import edu.umd.cs.piccolo.nodes.PImage; //导入方法依赖的package包/类

public HorizontalTiledNode( double totalWidth, Image leftImage, Image centerImage, Image rightImage ) {

PImage leftNode = new PImage( leftImage );

PImage centerNode = new PImage( centerImage );

PImage rightNode = new PImage( rightImage );

if ( leftNode.getHeight() != centerNode.getHeight() || centerNode.getHeight() != rightNode.getHeight() ) {

throw new IllegalArgumentException( "all images must have the same height" );

}

// compute the number of tiles required to fill the center

double leftWidth = leftNode.getFullBoundsReference().getWidth();

double centerWidth = centerNode.getFullBoundsReference().getWidth();

double rightWidth = rightNode.getFullBoundsReference().getWidth();

if ( centerNode.getWidth() > ( leftWidth + rightWidth + ( 2 * X_OVERLAP ) ) ) {

throw new IllegalArgumentException( "center image is too wide, it will overlap other images" );

}

double tiledWidth = totalWidth - leftWidth - rightWidth;

// parent all nodes to this node, which will later be converted to an image

PNode parentNode = new PNode();

// left

parentNode.addChild( leftNode );

// right

parentNode.addChild( rightNode );

rightNode.setOffset( totalWidth - rightWidth, 0 );

// tile the center, with overlap between tiles to hide seams

PNode previousNode = leftNode;

while ( tiledWidth > 0 ) {

PImage tileNode = new PImage( centerImage );

parentNode.addChild( tileNode );

tileNode.setOffset( previousNode.getFullBoundsReference().getMaxX() - X_OVERLAP, 0 );

// If tile extends too far into right side, shift the tile to the left.

if ( tileNode.getFullBoundsReference().getMaxX() > rightNode.getFullBoundsReference().getMinX() + X_OVERLAP ) {

tileNode.setOffset( rightNode.getFullBoundsReference().getMinX() + X_OVERLAP - tileNode.getFullBoundsReference().getWidth(), 0 );

}

tiledWidth = tiledWidth - centerWidth + X_OVERLAP;

previousNode = tileNode;

}

// convert to image

setImage( parentNode.toImage() );

}