/*
Copyright 2006 Jerry Huxtable

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
 */
package org.meteoinfo.image.filter;

import java.awt.*;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.awt.image.BufferedImageOp;
import java.awt.image.ColorModel;
import java.util.Random;

/**
 * A filter which produces an image simulating brushed metal.
 */
public class BrushedMetalFilter implements BufferedImageOp {

    private int radius = 10;
    private float amount = 0.1f;
    private int color = 0xff888888;
    private float shine = 0.1f;
    private boolean monochrome = true;
    private Random randomNumbers;

    /**
     * Constructs a BrushedMetalFilter object.
     */
    public BrushedMetalFilter() {
    }

    /**
     * Constructs a BrushedMetalFilter object.
     *
     * @param color an int specifying the metal color
     * @param radius an int specifying the blur size
     * @param amount a float specifying the amount of texture
     * @param monochrome a boolean -- true for monochrome texture
     * @param shine a float specifying the shine to add
     */
    public BrushedMetalFilter(int color, int radius, float amount, boolean monochrome, float shine) {
        this.color = color;
        this.radius = radius;
        this.amount = amount;
        this.monochrome = monochrome;
        this.shine = shine;
    }

    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];
        int[] outPixels = new int[width];

        randomNumbers = new Random(0);
        int a = color & 0xff000000;
        int r = (color >> 16) & 0xff;
        int g = (color >> 8) & 0xff;
        int b = color & 0xff;
        for (int y = 0; y < height; y++) {
            for (int x = 0; x < width; x++) {
                int tr = r;
                int tg = g;
                int tb = b;
                if (shine != 0) {
                    int f = (int) (255 * shine * Math.sin((double) x / width * Math.PI));
                    tr += f;
                    tg += f;
                    tb += f;
                }
                if (monochrome) {
                    int n = (int) (255 * (2 * randomNumbers.nextFloat() - 1) * amount);
                    inPixels[x] = a | (clamp(tr + n) << 16) | (clamp(tg + n) << 8) | clamp(tb + n);
                } else {
                    inPixels[x] = a | (random(tr) << 16) | (random(tg) << 8) | random(tb);
                }
            }

            if (radius != 0) {
                blur(inPixels, outPixels, width, radius);
                setRGB(dst, 0, y, width, 1, outPixels);
            } else {
                setRGB(dst, 0, y, width, 1, inPixels);
            }
        }
        return dst;
    }

    private int random(int x) {
        x += (int) (255 * (2 * randomNumbers.nextFloat() - 1) * amount);
        if (x < 0) {
            x = 0;
        } else if (x > 0xff) {
            x = 0xff;
        }
        return x;
    }

    private static int clamp(int c) {
        if (c < 0) {
            return 0;
        }
        if (c > 255) {
            return 255;
        }
        return c;
    }

    /**
     * Return a mod b. This differs from the % operator with respect to negative
     * numbers.
     *
     * @param a the dividend
     * @param b the divisor
     * @return a mod b
     */
    private static int mod(int a, int b) {
        int n = a / b;

        a -= n * b;
        if (a < 0) {
            return a + b;
        }
        return a;
    }

    public void blur(int[] in, int[] out, int width, int radius) {
        int widthMinus1 = width - 1;
        int r2 = 2 * radius + 1;
        int tr = 0, tg = 0, tb = 0;

        for (int i = -radius; i <= radius; i++) {
            int rgb = in[mod(i, width)];
            tr += (rgb >> 16) & 0xff;
            tg += (rgb >> 8) & 0xff;
            tb += rgb & 0xff;
        }

        for (int x = 0; x < width; x++) {
            out[x] = 0xff000000 | ((tr / r2) << 16) | ((tg / r2) << 8) | (tb / r2);

            int i1 = x + radius + 1;
            if (i1 > widthMinus1) {
                i1 = mod(i1, width);
            }
            int i2 = x - radius;
            if (i2 < 0) {
                i2 = mod(i2, width);
            }
            int rgb1 = in[i1];
            int rgb2 = in[i2];

            tr += ((rgb1 & 0xff0000) - (rgb2 & 0xff0000)) >> 16;
            tg += ((rgb1 & 0xff00) - (rgb2 & 0xff00)) >> 8;
            tb += (rgb1 & 0xff) - (rgb2 & 0xff);
        }
    }

    /**
     * Set the horizontal size of the blur.
     *
     * @param radius the radius of the blur in the horizontal direction
     * @see #getRadius
     */
    public void setRadius(int radius) {
        this.radius = radius;
    }

    /**
     * Get the horizontal size of the blur.
     *
     * @return the radius of the blur in the horizontal direction
     * @see #setRadius
     */
    public int getRadius() {
        return radius;
    }

    /**
     * Set the amount of noise to add in the range 0..1.
     *
     * @param amount the amount of noise
     * @see #getAmount
     */
    public void setAmount(float amount) {
        this.amount = amount;
    }

    /**
     * Get the amount of noise to add.
     *
     * @return the amount of noise
     * @see #setAmount
     */
    public float getAmount() {
        return amount;
    }

    /**
     * Set the amount of shine to add to the range 0..1.
     *
     * @param shine the amount of shine
     * @see #getShine
     */
    public void setShine(float shine) {
        this.shine = shine;
    }

    /**
     * Get the amount of shine to add in the range 0..1.
     *
     * @return the amount of shine
     * @see #setShine
     */
    public float getShine() {
        return shine;
    }

    /**
     * Set the color of the metal.
     *
     * @param color the color in ARGB form
     * @see #getColor
     */
    public void setColor(int color) {
        this.color = color;
    }

    /**
     * Get the color of the metal.
     *
     * @return the color in ARGB form
     * @see #setColor
     */
    public int getColor() {
        return color;
    }

    /**
     * Set the type of noise to add.
     *
     * @param monochrome true for monochrome noise
     * @see #getMonochrome
     */
    public void setMonochrome(boolean monochrome) {
        this.monochrome = monochrome;
    }

    /**
     * Get the type of noise to add.
     *
     * @return true for monochrome noise
     * @see #setMonochrome
     */
    public boolean getMonochrome() {
        return monochrome;
    }

    public BufferedImage createCompatibleDestImage(BufferedImage src, ColorModel dstCM) {
        if (dstCM == null) {
            dstCM = src.getColorModel();
        }
        return new BufferedImage(dstCM, dstCM.createCompatibleWritableRaster(src.getWidth(), src.getHeight()), dstCM.isAlphaPremultiplied(), null);
    }

    public Rectangle2D getBounds2D(BufferedImage src) {
        return new Rectangle(0, 0, src.getWidth(), src.getHeight());
    }

    public Point2D getPoint2D(Point2D srcPt, Point2D dstPt) {
        if (dstPt == null) {
            dstPt = new Point2D.Double();
        }
        dstPt.setLocation(srcPt.getX(), srcPt.getY());
        return dstPt;
    }

    public RenderingHints getRenderingHints() {
        return null;
    }

    /**
     * A convenience method for setting ARGB pixels in an image. This tries to
     * avoid the performance penalty of BufferedImage.setRGB unmanaging the
     * image.
     */
    private void setRGB(BufferedImage image, int x, int y, int width, int height, int[] pixels) {
        int type = image.getType();
        if (type == BufferedImage.TYPE_INT_ARGB || type == BufferedImage.TYPE_INT_RGB) {
            image.getRaster().setDataElements(x, y, width, height, pixels);
        } else {
            image.setRGB(x, y, width, height, pixels, 0, width);
        }
    }

    public String toString() {
        return "Texture/Brushed Metal...";
    }
}
