package cytoscape.visual.strokes;

import java.awt.Shape;
import java.awt.geom.GeneralPath;
import static cytoscape.visual.LineStyle.SINEWAVE;
import cytoscape.util.PropUtil;
import cytoscape.CytoscapeInit;

public class SineWaveStroke extends ShapeStroke {

	public SineWaveStroke(float width) {
		// second arg here is the advance - advance must equal wavelength below
		super( new Shape[] { getSineWave(width) }, 
		       PropUtil.getFloat( CytoscapeInit.getProperties(), "SineWaveStroke.wavelength", 10f), 
		       SINEWAVE, width );
	}

	public WidthStroke newInstanceForWidth(float w) {
		return new SineWaveStroke(w);
	}

	private static Shape getSineWave(final float width) {
		GeneralPath shape = new GeneralPath();

		// wavelength must equal advance specified in constructor or 
		// else the waves won't line up!
		final float wavelength = PropUtil.getFloat( CytoscapeInit.getProperties(), 
		                                            "SineWaveStroke.wavelength", 10f ); 
		final float amplitude = PropUtil.getFloat( CytoscapeInit.getProperties(), 
		                                           "SineWaveStroke.amplitude",5f ); 

		shape.moveTo(0f,0f);
		shape.lineTo(0f,width);
		shape.quadTo(0.25f*wavelength,amplitude+width,   0.5f*wavelength,width);
		shape.quadTo(0.75f*wavelength,-amplitude-width,      wavelength,width);
		shape.lineTo(wavelength,0f);
		shape.quadTo(0.75f*wavelength,-amplitude-width,   0.5f*wavelength,0f);
		shape.quadTo(0.25f*wavelength,amplitude+width,      0f,0f);

		return shape;
	}
}