toytoolkit: rename tile_mask to render_shadow

This function is used and clearly designed only for drawing the shadows.
Rename it so that it has name after what it does and also move some
common code into the function.

Signed-off-by: Marek Chalupa <mchqwerty@gmail.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

shared/cairo-util.c

@@ -137,13 +137,14 @@ blur_surface(cairo_surface_t *surface, int margin)
 }
 
 void
-tile_mask(cairo_t *cr, cairo_surface_t *surface,
+render_shadow(cairo_t *cr, cairo_surface_t *surface,
 	      int x, int y, int width, int height, int margin, int top_margin)
 {
 	cairo_pattern_t *pattern;
 	cairo_matrix_t matrix;
 	int i, fx, fy, vmargin;
 
+	cairo_set_source_rgba(cr, 0, 0, 0, 0.45);
 	cairo_set_operator(cr, CAIRO_OPERATOR_OVER);
 	pattern = cairo_pattern_create_for_surface (surface);
 	cairo_pattern_set_filter(pattern, CAIRO_FILTER_NEAREST);
@@ -429,8 +430,7 @@ theme_render_frame(struct theme *t,
 	if (flags & THEME_FRAME_MAXIMIZED)
 		margin = 0;
 	else {
-		cairo_set_source_rgba(cr, 0, 0, 0, 0.45);
-		tile_mask(cr, t->shadow,
+		render_shadow(cr, t->shadow,
 			      2, 2, width + 8, height + 8,
 			      64, 64);
 		margin = t->margin;

shared/cairo-util.h

@@ -32,7 +32,7 @@ void
 surface_flush_device(cairo_surface_t *surface);
 
 void
-tile_mask(cairo_t *cr, cairo_surface_t *surface,
+render_shadow(cairo_t *cr, cairo_surface_t *surface,
 	      int x, int y, int width, int height, int margin, int top_margin);
 
 void

xwayland/window-manager.c

@@ -973,9 +973,7 @@ weston_wm_window_draw_decoration(void *data)
 		cairo_set_source_rgba(cr, 0, 0, 0, 0);
 		cairo_paint(cr);
 
-		cairo_set_operator(cr, CAIRO_OPERATOR_OVER);
-		cairo_set_source_rgba(cr, 0, 0, 0, 0.45);
-		tile_mask(cr, t->shadow, 2, 2, width + 8, height + 8, 64, 64);
+		render_shadow(cr, t->shadow, 2, 2, width + 8, height + 8, 64, 64);
 	}
 
 	cairo_destroy(cr);