Add system for having multiple "patterns" and add a couple.

1 files changed, 54 insertions, 0 deletions

diff --git a/src/patterns/twinkle.c b/src/patterns/twinkle.c
new file mode 100644
index 0000000..564a30a
--- /dev/null
+++ b/src/patterns/twinkle.c
@@ -0,0 +1,54 @@
+#include <stdio.h>
+#include "byte_math.h"
+#include "pattern.h"
+
+static uint8_t pseudo_random(uint8_t x) {
+    return (1103515245 * x + 12345) & 0xFF; // & 0xFF ensures the result is 0-255
+}
+
+
+static rgb_t get_rgb(uint32_t time, size_t x)
+{
+  int r = 0, g = 0, b = 0;
+
+  uint8_t time8 = time & 0xff;
+  uint8_t time_offset = pseudo_random(x);
+
+  uint32_t adjusted_time = time - time_offset;
+
+  // The random number for this "metaframe." The metaframe is enough to show 1
+  // flash. It's used to keep the same LED's from consistently repeating.
+  uint32_t metaframe = adjusted_time >> 8;
+  uint8_t rand = pseudo_random(x + metaframe);
+  uint8_t speed = pseudo_random(rand) % 16;
+  uint8_t off = pseudo_random(rand + speed);
+
+  if (speed > 4) {
+    speed = 0;
+  }
+
+  uint32_t w_index = ((adjusted_time - off) * speed) & 0xff;
+  int w = 0;
+  if (w_index < 255) {
+    w = calc_w(w_index);
+  }
+
+
+  r = 0xff;
+  g = byte_scale(byte_sin(time8 + x * 2), 0x60);
+  b = 0;
+
+  rgb_t color;
+  color.color = 0;
+  color.r = clip(r + w);
+  color.g = clip(byte_scale(g, AS_BYTE(0.75)) + w);
+  color.b = clip(byte_scale(b, AS_BYTE(0.75)) + w);
+  return color;
+}
+
+static void reset(void)
+{
+}
+
+__attribute__((__section__(".patterns"))) volatile static pattern_t pat =
+    ((pattern_t){.get_rgb = get_rgb, .name = "Twinkle", .reset = reset});