/*
 * Copyright (c) 2000 David Flanagan.  All rights reserved.
 * This code is from the book Java Examples in a Nutshell, 2nd Edition.
 * It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied.
 * You may study, use, and modify it for any non-commercial purpose.
 * You may distribute it non-commercially as long as you retain this notice.
 * For a commercial use license, or to purchase the book (recommended),
 * visit http://www.davidflanagan.com/javaexamples2.
 */
package com.davidflanagan.examples.graphics;
import java.awt.*;
import java.awt.geom.*;

/** A demonstration of Java2D transformations */
public class Transforms implements GraphicsExample {
    public String getName() { return "Transforms"; } // From GraphicsExample
    public int getWidth() { return 750; }            // From GraphicsExample
    public int getHeight() { return 250; }           // From GraphicsExample

    Shape shape;                   // The shape to draw
    AffineTransform[] transforms;  // The ways to transform it
    String[] transformLabels;      // Labels for each transform

    /** 
     * This constructor sets up the Shape and AffineTransform objects we need
     **/
    public Transforms() {
	GeneralPath path = new GeneralPath();  	// Create a shape to draw
	path.append(new Line2D.Float(0.0f, 0.0f, 0.0f, 100.0f), false);
	path.append(new Line2D.Float(-10.0f, 50.0f, 10.0f, 50.0f), false);
	path.append(new Polygon(new int[] { -5, 0, 5 },
				new int[] { 5, 0, 5 }, 3), false);
	this.shape = path;  // Remember this shape

	// Set up some transforms to alter the shape
	this.transforms = new AffineTransform[6];
	// 1) the identity transform
	transforms[0] = new AffineTransform();  
	// 2) A scale tranform: 3/4 size
	transforms[1] = AffineTransform.getScaleInstance(0.75, 0.75);
	// 3) A shearing transform
	transforms[2] = AffineTransform.getShearInstance(-0.4, 0.0);
	// 4) A 30 degree clockwise rotation about the origin of the shape
	transforms[3] = AffineTransform.getRotateInstance(Math.PI*2/12);
	// 5) A 180 degree rotation about the midpoint of the shape
	transforms[4] = AffineTransform.getRotateInstance(Math.PI, 0.0, 50.0);
	// 6) A combination transform
	transforms[5] = AffineTransform.getScaleInstance(0.5, 1.5);
	transforms[5].shear(0.0, 0.4);
	transforms[5].rotate(Math.PI/2, 0.0, 50.0);  // 90 degrees

	// Define names for the transforms
	transformLabels = new String[] {
	    "identity", "scale", "shear", "rotate", "rotate", "combo"
	};
    }

    /** Draw the defined shape and label, using each transform */
    public void draw(Graphics2D g, Component c) {
	// Define basic drawing attributes
	g.setColor(Color.black);                                   // black
	g.setStroke(new BasicStroke(2.0f, BasicStroke.CAP_SQUARE,  // 2-pixel
				    BasicStroke.JOIN_BEVEL));
	g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,        // antialias
			   RenderingHints.VALUE_ANTIALIAS_ON);

	// Now draw the shape once using each of the transforms we've defined
	for(int i = 0; i < transforms.length; i++) {
	    AffineTransform save = g.getTransform();    // save current state
	    g.translate(i*125 + 50, 50);                // move origin
	    g.transform(transforms[i]);                 // apply transform
	    g.draw(shape);                              // draw shape
	    g.drawString(transformLabels[i], -25, 125); // draw label
	    g.drawRect(-40, -10, 80, 150);              // draw box
	    g.setTransform(save);                       // restore transform
	}
    }
}