C Library Functions - slocator (3)

NAME

slocator(3f) - [M_draw:INTERACTIVE] Find out where cursor is in screen coordinates (LICENSE:PD)

Synopsis
Description
Examples

SYNOPSIS

integer function slocator(xaddr, yaddr)
     real xaddr, yaddr

DESCRIPTION

Find out where the cursor is. xaddr and yaddr are set to the current location in screen coordinates. The return value of the function is set up in the same way as with locator. If the device has no locator device slocator returns -1.

EXAMPLES

Sample program:

! ! a routine to demonstrate using locator. ! program demo_slocator

use M_draw

implicit none

    character(len=20) :: dev
    integer bt
    real x, y, sx, sy
    logical act, curpnt
    integer :: ios

    print*,’Enter device name:’
    read(*,’(a)’,iostat=ios) dev
    if(ios.ne.0)dev=’ ’
    call vinit(dev)

    call color(D_BLACK)
    call clear()

    call color(D_BLUE)
    !
    !       draw some axes
    !
    call move2(0.0, 1.0)
    call draw2(0.0, -1.0)

    call move2(1.0, 0.0)
    call draw2(-1.0, 0.0)

    call color(D_GREEN)

    act = .false.
    curpnt = .false.
    !
    !       locator returns whether a mouse button has been
    !       pressed or not. In a device such as the tektronix
    !       where you have to wait for a keypress to get the
    !       position of the crosshairs locator returns 0
    !       automatically on every second call. A return value
    !       of 2 indicates the second mouse button has been pressed.
    !       A return value of 1 indicates the first mouse button has
    !       been pressed. We wait for the locator to return zero so
    !       that we know the mouse button has been released.
    !
    write(*,*)’ click two points to create a line segment’
    write(*,*)’ button 2 exits’

    INFINITE: do
       bt = slocator(x, y)
       !! write(*,*)’slocator returned ’,bt,’ and coordinates ’,x,y
       if (bt .eq. -1) then
          call vexit()
          print*,’No locator device found’
          stop
       elseif (bt .eq. 2) then
          call vexit()
          stop
       elseif (bt .eq. 0) then
          act = .true.
       elseif (act) then
          act = .false.
          if (bt .eq. 1) then
             if (curpnt) then
                call move2(sx, sy)
                call draw2(x, y)
                curpnt = .false.
             else
                curpnt = .true.
             endif

             sx = x
             sy = y
          endif
       endif
    enddo INFINITE

    end program demo_slocator

Nemo Release 3.1

slocator (3)

February 23, 2025

Generated by manServer 1.08 from a617b1a8-6afb-462a-a18f-432b5f33a88e using man macros.

C Library Functions - slocator (3)

NAME

CONTENTS

SYNOPSIS

DESCRIPTION

EXAMPLES