remove some inexact numbers, fix bug with FPS display in viewer

alanb2718 · Oct 9, 2016 · 0a607bb · 0a607bb
1 parent 860424e
commit 0a607bb
Show file tree

Hide file tree

Showing 4 changed files with 11 additions and 10 deletions.
diff --git a/reactive/abstract-reactive-thing.rkt b/reactive/abstract-reactive-thing.rkt
@@ -218,7 +218,7 @@
     (define/public (milliseconds-evaluated)
       (send this milliseconds))
     (define/public (seconds)
-      (/ (send this milliseconds-evaluated) 1000.0))
+      (/ (send this milliseconds-evaluated) 1000))
 
     ; Accessing the thing's image.  concrete-image should be overridden if the image needs to be evaluated before drawing it
     (define/public (image) myimage)
@@ -301,7 +301,7 @@
         ; sets another alert
         (set! alert (thread (lambda ()
                               ; seconds-to-sleep might be negative, if clock time advanced beyond the target already
-                              (cond [(> seconds-to-sleep 0.0) (sleep seconds-to-sleep)])
+                              (cond [(> seconds-to-sleep 0) (sleep seconds-to-sleep)])
                               ; we might already have gone by the target -- that's ok, since advance-time-syncd
                               ; won't do anything in that case
                               (send-syncd this advance-time-syncd target)

diff --git a/reactive/integral-preprocessor.rkt b/reactive/integral-preprocessor.rkt
@@ -37,7 +37,7 @@
 ; rather than human consumption, and the code is going to be really fast with or without simplication.
 (define (symbolic-integral expr var)
   (match expr
-    [v #:when (equal? v var) (list '* 0.5 (list 'expt var 2))]
+    [v #:when (equal? v var) (list '* 1/2 (list 'expt var 2))]
     [(? number? n) (list '* n var)]
     [(list '+ x y) (list '+ (symbolic-integral x var) (symbolic-integral y var))]
     [(cons '* (list-no-order (? number? n) x)) (list '* n (symbolic-integral x var))]

diff --git a/reactive/reactive-thing.rkt b/reactive/reactive-thing.rkt
@@ -98,7 +98,7 @@
 ;         The default is to try symbolic, and if that doesn't work, use numeric.  However, if #:symbolic is listed
 ;         explicitly, then either symbolic integration must succeed or the system raises an exception.
 ;     #:dt d -- time step (only allowed with #:numeric)
-; Example: (integral (sin x) #:var x #:numeric #:dt 0.1)
+; Example: (integral (sin x) #:var x #:numeric #:dt 1)
 ; A Racket macro ninja would check the restrictions in the macro itself, but here the integral-preprocessor function checks them.
 ; The integral-preprocessor function includes definitions of the default values for #:var and #:dt
 (require (for-syntax "integral-preprocessor.rkt"))
@@ -173,7 +173,7 @@
       ; to get around a bug where the integral expression is being evaluated on startup before all variables have values.
       (cond [(or (not (hash-has-key? accumulator-values id)) (eq? interesting 'first) (equal? (send this milliseconds-evaluated) 0))
              (hash-set! accumulator-values id (f))
-             0.0]
+             0]
             [else (- (f) (hash-ref accumulator-values id))]))
     ; Version of runtime integral method for use with code for numeric integration.  Calling this method should return the current
     ; value of (integral expr) plus do some bookkeeping.
@@ -191,7 +191,7 @@
              ; integral expression is being evaluated on startup before all variables have values.
              [new-sum (if (and (hash-has-key? accumulator-values id) (> (send this milliseconds-evaluated) 0))
                           (let* ([oldstruct (hash-ref accumulator-values id)]
-                                 [delta-sum (* 0.5 (+ new-expr-value (nstruct-expr-value oldstruct))
+                                 [delta-sum (* 1/2 (+ new-expr-value (nstruct-expr-value oldstruct))
                                                (- new-var-value (nstruct-var-value oldstruct)))])
                             (+ (nstruct-sum oldstruct) delta-sum))
                           0)])

diff --git a/reactive/viewer.rkt b/reactive/viewer.rkt
@@ -16,7 +16,7 @@
     (define my-time-display time-display)
     (define my-fps-display fps-display)
     (define my-sleep-time sleep-time)
-    (define last-frame-time (current-milliseconds))
+    (define last-frame-time (current-inexact-milliseconds))
     (super-new)
 
     (define/override (match-thread-receive r)
@@ -43,9 +43,10 @@
       (cond [running
              (send-thing my-thing show my-dc)
              (send my-time-display set-label (seconds->string (send my-thing seconds)))
-             (let ([dt (- (current-milliseconds) last-frame-time)])
-               (send my-fps-display set-label (string-append "FPS: " (~r (/ 1000 dt) #:precision 0)))
-               (set! last-frame-time (current-milliseconds)))]
+             (let ([dt (- (current-inexact-milliseconds) last-frame-time)])
+               (cond [(> dt 0)
+                      (send my-fps-display set-label (string-append "FPS: " (~r (/ 1000 dt) #:precision 0)))])
+               (set! last-frame-time (current-inexact-milliseconds)))]
             [else
              (send my-dc clear)
              (send my-time-display set-label " ")