From 940c4f37f36604eb6b9a82491143be88926d3461 Mon Sep 17 00:00:00 2001
From: Michael Miller <Makuna@hotmail.com>
Date: Thu, 16 Aug 2018 11:18:20 -0700
Subject: [PATCH] Ring Shift and Rotate (#220)

---
 keywords.txt                   |  2 ++
 src/internal/NeoRingTopology.h | 27 +++++++++++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/keywords.txt b/keywords.txt
index 89144fd..33587b5 100644
--- a/keywords.txt
+++ b/keywords.txt
@@ -150,6 +150,8 @@ Map	KEYWORD2
 MapProbe	KEYWORD2
 getWidth	KEYWORD2
 getHeight	KEYWORD2
+RingPixelShift	KEYWORD2
+RingPixelRotate	KEYWORD2
 getCountOfRings	KEYWORD2
 getPixelCountAtRing	KEYWORD2
 getPixelCount	KEYWORD2
diff --git a/src/internal/NeoRingTopology.h b/src/internal/NeoRingTopology.h
index 8e152f8..e598fa4 100644
--- a/src/internal/NeoRingTopology.h
+++ b/src/internal/NeoRingTopology.h
@@ -56,6 +56,33 @@ public:
         return _map(ring, pixel);
     }
 
+    uint16_t RingPixelShift(uint8_t ring, uint16_t pixel, int16_t shift)
+    {
+        int32_t ringPixel = pixel;
+        ringPixel += shift;
+
+        if (ringPixel < 0)
+        {
+            ringPixel = 0;
+        }
+        else 
+        {
+            uint16_t count = getPixelCountAtRing(ring);
+            if (ringPixel >= count)
+            {
+                ringPixel = count - 1;
+            }
+        }
+        return ringPixel;
+    }
+
+    uint16_t RingPixelRotate(uint8_t ring, uint16_t pixel, int16_t rotate)
+    {
+        int32_t ringPixel = pixel;
+        ringPixel += rotate;
+        return ringPixel % getPixelCountAtRing(ring);
+    }
+
     uint8_t getCountOfRings() const 
     {
         return _ringCount() - 1; // minus one as the Rings includes the extra value