# See the corresponding Python tutorial for detailed comments.

import gmsh

gmsh.initialize()

function createGeometryAndMesh()
    gmsh.clear()
    gmsh.model.add("t3")

    lc = 1e-2
    gmsh.model.geo.addPoint(0, 0, 0, lc, 1)
    gmsh.model.geo.addPoint(.1, 0,  0, lc, 2)
    gmsh.model.geo.addPoint(.1, .3, 0, lc, 3)
    gmsh.model.geo.addPoint(0, .3, 0, lc, 4)
    gmsh.model.geo.addLine(1, 2, 1)
    gmsh.model.geo.addLine(3, 2, 2)
    gmsh.model.geo.addLine(3, 4, 3)
    gmsh.model.geo.addLine(4, 1, 4)
    gmsh.model.geo.addCurveLoop([4, 1, -2, 3], 1)
    gmsh.model.geo.addPlaneSurface([1], 1)
    gmsh.model.geo.synchronize()
    gmsh.model.addPhysicalGroup(0, [1, 2], 1)
    gmsh.model.addPhysicalGroup(1, [1, 2], 2)
    gmsh.model.addPhysicalGroup(2, [1], 6)
    gmsh.model.setPhysicalName(2, 6, "My surface")

    h = 0.1
    angle = 90.

    ov = gmsh.model.geo.extrude([(2, 1)], 0, 0, h, [8, 2], [0.5, 1])

    ov = gmsh.model.geo.revolve([(2,28)], -0.1,0,0.1, 0,1,0, -pi / 2, [7])
    angle = gmsh.onelab.getNumber("Parameters/Twisting angle")[1]
    ov = gmsh.model.geo.twist([(2, 50)], 0, 0.15, 0.25, -2 * h, 0, 0, 1, 0, 0,
                              angle * pi / 180., [10], [], true)

    gmsh.model.geo.synchronize()

    gmsh.model.addPhysicalGroup(3, [1, 2, ov[2][2]], 101)

    gmsh.model.mesh.generate(3)
    gmsh.write("t3.msh")
end

gmsh.option.setNumber("Geometry.PointNumbers", 1)
gmsh.option.setColor("Geometry.Color.Points", 255, 165, 0)
gmsh.option.setColor("General.Color.Text", 255, 255, 255)
gmsh.option.setColor("Mesh.Color.Points", 255, 0, 0)

r, g, b, a = gmsh.option.getColor("Geometry.Points")
gmsh.option.setColor("Geometry.Surfaces", r, g, b, a)

gmsh.onelab.set("""[
  {
    "type":"number",
    "name":"Parameters/Twisting angle",
    "values":[90],
    "min":0,
    "max":120,
    "step":1
  }
]""")

createGeometryAndMesh()

function checkForEvent()
    action = gmsh.onelab.getString("ONELAB/Action")
    if length(action) > 0 && action[1] == "check"
        gmsh.onelab.setString("ONELAB/Action", [""])
        createGeometryAndMesh()
        gmsh.graphics.draw()
    end
    return true
end

if !("-nopopup" in ARGS)
    gmsh.fltk.initialize()
    while gmsh.fltk.isAvailable() == 1 && checkForEvent()
        gmsh.fltk.wait()
    end
end

gmsh.finalize()
