/*
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 com.jhlabs.image;

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

// original code Copyright (C) Jerry Huxtable 1998
//
// customizations (C) Michele Puccini 19/12/2001
// - conversion from float to int math
// - complete rewrite of applyMap()
// - implemented merge to dest function

public class ShapeFilter extends WholeImageFilter {

	public final static int LINEAR = 0;
	public final static int CIRCLE_UP = 1;
	public final static int CIRCLE_DOWN = 2;
	public final static int SMOOTH = 3;

	private float factor = 1.0f;
	protected Colormap colormap;
	private boolean useAlpha = true;
	private boolean invert = false;
	private boolean merge = false;
	private int type;

	private final static int one   = 41;
	private final static int sqrt2 = (int)(41*Math.sqrt(2));
	private final static int sqrt5 = (int)(41*Math.sqrt(5));

	public ShapeFilter() {
		colormap = new LinearColormap();
	}

	public void setFactor(float factor) {
		this.factor = factor;
	}

	public float getFactor() {
		return factor;
	}

	public void setColormap(Colormap colormap) {
		this.colormap = colormap;
	}

	public Colormap getColormap() {
		return colormap;
	}

	public void setUseAlpha(boolean useAlpha) {
		this.useAlpha = useAlpha;
	}

	public boolean getUseAlpha() {
		return useAlpha;
	}

	public void setType(int type) {
		this.type = type;
	}

	public int getType() {
		return type;
	}

	public void setInvert(boolean invert) {
		this.invert = invert;
	}

	public boolean getInvert() {
		return invert;
	}

	public void setMerge(boolean merge) {
		this.merge = merge;
	}

	public boolean getMerge() {
		return merge;
	}

	protected int[] filterPixels( int width, int height, int[] inPixels, Rectangle transformedSpace ) {
		int[] map = new int[width * height];
		makeMap(inPixels, map, width, height);
		int max = distanceMap(map, width, height);
		applyMap(map, inPixels, width, height, max);

		return inPixels;
	}

	public int distanceMap(int[] map, int width, int height) {
		int xmax = width - 3;
		int ymax = height - 3;
		int max = 0;
		int v;
		
		for (int y = 0; y < height; y++) {
			for (int x = 0; x < width; x++) {
				int offset = x + y * width;
				if (map[offset] > 0) {
					if (x < 2 || x > xmax || y < 2 || y > ymax)
						v = setEdgeValue(x, y, map, width, offset, xmax, ymax);
					else
						v = setValue(map, width, offset);
					if (v > max)
						max = v;
				}
			}
		}
		for (int y = height-1; y >= 0; y--) {
			for (int x = width-1; x >= 0; x--) {
				int offset = x + y * width;
				if (map[offset] > 0) {
					if (x < 2 || x > xmax || y < 2 || y > ymax)
						v = setEdgeValue(x, y, map, width, offset, xmax, ymax);
					else
						v = setValue(map, width, offset);
					if (v > max)
						max = v;
				}
			}
		}
		return max;
	}

	private void makeMap(int[] pixels, int[] map, int width, int height) {
		for (int y = 0; y < height; y++) {
			for (int x = 0; x < width; x++) {
				int offset = x + y * width;
				int b = useAlpha ? (pixels[offset] >> 24) & 0xff : PixelUtils.brightness(pixels[offset]);
//				map[offset] = b * one;
				map[offset] = b * one / 10;
			}
		}
	}

	private void applyMap(int[] map, int[] pixels, int width, int height, int max) {
		if (max == 0)
			max = 1;
		for (int y = 0; y < height; y++) {
			for (int x = 0; x < width; x++) {
				int offset = x + y * width;
				int m = map[offset];
				float v = 0;
				int sa = 0, sr = 0, sg = 0, sb = 0;

				if (m == 0) {
					// default color
					sa = sr = sg = sb = 0;
					sa = (pixels[offset] >> 24) & 0xff;
				} else {
					// get V from map
					v = ImageMath.clamp(factor * m / max, 0, 1);
					switch (type) {
					case CIRCLE_UP :
						v = (ImageMath.circleUp(v));
						break;
					case CIRCLE_DOWN :
						v = (ImageMath.circleDown(v));
						break;
					case SMOOTH :
						v = (ImageMath.smoothStep(0, 1, v));
						break;
					}

					if (colormap == null) {
						sr = sg = sb = (int)(v*255);
					} else {
						int c = (colormap.getColor(v));

						sr = (c >> 16) & 0xFF;
						sg = (c >> 8) & 0xFF;
						sb = (c) & 0xFF;
					}
					
					sa = useAlpha ? (pixels[offset] >> 24) & 0xff : PixelUtils.brightness(pixels[offset]);
					
