circle Subroutine

public subroutine circle(x, y, radius)

NAME

circle(3f) - [M_pixel:ARCS] draw a circle using current line width and color
(LICENSE:PD)

SYNOPSIS

definition:

subroutine circle(x,y,radius)
real,intent(in) :: x
real,intent(in) :: y
real,intent(in) :: radius

DESCRIPTION

Draw a circle using the current line width and color into the pixel
array. Units are in world coordinates.

OPTIONS

X,Y        Coordinates for the center of the circle
RADIUS     Radius of the circle

EXAMPLE

Sample program:

program demo_circle
use M_pixel
use M_writegif, only : writegif
implicit none
   !! set up drawing surface
   call prefsize(400,400)
   call vinit()
   call ortho2(left=-100.0, right=100.0, bottom=-100.0, top=100.0)
   call color(3)
   call clear()
   call color(4)
   call linewidth(200)
   !! draw some circles
   call circle(0.0, 0.0, 90.0)
   call color(1)
   call circle(0.0, 0.0, 40.0)
   call color(2)
   call circle(-25.0, 25.0, 20.0)
   call circle(-25.0,-25.0, 20.0)
   call circle( 25.0, 25.0, 20.0)
   call circle( 25.0,-25.0, 20.0)
   !! render the pixel map
   call writegif('circle.3m_pixel.gif',P_pixel,P_colormap)
   !! display the graphic assuming display(1) is available
   call execute_command_line('display circle.3m_pixel.gif')
   !! exit graphics mode
   call vexit()
end program demo_circle

AUTHOR

John S. Urban

LICENSE

Public Domain

Arguments

Type IntentOptional Attributes Name
real, intent(in) :: x
real, intent(in) :: y
real, intent(in) :: radius

Contents

Source Code

circle

Source Code

subroutine circle(x,y,radius)

! ident_14="@(#) M_pixel circle(3f) draw a circle using current line width and color"

real,intent(in) :: x
real,intent(in) :: y
real,intent(in) :: radius

real               :: degrees
real               :: increment
integer            :: i
real               :: xx1,yy1, xx2,yy2

increment=360.0/P_NSEGS

do i=1,P_NSEGS

   degrees=(i-1)*increment
   xx1=x+radius*cosd(degrees)
   yy1=y+radius*sind(degrees)

   degrees=i*increment
   xx2=x+radius*cosd(degrees)
   yy2=y+radius*sind(degrees)

   call line(xx1,yy1,xx2,yy2)
enddo

end subroutine circle