From 24417941794557b9865d9a60a4ae21de37d6393a Mon Sep 17 00:00:00 2001
From: rocman <rocman@vip.qq.com>
Date: Mon, 23 May 2016 20:13:45 +0800
Subject: [PATCH 1/3] add a mapping ability to the interpolate method

---
 Libraries/Animated/src/Interpolation.js | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/Libraries/Animated/src/Interpolation.js b/Libraries/Animated/src/Interpolation.js
index 32d363ccbbed51..d1a6a0ddb14031 100644
--- a/Libraries/Animated/src/Interpolation.js
+++ b/Libraries/Animated/src/Interpolation.js
@@ -75,6 +75,7 @@ class Interpolation {
       );
 
       var range = findRange(input, inputRange);
+      var mapping = config.mapping || passThrough;
       return interpolate(
         input,
         inputRange[range],
@@ -84,11 +85,16 @@ class Interpolation {
         easing,
         extrapolateLeft,
         extrapolateRight,
+        mapping,
       );
     };
   }
 }
 
+function passThrough(input: any): any {
+  return input;
+}
+
 function interpolate(
   input: number,
   inputMin: number,
@@ -98,13 +104,14 @@ function interpolate(
   easing: ((input: number) => number),
   extrapolateLeft: ExtrapolateType,
   extrapolateRight: ExtrapolateType,
+  mapping: ((input: number) => any)
 ) {
   var result = input;
 
   // Extrapolate
   if (result < inputMin) {
     if (extrapolateLeft === 'identity') {
-      return result;
+      return mapping(result);
     } else if (extrapolateLeft === 'clamp') {
       result = inputMin;
     } else if (extrapolateLeft === 'extend') {
@@ -114,7 +121,7 @@ function interpolate(
 
   if (result > inputMax) {
     if (extrapolateRight === 'identity') {
-      return result;
+      return mapping(result);
     } else if (extrapolateRight === 'clamp') {
       result = inputMax;
     } else if (extrapolateRight === 'extend') {
@@ -123,14 +130,14 @@ function interpolate(
   }
 
   if (outputMin === outputMax) {
-    return outputMin;
+    return mapping(outputMin);
   }
 
   if (inputMin === inputMax) {
     if (input <= inputMin) {
-      return outputMin;
+      return mapping(outputMin);
     }
-    return outputMax;
+    return mapping(outputMin);
   }
 
   // Input Range
@@ -154,7 +161,7 @@ function interpolate(
     result = result * (outputMax - outputMin) + outputMin;
   }
 
-  return result;
+  return mapping(result);
 }
 
 function colorToRgba(input: string): string {
@@ -233,7 +240,7 @@ function createInterpolationFromStringOutputRange(
     // 'rgba(${interpolations[0](input)}, ${interpolations[1](input)}, ...'
     return outputRange[0].replace(stringShapeRegex, () => {
       const val = +interpolations[i++](input);
-      const rounded = shouldRound && i < 4 ? Math.round(val) : Math.round(val * 1000) / 1000;
+      const rounded = shouldRound && i < 4 ? Math.round(val) : val;
       return String(rounded);
     });
   };

From 06885230a962b6a8ef93000d6526e1d74757ea5a Mon Sep 17 00:00:00 2001
From: rocman <rocman@vip.qq.com>
Date: Mon, 23 May 2016 20:16:19 +0800
Subject: [PATCH 2/3] rollback one line

---
 Libraries/Animated/src/Interpolation.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Libraries/Animated/src/Interpolation.js b/Libraries/Animated/src/Interpolation.js
index d1a6a0ddb14031..d8c8d66e0fee67 100644
--- a/Libraries/Animated/src/Interpolation.js
+++ b/Libraries/Animated/src/Interpolation.js
@@ -240,7 +240,7 @@ function createInterpolationFromStringOutputRange(
     // 'rgba(${interpolations[0](input)}, ${interpolations[1](input)}, ...'
     return outputRange[0].replace(stringShapeRegex, () => {
       const val = +interpolations[i++](input);
-      const rounded = shouldRound && i < 4 ? Math.round(val) : val;
+      const rounded = shouldRound && i < 4 ? Math.round(val) : Math.round(val * 1000) / 1000;
       return String(rounded);
     });
   };

From 78e47b4981aa8f189fcb83dd1be7e5266e10274a Mon Sep 17 00:00:00 2001
From: rocman <rocman@vip.qq.com>
Date: Wed, 25 May 2016 09:49:55 +0800
Subject: [PATCH 3/3] mapping(outputMin) -> mapping(outputMax)

---
 Libraries/Animated/src/Interpolation.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Libraries/Animated/src/Interpolation.js b/Libraries/Animated/src/Interpolation.js
index d8c8d66e0fee67..1539f309f4c327 100644
--- a/Libraries/Animated/src/Interpolation.js
+++ b/Libraries/Animated/src/Interpolation.js
@@ -137,7 +137,7 @@ function interpolate(
     if (input <= inputMin) {
       return mapping(outputMin);
     }
-    return mapping(outputMin);
+    return mapping(outputMax);
   }
 
   // Input Range