main
Matthew Butterick 9 years ago
parent 528569efd5
commit f4eaf84dc2

@ -5,49 +5,38 @@
[record-dc% (Class (init-field)
(get-text-extent (String (Instance (Class (init-field))) Any . -> . (values Nonnegative-Real Nonnegative-Real Nonnegative-Real Nonnegative-Real))))]
[make-font ((#:size Nonnegative-Float) (#:style Symbol) (#:weight Symbol) (#:face String) . -> . (Instance (Class (init-field))))])
(require/typed sugar/cache [make-caching-proc (Procedure . -> . Procedure)])
(require/typed racket/serialize [serialize (Any . -> . Any)]
[deserialize (Any . -> . (HashTable Any Any))])
(provide measure-text measure-ascent round-float update-text-cache-file load-text-cache-file make-font/caching)
(provide measure-text measure-ascent round-float update-text-cache-file load-text-cache-file)
(define precision 4.0)
(define base (flexpt 10.0 precision))
(define base (expt 10.0 precision))
(define max-size 1024.0)
(define dc (new record-dc%))
(define-type Measurement-Result-Type (List Float Float Float Float))
(define mrt? (make-predicate Measurement-Result-Type))
(define-type MMS-Type ((String String) (Symbol Symbol) . ->* . Measurement-Result-Type))
(define current-text-cache (make-parameter ((inst make-hash (List String String Symbol Symbol) Measurement-Result-Type) '())))
(define current-text-cache-changed? : (Parameterof Boolean) (make-parameter #f))
(define current-font-cache (make-parameter ((inst make-hash (List String Symbol Symbol) (Instance (Class (init-field)))) '())))
(: round-float (Float . -> . Float))
(define (round-float x)
(/ (round (* base x)) base))
(define-syntax (values->list stx)
(syntax-case stx ()
[(_ values-expr) #'(call-with-values (λ () values-expr) list)]))
(define dc (new record-dc%))
(define max-size 1024.0) ; use fixnum to trigger faster bitshift division
;; changing max-size invalidates font cache (because it's based on max size, duh)
(define make-font/caching
(make-caching-proc (λ (font weight style)
(make-font #:size max-size #:style style #:weight weight #:face font))))
(define (get-cache-file-path)
(: get-cache-file-path (-> Path))
(define (get-cache-file-path)
(build-path "font.cache"))
(define current-text-cache (make-parameter ((inst make-hash (List String String Symbol Symbol) Measurement-Result-Type) '())))
(define current-text-cache-changed? : (Parameterof Boolean) (make-parameter #f))
(define current-font-cache (make-parameter ((inst make-hash (List String Symbol Symbol) (Instance (Class (init-field)))) '())))
(: update-text-cache-file (-> Void))
(define (update-text-cache-file)
(when (current-text-cache-changed?)
(write-to-file (serialize (current-text-cache)) (get-cache-file-path) #:exists 'replace)
(current-text-cache-changed? #f)))
(: load-text-cache-file (-> Void))
(define (load-text-cache-file)
(define cache-file-path (get-cache-file-path))
@ -56,16 +45,17 @@
((inst make-hash (List String String Symbol Symbol) Measurement-Result-Type) '()))))
(define-type Measurement-Result-Type (List Float Float Float Float))
(define mrt? (make-predicate Measurement-Result-Type))
(define-type MMS-Type ((String String) (Symbol Symbol) . ->* . Measurement-Result-Type))
(: get-cached-font (String Symbol Symbol . -> . (Instance (Class (init-field)))))
(define (get-cached-font font weight style)
(hash-ref! (current-font-cache) (list font weight style) (λ() (make-font #:size max-size #:style style #:weight weight #:face font))))
(: measure-max-size-base (String String Symbol Symbol . -> . Measurement-Result-Type))
(define (measure-max-size-base text font weight style)
(: hash-updater (-> Measurement-Result-Type))
(define (hash-updater)
(current-text-cache-changed? #t)
(define font-instance (hash-ref! (current-font-cache) (list font weight style) (λ() (make-font #:size max-size #:style style #:weight weight #:face font))))
(define font-instance (get-cached-font font weight style))
;; 'combine' boolean only makes a difference for two or more chars, so use (>= (string-length text) 1) for speed
(define-values (width height descent extra) (send dc get-text-extent text font-instance (>= (string-length text) 1)))
;; avoid `map` here because it requires a cast to ensure the type
@ -74,26 +64,26 @@
((inst hash-ref! (List String String Symbol Symbol) Measurement-Result-Type) (current-text-cache) (list text font weight style) hash-updater))
;; todo: why did I add this measure-cache? It helps performance, but why?
;; see https://github.com/mbutterick/quad/commit/294c5b59a3d94afd53a0d9f46202dca38bee256e
;; oh: because I couldn't yet make it work with define/caching
;; rather than use define/caching from the (untyped) sugar/cache, implement the cache "manually"
(define measure-cache ((inst make-hash (List String String Symbol Symbol) Measurement-Result-Type)))
(: measure-max-size MMS-Type)
(define (measure-max-size text font [weight 'normal] [style 'normal])
(hash-ref! measure-cache (list text font weight style) (λ () (measure-max-size-base text font weight style))))
(define-syntax-rule (width x) (first x))
(define-syntax-rule (height x) (second x))
(define-syntax-rule (descent x) (third x))
#;(define-syntax-rule (extra x) (fourth x))
;; works by taking max size and scaling it down. Allows caching of results.
(: measure-text ((String Positive-Float String) (Symbol Symbol) . ->* . Float))
(define (measure-text text size font [weight 'normal] [style 'normal])
(define raw-width (width (measure-max-size text font weight style)))
(round-float (/ (* raw-width size) max-size)))
;; works by taking max size and scaling it down. Allows caching of results.
(: measure-ascent ((String Positive-Float String) (Symbol Symbol) . ->* . Float))
(define (measure-ascent text size font [weight 'normal] [style 'normal])

@ -93,9 +93,11 @@
(inherit render-element)
(define make-font/caching
(make-caching-proc (λ (font size style weight)
(make-font #:face font #:size size #:style style #:weight weight))))
(define font-cache ((inst make-hash (List String Nonnegative-Flonum Symbol Symbol) (Instance (Class (init-field)))) '()))
(: get-cached-font (String Nonnegative-Flonum Symbol Symbol . -> . (Instance (Class (init-field)))))
(define (get-cached-font font size style weight)
(hash-ref! font-cache (list font size style weight) (λ () (make-font #:face font #:size size #:style style #:weight weight))))
(define/override (render-word w)
@ -105,7 +107,7 @@
(define word-weight (cast (quad-attr-ref/parameter w world:font-weight-key) Symbol))
(define word-color (cast (quad-attr-ref/parameter w world:font-color-key) String))
(define word-background (cast (quad-attr-ref/parameter w world:font-background-key) String))
(send dc set-font (make-font/caching word-font word-size word-style word-weight))
(send dc set-font (get-cached-font word-font word-size word-style word-weight))
(define foreground-color (send the-color-database find-color word-color))
(when foreground-color
(send dc set-text-foreground foreground-color))

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