From: Simon Tatham <anakin@pobox.com>
Date: Sun, 28 Aug 2005 13:52:58 +0000 (+0000)
Subject: There seems to be some odd behaviour when GTK is asked to draw an
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ian/git?a=commitdiff_plain;h=8f46a30e69ca959dc73e7ad221ced4c98cf54528;p=sgt-puzzles.git

There seems to be some odd behaviour when GTK is asked to draw an
outline polygon with a clipping rectangle active. I don't know or
care whether this is GTK or my X server or what, but I'm working
around it by drawing the lines myself, which seems to sort it out.

[originally from svn r6227]
---

diff --git a/gtk.c b/gtk.c
index b72752a..1cf5136 100644
--- a/gtk.c
+++ b/gtk.c
@@ -373,7 +373,17 @@ void gtk_draw_poly(void *handle, int *coords, int npoints,
     }
     assert(outlinecolour >= 0);
     gdk_gc_set_foreground(fe->gc, &fe->colours[outlinecolour]);
-    gdk_draw_polygon(fe->pixmap, fe->gc, FALSE, points, npoints);
+
+    /*
+     * In principle we ought to be able to use gdk_draw_polygon for
+     * the outline as well. In fact, it turns out to interact badly
+     * with a clipping region, for no terribly obvious reason, so I
+     * draw the outline as a sequence of lines instead.
+     */
+    for (i = 0; i < npoints; i++)
+	gdk_draw_line(fe->pixmap, fe->gc,
+		      points[i].x, points[i].y,
+		      points[(i+1)%npoints].x, points[(i+1)%npoints].y);
 
     sfree(points);
 }