anchor.diff:            (initialize pos vel particles)
             (sync-memory-block pos :host-to-device)
             (sync-memory-block vel :host-to-device)
  -;          (output 0 pos)
  +          ;(output 0 pos)
             ;; Do simulation.
             (time
              (loop repeat 300
  
positive.code:                  ;; Synchronize CUDA context.
                   (synchronize-context)
                   ;; Output POV file.
                   ;(sync-memory-block pos :device-to-host)
                   ;(output i pos)
                  )))))))
  
negative.code: ;;
  ;; Parameters
  
  (defglobal h float 0.005)
  (defglobal dt float 0.0004)
  (defglobal pi float 3.1415927)
  (defglobal visc float 0.2)
  (defglobal limit float 200.0)
  (defglobal pmass float (/ 0.00020543 8.0))
  (defglobal radius float 0.002)
  (defglobal epsilon float 0.00001)
  (defglobal extdamp float 512.0)
  (defglobal simscale float 0.004)
  (defglobal intstiff float 3.0)
  (defglobal extstiff float 20000.0)
  (defglobal restdensity float 600.0)
  (defglobal g float4)
  (defglobal box-min float4)
  