[gthumb] image scale: use cairo to implement the nearest method

[Paolo Bacchilega <paobac src gnome org>]

commit 61b1adc4f480835bf3a5f4446137d0352313eee9
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Fri Jun 28 17:10:44 2013 +0200

    image scale: use cairo to implement the nearest method

 gthumb/cairo-scale.c |   25 +++++++++++++++++++++++--
 1 files changed, 23 insertions(+), 2 deletions(-)
---
diff --git a/gthumb/cairo-scale.c b/gthumb/cairo-scale.c
index b0815c7..5a72048 100644
--- a/gthumb/cairo-scale.c
+++ b/gthumb/cairo-scale.c
@@ -39,6 +39,7 @@ _cairo_image_surface_scale_nearest (cairo_surface_t *image,
                                    int              new_width,
                                    int              new_height)
 {
+#if 0
        cairo_surface_t *scaled;
        int              src_width;
        int              src_height;
@@ -76,7 +77,7 @@ _cairo_image_surface_scale_nearest (cairo_surface_t *image,
        p_dest_row = p_dest;
        p_src_row = p_src;
        max_row = GINT_TO_FIXED (src_height - 1);
-       max_col= GINT_TO_FIXED (src_width - 1);
+       max_col = GINT_TO_FIXED (src_width - 1);
        /* pick the pixel in the middle to avoid the shift effect. */
        y_src = gfixed_div (step_y, GFIXED_2);
        for (y = 0; y < new_height; y++) {
@@ -100,10 +101,30 @@ _cairo_image_surface_scale_nearest (cairo_surface_t *image,
        cairo_surface_mark_dirty (scaled);
 
        return scaled;
-}
+#else
 
+       cairo_surface_t *output;
+       cairo_t         *cr;
+
+       output = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
+                                            new_width,
+                                            new_height);
+       cr = cairo_create (output);
+       cairo_scale (cr,
+                    (double) new_width / cairo_image_surface_get_width (image),
+                    (double) new_height / cairo_image_surface_get_height (image));
+       cairo_set_source_surface (cr, image, 0.0, 0.0);
+       cairo_pattern_set_filter (cairo_get_source (cr), CAIRO_FILTER_NEAREST);
+       cairo_rectangle (cr, 0.0, 0.0, cairo_image_surface_get_width (image), cairo_image_surface_get_height 
(image));
+       cairo_fill (cr);
+       cairo_surface_flush (output);
+
+       cairo_destroy (cr);
+
+       return output;
 
 #endif
+}
 
 
 /* -- _cairo_image_surface_scale_filter --