1: !
  2: !
  3: !  This example demonstrates use of PetscDrawZoom()
  4: !
  5: !          This function is called repeatedly by PetscDrawZoom() to
  6: !      redraw the figure
  7: !
  8: #include <petsc/finclude/petscsys.h>
  9: #include <petsc/finclude/petscdraw.h>
 10: module ex4fmodule
 11:   use petscsys
 12:   use petscdraw
 13:   implicit none
 14: contains
 15:   subroutine zoomfunction(draw, dummy, ierr)

 17:     PetscReal val
 18:     PetscInt, parameter :: max = 256
 19:     PetscDraw draw
 20:     integer dummy
 21:     PetscErrorCode, intent(out) :: ierr
 22:     PetscInt32 i

 24:     do i = 0, max - 1
 25:       val = real(i, PETSC_REAL_KIND)/real(max, PETSC_REAL_KIND)
 26:       PetscCall(PetscDrawLine(draw, 0.0_PETSC_REAL_KIND, val, 1.0_PETSC_REAL_KIND, val, i, ierr))
 27:     end do
 28:     ierr = 0
 29:   end
 30: end module
 31: program main
 32:   use petscsys
 33:   use petscdraw
 34:   use ex4fmodule
 35:   implicit none

 37:   PetscDraw draw
 38:   PetscErrorCode ierr
 39:   integer4, parameter :: x = 0, y = 0, width = 256, height = 256

 41:   PetscCallA(PetscInitialize(ierr))
 42:   PetscCallA(PetscDrawCreate(PETSC_COMM_WORLD, PETSC_NULL_CHARACTER, 'Title', x, y, width, height, draw, ierr))
 43:   PetscCallA(PetscDrawSetFromOptions(draw, ierr))
 44:   PetscCallA(PetscDrawZoom(draw, zoomfunction, PETSC_NULL_INTEGER, ierr))
 45:   PetscCallA(PetscDrawDestroy(draw, ierr))
 46:   PetscCallA(PetscFinalize(ierr))
 47: end

 49: !/*TEST
 50: !
 51: !   build:
 52: !     requires: x
 53: !
 54: !   test:
 55: !     output_file: output/empty.out
 56: !
 57: !TEST*/