add rotation, need more tests

genplotting.f90

@@ -11,8 +11,9 @@ module genplotting
   real      ::    xoffset, yoffset, xscale, yscale
   private   ::    xoffset, yoffset, xscale, yscale
 
-  real      ::    rotation
-  private   ::    rotation
+  real      ::    rotation, rotmatrix(3,3)
+  private   ::    rotation, rotmatrix, compute_rot_matrix
+  private   ::    print_rot_matrix
 
   integer   ::    outunit = 6
   private   ::    outunit
@@ -21,7 +22,7 @@ contains
 ! ---------------------------------------------------------
 ! the first parameter _must_ be 0.
 ! the second can be
-!    - the name of a file for recoding plot instructions
+!    - the name of a file for recording plot instructions
 !  or
 !    - an empty string for send plot command to stdout
 !
@@ -44,6 +45,7 @@ subroutine genp_init (foo, fname)
   ymin = 9e9       ;       ymax = -9e9
   xoffset = 0.0    ;       yoffset = 0.0
   xscale  = 1.0    ;       yscale  = 1.0
+
   rotation = 0.0
 
 end subroutine
@@ -67,6 +69,56 @@ subroutine genp_get_scale(sx, sy)
   sx = xscale      ;      sy = yscale
 end subroutine
 ! ---------------------------------------------------------
+! this is a private procedure, don't call it from your prog
+subroutine compute_rot_matrix(angle)
+  real, intent(in)    :: angle
+  write (0, '("compute rot matrix for", F8.5, " radians")') &
+                                     angle
+  rotmatrix (1, 1) =  cos(angle)
+  rotmatrix (1, 2) =  sin(angle)
+  rotmatrix (1, 3) =  0.0
+
+  rotmatrix (2, 1) = -sin(angle)
+  rotmatrix (2, 2) =  cos(angle)
+  rotmatrix (2, 3) =  0.0
+
+  rotmatrix (3, 1) =  0.0
+  rotmatrix (3, 2) =  0.0
+  rotmatrix (3, 3) =  1.0
+
+end subroutine
+!                  -----------------
+!    we have computed some fancy numbers
+!                      and we want to see them !
+subroutine print_rot_matrix(fd)
+  integer, intent(in)    :: fd
+
+  integer                :: i, j
+  do i=1, 3
+    do j=1, 3
+      write (fd, '("   ", F8.5)', advance='no') rotmatrix(i,j)
+    end do
+    write(fd, *)
+  end do
+end subroutine
+! ---------------------------------------------------------
+subroutine genp_set_rotation(angle)
+  real, intent(in)     :: angle
+  rotation = angle
+  !       compute the matrix here !
+  call compute_rot_matrix(angle)
+  ! call print_rot_matrix(0)
+end subroutine
+
+real function genp_get_rotation()
+  genp_get_rotation = rotation
+end function
+
+subroutine genp_get_rot_matrix (dst)
+  real, intent(out)   :: dst(3, 3)
+  dst = rotmatrix
+end subroutine
+! ---------------------------------------------------------
 subroutine genp_move (px, py)
   real, intent(in)        :: px, py
   real                    :: lx, ly
@@ -138,7 +190,7 @@ end subroutine
 subroutine genp_end (foo)
   integer, intent(in)    :: foo
 
-  write (0, '("--- genp_end ---")')
+  write (0, '("------------- genp_end -------------")')
   write (0, '("minmax X ", 2F18.5)') xmin, xmax
   write (0, '("minmax Y ", 2F18.5)') ymin, ymax