Merge pull request #20 from dmarx/fix_easing_again

fix easing for realsies this time

setup.py

@@ -12,7 +12,7 @@
 
 setup(
     name='keyframed',
-    version='0.2.0',
+    version='0.2.1',
     author='David Marx',
     long_description=README,
     long_description_content_type='text/markdown',

src/keyframed/curve.py

@@ -169,12 +169,24 @@ def get_ease_end_t(self) -> Number:
     def use_easing(self, k) -> bool:
         if self.f is None:
             return False
-        return self.start_t < k < self.end_t 
-
+        try:
+            start = self.start_t
+            end = self.end_t
+        except IndexError:
+            return False
+        if (start is None) or (end is None):
+            return False
+        return start < k < end
+    def __call__(self,k:Number) -> Number:
+        if not self.use_easing(k):
+            return k
+        span = self.end_t - self.start_t
+        t = (k-self.start_t) / span
+        #t = (self.end_t-k) / span
+        t_new = self.f(t)
+        k_new = self.start_t + t_new*span
+        return k_new
 
-# NB: It's worrisome to me that I had to separately implement __call__ for EaseIn and EaseOut
-#     rather than just using a shared __call__ implementation on EasingFunction. I think I inverted
-#     some stuff in EaseOut maybe?
 
 class EaseIn(EasingFunction):
     def get_ease_start_t(self) -> Number:
@@ -189,15 +201,7 @@ def get_ease_end_t(self) -> Number:
         for k in self.curve.keyframes:
             if self.curve[k] != 0:
                 return k
-    def __call__(self,k:Number) -> Number:
-        if not self.use_easing(k):
-            return k
-        span = self.end_t - self.start_t
-        t = (k-self.start_t) / span
-        #t = (self.end_t-k) / span
-        t_new = self.f(t)
-        k_new = self.start_t + t_new*span
-        return k_new
+
 
 class EaseOut(EasingFunction):
     def get_ease_start_t(self) -> Number:
@@ -224,15 +228,15 @@ def get_ease_end_t(self) -> Number:
             k_prev = k
         else:
             return self.curve.keyframes[-1]
-    def __call__(self,k:Number) -> Number:
-        if not self.use_easing(k):
-            return k
-        span = self.end_t - self.start_t
-        #t = (k-self.start_t) / span
-        t = (self.end_t-k) / span
-        t_new = self.f(t)
-        k_new = self.start_t + t_new*span
-        return k_new
+    # def __call__(self,k:Number) -> Number:
+    #     if not self.use_easing(k):
+    #         return k
+    #     span = self.end_t - self.start_t
+    #     #t = (k-self.start_t) / span
+    #     t = (self.end_t-k) / span
+    #     t_new = self.f(t)
+    #     k_new = self.start_t + t_new*span
+    #     return k_new
 
 class Curve:
     """

tests/test_easing.py

@@ -144,9 +144,10 @@ def test_actual_use_case1():
     import math
     def sin2(t):
         return math.sin(t * math.pi / 2) ** 2
-    def cos2(t):
-        return math.cos(t * math.pi / 2) ** 2
-    curve = Curve({0:1, 30:0.5, 50:0}, default_interpolation='linear', ease_in=sin2, ease_out=cos2)
+    #def cos2(t):
+    #    return math.cos(t * math.pi / 2) ** 2
+    #curve = Curve({0:1, 30:0.5, 50:0}, default_interpolation='linear', ease_in=sin2, ease_out=cos2)
+    curve = Curve({0:1, 30:0.5, 50:0}, default_interpolation='linear', ease_in=sin2, ease_out=sin2)
     #print(curve.ease_in.start_t, curve.ease_in.end_t)
     #print(curve.ease_out.start_t, curve.ease_out.end_t)
     #xs = list(range(50))
@@ -163,9 +164,10 @@ def test_actual_use_case2():
     import math
     def sin2(t):
         return math.sin(t * math.pi / 2) ** 2
-    def cos2(t):
-        return math.cos(t * math.pi / 2) ** 2
-    curve = Curve({20:0, 40:1, 70:0}, default_interpolation='linear', ease_in=sin2, ease_out=cos2)
+    #def cos2(t):
+    #    return math.cos(t * math.pi / 2) ** 2
+    #curve = Curve({20:0, 40:1, 70:0}, default_interpolation='linear', ease_in=sin2, ease_out=cos2)
+    curve = Curve({20:0, 40:1, 70:0}, default_interpolation='linear', ease_in=sin2, ease_out=sin2)
     # print(curve.ease_in.start_t, curve.ease_in.end_t)
     # print(curve.ease_out.start_t, curve.ease_out.end_t)
     # xs = list(range(70))
@@ -183,4 +185,16 @@ def cos2(t):
     assert abs(curve[55] -  0.5) < EPS
     assert curve[70] == 0
     # yeah I def need to do something about this.
-    assert curve[80] == 0 # throws an index error. probably not great.
+    assert curve[80] == 0 # throws an index error. probably not great.
+
+###################
+
+def test_easing_not_break_small_curve():
+    """
+    current implementation of easing presumes Curve contains at least
+    two Keyframes. This is bad.
+    """
+    curve = Curve(ease_in = lambda x:x)
+    curve[0]
+    curve[1]
+    curve[2]