Add segments and double_circle patterns with shared presets

Introduce double_circle and segments-based patterns on the Pico, refactor the Presets engine to expose a logical ring over all strips, and migrate presets/test code from the old point pattern to segments while switching to a top-level presets.json.

Made-with: Cursor

pico/test/test_double_circle.py

@@ -0,0 +1,157 @@
+"""
+On-device test for the double_circle pattern using mpremote.
+
+Usage (from pico/ dir or project root with adjusted paths):
+
+    mpremote connect <device> cp src/*.py :
+    mpremote connect <device> cp src/patterns/*.py :patterns
+    mpremote connect <device> cp lib/*.py :
+    mpremote connect <device> cp test/test_double_circle.py :
+    mpremote connect <device> run test_double_circle.py
+
+This script:
+  - Instantiates Presets
+  - Creates a few in-memory 'double_circle' presets with different centers, widths, and colors
+  - Selects each one so you can visually confirm the symmetric bands and color gradients
+"""
+
+from presets import Presets, Preset
+
+
+def make_double_circle_preset(
+    name, center, half_width, colors, direction=0, step_size=1, brightness=255
+):
+    """
+    Helper to build a Preset for the 'double_circle' pattern.
+
+    center: logical index (0-based, on reference strip 0)
+    half_width: number of LEDs each side of center
+    colors: [color1, color2] where each color is (r,g,b)
+    """
+    cs = list(colors)[:2]
+    while len(cs) < 2:
+        cs.append((0, 0, 0))
+
+    data = {
+        "p": "double_circle",
+        "c": cs,
+        "b": brightness,
+        "n1": center,
+        "n2": half_width,
+        "n3": direction,
+        "n4": step_size,
+    }
+    return name, Preset(data)
+
+
+def show_and_wait(presets, name, preset_obj, wait_ms):
+    """Select a static double_circle preset and hold it for wait_ms."""
+    presets.presets[name] = preset_obj
+    presets.select(name)
+    # DoubleCircle draws immediately in run(), then just yields; one tick is enough.
+    presets.tick()
+
+    import utime
+
+    start = utime.ticks_ms()
+    while utime.ticks_diff(utime.ticks_ms(), start) < wait_ms:
+        presets.tick()
+
+
+def main():
+    presets = Presets()
+    presets.load()
+
+    num_leds = presets.strip_length(0)
+    if num_leds <= 0:
+        print("No strips; aborting double_circle test.")
+        return
+
+    print("Starting double_circle pattern test...")
+
+    quarter = num_leds // 4
+    half = num_leds // 2
+
+    dc_presets = []
+
+    # 1. Center at top (0), moderate width, color1 at center (n3=0)
+    dc_presets.append(
+        make_double_circle_preset(
+            "dc_top_red_to_blue",
+            center=0,
+            half_width=quarter,
+            colors=[(255, 0, 0), (0, 0, 255)],
+            direction=0,
+        )
+    )
+
+    # 2. Center at bottom (half), narrow band, color1 at endpoints (n3=1)
+    dc_presets.append(
+        make_double_circle_preset(
+            "dc_bottom_green_to_purple",
+            center=half,
+            half_width=quarter // 2,
+            colors=[(0, 255, 0), (128, 0, 128)],
+            direction=1,
+        )
+    )
+
+    # 3. Center at quarter, wide band, both directions for comparison
+    dc_presets.append(
+        make_double_circle_preset(
+            "dc_quarter_white_to_cyan_inward",
+            center=quarter,
+            half_width=half,
+            colors=[(255, 255, 255), (0, 255, 255)],
+            direction=0,
+        )
+    )
+
+    dc_presets.append(
+        make_double_circle_preset(
+            "dc_quarter_white_to_cyan_outward",
+            center=quarter,
+            half_width=half,
+            colors=[(255, 255, 255), (0, 255, 255)],
+            direction=1,
+        )
+    )
+
+    # 4. Explicit test: n1 = 50, n2 = 40 (half of 80) inward
+    dc_presets.append(
+        make_double_circle_preset(
+            "dc_n1_50_n2_40_inward",
+            center=50,
+            half_width=40,
+            colors=[(255, 100, 0), (0, 0, 0)],
+            direction=0,
+        )
+    )
+
+    # 5. Explicit test: n1 = num_leds//2, n2 = num_leds//4 outward, stepping as fast as possible
+    center_half = num_leds // 2
+    radius_quarter = max(1, num_leds // 4)
+    dc_presets.append(
+        make_double_circle_preset(
+            "dc_n1_half_n2_quarter_outward",
+            center=center_half,
+            half_width=radius_quarter,
+            colors=[(0, 150, 255), (0, 0, 0)],
+            direction=1,
+            step_size=radius_quarter,  # jump to full radius in one step
+        )
+    )
+
+    # Show each for ~4 seconds
+    for name, preset_obj in dc_presets:
+        print("Showing double_circle preset:", name)
+        show_and_wait(presets, name, preset_obj, wait_ms=4000)
+
+    print("Double_circle pattern test finished. Turning off LEDs.")
+    presets.select("off")
+    presets.tick()
+
+
+if __name__ == "__main__":
+    main()
+