/*
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.geom.Point2D;
import java.awt.image.BufferedImage;

/**
 * A Filter which produces the effect of looking into a kaleidoscope.
 */
public class KaleidoscopeFilter extends TransformFilter {

    private float angle = 0;
    private float angle2 = 0;
    private float centreX = 0.5f;
    private float centreY = 0.5f;
    private int sides = 3;
    private float radius = 0;

    private float icentreX;
    private float icentreY;

    /**
     * Construct a KaleidoscopeFilter with no distortion.
     */
    public KaleidoscopeFilter() {
        setEdgeAction(CLAMP);
    }

    /**
     * Set the number of sides of the kaleidoscope.
     *
     * @param sides the number of sides
     * min-value 2
     * @see #getSides
     */
    public void setSides(int sides) {
        this.sides = sides;
    }

    /**
     * Get the number of sides of the kaleidoscope.
     *
     * @return the number of sides
     * @see #setSides
     */
    public int getSides() {
        return sides;
    }

    /**
     * Set the angle of the kaleidoscope.
     *
     * @param angle the angle of the kaleidoscope.
     * @see #getAngle
     */
    public void setAngle(float angle) {
        this.angle = angle;
    }

    /**
     * Get the angle of the kaleidoscope.
     *
     * @return the angle of the kaleidoscope.
     * @see #setAngle
     */
    public float getAngle() {
        return angle;
    }

    /**
     * Set the secondary angle of the kaleidoscope.
     *
     * @param angle2 the angle
     * @see #getAngle2
     */
    public void setAngle2(float angle2) {
        this.angle2 = angle2;
    }

    /**
     * Get the secondary angle of the kaleidoscope.
     *
     * @return the angle
     * @see #setAngle2
     */
    public float getAngle2() {
        return angle2;
    }

    /**
     * Set the centre of the effect in the X direction as a proportion of the
     * image size.
     *
     * @param centreX the center
     * @see #getCentreX
     */
    public void setCentreX(float centreX) {
        this.centreX = centreX;
    }

    /**
     * Get the centre of the effect in the X direction as a proportion of the
     * image size.
     *
     * @return the center
     * @see #setCentreX
     */
    public float getCentreX() {
        return centreX;
    }

    /**
     * Set the centre of the effect in the Y direction as a proportion of the
     * image size.
     *
     * @param centreY the center
     * @see #getCentreY
     */
    public void setCentreY(float centreY) {
        this.centreY = centreY;
    }

    /**
     * Get the centre of the effect in the Y direction as a proportion of the
     * image size.
     *
     * @return the center
     * @see #setCentreY
     */
    public float getCentreY() {
        return centreY;
    }

    /**
     * Set the centre of the effect as a proportion of the image size.
     *
     * @param centre the center
     * @see #getCentre
     */
    public void setCentre(Point2D centre) {
        this.centreX = (float) centre.getX();
        this.centreY = (float) centre.getY();
    }

    /**
     * Get the centre of the effect as a proportion of the image size.
     *
     * @return the center
     * @see #setCentre
     */
    public Point2D getCentre() {
        return new Point2D.Float(centreX, centreY);
    }

    /**
     * Set the radius of the effect.
     *
     * @param radius the radius
     * min-value 0
     * @see #getRadius
     */
    public void setRadius(float radius) {
        this.radius = radius;
    }

    /**
     * Get the radius of the effect.
     *
     * @return the radius
     * @see #setRadius
     */
    public float getRadius() {
        return radius;
    }

    public BufferedImage filter(BufferedImage src, BufferedImage dst) {
        icentreX = src.getWidth() * centreX;
        icentreY = src.getHeight() * centreY;
        return super.filter(src, dst);
    }

    protected void transformInverse(int x, int y, float[] out) {
        double dx = x - icentreX;
        double dy = y - icentreY;
        double r = Math.sqrt(dx * dx + dy * dy);
        double theta = Math.atan2(dy, dx) - angle - angle2;
        theta = ImageMath.triangle((float) (theta / Math.PI * sides * .5));
        if (radius != 0) {
            double c = Math.cos(theta);
            double radiusc = radius / c;
            r = radiusc * ImageMath.triangle((float) (r / radiusc));
        }
        theta += angle;

        out[0] = (float) (icentreX + r * Math.cos(theta));
        out[1] = (float) (icentreY + r * Math.sin(theta));
    }

    public String toString() {
        return "Distort/Kaleidoscope...";
    }

}
