feat: even more matrix stream examples

test/pixelstream/shared-frame-utils.js

@@ -74,6 +74,33 @@ function fadeFrame(frame, factor) {
   }
 }
 
+function addRgbToFrame(frame, index, rgb) {
+  if (index < 0 || index >= frame.length) {
+    return;
+  }
+
+  const current = hexToRgb(frame[index]);
+  const updated = {
+    r: clamp(current.r + rgb.r, 0, 255),
+    g: clamp(current.g + rgb.g, 0, 255),
+    b: clamp(current.b + rgb.b, 0, 255),
+  };
+  frame[index] = rgbToHex(updated);
+}
+
+function addHexColor(frame, index, hexColor, intensity = 1) {
+  if (intensity <= 0) {
+    return;
+  }
+
+  const base = hexToRgb(hexColor);
+  addRgbToFrame(frame, index, {
+    r: base.r * intensity,
+    g: base.g * intensity,
+    b: base.b * intensity,
+  });
+}
+
 module.exports = {
   SERPENTINE_WIRING,
   clamp,
@@ -85,5 +112,7 @@ module.exports = {
   createFrame,
   frameToPayload,
   fadeFrame,
+  addRgbToFrame,
+  addHexColor,
 };