From 8a4f19c917150b1c263ea8285fbf586277dfb559 Mon Sep 17 00:00:00 2001
From: Mira Grudzinska <mira@lottiefiles.com>
Date: Fri, 10 May 2024 00:54:31 +0200
Subject: [PATCH] lottie: replace cubics with lines where possible

When the loaded control points are zero (in and out),
there is no need to apply bezier curves - they can be
replaced with straight lines.
---
 src/common/tvgMath.h                   |  6 ++++++
 src/loaders/lottie/tvgLottieParser.cpp | 27 +++++++++++++++++---------
 2 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/src/common/tvgMath.h b/src/common/tvgMath.h
index 60ea1d21b..a69b0964d 100644
--- a/src/common/tvgMath.h
+++ b/src/common/tvgMath.h
@@ -62,6 +62,12 @@ static inline bool mathZero(float a)
 }
 
 
+static inline bool mathZero(const Point& p)
+{
+    return mathZero(p.x) && mathZero(p.y);
+}
+
+
 static inline bool mathEqual(float a, float b)
 {
     return (fabsf(a - b) < FLT_EPSILON);
diff --git a/src/loaders/lottie/tvgLottieParser.cpp b/src/loaders/lottie/tvgLottieParser.cpp
index 7a1027832..b571782c9 100644
--- a/src/loaders/lottie/tvgLottieParser.cpp
+++ b/src/loaders/lottie/tvgLottieParser.cpp
@@ -246,18 +246,27 @@ void LottieParser::getValue(PathSet& path)
     outPts.push(*pt);
 
     for (++pt, ++out, ++in; pt < pts.end(); ++pt, ++out, ++in) {
-        outCmds.push(PathCommand::CubicTo);
-        outPts.push(*(pt - 1) + *(out - 1));
-        outPts.push(*pt + *in);
-        outPts.push(*pt);
+        if (mathZero(*(out - 1)) && mathZero(*in)) {
+            outPts.push(*pt);
+            outCmds.push(PathCommand::LineTo);
+        } else {
+            outPts.push(*(pt - 1) + *(out - 1));
+            outPts.push(*pt + *in);
+            outPts.push(*pt);
+            outCmds.push(PathCommand::CubicTo);
+        }
     }
 
     if (closed) {
-        outPts.push(pts.last() + outs.last());
-        outPts.push(pts.first() + ins.first());
-        outPts.push(pts.first());
-        outCmds.push(PathCommand::CubicTo);
-        outCmds.push(PathCommand::Close);
+        if (mathZero(outs.last()) && mathZero(ins.first())) {
+            outCmds.push(PathCommand::Close);
+        } else {
+            outPts.push(pts.last() + outs.last());
+            outPts.push(pts.first() + ins.first());
+            outPts.push(pts.first());
+            outCmds.push(PathCommand::CubicTo);
+            outCmds.push(PathCommand::Close);
+        }
     }
 
     path.pts = outPts.data;