diff --git a/src/ViewportWidget.cpp b/src/ViewportWidget.cpp
index 326150d..e0cae3f 100644
--- a/src/ViewportWidget.cpp
+++ b/src/ViewportWidget.cpp
@@ -373,6 +373,30 @@ void ViewportWidget::paintGL()
                 else refDir = QVector3D(0, 1, 0);
             }
 
+            if (angleFromInput) {
+                QVector3D currentMouseWorldPos = unproject(m_currentMousePos, m_currentPlane);
+                QVector3D mouseVec = currentMouseWorldPos - startPos;
+
+                double mouseAngle;
+                if (m_currentPlane == SketchPlane::XY) mouseAngle = qRadiansToDegrees(atan2(mouseVec.z(), mouseVec.x()));
+                else if (m_currentPlane == SketchPlane::XZ) mouseAngle = qRadiansToDegrees(atan2(mouseVec.y(), mouseVec.x()));
+                else mouseAngle = qRadiansToDegrees(atan2(mouseVec.z(), mouseVec.y()));
+
+                double refAngleForQuadrant;
+                if (m_currentPlane == SketchPlane::XY) refAngleForQuadrant = qRadiansToDegrees(atan2(refDir.z(), refDir.x()));
+                else if (m_currentPlane == SketchPlane::XZ) refAngleForQuadrant = qRadiansToDegrees(atan2(refDir.y(), refDir.x()));
+                else refAngleForQuadrant = qRadiansToDegrees(atan2(refDir.z(), refDir.y()));
+
+                double relativeMouseAngle = mouseAngle - refAngleForQuadrant;
+                while (relativeMouseAngle <= -180.0) relativeMouseAngle += 360.0;
+                while (relativeMouseAngle > 180.0) relativeMouseAngle -= 360.0;
+
+                if ((relativeMouseAngle >= 45 && relativeMouseAngle < 135) ||
+                    (relativeMouseAngle >= 135 || relativeMouseAngle < -135)) {
+                    refDir = -refDir;
+                }
+            }
+
             double refAngle, lineAngle;
             if (m_currentPlane == SketchPlane::XY) {
                 refAngle = atan2(refDir.z(), refDir.x());