/*
** Copyright 2005 Huxtable.com. All rights reserved.
*/

package com.cvte.blurfilter;

import java.awt.*;
import java.awt.image.*;
import java.awt.geom.*;

public class SmartBlurFilter extends AbstractBufferedImageOp {

	private int hRadius = 5;
	private int vRadius = 5;
	private int threshold = 10;
	
    public BufferedImage filter( BufferedImage src, BufferedImage dst ) {
        int width = src.getWidth();
        int height = src.getHeight();

        if ( dst == null )
            dst = createCompatibleDestImage( src, null );

        int[] inPixels = new int[width*height];
        int[] outPixels = new int[width*height];
        getRGB( src, 0, 0, width, height, inPixels );

		Kernel kernel = GaussianFilter.makeKernel(hRadius);
		thresholdBlur( kernel, inPixels, outPixels, width, height, true );
		thresholdBlur( kernel, outPixels, inPixels, height, width, true );

        setRGB( dst, 0, 0, width, height, inPixels );
        return dst;
    }

	/**
	 * Convolve with a kernel consisting of one row
	 */
	public void thresholdBlur(Kernel kernel, int[] inPixels, int[] outPixels, int width, int height, boolean alpha) {
		int index = 0;
		float[] matrix = kernel.getKernelData( null );
		int cols = kernel.getWidth();
		int cols2 = cols/2;

		for (int y = 0; y < height; y++) {
			int ioffset = y*width;
            int outIndex = y;
			for (int x = 0; x < width; x++) {
				float r = 0, g = 0, b = 0, a = 0;
				int moffset = cols2;

                int rgb1 = inPixels[ioffset+x];
                int a1 = (rgb1 >> 24) & 0xff;
                int r1 = (rgb1 >> 16) & 0xff;
                int g1 = (rgb1 >> 8) & 0xff;
                int b1 = rgb1 & 0xff;
				float af = 0, rf = 0, gf = 0, bf = 0;
                for (int col = -cols2; col <= cols2; col++) {
					float f = matrix[moffset+col];

					if (f != 0) {
						int ix = x+col;
						if (!(0 <= ix && ix < width))
							ix = x;
						int rgb2 = inPixels[ioffset+ix];
                        int a2 = (rgb2 >> 24) & 0xff;
                        int r2 = (rgb2 >> 16) & 0xff;
                        int g2 = (rgb2 >> 8) & 0xff;
                        int b2 = rgb2 & 0xff;

						int d;
                        d = a1-a2;
                        if ( d >= -threshold && d <= threshold ) {
                            a += f * a2;
                            af += f;
                        }
                        d = r1-r2;
                        if ( d >= -threshold && d <= threshold ) {
                            r += f * r2;
                            rf += f;
                        }
                        d = g1-g2;
                        if ( d >= -threshold && d <= threshold ) {
                            g += f * g2;
                            gf += f;
                        }
                        d = b1-b2;
                        if ( d >= -threshold && d <= threshold ) {
                            b += f * b2;
                            bf += f;
                        }
					}
				}
                a = af == 0 ? a1 : a/af;
                r = rf == 0 ? r1 : r/rf;
                g = gf == 0 ? g1 : g/gf;
                b = bf == 0 ? b1 : b/bf;
				int ia = alpha ? PixelUtils.clamp((int)(a+0.5)) : 0xff;
				int ir = PixelUtils.clamp((int)(r+0.5));
				int ig = PixelUtils.clamp((int)(g+0.5));
				int ib = PixelUtils.clamp((int)(b+0.5));
				outPixels[outIndex] = (ia << 24) | (ir << 16) | (ig << 8) | ib;
                outIndex += height;
			}
		}
	}

	public void setHRadius(int hRadius) {
		this.hRadius = hRadius;
	}
	
	public int getHRadius() {
		return hRadius;
	}
	
	public void setVRadius(int vRadius) {
		this.vRadius = vRadius;
	}
	
	public int getVRadius() {
		return vRadius;
	}
	
	public void setRadius(int radius) {
		this.hRadius = this.vRadius = radius;
	}
	
	public int getRadius() {
		return hRadius;
	}
	
	public void setThreshold(int threshold) {
		this.threshold = threshold;
	}
	
	public int getThreshold() {
		return threshold;
	}
	
	public String toString() {
		return "Blur/Smart Blur...";
	}
}
