-void gradient_render(Surface *sf, int w, int h);
-void gradient_vertical(Surface *sf, int w, int h);
-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_pipecross(Surface *sf, int w, int h);
-void gradient_rectangle(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);
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-void render_gl_gradient(Surface *sf, int x, int y, int w, int h);