From a22702df4dd1e201f013b52ad699c148e5a5c9d8 Mon Sep 17 00:00:00 2001
From: Jimmy <git@jimmy.nz>
Date: Mon, 20 Apr 2026 23:37:43 +1200
Subject: [PATCH] feat(patterns): add radiate animation

---
 src/patterns/radiate.py | 89 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)
 create mode 100644 src/patterns/radiate.py

diff --git a/src/patterns/radiate.py b/src/patterns/radiate.py
new file mode 100644
index 0000000..f3ad4b6
--- /dev/null
+++ b/src/patterns/radiate.py
@@ -0,0 +1,89 @@
+import utime
+
+
+class Radiate:
+    def __init__(self, driver):
+        self.driver = driver
+
+    def run(self, preset):
+        """Radiate from nodes every n1 LEDs, retriggering every delay (d).
+
+        - n1: node spacing in LEDs
+        - n2: outbound travel time in ms
+        - n3: return travel time in ms
+        - d: retrigger interval in ms
+        """
+        colors = preset.c if preset.c else [(255, 255, 255)]
+        base_on = colors[0]
+        base_off = colors[1] if len(colors) > 1 else (0, 0, 0)
+
+        spacing = max(1, int(preset.n1))
+        outward_ms = max(1, int(preset.n2))
+        return_ms = max(1, int(preset.n3))
+        max_dist = spacing // 2
+
+        lit_color = self.driver.apply_brightness(base_on, preset.b)
+        off_color = self.driver.apply_brightness(base_off, preset.b)
+
+        now = utime.ticks_ms()
+        last_trigger = now
+        active_pulses = [now]
+
+        if not preset.a:
+            # Single-step render uses only the first instant pulse.
+            active_pulses = [utime.ticks_ms()]
+
+        while True:
+            now = utime.ticks_ms()
+            delay_ms = max(1, int(preset.d))
+            spacing = max(1, int(preset.n1))
+            outward_ms = max(1, int(preset.n2))
+            return_ms = max(1, int(preset.n3))
+            max_dist = spacing // 2
+            lit_color = self.driver.apply_brightness(base_on, preset.b)
+            off_color = self.driver.apply_brightness(base_off, preset.b)
+
+            if preset.a and utime.ticks_diff(now, last_trigger) >= delay_ms:
+                active_pulses.append(now)
+                last_trigger = utime.ticks_add(last_trigger, delay_ms)
+
+            # Drop pulses once their out-and-back lifetime ends.
+            pulse_lifetime = outward_ms + return_ms
+            kept = []
+            for start in active_pulses:
+                age = utime.ticks_diff(now, start)
+                if age <= pulse_lifetime:
+                    kept.append(start)
+            active_pulses = kept
+
+            for i in range(self.driver.num_leds):
+                # Nearest node distance for a repeating node grid every `spacing` LEDs.
+                offset = i % spacing
+                dist = min(offset, spacing - offset)
+
+                lit = False
+                for start in active_pulses:
+                    age = utime.ticks_diff(now, start)
+                    if age < 0:
+                        continue
+                    if age <= outward_ms:
+                        front = (age * max_dist) / outward_ms
+                    elif age <= outward_ms + return_ms:
+                        back_age = age - outward_ms
+                        front = ((return_ms - back_age) * max_dist) / return_ms
+                    else:
+                        continue
+
+                    if dist <= front:
+                        lit = True
+                        break
+
+                self.driver.n[i] = lit_color if lit else off_color
+
+            self.driver.n.write()
+
+            if not preset.a:
+                yield
+                return
+
+            yield