From e189df81b156cfe0b9465ba90d7a99536c1af2b8 Mon Sep 17 00:00:00 2001
From: Grant Sanderson <grant@3blue1brown.com>
Date: Tue, 10 Jan 2023 15:32:05 -0800
Subject: [PATCH] Change default endpoint angle to be 0

---
 manimlib/mobject/types/vectorized_mobject.py       | 14 ++++++--------
 manimlib/shaders/quadratic_bezier_stroke/geom.glsl | 13 ++-----------
 2 files changed, 8 insertions(+), 19 deletions(-)

diff --git a/manimlib/mobject/types/vectorized_mobject.py b/manimlib/mobject/types/vectorized_mobject.py
index fbea2fe3..525ae9f5 100644
--- a/manimlib/mobject/types/vectorized_mobject.py
+++ b/manimlib/mobject/types/vectorized_mobject.py
@@ -1071,18 +1071,16 @@ class VMobject(Mobject):
         sgn = np.sign(cross2d(vect_to_vert, vect_from_vert))
         self.data["joint_angle"][:, 0] = sgn * angle
 
-        # To communicate to the shader that a given anchor point
-        # sits at the end of a curve, we set its angle equal
-        # to something outside the range [-pi, pi].
-        # An arbitrary constant is used
+        # If a given anchor point sits at the end of a curve,
+        # we set its angle equal to 0
         ends_mismatch = (a1[-1] != a0[0]).any()
         if ends_mismatch:
-            self.data["joint_angle"][0] = DISJOINT_CONST
-            self.data["joint_angle"][-1] = DISJOINT_CONST
+            self.data["joint_angle"][0] = 0
+            self.data["joint_angle"][-1] = 0
 
         mis_matches = (a0[1:] != a1[:-1]).any(1)
-        self.data["joint_angle"][3::3][mis_matches] = DISJOINT_CONST
-        self.data["joint_angle"][2:-1:3][mis_matches] = DISJOINT_CONST
+        self.data["joint_angle"][3::3][mis_matches] = 0
+        self.data["joint_angle"][2:-1:3][mis_matches] = 0
 
         return self.data["joint_angle"]
 
diff --git a/manimlib/shaders/quadratic_bezier_stroke/geom.glsl b/manimlib/shaders/quadratic_bezier_stroke/geom.glsl
index 4a5d009f..38bdf10b 100644
--- a/manimlib/shaders/quadratic_bezier_stroke/geom.glsl
+++ b/manimlib/shaders/quadratic_bezier_stroke/geom.glsl
@@ -42,7 +42,6 @@ const int BEVEL_JOINT = 2;
 const int MITER_JOINT = 3;
 
 const float PI = 3.141592653;
-const float DISJOINT_CONST = 404.0;
 const float ANGLE_THRESHOLD = 1e-3;
 
 
@@ -152,18 +151,10 @@ void main() {
         }
     }
 
-    // Set joint information
+    // Set joint information, potentially recomputing based on perspective
     float angle_from_prev = v_joint_angle[0];
     float angle_to_next = v_joint_angle[2];
-    if(angle_from_prev == DISJOINT_CONST){
-        // TODO, add anti-aliasing patch to curve start
-        angle_from_prev = 0.0;
-    }
-    if(angle_to_next == DISJOINT_CONST){
-        // TODO, add anti-aliasing patch to curve end
-        angle_to_next = 0.0;
-    }
-    // Recompute angles based on perspective
+
     if(angle_from_prev > 0.0 && unit_normal != vec3(0.0, 0.0, 1.0)){
         vec3 v01 = verts[1] - verts[0];
         vec3 from_prev = rotate(v01, angle_from_prev, unit_normal);