gtkcairoblur: Minor restructure

This just moves get_box_filter_size to the top and makes
it a macro (so it can be used as a constant later).

https://bugzilla.gnome.org/show_bug.cgi?id=746468

diff --git a/gtk/gtkcairoblur.c b/gtk/gtkcairoblur.c
index 406e09b9146436dace15e5c01b1f2c16e94d1985..82f5d33f48b2475f29bb0bc880c324a917617750 100644 (file)
--- a/gtk/gtkcairoblur.c
+++ b/gtk/gtkcairoblur.c
@@ -25,6 +25,19 @@
 #include <math.h>
 #include <string.h>
 
+/*
+ * Gets the size for a single box blur.
+ *
+ * Much of this, the 3 * sqrt(2 * pi) / 4, is the known value for
+ * approximating a Gaussian using box blurs.  This yields quite a good
+ * approximation for a Gaussian.  For more details, see:
+ * http://www.w3.org/TR/SVG11/filters.html#feGaussianBlurElement
+ * https://bugzilla.mozilla.org/show_bug.cgi?id=590039#c19
+ */
+#define GAUSSIAN_SCALE_FACTOR ((3.0 * sqrt(2 * G_PI) / 4))
+
+#define get_box_filter_size(radius) ((int)(GAUSSIAN_SCALE_FACTOR * radius))
+
 /* This applies a single box blur pass to a horizontal range of pixels;
  * since the box blur has the same weight for all pixels, we can
  * implement an efficient sliding window algorithm where we add
@@ -140,23 +153,6 @@ flip_buffer (guchar *dst_buffer,
 #undef BLOCK_SIZE
 }
 
-/*
- * Gets the size for a single box blur.
- *
- * Much of this, the 3 * sqrt(2 * pi) / 4, is the known value for
- * approximating a Gaussian using box blurs.  This yields quite a good
- * approximation for a Gaussian.  For more details, see:
- * http://www.w3.org/TR/SVG11/filters.html#feGaussianBlurElement
- * https://bugzilla.mozilla.org/show_bug.cgi?id=590039#c19
- */
-#define GAUSSIAN_SCALE_FACTOR ((3.0 * sqrt(2 * G_PI) / 4))
-
-static int
-get_box_filter_size (double radius)
-{
-  return GAUSSIAN_SCALE_FACTOR * radius;
-}
-
 static void
 _boxblur (guchar  *buffer,
           int      width,