first video -> big commit :)

GravityField/essai.f90

@@ -9,21 +9,30 @@ program essai
 
   implicit none
 
-  type(massbody)          :: planets(60)
+  ! some configuration constants
+  integer, parameter      :: S_WIDTH  = 800
+  integer, parameter      :: S_HEIGHT = 600
+  integer, parameter      :: NB_BODY  = 51
+
+  type(massbody)          :: planets(NB_BODY)
   integer                 :: foo
   character(len=100)      :: filename
 
   call init_random()
+  call create_some_planets(planets, 45e5, S_WIDTH, S_HEIGHT)
 
-  call create_some_planets(planets, 45e5)
-
-  do foo=0, 72
-    write (filename, "(a, i5.5, a)") 'WS/A', foo, '.pgm'
-    call build_and_write_a_field(640, 480, planets, filename)
-    print *, trim(filename)
+  do foo=0, 1999
+    write (filename, "(a, i5.5, a)") 'WS/', foo, '.pgm'
+    call build_and_write_a_field(S_WIDTH, S_HEIGHT, planets, filename)
+    ! print *, trim(filename)
     ! OMG! two magic numbers, wtf?
-    planets(1)%posx = planets(1)%posx + 8.08
-    planets(1)%posy = planets(1)%posy + 6.42
+    planets(1)%posx = planets(1)%posx + 3 + (4.5*rand())
+    planets(1)%posy = planets(1)%posy + 3 + (2.1*rand())
+    if (planets(1)%posx .GT. S_WIDTH)   planets(1)%posx = 0.0
+    if (planets(1)%posy .GT. S_HEIGHT)  planets(1)%posy = 0.0
+
+    call boulegue_les_astres(planets, 2.21)
+
   enddo
 
   STOP 'BECAUSE YOLO'
@@ -31,98 +40,21 @@ program essai
 contains
 !-----------------------------------------------------------------------
 !-
-!    Yes, I know, this is a disturbing kluge, but I like it :}
-!    May be, it's time to read the doc of modern Fortran
+!    Et si on bougeait un peu tous ces corps planétaires ?
 !-
-subroutine init_random()
+subroutine boulegue_les_astres(astres, factor)
+  type(massbody), intent(inout)     :: astres(:)
+  real, intent(in)                  :: factor
 
-  integer, dimension(3) :: tarray
-  integer               :: t3
-  real                  :: dummy
-  call itime(tarray)
-  t3 = 8971*tarray(1) + 443*tarray(2) + tarray(3)
-  write(0, '(A,3I3,A,I6)') "sranding: ", tarray, " --> ", t3
-  call srand(t3)
-  ! after initializing the random generator engine,
-  ! you MUST use it for initializing the initializer
-  dummy = rand()
-  write(0, *) 'dummy was ', dummy
-
-end subroutine
-!-----------------------------------------------------------------------
-!-
-!     make a few solid body to play with...
-!-
-subroutine create_some_planets(planets, coef)
-  type(massbody), intent(inout)     :: planets(:)
-  real, intent(in)                  :: coef
   integer                           :: foo
-  ! real                              :: quux, quuy
-  character(100)                    :: fmt
 
-  fmt = "(I4, '   : ', 2(F9.2, '  '), e11.3, I7)"
-
-  do foo=1, ubound(planets, 1)
-    if (foo .EQ. 1) then
-      planets(1)%posx   = 20
-      planets(1)%posy   = 20
-      planets(1)%mass   = 9e8
-      planets(1)%serial = 1337
-    else
-      planets(foo)%posx     = rand() * 639.999
-      planets(foo)%posy     = rand() * 479.999
-      planets(foo)%mass     = 7e6 + coef*foo
-      planets(foo)%serial   = foo
-    endif
-    write (*, fmt) foo, planets(foo)
+  do foo = 2, ubound(astres, 1)
+      astres(foo)%posx = astres(foo)%posx + factor*(rand() - 0.5)
+      astres(foo)%posy = astres(foo)%posy + factor*(rand() - 0.5)
   enddo
 
-  ! STOP 'ABEND'
 
 end subroutine
-!-----------------------------------------------------------------------
-!-
-!   compute a field with only one body; and write pic file
-!-
-subroutine build_and_write_a_field(szx, szy, moons, fname)
-  integer, intent(in)                :: szx, szy
-  type(massbody), intent(in)         :: moons(:)
-  character(len=*), intent(in)       :: fname
-
-  real                                  :: maxi, mini
-  integer                               :: errcode, foo
-  real,    dimension(:,:), allocatable  :: field, tmpf
-  integer, dimension(:,:), allocatable  :: greymap
-
-  allocate(field(szx, szy), stat=errcode)
-  allocate(tmpf(szx, szy), stat=errcode)
-
-  field = 0.0
-  do foo=1, ubound(moons, 1)
-    call compute_a_field(tmpf, moons(foo))
-    tmpf = tmpf * 0.019
-    field = field + tmpf
-  enddo
-
-  maxi = maxval(field)
-  mini = minval(field)
-  ! print *, "field: ", mini, maxi, maxi-mini
-
-  allocate(greymap(szx, szy), stat=errcode)
-  greymap = 0
-  ! convert from real value to 16 bits int values
-  where (field < 65530.0)
-    greymap = int(field)
-  end where
-
-  call spit_as_pgm_16(greymap, trim(fname))
-
-  ! make valgrind happy
-  deallocate(field)
-  deallocate(greymap)
-
-end subroutine
-
 !-----------------------------------------------------------------------
 !-----------------------------------------------------------------------