GmshModelGeo example 1

In this example we test following methods:

In this example we create a square geometry and mesh.

Usage

PROGRAM main
USE easifemBase
USE easifemClasses
IMPLICIT NONE

  TYPE( gmsh_ ) :: gmsh

• Instance of [[Gmsh_]].

  INTEGER( I4B ) :: ierr, tag
  REAL( DFP ), PARAMETER :: LENGTH=1.0, WIDTH=1.0
  REAL( DFP ) :: x, y, z, meshSize
  CHARACTER( LEN = 120 ), ALLOCATABLE :: names( : )
  CHARACTER( LEN = 120 ) :: name

• [[Gmsh_#Initialize]]
• [[GmshModel_#Add]]
• [[GmshModel_#SetFileName]]

  ierr = gmsh%initialize()
  ierr = gmsh%model%add("t1")
  ierr = gmsh%model%setFileName('t1.geo')

Point

• [[GmshModelGeo_#AddPoint]]

Point-1: Specifying tag explicitly

  x = 0.0; y = 0.0; z = 0.0; meshSize = 0.1; tag=1
  ierr = gmsh%model%geo%addPoint(x,y,z,meshSize,tag)
  call ok(ierr .NE. 0_I4B, "(a) ")

Point-2: Not Specifying the tag:

  x = LENGTH; y = 0.0; z = 0.0; meshSize = 0.1
  tag = gmsh%model%geo%addPoint(x,y,z,meshSize)
  call ok(tag .eq. 2_I4B, "(b) ")

Point-3: Setting tag=-1 equivalent to not specifying the tag explicitly.

  x = LENGTH; y = WIDTH; z = 0.0; meshSize = 0.1; tag=-1
  ierr = gmsh%model%geo%addPoint(x,y,z,meshSize,tag)
  call ok(ierr .eq. 3_I4B, "(c) ")

Point-4: Specifying tag explicitly.

  x = 0.0; y = WIDTH; z = 0.0; meshSize = 0.1; tag=4
  ierr = gmsh%model%geo%addPoint(x,y,z,meshSize,tag)
  call ok(ierr .NE. 0_I4B, "(d) ")

Line

• [[GmshModelGeo_#AddLine]]

Line-1: explicit tag

  ierr = gmsh%model%geo%addLine(startTag=1,endTag=2,tag=1)
  call ok(ierr .NE. 0_I4B, "(e) ")

Line-2: automatic tag

  tag = gmsh%model%geo%addLine(2,3)
  call ok(tag .EQ. 2_I4B, "(f) ")

Line-3: if tag=-1 it means automatic tag.

  tag = gmsh%model%geo%addLine(3,4,-1)
  call ok(tag .EQ. 3_I4B, "(f) ")

Line-4:

  ierr = gmsh%model%geo%addLine(4,1,4)
  call ok(ierr .NE. 0_I4B, "(g) ")

CurveLoop

!!! note "GmshModelGeo/AddCurveLoop" [[GmshModelGeo_#AddCurveLoop]]

• reorient is optional, default value is false.
• tag is optional

  ierr = gmsh%model%geo%addCurveLoop( &
    & curveTags=[1,2,3,4], tag=1, reorient=.TRUE.)
  call ok(ierr .NE. 0_I4B, "(h) ")

PlaneSurface

• [[GmshModelGeo_#AddPlaneSurface]]

• tag is explicitly given.

  ierr = gmsh%model%geo%addPlaneSurface(wireTags=[1], tag=1)
  call ok(ierr .NE. 0_I4B, "(i) ")

Synchronize

• [[GmshModelGeo_#Synchronize]]

ierr = gmsh%model%geo%Synchronize()

FLTK

• [[GmshModelMesh_#Generate]]
• [[GmshFLTK_#SetStatusMessage]]

  block
    integer(i4b), allocatable :: elems(:)
    !
    ierr = gmsh%model%mesh%generate(2)
    !
    ierr = gmsh%fltk%run()
    ierr = gmsh%fltk%setStatusMessage("Select an element, or press 'q' to quit", .True.)
    !
    do
      !!ierr = gmsh%fltk%setStatusMessage("Select an element, or press 'q' to quit", .True.)
      !!elems = gmsh%fltk%SelectElements()
      ierr = gmsh%fltk%wait()
      !if( gmsh%fltk%isAvailable()) then
      !  call display( elems, "elems = ")
      !else
        exit
      !end if
    end do
  end block

Cleanup

• [[Gmsh_#Finalize]]

  ierr = gmsh%finalize()
END PROGRAM main