Index: work/gtk/layersel/layersel.c
===================================================================
--- work/gtk/layersel/layersel.c	(revision 8497)
+++ work/gtk/layersel/layersel.c	(revision 8498)
@@ -49,6 +49,14 @@
 	return ls->grp_row;
 }
 
+#define set_pixel(dst, r, g, b, a) \
+do { \
+	p[0] = r; \
+	p[1] = g; \
+	p[2] = b; \
+	p[3] = a; \
+} while(0)
+
 static GtkWidget *test_pixbuf_pixel_manipulated(int filled)
 {
 	GdkPixbuf *pixbuf;
@@ -74,24 +82,12 @@
 		w = width;
 		p = pixels;
 		while (w--) {
-			if ((height == 0) || (height == max_height-1) || (w == 0) || (w == width-1)) {
-				p[0] = 0x0;
-				p[1] = 0x0;
-				p[2] = 0x0;
-				p[3] = 0xff;
-			}
-			else if ((width-w+5 < height) || (filled)) {
-				p[0] = r;
-				p[1] = g;
-				p[2] = b;
-				p[3] = a;
-			}
-			else {
-				p[0] = 0xff;
-				p[1] = 0xff;
-				p[2] = 0xff;
-				p[3] = 0xff;
-			}
+			if ((height == 0) || (height == max_height-1) || (w == 0) || (w == width-1))
+				set_pixel(p, 0, 0, 0, 0xff); /* frame */
+			else if ((width-w+5 < height) || (filled))
+				set_pixel(p, r, g, b, a); /* layer color fill (full or up-left triangle) */
+			else
+				set_pixel(p, 0xff, 0xff, 0xff, 0xff); /* the unfilled part when triangle */
 			p += 4;
 		}
 		pixels += gdk_pixbuf_get_rowstride(pixbuf);