From 039f7ffe585b3267d77bbb9c6a572198146727dd Mon Sep 17 00:00:00 2001
From: Grant Sanderson <grant@3blue1brown.com>
Date: Sat, 18 Aug 2018 20:13:49 -0700
Subject: [PATCH] Simple and small performance improvements

---
 utils/bezier.py           |  4 ++--
 utils/color.py            | 19 ++++++++++++++++---
 utils/simple_functions.py | 11 +++++++++++
 3 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/utils/bezier.py b/utils/bezier.py
index acf18533..f61c47e5 100644
--- a/utils/bezier.py
+++ b/utils/bezier.py
@@ -1,7 +1,7 @@
 import numpy as np
 
 from scipy import linalg
-from utils.simple_functions import choose
+from utils.simple_functions import choose_using_cache
 from utils.space_ops import get_norm
 
 CLOSED_THRESHOLD = 0.001
@@ -10,7 +10,7 @@ CLOSED_THRESHOLD = 0.001
 def bezier(points):
     n = len(points) - 1
     return lambda t: sum([
-        ((1 - t)**(n - k)) * (t**k) * choose(n, k) * point
+        ((1 - t)**(n - k)) * (t**k) * choose_using_cache(n, k) * point
         for k, point in enumerate(points)
     ])
 
diff --git a/utils/color.py b/utils/color.py
index 500d5b9c..4625fa45 100644
--- a/utils/color.py
+++ b/utils/color.py
@@ -11,9 +11,12 @@ from utils.simple_functions import clip_in_place
 
 
 def color_to_rgb(color):
-    if not isinstance(color, Color):
-        color = Color(color)
-    return np.array(color.get_rgb())
+    if isinstance(color, str):
+        return hex_to_rgb(color)
+    elif isinstance(color, Color):
+        return np.array(color.get_rgb())
+    else:
+        raise Exception("Invalid color type")
 
 
 def color_to_rgba(color, alpha=1):
@@ -35,6 +38,16 @@ def rgb_to_hex(rgb):
     return "#" + "".join('%02x' % int(255 * x) for x in rgb)
 
 
+def hex_to_rgb(hex_code):
+    hex_part = hex_code[1:]
+    if len(hex_part) == 3:
+        "".join([2 * c for c in hex_part])
+    return np.array([
+        int(hex_part[i:i + 2], 16) / 255
+        for i in range(0, 6, 2)
+    ])
+
+
 def invert_color(color):
     return rgb_to_color(1.0 - color_to_rgb(color))
 
diff --git a/utils/simple_functions.py b/utils/simple_functions.py
index 23669e70..35ad2c97 100644
--- a/utils/simple_functions.py
+++ b/utils/simple_functions.py
@@ -8,6 +8,17 @@ def sigmoid(x):
     return 1.0 / (1 + np.exp(-x))
 
 
+CHOOSE_CACHE = {}
+
+
+def choose_using_cache(n, r):
+    if n not in CHOOSE_CACHE:
+        CHOOSE_CACHE[n] = {}
+    if r not in CHOOSE_CACHE[n]:
+        CHOOSE_CACHE[n][r] = choose(n, r)
+    return CHOOSE_CACHE[n][r]
+
+
 def choose(n, r):
     if n < r:
         return 0