Ease center (#238)

* New Center Ease methods

* New Version

keywords.txt

@@ -146,24 +146,31 @@ setTimeScale	KEYWORD2
 QuadraticIn	KEYWORD2
 QuadraticOut	KEYWORD2
 QuadraticInOut	KEYWORD2
+QuadraticCenter	KEYWORD2
 CubicIn	KEYWORD2
 CubicOut	KEYWORD2
 CubicInOut	KEYWORD2
+CubicCenter	KEYWORD2
 QuarticIn	KEYWORD2
 QuarticOut	KEYWORD2
 QuarticInOut	KEYWORD2
+QuarticCenter	KEYWORD2
 QuinticIn	KEYWORD2
 QuinticOut	KEYWORD2
 QuinticInOut	KEYWORD2
+QuinticCenter	KEYWORD2
 SinusoidalIn	KEYWORD2
 SinusoidalOut	KEYWORD2
 SinusoidalInOut	KEYWORD2
+SinusoidalCenter	KEYWORD2
 ExponentialIn	KEYWORD2
 ExponentialOut	KEYWORD2
 ExponentialInOut	KEYWORD2
+ExponentialCenter	KEYWORD2
 CircularIn	KEYWORD2
 CircularOut	KEYWORD2
 CircularInOut	KEYWORD2
+CircularCenter	KEYWORD2
 Gamma	KEYWORD2
 Map	KEYWORD2
 MapProbe	KEYWORD2

library.json

@@ -8,7 +8,7 @@
     "type": "git",
     "url": "https://github.com/Makuna/NeoPixelBus"
   },
-  "version": "2.3.4",
+  "version": "2.3.5",
   "frameworks": "arduino",
   "platforms": "*"
 }

library.properties

@@ -1,5 +1,5 @@
 name=NeoPixelBus by Makuna
-version=2.3.4
+version=2.3.5
 author=Michael C. Miller (makuna@live.com)
 maintainer=Michael C. Miller (makuna@live.com)
 sentence=A library that makes controlling NeoPixels (WS2811, WS2812, WS2813 & SK6812) and DotStars (APA102) easy.

src/internal/NeoEase.h

@@ -71,6 +71,20 @@ public:
         }
     }
 
+    static float QuadraticCenter(float unitValue)
+    {
+        unitValue *= 2.0f;
+        if (unitValue < 1.0f)
+        {
+            return (-0.5f * (unitValue * unitValue - 2.0f));
+        }
+        else
+        {
+            unitValue -= 1.0f;
+            return (0.5f * (unitValue * unitValue + 1.0f));
+        }
+    }
+
     static float CubicIn(float unitValue)
     {
         return (unitValue * unitValue * unitValue);
@@ -96,6 +110,13 @@ public:
         }
     }
 
+    static float CubicCenter(float unitValue)
+    {
+        unitValue *= 2.0f;
+        unitValue -= 1.0f;
+        return (0.5f * (unitValue * unitValue * unitValue) + 1);
+    }
+
     static float QuarticIn(float unitValue)
     {
         return (unitValue * unitValue * unitValue * unitValue);
@@ -121,6 +142,20 @@ public:
         }
     }
 
+    static float QuarticCenter(float unitValue)
+    {
+        unitValue *= 2.0f;
+        unitValue -= 1.0f;
+        if (unitValue < 0.0f)
+        {
+              return (-0.5f * (unitValue * unitValue * unitValue * unitValue - 1.0f));
+        }
+        else
+        {
+            return (0.5f * (unitValue * unitValue * unitValue * unitValue + 1.0f));
+        }
+    }
+
     static float QuinticIn(float unitValue)
     {
         return (unitValue * unitValue * unitValue * unitValue * unitValue);
@@ -146,6 +181,13 @@ public:
         }
     }
 
+    static float QuinticCenter(float unitValue)
+    {
+        unitValue *= 2.0f;
+        unitValue -= 1.0f;
+        return (0.5f * (unitValue * unitValue * unitValue * unitValue * unitValue + 1.0f));
+    }
+
     static float SinusoidalIn(float unitValue)
     {
         return (-cos(unitValue * HALF_PI) + 1.0f);
@@ -161,6 +203,19 @@ public:
         return -0.5 * (cos(PI * unitValue) - 1.0f);
     }
 
+    static float SinusoidalCenter(float unitValue)
+    {
+        if (unitValue < 0.5f)
+        {
+            return (0.5 * sin(PI * unitValue));
+        }
+        else
+        {
+            return (-0.5 * (cos(PI * (unitValue-0.5f)) + 1.0f));
+        }
+        
+    }
+
     static float ExponentialIn(float unitValue)
     {
         return (pow(2, 10.0f * (unitValue - 1.0f)));
@@ -185,6 +240,20 @@ public:
         }
     }
 
+    static float ExponentialCenter(float unitValue)
+    {
+        unitValue *= 2.0f;
+        if (unitValue < 1.0f)
+        {
+            return (0.5f * (-pow(2, -10.0f * unitValue) + 1.0f));
+        }
+        else
+        {
+            unitValue -= 2.0f;
+            return (0.5f * (pow(2, 10.0f * unitValue) + 1.0f));
+        }
+    }
+
     static float CircularIn(float unitValue)
     {
         if (unitValue == 1.0f)
@@ -217,6 +286,25 @@ public:
         }
     }
 
+    static float CircularCenter(float unitValue)
+    {
+        unitValue *= 2.0f;
+        unitValue -= 1.0f;
+        if (unitValue == 0.0f)
+        {
+            return 1.0f;
+        }
+        else if (unitValue < 0.0f)
+        {
+            return (0.5f * sqrt(1.0f - unitValue * unitValue));
+        }
+        else
+        {
+            unitValue -= 2.0f;
+            return (-0.5f * (sqrt(1.0f - unitValue * unitValue) - 1.0f ) + 0.5f);
+        }
+    }
+
     static float Gamma(float unitValue)
     {
         return pow(unitValue, 1.0f / 0.45f);