split julia

Fraktalism/julias.f90

@@ -0,0 +1,52 @@
+module julias
+  implicit none
+  contains
+
+!===============================================================
+!-
+!      some problems with color mapping, need more work
+!-
+subroutine simple_julia(pic, cx, cy, maxiter)
+    implicit none
+    integer, intent(inout), dimension (:,:)  ::  pic
+    real, intent(in)                         ::  cx, cy
+    integer, intent(in)                      ::  maxiter
+
+    integer      ::  ix, iy, width, height
+    real         ::  fx, fy, fv
+    complex      ::  Z, C
+    integer      ::  iter
+    logical      ::  over_iter
+
+    width  = ubound(pic, 1)
+    height = ubound(pic, 2)
+    C = complex(cx, cy)
+    print *, "Const = ", C
+    ! ready ? ok, clear the picture
+    pic = 0
+    do ix = 1, width
+      fx = (float(ix) / (float(width)/4.0) - 2.0)
+      do iy = 1, height
+        fy = (float(iy) / (float(height)/4.0) - 2.0)
+          ! ------ traitement du pixel
+          iter = 0  ; over_iter = .FALSE.
+          Z = complex(fx, fy)
+          do while (real(Z)*real(Z) + imag(Z)*imag(Z) .LT. 4.0) 
+            Z = (Z * Z) + C
+            iter = iter + 1
+            if (iter .GE. maxiter) then
+              over_iter = .TRUE.
+              exit
+            endif
+          end do
+          if (over_iter) then
+            pic(ix, iy) = 0
+          else
+            pic(ix, iy) = iter*12
+          endif
+      enddo      ! iy
+    enddo        ! ix
+
+end subroutine simple_julia
+!===============================================================
+end module