void gradient_horizontal(Surface *sf, int w, int h);
void gradient_diagonal(Surface *sf, int w, int h);
void gradient_crossdiagonal(Surface *sf, int w, int h);
+void gradient_pyramid(Surface *sf, int w, int h);
void gradient_solid(Appearance *l, int x, int y, int w, int h);
void highlight(pixel32 *x, pixel32 *y, gboolean raised);