un commit pour montrer aux gens

GravityField/Makefile

@@ -2,7 +2,7 @@
 #    Fortraneries by tTh - Gravity Field
 #
 
-GFOPT   = -Wall -Wextra -g -time -pg -I../Modules
+GFOPT   = -Wall -Wextra -g -time -I../Modules
 MODOBJ  = '../Modules/spitpgm.o'
 
 all:	essai

GravityField/essai.f90

@@ -9,48 +9,107 @@ program essai
 
   implicit none
 
-  type(massbody)          :: planet
+  type(massbody)          :: planets(60)
   integer                 :: foo
   character(len=100)      :: filename
 
-  planet%posx   = 337.314
+  call init_random()
-  planet%posy   = 164.666
-  planet%mass   = 1e8
-  planet%serial = 42
 
-  do foo=0, 48
+  call create_some_planets(planets, 45e5)
-    write (filename, "(a, i5.5, a)") 'WS/', foo, '.pgm'
+
-    call build_and_write_a_field(800, 600, planet, filename)
+  do foo=0, 72
-    planet%posx = planet%posx + 6.99
+    write (filename, "(a, i5.5, a)") 'WS/A', foo, '.pgm'
-    planet%posy = planet%posy + 2.55
+    call build_and_write_a_field(640, 480, 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
   enddo
 
-  STOP 'YOLO'
+  STOP 'BECAUSE YOLO'
 
 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
+!-
+subroutine init_random()
+
+  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)
+  enddo
+
+  ! STOP 'ABEND'
+
+end subroutine
+!-----------------------------------------------------------------------
+!-
 !   compute a field with only one body; and write pic file
 !-
-subroutine build_and_write_a_field(szx, szy, moon, fname)
+subroutine build_and_write_a_field(szx, szy, moons, fname)
   integer, intent(in)                :: szx, szy
-  type(massbody), intent(in)         :: moon
+  type(massbody), intent(in)         :: moons(:)
   character(len=*), intent(in)       :: fname
 
-  real                               :: maxi, mini
+  real                                  :: maxi, mini
-  integer                            :: errcode
+  integer                               :: errcode, foo
-  real,    dimension(:,:), allocatable  :: field
+  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
 
-  call compute_a_field(field, moon)
   maxi = maxval(field)
   mini = minval(field)
-  print *, "field: ", mini, maxi, maxi-mini
+  ! print *, "field: ", mini, maxi, maxi-mini
 
   allocate(greymap(szx, szy), stat=errcode)
-  greymap = 65535
+  greymap = 0
   ! convert from real value to 16 bits int values
   where (field < 65530.0)
     greymap = int(field)

GravityField/realfield.f90

@@ -27,11 +27,12 @@ function compute_gravity(fx, fy, body)
   rx = fx - body%posx
   ry = fy - body%posy
   dist = sqrt( (rx*rx) + (ry*ry) )
-  if (dist .LT. 4.50) then
+  if (dist .LT. 0.11) then
-    write (0, *) "dist too small ", dist
+    ! write (0, *) "dist too small ", dist
     compute_gravity = 0e0
+  else
+    compute_gravity = body%mass / (dist ** 2)
   endif
-  compute_gravity = body%mass / (dist ** 2)
 
 end function
 
@@ -63,7 +64,6 @@ subroutine compute_a_field(field, moon)
 
 end subroutine
 !-----------------------------------------------------------------------
-
 !-----------------------------------------------------------------------
 
 end module

GravityField/runme.sh

@@ -4,7 +4,7 @@ set -e				# stop on error
 
 make essai
 
-./essai
+time ./essai
 
-convert -delay 10 WS/*.pgm foo.gif
+convert -delay 20 WS/A*.pgm foo.gif