I guess I've been waiting for a reason to sort out text paths. The `dc-path%' class now has a `text-outline' method (as of the latest in the git repo).
At Sun, 25 Dec 2011 00:00:44 -0700, Michael W wrote: > Merry Christmas, Racketeers! > > Is there an easy way to draw text to a bitmap% with a gradient? > > I briefly looked into adding linear-gradient% and > radial-gradient% support to slideshow/pict but unfortunately we > can't draw text using an arbitrary brush% as the draw-text method > of dc% ignores that. > > My current trick is to draw the gradient to one bitmap, draw the > text to another bitmap, and then draw the first bitmap to a third > bitmap while copying the mask of the second. Is there a better > way? > > ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; > #lang racket > (require slideshow/pict > racket/draw) > > (define (compose-picts base alpha) > ;; Return a bitmap% with the colors of base but the alpha of alpha. > (define-values (w h) > (values (inexact->exact (ceiling (pict-width base))) > (inexact->exact (ceiling (pict-height base))))) > (define-values (base-bitmap alpha-bitmap final-bitmap) > (values (make-bitmap w h) > (make-bitmap w h) > (make-bitmap w h))) > (define-values (base-dc alpha-dc final-dc) > (apply values (map (λ(bm) (new bitmap-dc% [bitmap bm])) > (list base-bitmap alpha-bitmap final-bitmap)))) > (send base-dc set-smoothing 'aligned) > (draw-pict base base-dc 0 0) > (send alpha-dc set-smoothing 'aligned) > (draw-pict alpha alpha-dc 0 0) > (send final-dc draw-bitmap base-bitmap 0 0 'solid #f alpha-bitmap) > final-bitmap) > > ;; The text to render > (define my-text > (scale (text "Hello World") 4)) > > ;; The linear-gradient% to render > (define gradient > (new linear-gradient% [x0 0] [y0 0] [x1 0] [y1 (pict-height my-text)] > [stops (list (list 0.0 (make-object color% 0 0 0)) > (list 1.0 (make-object color% 255 0 0)))])) > > ;; A box containing the gradient > (define gradient-box > (dc > (λ(dc w h) > (send dc set-pen (make-object pen% "white" 1 'transparent)) > (send dc set-brush (new brush% [gradient gradient])) > (send dc draw-rectangle > 0 0 (pict-width my-text) (pict-height my-text))) > (pict-width my-text) (pict-height my-text))) > > ;; The final result: Gradient-filled text! > (bitmap (compose-picts gradient-box my-text)) > > -- > Heave ho, > _mike ____________________ Racket Users list: http://lists.racket-lang.org/users
