Re: Bug in gnome-canvas-polygon.c

[Lyndon Drake <lyndon stat auckland ac nz>]

On Tue, Jan 26, 1999 at 04:15:39PM +1300, Lyndon Drake wrote:
> Hi,
> 
> I am using the Gnome canvas for plotting data, and it appears that
> there is a bug in the polygon item code.  Specifically, giving it a
> color argument of type "outline_color_gdk" or "fill_color_gdk" will
> cause wierd drawing problems, when using an aa canvas.  The problem
> is in gnome_canvas_polygon_set_args, lines 410 to 415 and 446 to 451.
> The code needs to take into account the anti-aliased canvas, but the
> current code just sets the gc color.
> 

Attached to this message is a patch which seems to fix the problem
(at least, it works for me).  I created the patch by doing

diff -u gnome-canvas-polygon.c.orig gnome-canvas-polygon.c

I hope this is the correct way to do it.

Lyndon
--- gnome-canvas-polygon.c.orig	Tue Jan 26 16:56:16 1999
+++ gnome-canvas-polygon.c	Tue Jan 26 16:25:52 1999
@@ -365,7 +365,7 @@
 	GnomeCanvasItem *item;
 	GnomeCanvasPolygon *poly;
 	GnomeCanvasPoints *points;
-	GdkColor color;
+	GdkColor color, *colorp;
 
 	item = GNOME_CANVAS_ITEM (object);
 	poly = GNOME_CANVAS_POLYGON (object);
@@ -408,9 +408,17 @@
 		break;
 
 	case ARG_FILL_COLOR_GDK:
-		poly->fill_set = TRUE;
-		poly->fill_pixel = ((GdkColor *) GTK_VALUE_BOXED (*arg))->pixel;
-		set_gc_foreground (poly->fill_gc, poly->fill_pixel);
+	        colorp = (GdkColor *) GTK_VALUE_BOXED (*arg);
+		poly->fill_set = TRUE;	     
+		poly->fill_pixel = colorp->pixel;
+		if (item->canvas->aa)
+		  poly->fill_rgba =
+		    (((colorp->red & 0xff00) << 16) |
+		     ((colorp->green & 0xff00) << 8) |
+		     (colorp->blue & 0xff00) |
+		     0xff);
+		else
+		  set_gc_foreground (poly->fill_gc, poly->fill_pixel);
 		gnome_canvas_item_request_update (item);
 		break;
 
@@ -444,9 +452,17 @@
 		break;
 
 	case ARG_OUTLINE_COLOR_GDK:
+	        colorp = (GdkColor *) GTK_VALUE_BOXED (*arg);
 		poly->outline_set = TRUE;
-		poly->outline_pixel = ((GdkColor *) GTK_VALUE_BOXED (*arg))->pixel;
-		set_gc_foreground (poly->outline_gc, poly->outline_pixel);
+		poly->outline_pixel = colorp->pixel;
+		if(item->canvas->aa)
+		  poly->outline_rgba =
+		    (((colorp->red & 0xff00) << 16) |
+		     ((colorp->green & 0xff00) << 8) |
+		     (colorp->blue & 0xff00) |
+		     0xff);
+		else
+		  set_gc_foreground (poly->outline_gc, poly->outline_pixel);
 		gnome_canvas_item_request_update (item);
 		break;