starfield use the setoffset func

starfield.f90

@@ -0,0 +1,47 @@
+program starfield
+  use genplotting
+  implicit none
+
+  write (0, '(A)') "----[ genplotting starfield ]----"
+
+  call genp_init (0, 'starfield.scratch')
+  call do_starfield (105)
+  call genp_end (0)
+
+contains
+! ---------------------------------------------------------
+subroutine plot_a_star(at_x, at_y, sz, col)
+  real, intent(in)        :: at_x, at_y, sz
+  integer, intent(in)     :: col
+  integer                 :: idx
+  real                    :: rad, xv, yv
+
+  write(0, '("plot a star ", 2F8.3)') at_x, at_y
+  call genp_set_offset(at_x, at_y)
+
+  do idx=0, 360, 30
+    rad = 0.04 + (real(idx) * (3.14159 / 180))
+    xv = sz * sin(rad)    ;    yv = sz * cos(rad)
+    call genp_move(0.0, 0.0)
+    call genp_draw(xv, yv, col)
+  enddo
+
+end subroutine
+! ---------------------------------------------------------
+subroutine do_starfield (nbstar)
+  integer, intent(in)     :: nbstar
+
+  integer         idx, color
+  real            px, py, sz
+
+  do idx=0, nbstar
+    px = (rand(0) * 10.00) - 5.00
+    py = (rand(0) * 10.00) - 5.00
+    sz = (rand(0) *  0.16) + 0.19
+    color = 1 + mod(idx, 7)
+    call plot_a_star(px, py, sz, color)
+  end do
+end subroutine
+! ---------------------------------------------------------
+! ---------------------------------------------------------
+end program