = [PURPLE, ORANGE].iter().cycle().cloned();
+        Harrogate {
+            porch_front: front_pattern.take(PORCH_FRONT_LEN),
+            porch_back: back_buffer.iter().cloned(),
+        }
+        .render_to(lights);
+    };
+
+    loop {
+        // animate brightness variation
+        wave1.tick(&mut rng);
+        wave2.tick(&mut rng);
+
+        // push into buffer
+        back_buffer.rotate_right(1);
+        back_buffer[0] = wave1.rgb(BG_WAVE_1) + wave2.rgb(BG_WAVE_2);
+        back_buffer[PORCH_BACK_LEN - 1].1 = 255;
+
+        // render
+        draw(&back_buffer);
+
+        delay(TIC);
+    }
+}
diff --git a/harrogate/src/main.rs b/harrogate/src/main.rs
index 90f8dbe..a695ef4 100644
--- a/harrogate/src/main.rs
+++ b/harrogate/src/main.rs
@@ -16,6 +16,7 @@ mod july_4;
 mod halloween_2020;
 mod halloween_2021;
 mod halloween_2022;
+mod halloween_2023;
 mod november_2020;
 mod new_years_eve_2020;
 mod door_light;
@@ -57,6 +58,9 @@ fn main() -> ! {
     #[cfg(feature = "halloween-2022")]
     halloween_2022::run(&mut lights);
 
+    #[cfg(feature = "halloween-2023")]
+    halloween_2023::run(&mut lights);
+
     #[cfg(feature = "new-years-eve-2020")]
     new_years_eve_2020::run(&mut lights);