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

// Morpological Erode Filter
public class erode_filt extends EffectFilter
{
	int masksize;
	int[] mask;
	
	// Create object and initialize data
	public erode_filt(int size, int[] input)
	{
		masksize = size;
		mask = input;
	}
	
	// Runs algorithm
	public void performEffect()
	{
		int elements = masksize*masksize;
		int radius=(elements-1)/2; 
		int pointOffset=0;
		int newPixels[] = new int[width*height];	
		int indent = (int) Math.floor(masksize/2);
		int minr, minb, ming;
		
		// Moves through the input array pixel by pixel
		for (int y=indent;y<height-indent;y++)
		{
			for (int x=indent;x<width-indent;x++)
			{
				// Location of centre of mask
				pointOffset = y*width+x;

				minr = 255;
				ming = 255;
				minb = 255;

				// Finds and outputs max of RGB values covered by mask
				for (int m=-indent;m<=indent;m++)
				{
					for (int n=-indent;n<=indent;n++)
					{
						if (mask[radius+n+m*masksize] !=0)
						{
							minr = Math.min(minr,((pixels[pointOffset+n+m*width]
							>>16)&0xff)*mask[radius+n+m*masksize]);
							ming = Math.min(ming,((pixels[pointOffset+n+m*width]
							>>8)&0xff)*mask[radius+n+m*masksize]);
							minb = Math.min(minb,(pixels[pointOffset+n+m*width]
							&0xff)*mask[radius+n+m*masksize]);
						}
					}
				}

				newPixels[pointOffset] = (255<<24) | minr<<16 | ming<<8 | minb;					
			}
		}
				
		this.pixels = newPixels;
	}
}