					// invert v if necessary
					if (invert) {
						sr = 255-sr;
						sg = 255-sg;
						sb = 255-sb;
					}
				}

				// write results
				if (merge) {
					// merge with source
					int transp = 255;
					int col = pixels[offset];

					int a = (col & 0xFF000000) >> 24;
					int	r = (col & 0xFF0000) >> 16;
					int	g = (col & 0xFF00) >> 8;
					int	b = (col & 0xFF);

					r = (int)((sr*r/transp));
					g = (int)((sg*g/transp));
					b = (int)((sb*b/transp));
				
					// clip colors
					if (r < 0)
						r = 0;
					if (r > 255)
						r = 255; 
					if (g < 0)
						g = 0;
					if (g > 255)
						g = 255; 
					if (b < 0)
						b = 0;
					if (b > 255)
						b = 255;
					
					pixels[offset] = (a << 24) | (r << 16) | (g << 8) | b;
				} else {
					// write gray shades
					pixels[offset] = (sa << 24) | (sr << 16) | (sg << 8) | sb;
				}
			}
		}
	}

	private int setEdgeValue(int x, int y, int[] map, int width, int offset, int xmax, int ymax) {
		int min, v;
		int r1, r2, r3, r4, r5;

		r1 = offset - width - width - 2;
		r2 = r1 + width;
		r3 = r2 + width;
		r4 = r3 + width;
		r5 = r4 + width;

		if (y == 0 || x == 0 || y == ymax+2 || x == xmax+2)
			return map[offset] = one;

		v = map[r2 + 2] + one;
		min = v;
		
		v = map[r3 + 1] + one;
		if (v < min)
			min = v;
		
		v = map[r3 + 3] + one;
		if (v < min)
			min = v;
		
		v = map[r4 + 2] + one;
		if (v < min)
			min = v;
		
		v = map[r2 + 1] + sqrt2;
		if (v < min)
			min = v;
			
		v = map[r2 + 3] + sqrt2;
		if (v < min)
			min = v;
			
		v = map[r4 + 1] + sqrt2;
		if (v < min)
			min = v;
			
		v = map[r4 + 3] + sqrt2;
		if (v < min)
			min = v;
		
		if (y == 1 || x == 1 || y == ymax+1 || x == xmax+1)
			return map[offset] = min;

		v = map[r1 + 1] + sqrt5;
		if (v < min)
			min = v;
			
		v = map[r1 + 3] + sqrt5;
		if (v < min)
			min = v;
			
		v = map[r2 + 4] + sqrt5;
		if (v < min)
			min = v;
			
		v = map[r4 + 4] + sqrt5;
		if (v < min)
			min = v;
			
		v = map[r5 + 3] + sqrt5;
		if (v < min)
			min = v;
			
		v = map[r5 + 1] + sqrt5;
		if (v < min)
			min = v;
			
		v = map[r4] + sqrt5;
		if (v < min)
			min = v;
			
		v = map[r2] + sqrt5;
		if (v < min)
			min = v;

		return map[offset] = min;
	}

	private int setValue(int[] map, int width, int offset) {
		int min, v;
		int r1, r2, r3, r4, r5;

		r1 = offset - width - width - 2;
		r2 = r1 + width;
		r3 = r2 + width;
		r4 = r3 + width;
		r5 = r4 + width;

		v = map[r2 + 2] + one;
		min = v;
		v = map[r3 + 1] + one;
		if (v < min)
			min = v;
		v = map[r3 + 3] + one;
		if (v < min)
			min = v;
		v = map[r4 + 2] + one;
		if (v < min)
			min = v;
		
		v = map[r2 + 1] + sqrt2;
		if (v < min)
			min = v;
		v = map[r2 + 3] + sqrt2;
		if (v < min)
			min = v;
		v = map[r4 + 1] + sqrt2;
		if (v < min)
			min = v;
		v = map[r4 + 3] + sqrt2;
		if (v < min)
			min = v;
		
		v = map[r1 + 1] + sqrt5;
		if (v < min)
			min = v;
		v = map[r1 + 3] + sqrt5;
		if (v < min)
			min = v;
		v = map[r2 + 4] + sqrt5;
		if (v < min)
			min = v;
		v = map[r4 + 4] + sqrt5;
		if (v < min)
			min = v;
		v = map[r5 + 3] + sqrt5;
		if (v < min)
			min = v;
		v = map[r5 + 1] + sqrt5;
		if (v < min)
			min = v;
		v = map[r4] + sqrt5;
		if (v < min)
			min = v;
		v = map[r2] + sqrt5;
		if (v < min)
			min = v;

		return map[offset] = min;
	}
	
	public String toString() {
		return "Stylize/Shapeburst...";
	}

}