package org.jzy3d.contour;

import java.awt.image.BufferedImage;

import org.jzy3d.maths.Range;
import org.jzy3d.plot3d.builder.Mapper;


/**
 * Computes the contour matrix of a {@link Mapper}, and returns it
 * as a {@link BufferedImage}.
 * 
 * @author Juan Barandiaran
 * @author Martin Pernollet
 */
public class MapperContourPictureGenerator extends AbstractContourGenerator implements IContourPictureGenerator {
	public static int PIXEL_NEIGHBOUR_THRESHOLD = 2;
	public static float LINE_STRIP_WIDTH = 2;
	public static int MERGE_STRIP_DIST = 1;
	
	public MapperContourPictureGenerator(Mapper mapper, Range xrange, Range yrange) {
		this.mapper = mapper;
		this.xrange = xrange;
		this.yrange = yrange;
	}
	
	/**********************************************/
	
	@Override
	public double[][] getContourMatrix(int xRes, int yRes, int nLevels) {
		return computeContour(xRes, yRes, nLevels);
	}

	@Override
	public BufferedImage getContourImage(IContourColoringPolicy policy, int xRes, int yRes, int nLevels) {
		double[][] contours = computeContour(xRes, yRes, nLevels);
		return buildImage(xRes, yRes, contours, policy);
	}
	
	@Override
	public BufferedImage getContourImage(IContourColoringPolicy policy, int xRes, int yRes, double[] sortedLevels) {
		double[][] contours = computeContour(xRes, yRes, sortedLevels);
		return buildImage(xRes, yRes, contours, policy);
	}

	@Override
	public BufferedImage getFilledContourImage(IContourColoringPolicy policy, int xRes, int yRes, int nLevels) {
		double[][] contours = computeFilledContour(xRes, yRes, nLevels);
		return buildImage(xRes, yRes, contours, policy);
	}

	@Override
	public BufferedImage getHeightMap(IContourColoringPolicy policy, int xRes, int yRes, int nLevels) {
		double[][] contours = computeXYColors(xRes, yRes, nLevels);
		return buildImage(xRes, yRes, contours, policy);
	}
	
	/**********************************************/

	protected BufferedImage buildImage(int xRes, int yRes, double[][] contours, IContourColoringPolicy policy){
		// Build an image with a size
		BufferedImage image = new BufferedImage(xRes, yRes,
				BufferedImage.TYPE_INT_RGB);
		for (int x = 0; x < xRes; x++)
			for (int y = 0; y < yRes; y++)
				image.setRGB(x, y, policy.getRGB(contours[x][y]));
		return image;
	}

	/**********************************************/
	
	/**
	 * Calculates the Height of the surface for each point in the XY plane
	 * 
	 **/
	@Override
    protected void computeHeightMatrix(double matrix[][], int xRes, int yRes) {
		double value;
		minValue = Double.MAX_VALUE;
		maxValue = -Double.MAX_VALUE;

		// TODO: This matrix filling could be done at the same time the surface
		// is computed to save time and avoid calling the mapper.f() two times
		// for each point.
		double xstep = xrange.getRange() / (double) (xRes - 1);
		double ystep = yrange.getRange() / (double) (yRes - 1);
		for (int xi = 0; xi < xRes; xi++) {
			for (int yi = 0; yi < yRes; yi++) {
				double x = xrange.getMin() + xi * xstep;
				double y = yrange.getMin() + yi * ystep;

				value = mapper.f(x, y);

				// Y coordinate in the matrix is inverted because
				// DrawableTexture
				// is handled like this
				matrix[xi][yRes - 1 - yi] = value;
				if (value < minValue)
					minValue = value;
				if (value > maxValue)
					maxValue = value;
			}
		}
	}
	
	protected Mapper mapper;
	protected Range xrange;
	protected Range yrange;

}