[cairo] default rendering engine

[Carl Worth]

On Mon, 3 May 2004 13:08:39 -0700, Bill Spitzak wrote:
> Thanks for the info. I suspect now the problem is my Xserver:
> 
> name of display:    :0.0
> version number:    11.0
> vendor string:    Mandrake Linux (XFree86 4.3, patch level 23mdk)
> vendor release number:    40300000
> XFree86 version: 4.3.0
> 
> with the Nvidia driver.
> 
> For me, this simple change of the cairo-demo/X11/cairo-demo will crash the X 
> server immediatly when you resize the window:

The change you sent definitely does not crash my server (X.org version
6.7.0 with the ati driver).

But your patch also modifies the program significantly: It continually
translates the entire drawing on every expose, (since you're re-using
the same cairo_t without a save/restore pair). I wonder if the extreme
coordinates you get that way aren't tickling a bug somewhere. Try the
following patch which adds the missing save/restore to see if anything
is different.

-Carl

Index: cairo-demo.c
===================================================================
RCS file: /mirrors/freedesktop/cairo/cairo-demo/X11/cairo-demo.c,v
retrieving revision 1.8
diff -u -p -r1.8 cairo-demo.c
--- a/cairo-demo.c      11 May 2004 14:45:32 -0000      1.8
+++ b/cairo-demo.c      4 Jun 2004 14:24:56 -0000
@@ -218,7 +218,7 @@ win_draw(win_t *win)
 {
 #define NUM_DASH 2
     static double dash[NUM_DASH] = {SIZE/4.0, SIZE/4.0};
-    cairo_t *cr;
+    static cairo_t *cr = 0;
 #ifndef CAIRO_HAS_XCB_SURFACE
     Drawable drawable = win->win;
 #else /* CAIRO_HAS_XCB_SURFACE */
@@ -232,12 +232,15 @@ win_draw(win_t *win)
     XCBClearArea(win->dpy, 0, win->win, 0, 0, 0, 0);
 #endif /* CAIRO_HAS_XCB_SURFACE */
 
+    if (!cr) {
     cr = cairo_create();
 #ifndef CAIRO_HAS_XCB_SURFACE
     cairo_set_target_drawable (cr, win->dpy, drawable);
 #else /* CAIRO_HAS_XCB_SURFACE */
     cairo_set_target_xcb (cr, win->dpy, drawable, win->visual, 0);
 #endif /* CAIRO_HAS_XCB_SURFACE */
+    }
+    cairo_save (cr);
     cairo_set_rgb_color(cr, 1, 1, 1);
 
     cairo_save(cr);
@@ -301,7 +304,8 @@ win_draw(win_t *win)
        exit(0);
     }
 
-    cairo_destroy(cr);
+    cairo_restore (cr);
+    //cairo_destroy(cr);
 }
 
 #ifdef CAIRO_HAS_XCB_SURFACE