From f7b72f1ed133882f1d5a75ede5fe6b6fc4cbea1d Mon Sep 17 00:00:00 2001
From: Nicholas Guriev <nicholas@guriev.su>
Date: Sat, 26 Feb 2022 20:11:25 +0300
Subject: [PATCH] =?UTF-8?q?Stop=20computing=20B=C3=A9zier=20curve=20length?=
 =?UTF-8?q?=20when=20float=20overflow=20occurs=20after=20splitting?=
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---
 src/vector/vbezier.cpp |  8 +++++++-
 src/vector/vbezier.h   | 13 +++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/vector/vbezier.cpp b/src/vector/vbezier.cpp
index 15889299..ea8745f9 100644
--- a/src/vector/vbezier.cpp
+++ b/src/vector/vbezier.cpp
@@ -52,7 +52,13 @@ float VBezier::length() const
     if ((len - chord) > 0.01) {
         VBezier left, right;
         split(&left, &right);
-        return left.length() + right.length();
+
+        float sum = 0;
+        if (*this != left)
+            sum += left.length();
+        if (*this != right)
+            sum += right.length();
+        return sum;
     }
 
     return len;
diff --git a/src/vector/vbezier.h b/src/vector/vbezier.h
index 18b7c596..df18c4f9 100644
--- a/src/vector/vbezier.h
+++ b/src/vector/vbezier.h
@@ -23,11 +23,14 @@
 #ifndef VBEZIER_H
 #define VBEZIER_H
 
+#include <tuple>
 #include <vpoint.h>
 
 V_BEGIN_NAMESPACE
 
 class VBezier {
+    friend bool operator == (const VBezier &l, const VBezier &r);
+
 public:
     VBezier() = default;
     VPointF     pointAt(float t) const;
@@ -134,6 +137,16 @@ inline void VBezier::split(VBezier *firstHalf, VBezier *secondHalf) const
     firstHalf->y4 = secondHalf->y1 = (firstHalf->y3 + secondHalf->y2) * 0.5f;
 }
 
+inline bool operator == (const VBezier &l, const VBezier &r)
+{
+    return std::tie(l.x1, l.y1, l.x2, l.y2, l.x3, l.y3, l.x4, l.y4)
+        == std::tie(r.x1, r.y1, r.x2, r.y2, r.x3, r.y3, r.x4, r.y4);
+}
+inline bool operator != (const VBezier &l, const VBezier &r)
+{
+    return !(l == r);
+}
+
 V_END_NAMESPACE
 
 #endif  // VBEZIER_H