Layer selector: Add prototype and empty function body for function that

fills all layers with colors from a given color palette.

include/gds-render/layer/layer-selector.h

@@ -33,6 +33,7 @@
 
 #include <gtk/gtk.h>
 #include <glib.h>
+#include <gds-render/layer/color-palette.h>
 
 G_BEGIN_DECLS
 
@@ -90,6 +91,14 @@ GList *layer_selector_export_rendered_layer_info(LayerSelector *selector);
  */
 void layer_selector_force_sort(LayerSelector *selector, enum layer_selector_sort_algo sort_function);
 
+/**
+ * @brief Apply colors from palette to all layers. Aditionally set alpha
+ * @param layer_selector LayerSelector object
+ * @param palette Color palette to use
+ * @param global_alpha Additional alpha value that is applied to all layers
+ */
+void layer_selector_auto_color_layers(LayerSelector *layer_selector, ColorPalette *palette, double global_alpha);
+
 G_END_DECLS
 
 #endif /* __LAYER_SELECTOR_H__ */