add a new uselessgraphic: squarmania

.gitignore

@@ -11,4 +11,5 @@ starfield
 randomwalk
 oscilloscope
 lissajous
+squarmania
 

Makefile

@@ -57,3 +57,13 @@ lissajous.png:	lissajous Makefile
 	convert WS/a.tga $@
 
 # -----------------------------------------------
+
+squarmania:	squarmania.f90 Makefile genplotting.o
+	gfortran -Wall $< genplotting.o -o $@
+
+squarmania.png:	squarmania Makefile
+	./squarmania
+	genplot2 -s 512x512 WS/squarmania.scratch WS/a.tga
+	convert WS/a.tga $@
+
+# -----------------------------------------------

squarmania.f90

@@ -0,0 +1,50 @@
+!
+!                    SQUARMANIA
+!       new Thu Apr 23 04:27:03 PM UTC 2026
+!
+! this crapware is released by tTh under the
+!             DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
+!
+program squarmania
+  use genplotting
+  implicit none
+
+  write (0, '(A)') "----[ genplotting squarmania ]----"
+
+  call genp_init (0, 'WS/squarmania.scratch')
+  call do_squarmania (35, 0.93)
+  call genp_end (0)
+
+contains
+! ---------------------------------------------------------
+subroutine do_squarmania (nbr, k0)
+  integer, intent(in)   :: nbr
+  real, intent(in)      :: k0
+
+  integer    :: idx
+  real       :: xa, xb, xc, xd, ya, yb, yc, yd
+  real       :: va, vb, vc, vd, wa, wb, wc, wd, k2
+
+  k2 = 1.0 - k0
+  xa =  1  ; ya =  1    ;   xb =  1  ; yb = -1
+  xc = -1  ; yc = -1    ;   xd = -1  ; yd =  1
+
+  do idx=1, nbr
+    call genp_move(xa, ya)
+    call genp_draw(xb, yb, 1)  ; call genp_draw(xc, yc, 2)
+    call genp_draw(xd, yd, 3)  ; call genp_draw(xa, ya, 4)
+
+    va = k0*xa + k2*xb         ;  wa = k0*ya + k2*yb
+    vb = k0*xb + k2*xc         ;  wb = k0*yb + k2*yc
+    vc = k0*xc + k2*xd         ;  wc = k0*yc + k2*yd
+    vd = k0*xd + k2*xa         ;  wd = k0*yd + k2*ya
+
+    xa = va ; xb = vb ; xc = vc ; xd = vd
+    ya = wa ; yb = wb ; yc = wc ; yd = wd
+
+  enddo
+
+end subroutine
+
+! ---------------------------------------------------------
+end program