/*
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;

/**
 * A filter which draws a gradient interpolated between four colors defined at the corners of the image.
 */
public class FourColorFilter extends PointFilter {
	
	private int width;
	private int height;
	private int colorNW;
	private int colorNE;
	private int colorSW;
	private int colorSE;
	private int rNW, gNW, bNW;
	private int rNE, gNE, bNE;
	private int rSW, gSW, bSW;
	private int rSE, gSE, bSE;

	public FourColorFilter() {
		setColorNW( 0xffff0000 );
		setColorNE( 0xffff00ff );
		setColorSW( 0xff0000ff );
		setColorSE( 0xff00ffff );
	}

	public void setColorNW( int color ) {
		this.colorNW = color;
		rNW = (color >> 16) & 0xff;
		gNW = (color >> 8) & 0xff;
		bNW = color & 0xff;
	}

	public int getColorNW() {
		return colorNW;
	}

	public void setColorNE( int color ) {
		this.colorNE = color;
		rNE = (color >> 16) & 0xff;
		gNE = (color >> 8) & 0xff;
		bNE = color & 0xff;
	}

	public int getColorNE() {
		return colorNE;
	}

	public void setColorSW( int color ) {
		this.colorSW = color;
		rSW = (color >> 16) & 0xff;
		gSW = (color >> 8) & 0xff;
		bSW = color & 0xff;
	}

	public int getColorSW() {
		return colorSW;
	}

	public void setColorSE( int color ) {
		this.colorSE = color;
		rSE = (color >> 16) & 0xff;
		gSE = (color >> 8) & 0xff;
		bSE = color & 0xff;
	}

	public int getColorSE() {
		return colorSE;
	}

	public void setDimensions(int width, int height) {
		this.width = width;
		this.height = height;
		super.setDimensions(width, height);
	}

	public int filterRGB(int x, int y, int rgb) {
		float fx = (float)x / width;
		float fy = (float)y / height;
		float p, q;

		p = rNW + (rNE - rNW) * fx;
		q = rSW + (rSE - rSW) * fx;
		int r = (int)( p + (q - p) * fy + 0.5f );

		p = gNW + (gNE - gNW) * fx;
		q = gSW + (gSE - gSW) * fx;
		int g = (int)( p + (q - p) * fy + 0.5f );

		p = bNW + (bNE - bNW) * fx;
		q = bSW + (bSE - bSW) * fx;
		int b = (int)( p + (q - p) * fy + 0.5f );

		return 0xff000000 | (r << 16) | (g << 8) | b;
	}
	
	public String toString() {
		return "Texture/Four Color Fill...";
	}
}
