progress on transformation matrix

genplotting.f90

@@ -122,6 +122,11 @@ end subroutine
 subroutine genp_move (px, py)
   real, intent(in)        :: px, py
   real                    :: lx, ly
+  real                    :: pt(3)
+
+! ====== insert rotation here ?
+  pt(1) = px  ;  pt(2) = py  ;  pt(3) = 0.0
+
   lx = (px*xscale) + xoffset
   ly = (py*yscale) + yoffset
   write (outunit, '(2F12.5, I5)') lx, ly, -1
@@ -135,6 +140,9 @@ subroutine genp_draw (px, py, color)
   real, intent(in)        :: px, py
   integer, intent(in)     :: color
   real                    :: lx, ly
+
+! ====== insert rotation here ?
+
   lx = (px*xscale) + xoffset
   ly = (py*yscale) + yoffset
   write (outunit, '(2F12.5, I5)') lx, ly, color
@@ -187,6 +195,18 @@ subroutine genp_circle(radius, steps, color)
 
 end subroutine
 ! ---------------------------------------------------------
+!    draw a square centered on 0,0
+subroutine genp_square (amp, color)
+  real, intent(in)     :: amp
+  integer, intent(in)  :: color
+  real                 :: ha
+  ha = amp / 2.0
+  call genp_move(-ha, -ha)
+  call genp_draw(-ha,  ha, color)
+  call genp_draw( ha,  ha, color)
+  call genp_draw( ha, -ha, color)
+end subroutine
+! ---------------------------------------------------------
 subroutine genp_end (foo)
   integer, intent(in)    :: foo
 
@@ -194,6 +214,7 @@ subroutine genp_end (foo)
   write (0, '("minmax X ", 2F18.5)') xmin, xmax
   write (0, '("minmax Y ", 2F18.5)') ymin, ymax
 
+  !          XXX   NASTY BUG HERE !
   write (outunit, '(2F18.5, I6)') xmin*1.05, ymin*1.05, -1
   write (outunit, '(2F18.5, I6)') xmin*1.05, ymax*1.05,  0
   write (outunit, '(2F18.5, I6)') xmax*1.05, ymax*1.05,  0