[gnome-control-center] um-user: Use GdkCairo operations to draw on the pixbuf

[Jasper St. Pierre <jstpierre src gnome org>]

commit eaef6e5d50140fd7ff9803f79c71e6ccfca18838
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Tue Aug 14 17:14:10 2012 -0300

    um-user: Use GdkCairo operations to draw on the pixbuf
    
    Remove a bunch of bit twiddling code.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=682391

 panels/user-accounts/um-user.c |  139 +--------------------------------------
 1 files changed, 4 insertions(+), 135 deletions(-)
---
diff --git a/panels/user-accounts/um-user.c b/panels/user-accounts/um-user.c
index 479b132..3b84cae 100644
--- a/panels/user-accounts/um-user.c
+++ b/panels/user-accounts/um-user.c
@@ -381,119 +381,6 @@ check_user_file (const char *filename,
         return TRUE;
 }
 
-static cairo_surface_t *
-surface_from_pixbuf (GdkPixbuf *pixbuf)
-{
-        cairo_surface_t *surface;
-        cairo_t         *cr;
-
-        surface = cairo_image_surface_create (gdk_pixbuf_get_has_alpha (pixbuf) ?
-                                              CAIRO_FORMAT_ARGB32 : CAIRO_FORMAT_RGB24,
-                                              gdk_pixbuf_get_width (pixbuf),
-                                              gdk_pixbuf_get_height (pixbuf));
-        cr = cairo_create (surface);
-        gdk_cairo_set_source_pixbuf (cr, pixbuf, 0, 0);
-        cairo_paint (cr);
-        cairo_destroy (cr);
-
-        return surface;
-}
-
-/**
- * go_cairo_convert_data_to_pixbuf:
- * @src: a pointer to pixel data in cairo format
- * @dst: a pointer to pixel data in pixbuf format
- * @width: image width
- * @height: image height
- * @rowstride: data rowstride
- *
- * Converts the pixel data stored in @src in CAIRO_FORMAT_ARGB32 cairo format
- * to GDK_COLORSPACE_RGB pixbuf format and move them
- * to @dst. If @src == @dst, pixel are converted in place.
- **/
-
-static void
-go_cairo_convert_data_to_pixbuf (unsigned char *dst,
-                                 unsigned char const *src,
-                                 int width,
-                                 int height,
-                                 int rowstride)
-{
-        int i,j;
-        unsigned int t;
-        unsigned char a, b, c;
-
-        g_return_if_fail (dst != NULL);
-
-#define MULT(d,c,a,t) G_STMT_START { t = (a)? c * 255 / a: 0; d = t;} G_STMT_END
-
-        if (src == dst || src == NULL) {
-                for (i = 0; i < height; i++) {
-                        for (j = 0; j < width; j++) {
-#if G_BYTE_ORDER == G_LITTLE_ENDIAN
-                                MULT(a, dst[2], dst[3], t);
-                                MULT(b, dst[1], dst[3], t);
-                                MULT(c, dst[0], dst[3], t);
-                                dst[0] = a;
-                                dst[1] = b;
-                                dst[2] = c;
-#else
-                                MULT(a, dst[1], dst[0], t);
-                                MULT(b, dst[2], dst[0], t);
-                                MULT(c, dst[3], dst[0], t);
-                                dst[3] = dst[0];
-                                dst[0] = a;
-                                dst[1] = b;
-                                dst[2] = c;
-#endif
-                                dst += 4;
-                        }
-                        dst += rowstride - width * 4;
-                }
-        } else {
-                for (i = 0; i < height; i++) {
-                        for (j = 0; j < width; j++) {
-#if G_BYTE_ORDER == G_LITTLE_ENDIAN
-                                MULT(dst[0], src[2], src[3], t);
-                                MULT(dst[1], src[1], src[3], t);
-                                MULT(dst[2], src[0], src[3], t);
-                                dst[3] = src[3];
-#else
-                                MULT(dst[0], src[1], src[0], t);
-                                MULT(dst[1], src[2], src[0], t);
-                                MULT(dst[2], src[3], src[0], t);
-                                dst[3] = src[0];
-#endif
-                                src += 4;
-                                dst += 4;
-                        }
-                        src += rowstride - width * 4;
-                        dst += rowstride - width * 4;
-                }
-        }
-#undef MULT
-}
-
-static void
-cairo_to_pixbuf (guint8    *src_data,
-                 GdkPixbuf *dst_pixbuf)
-{
-        unsigned char *src;
-        unsigned char *dst;
-        guint          w;
-        guint          h;
-        guint          rowstride;
-
-        w = gdk_pixbuf_get_width (dst_pixbuf);
-        h = gdk_pixbuf_get_height (dst_pixbuf);
-        rowstride = gdk_pixbuf_get_rowstride (dst_pixbuf);
-
-        dst = gdk_pixbuf_get_pixels (dst_pixbuf);
-        src = src_data;
-
-        go_cairo_convert_data_to_pixbuf (dst, src, w, h, rowstride);
-}
-
 static GdkPixbuf *
 frame_pixbuf (GdkPixbuf *source)
 {
@@ -502,10 +389,8 @@ frame_pixbuf (GdkPixbuf *source)
         cairo_surface_t *surface;
         guint            w;
         guint            h;
-        guint            rowstride;
         int              frame_width;
         double           radius;
-        guint8          *data;
 
         frame_width = 2;
 
@@ -513,21 +398,8 @@ frame_pixbuf (GdkPixbuf *source)
         h = gdk_pixbuf_get_height (source) + frame_width * 2;
         radius = w / 10;
 
-        dest = gdk_pixbuf_new (GDK_COLORSPACE_RGB,
-                               TRUE,
-                               8,
-                               w,
-                               h);
-        rowstride = gdk_pixbuf_get_rowstride (dest);
-
-
-        data = g_new0 (guint8, h * rowstride);
-
-        surface = cairo_image_surface_create_for_data (data,
-                                                       CAIRO_FORMAT_ARGB32,
-                                                       w,
-                                                       h,
-                                                       rowstride);
+        surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
+                                              w, h);
         cr = cairo_create (surface);
         cairo_surface_destroy (surface);
 
@@ -540,15 +412,12 @@ frame_pixbuf (GdkPixbuf *source)
         cairo_set_source_rgba (cr, 0.5, 0.5, 0.5, 0.3);
         cairo_fill_preserve (cr);
 
-        surface = surface_from_pixbuf (source);
-        cairo_set_source_surface (cr, surface, frame_width, frame_width);
+        gdk_cairo_set_source_pixbuf (cr, source, frame_width, frame_width);
         cairo_fill (cr);
-        cairo_surface_destroy (surface);
 
-        cairo_to_pixbuf (data, dest);
+        dest = gdk_pixbuf_get_from_surface (surface, 0, 0, w, h);
 
         cairo_destroy (cr);
-        g_free (data);
 
         return dest;
 }