From f74c0de6adf87505e8ff076e85791e7acf6cc3b4 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Fri, 29 Oct 2010 15:11:29 -0600
Subject: [PATCH] use alignment when installing regions

---
 collects/racket/draw/private/dc.rkt     | 6 ++++--
 collects/racket/draw/private/region.rkt | 9 +++++----
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/collects/racket/draw/private/dc.rkt b/collects/racket/draw/private/dc.rkt
index 6db3066948..708f20e2ac 100644
--- a/collects/racket/draw/private/dc.rkt
+++ b/collects/racket/draw/private/dc.rkt
@@ -453,7 +453,8 @@
       (set! desc-layoutss (make-vector (vector-length font-maps) #f))
       (do-reset-matrix cr)
       (when clipping-region
-        (send clipping-region install-region cr scroll-dx scroll-dy)))
+        (send clipping-region install-region cr scroll-dx scroll-dy
+              (lambda (x) (align-x x)) (lambda (y) (align-y y)))))
 
     (define smoothing 'unsmoothed)
 
@@ -601,7 +602,8 @@
        (reset-clip cr)
        (when clipping-region
          (send clipping-region lock-region 1)
-         (send clipping-region install-region cr scroll-dx scroll-dy))))
+         (send clipping-region install-region cr scroll-dx scroll-dy
+               (lambda (x) (align-x x)) (lambda (y) (align-y y))))))
 
     (define/public (get-clipping-matrix)
       (let* ([cm (make-cairo_matrix_t (cairo_matrix_t-xx matrix)
diff --git a/collects/racket/draw/private/region.rkt b/collects/racket/draw/private/region.rkt
index a9d435ede3..0e7e261527 100644
--- a/collects/racket/draw/private/region.rkt
+++ b/collects/racket/draw/private/region.rkt
@@ -108,7 +108,8 @@
                           (max r (+ l2 w2))
                           (max b (+ t2 h2)))))))))
 
-    (define/public (install-region cr scroll-dx scroll-dy [init (void)] [install (lambda (cr v) (cairo_clip cr))])
+    (define/public (install-region cr scroll-dx scroll-dy align-x align-y 
+                                   [init (void)] [install (lambda (cr v) (cairo_clip cr))])
       (let ([default-fill-rule (if (ormap (lambda (pr) (eq? (cdr pr) 'odd-even)) paths)
                                    CAIRO_FILL_RULE_EVEN_ODD
                                    CAIRO_FILL_RULE_WINDING)]
@@ -121,7 +122,7 @@
           (cairo_set_matrix cr (make-cairo_matrix_t 1 0 0 1 scroll-dx scroll-dy)))
         (for/fold ([v init]) ([pr (in-list paths)])
           (cairo_new_path cr)
-          (send (car pr) do-path cr values values)
+          (send (car pr) do-path cr align-x align-y)
           (cairo_set_fill_rule cr
                                (case (cdr pr)
                                  [(odd-even) CAIRO_FILL_RULE_EVEN_ODD]
@@ -139,7 +140,7 @@
        in-cairo-context
        (lambda (cr)
          (cairo_save cr)
-         (install-region cr 0 0)
+         (install-region cr 0 0 values values)
          (begin0
           (proc cr)
           (cairo_restore cr)))))
@@ -181,7 +182,7 @@
                           ;; no transformation needed
                           (values x y))])
           (begin0 
-           (install-region cr #t (lambda (cr v) (and v (cairo_in_fill cr x y))))
+           (install-region cr #t values values (lambda (cr v) (and v (cairo_in_fill cr x y))))
            (call-as-atomic
             (cond
              [temp-cr (cairo_destroy cr)]