JBox2D Debug Draw using Slick2D

Slick2DJBox2DDebugDraw.java

package lessur.engine.physics;

import org.jbox2d.callbacks.DebugDraw;
import org.jbox2d.collision.AABB;
import org.jbox2d.common.Color3f;
import org.jbox2d.common.MathUtils;
import org.jbox2d.common.OBBViewportTransform;
import org.jbox2d.common.Transform;
import org.jbox2d.common.Vec2;
import org.jbox2d.pooling.arrays.IntArray;
import org.jbox2d.pooling.arrays.Vec2Array;
import org.newdawn.slick.Color;
import org.newdawn.slick.GameContainer;
import org.newdawn.slick.Graphics;
import org.newdawn.slick.geom.Polygon;

/**
 * Implementation of JBox2d's DebugDraw using Slick2d
 * @version 2.0
 * @author liamzebedee
 * 
 * Created by Liam Edwards-Playne | http://cryptum.net
 * Licensed under GPLv2 license
 * 
 * Copyright (C) 2011 Liam Edwards-Playne
 */
/*
 * Example Code
 *

Slick2DJBox2DDebugDraw debugDraw = new Slick2DJBox2DDebugDraw(gameContainer);
debugDraw.setFlags(DebugDraw.e_shapeBit);
world.setDebugDraw(debugDraw); // Where world is your JBox2D world

 *
 * Available flags from JBox2D DebugDraw:
 *

public static final int e_shapeBit			= 0x0001; // < draw shapes
public static final int e_jointBit			= 0x0002; // < draw joint connections
public static final int e_coreShapeBit		= 0x0004; // < draw core (TOI) shapes
public static final int e_aabbBit			= 0x0008; // < draw axis aligned bounding boxes
public static final int e_obbBit			= 0x0010; // < draw oriented bounding boxes
public static final int e_pairBit			= 0x0020; // < draw broad-phase pairs
public static final int e_centerOfMassBit	= 0x0040; // < draw center of mass frame
public static final int e_controllerBit		= 0x0080; // < draw controllers

 *
 * @see http://code.google.com/p/jbox2d/source/browse/branches/jbox2d-2.0.1/src/org/jbox2d/dynamics/DebugDraw.java
 */
public class Slick2DJBox2DDebugDraw extends DebugDraw {
	GameContainer gameContainer;
	
	// Total render points for each circle
	public static int CIRCLE_POINTS = 20;
	private final Vec2Array vec2Array = new Vec2Array();
	private final Vec2 sp1 = new Vec2();
	private final Vec2 sp2 = new Vec2();
	private final Vec2 saxis = new Vec2();
	// TODO change IntegerArray to a specific class for int[] arrays
	private final Vec2 temp = new Vec2();
	private final static IntArray xIntsPool = new IntArray();
	private final static IntArray yIntsPool = new IntArray();
	private final Vec2 temp2 = new Vec2();

	public Slick2DJBox2DDebugDraw(final GameContainer gameContainer) {
		super(new OBBViewportTransform());
		this.viewportTransform.setYFlip(true);
		this.viewportTransform.setExtents(gameContainer.getWidth() / 2, gameContainer.getHeight() / 2);
		this.gameContainer = gameContainer;
	}

	/**
	 * @see org.jbox2d.callbacks.DebugDraw#drawCircle1(org.jbox2d.common.Vec2, float, org.jbox2d.common.Color3f)
	 */
	@Override
	public void drawCircle(final Vec2 center, final float radius, final Color3f color) {
		final Vec2[] vecs = vec2Array.get(CIRCLE_POINTS );
		generateCirle(center, radius, vecs, CIRCLE_POINTS);
		drawPolygon(vecs, CIRCLE_POINTS, color);
	}
	
	/**
	 * @see org.jbox2d.callbacks.DebugDraw#drawPoint(org.jbox2d.common.Vec2, float, org.jbox2d.common.Color3f)
	 */
	@Override
	public void drawPoint(final Vec2 argPoint, final float argRadiusOnScreen, final Color3f argColor) {
		Graphics g = this.gameContainer.getGraphics();
		getWorldToScreenToOut(argPoint, sp1);
		g.setColor(new Color(argColor.x,argColor.y,argColor.z));

		sp1.x -= argRadiusOnScreen;
		sp1.y -= argRadiusOnScreen;
		g.fillOval((int)sp1.x, (int)sp1.y, (int)argRadiusOnScreen*2, (int)argRadiusOnScreen*2);
		g.setColor(Color.white);
	}

	/**
	 * @see org.jbox2d.callbacks.DebugDraw#drawSegment(org.jbox2d.common.Vec2, org.jbox2d.common.Vec2, org.jbox2d.common.Color3f)
	 */
	@Override
	public void drawSegment(final Vec2 p1, final Vec2 p2, final Color3f color) {
		Graphics g = this.gameContainer.getGraphics();
		getWorldToScreenToOut(p1, sp1);
		getWorldToScreenToOut(p2, sp2);
		g.setColor(new Color(color.x,color.y,color.z));

		g.drawLine((int)sp1.x, (int)sp1.y, (int)sp2.x, (int)sp2.y);
		g.setColor(Color.white);
	}

	public void drawAABB(final AABB argAABB, final Color3f color) {
		Graphics g = this.gameContainer.getGraphics();
		g.setColor(new Color(color.x, color.y, color.z));
		final Vec2 vecs[] = vec2Array.get(4);
		argAABB.getVertices(vecs);
		drawPolygon(vecs, 4, color);
		g.setColor(Color.white);
	}

