//package com.ryanm.util.image;
import java.awt.Graphics;
import java.awt.Polygon;
import java.awt.image.BufferedImage;
/**
* @author ryanm
*/
public class ImageClip
{
/**
* Clips the input image to the specified shape
*
* @param image
* the input image
* @param clipVerts
* list of x, y pairs defining the clip shape, normalised
* to image dimensions (think texture coordinates)
* @return The smallest image containing those pixels that fall
* inside the clip shape
*/
public static BufferedImage clip( BufferedImage image, float... clipVerts )
{
assert clipVerts.length >= 6;
assert clipVerts.length % 2 == 0;
int[] xp = new int[ clipVerts.length / 2 ];
int[] yp = new int[ xp.length ];
int minX = image.getWidth(), minY = image.getHeight(), maxX = 0, maxY = 0;
for( int j = 0; j < xp.length; j++ )
{
xp[ j ] = Math.round( clipVerts[ 2 * j ] * image.getWidth() );
yp[ j ] = Math.round( clipVerts[ 2 * j + 1 ] * image.getHeight() );
minX = Math.min( minX, xp[ j ] );
minY = Math.min( minY, yp[ j ] );
maxX = Math.max( maxX, xp[ j ] );
maxY = Math.max( maxY, yp[ j ] );
}
for( int i = 0; i < xp.length; i++ )
{
xp[ i ] -= minX;
yp[ i ] -= minY;
}
Polygon clip = new Polygon( xp, yp, xp.length );
BufferedImage out = new BufferedImage( maxX - minX, maxY - minY, image.getType() );
Graphics g = out.getGraphics();
g.setClip( clip );
g.drawImage( image, -minX, -minY, null );
g.dispose();
return out;
}
}