Small improvements in Path::flatArc()

trdenton · Feb 18, 2018 · b0f4a7c · b0f4a7c
1 parent 0e658f7
commit b0f4a7c
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Showing 2 changed files with 13 additions and 5 deletions.
diff --git a/libs/librepcb/common/geometry/path.cpp b/libs/librepcb/common/geometry/path.cpp
@@ -276,12 +276,19 @@ Path Path::octagon(const Length& width, const Length& height) noexcept
     return p;
 }
 
-Path Path::flatArc(const Point& p1, const Point& p2, const Angle& angle, qreal tolerance) noexcept
+Path Path::flatArc(const Point& p1, const Point& p2, const Angle& angle,
+                   const Length& maxTolerance) noexcept
 {
+    // return straight line if radius is smaller than half of the allowed tolerance
+    Length radiusAbs = Toolbox::arcRadius(p1, p2, angle).abs();
+    if (radiusAbs <= maxTolerance.abs() / 2) {
+        return line(p1, p2);
+    }
+
     // calculate how many lines we need to create
-    Length radius = Toolbox::arcRadius(p1, p2, angle).abs();
-    qreal y = qBound(0.0, tolerance, (qreal)radius.toNm() / 4);
-    qreal stepsPerRad = qMin(0.5 / qAcos(1 - y / radius.toNm()), radius.toNm() / 2.0);
+    qreal radiusAbsNm = static_cast<qreal>(radiusAbs.toNm());
+    qreal y = qBound(0.0, static_cast<qreal>(maxTolerance.toNm()), radiusAbsNm / 4);
+    qreal stepsPerRad = qMin(0.5 / qAcos(1 - y / radiusAbsNm), radiusAbsNm / 2);
     int steps = qCeil(stepsPerRad * angle.abs().toRad());
 
     // some other very complex calculations...

diff --git a/libs/librepcb/common/geometry/path.h b/libs/librepcb/common/geometry/path.h
@@ -96,7 +96,8 @@ class Path final : public SerializableObject
         static Path rect(const Point& p1, const Point& p2) noexcept;
         static Path centeredRect(const Length& width, const Length& height) noexcept;
         static Path octagon(const Length& width, const Length& height) noexcept;
-        static Path flatArc(const Point& p1, const Point& p2, const Angle& angle, qreal tolerance) noexcept;
+        static Path flatArc(const Point& p1, const Point& p2, const Angle& angle,
+                            const Length& maxTolerance) noexcept;
         static QPainterPath toQPainterPathPx(const QList<Path>& paths) noexcept;