	/**
	 * @see org.jbox2d.callbacks.DebugDraw#drawSolidCircle(org.jbox2d.common.Vec2, float, org.jbox2d.common.Vec2, org.jbox2d.common.Color3f)
	 */
	@Override
	public void drawSolidCircle(final Vec2 center, final float radius, final Vec2 axis, final Color3f color) {
		Graphics g = this.gameContainer.getGraphics();
		final Vec2[] vecs = vec2Array.get(CIRCLE_POINTS);
		generateCirle(center, radius, vecs, CIRCLE_POINTS);
		drawSolidPolygon(vecs, CIRCLE_POINTS, color);
		if(axis != null) {
			saxis.set(axis).mulLocal(radius).addLocal(center);
			drawSegment(center, saxis, color);
		}
		g.setColor(Color.white);
	}

	/**
	 * @see org.jbox2d.callbacks.DebugDraw#drawSolidPolygon(org.jbox2d.common.Vec2[], int, org.jbox2d.common.Color3f)
	 */
	@Override
	public void drawSolidPolygon(final Vec2[] vertices, final int vertexCount, final Color3f color) {
		Graphics g = this.gameContainer.getGraphics();
		final int[] xInts = xIntsPool.get(vertexCount);
		final int[] yInts = yIntsPool.get(vertexCount);
		final Polygon p = new Polygon();

		for(int i = 0; i < vertexCount; i++) {
			getWorldToScreenToOut(vertices[i], temp);
			xInts[i] = (int) temp.x;
			yInts[i] = (int) temp.y;
			p.addPoint(xInts[i], yInts[i]);
		}

		g.setColor(new Color(color.x,color.y,color.z));
		g.fill(p); //Draws shape filled with colour
		g.setColor(Color.white);
	}

	/**
	 * @see org.jbox2d.callbacks.DebugDraw#drawString(float, float, java.lang.String, org.jbox2d.common.Color3f)
	 */
	@Override
	public void drawString(final float x, final float y, final String s, final Color3f color) {
		Graphics g = this.gameContainer.getGraphics();
		g.setColor(new Color(color.x, color.y, color.z));
		g.drawString(s, x, y);
		g.setColor(Color.white);
	}

	/**
	 * @see org.jbox2d.callbacks.DebugDraw#drawTransform(org.jbox2d.common.Transform)
	 */
	@Override
	public void drawTransform(final Transform xf) {
		Graphics g = this.gameContainer.getGraphics();
		getWorldToScreenToOut(xf.position, temp);
		temp2.setZero();
		final float k_axisScale = 0.4f;

		g.setColor(new Color(1,0,0));
		temp2.x = xf.position.x + k_axisScale * xf.R.col1.x;
		temp2.y = xf.position.y + k_axisScale * xf.R.col1.y;
		getWorldToScreenToOut(temp2, temp2);
		g.drawLine((int)temp.x, (int)temp.y, (int)temp2.x, (int)temp2.y);

		g.setColor(new Color(0,1,0));
		temp2.x = xf.position.x + k_axisScale * xf.R.col2.x;
		temp2.y = xf.position.y + k_axisScale * xf.R.col2.y;
		getWorldToScreenToOut(temp2, temp2);
		g.drawLine((int)temp.x, (int)temp.y, (int)temp2.x, (int)temp2.y);
		g.setColor(Color.white);
	}

	// Circle Generator	
	private void generateCirle(final Vec2 argCenter, final float argRadius, final Vec2[] argPoints, final int argNumPoints) {
		Graphics g = this.gameContainer.getGraphics();
		final float inc = MathUtils.TWOPI / argNumPoints;

		for(int i=0; i<argNumPoints; i++){
			argPoints[i].x = (argCenter.x + MathUtils.cos(i*inc)*argRadius);
			argPoints[i].y = (argCenter.y + MathUtils.sin(i*inc)*argRadius);
		}
		g.setColor(Color.white);
	}
}

Hi, I'm looking forward to use the debugdraw implementation but in the current Transform class used in the drawTransform method you have there, I don't have that position vector nor the R value

https://code.google.com/p/jbox2d/source/browse/trunk/jbox2d-library/src/main/java/org/jbox2d/common/Transform.java

That's the Transform class that jbox2d currently has and if I copy this class to my project it get errors on lines 181 and 182.

Could this be outdated?

Thanks!

Ok, I reviewed by the time (2011) that this was written approx. and yeah it did had those values, but apparently they did some really hard modifications on their stuff over two years, still trying to update that drawTransform() method of yours, thank you!

still no answers but that's a good point you are raising rastadrian.
I've got the same issue, position and R are getting red..
I can't find any other Debugraw on the internet. Sad.