ENH: construct axisAngleRotation from x/y/z axis enumeration (#863)

- can be helpful for handling rotations within global planes

src/meshTools/coordinate/rotation/axisAngleRotation.C

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2018 OpenCFD Ltd.
+    \\  /    A nd           | Copyright (C) 2018-2019 OpenCFD Ltd.
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -106,6 +106,22 @@ Foam::coordinateRotations::axisAngle::axisAngle
 }
 
 
+Foam::coordinateRotations::axisAngle::axisAngle
+(
+    const vector::components axis,
+    scalar angle,
+    bool degrees
+)
+:
+    coordinateRotation(),
+    axis_(Zero),
+    angle_(angle),
+    degrees_(degrees)
+{
+    axis_[axis] = 1;
+}
+
+
 Foam::coordinateRotations::axisAngle::axisAngle(const dictionary& dict)
 :
     axisAngle

src/meshTools/coordinate/rotation/axisAngleRotation.H

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2018 OpenCFD Ltd.
+    \\  /    A nd           | Copyright (C) 2018-2019 OpenCFD Ltd.
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -50,7 +50,7 @@ Note
     The rotation axis will be normalized internally.
 
 SourceFiles
-    axisAngle.C
+    axisAngleRotation.C
 
 \*---------------------------------------------------------------------------*/
 
@@ -111,6 +111,9 @@ public:
         //- Construct from axis and angle
         axisAngle(const vector& axis, scalar angle, bool degrees);
 
+        //- Construct from x/y/z axis enumeration and angle
+        axisAngle(const vector::components axis, scalar angle, bool degrees);
+
         //- Construct from dictionary
         explicit axisAngle(const dictionary& dict);