Java tutorial
/******************************************************************************* * Copyright 2011 See AUTHORS file. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. ******************************************************************************/ package com.badlogic.gdx.physics.box2d; import java.util.Iterator; import java.util.List; import com.badlogic.gdx.Gdx; import com.badlogic.gdx.graphics.Color; import com.badlogic.gdx.graphics.g2d.SpriteBatch; import com.badlogic.gdx.graphics.glutils.ShapeRenderer; import com.badlogic.gdx.graphics.glutils.ShapeRenderer.ShapeType; import com.badlogic.gdx.math.Matrix4; import com.badlogic.gdx.math.Vector2; import com.badlogic.gdx.physics.box2d.BodyDef.BodyType; import com.badlogic.gdx.physics.box2d.JointDef.JointType; import com.badlogic.gdx.physics.box2d.Shape.Type; import com.badlogic.gdx.physics.box2d.joints.PulleyJoint; import com.badlogic.gdx.utils.Array; public class Box2DDebugRenderer { /** the immediate mode renderer to output our debug drawings **/ protected ShapeRenderer renderer; /** a spritebatch and a font for text rendering **/ public SpriteBatch batch; /** vertices for polygon rendering **/ private static Vector2[] vertices = new Vector2[1000]; private static Vector2 lower; private static Vector2 upper; private final static Array<Body> bodies = new Array<Body>(); private final static Array<Joint> joints = new Array<Joint>(); private boolean drawBodies; private boolean drawJoints; private boolean drawAABBs; private boolean drawInactiveBodies; private boolean drawVelocities; private boolean drawContacts; public Box2DDebugRenderer() { this(true, true, false, true, false, true); } public Box2DDebugRenderer(boolean drawBodies, boolean drawJoints, boolean drawAABBs, boolean drawInactiveBodies, boolean drawVelocities, boolean drawContacts) { // next we setup the immediate mode renderer renderer = new ShapeRenderer(); // next we create a SpriteBatch and a font batch = new SpriteBatch(); lower = new Vector2(); upper = new Vector2(); // initialize vertices array for (int i = 0; i < vertices.length; i++) vertices[i] = new Vector2(); this.drawBodies = drawBodies; this.drawJoints = drawJoints; this.drawAABBs = drawAABBs; this.drawInactiveBodies = drawInactiveBodies; this.drawVelocities = drawVelocities; this.drawContacts = drawContacts; } /** This assumes that the projection matrix has already been set. */ public void render(World world, Matrix4 projMatrix) { renderer.setProjectionMatrix(projMatrix); renderBodies(world); } private final Color SHAPE_NOT_ACTIVE = new Color(0.5f, 0.5f, 0.3f, 1); private final Color SHAPE_STATIC = new Color(0.5f, 0.9f, 0.5f, 1); private final Color SHAPE_KINEMATIC = new Color(0.5f, 0.5f, 0.9f, 1); private final Color SHAPE_NOT_AWAKE = new Color(0.6f, 0.6f, 0.6f, 1); private final Color SHAPE_AWAKE = new Color(0.9f, 0.7f, 0.7f, 1); private final Color JOINT_COLOR = new Color(0.5f, 0.8f, 0.8f, 1); private final Color AABB_COLOR = new Color(1.0f, 0, 1.0f, 1f); private final Color VELOCITY_COLOR = new Color(1.0f, 0, 0f, 1f); private void renderBodies(World world) { renderer.begin(ShapeType.Line); if (drawBodies || drawAABBs) { world.getBodies(bodies); for (Iterator<Body> iter = bodies.iterator(); iter.hasNext();) { Body body = iter.next(); if (body.isActive() || drawInactiveBodies) renderBody(body); } } if (drawJoints) { world.getJoints(joints); for (Iterator<Joint> iter = joints.iterator(); iter.hasNext();) { Joint joint = iter.next(); drawJoint(joint); } } renderer.end(); if (drawContacts) { renderer.begin(ShapeType.Point); for (Contact contact : world.getContactList()) drawContact(contact); renderer.end(); } } protected void renderBody(Body body) { Transform transform = body.getTransform(); int len = body.getFixtureList().size; Array<Fixture> fixtures = body.getFixtureList(); for (int i = 0; i < len; i++) { Fixture fixture = fixtures.get(i); if (drawBodies) { if (body.isActive() == false && drawInactiveBodies) drawShape(fixture, transform, SHAPE_NOT_ACTIVE); else if (body.getType() == BodyType.StaticBody) drawShape(fixture, transform, SHAPE_STATIC); else if (body.getType() == BodyType.KinematicBody) drawShape(fixture, transform, SHAPE_KINEMATIC); else if (body.isAwake() == false) drawShape(fixture, transform, SHAPE_NOT_AWAKE); else drawShape(fixture, transform, SHAPE_AWAKE); } if (drawAABBs) { drawAABB(fixture, transform); } } } private void drawAABB(Fixture fixture, Transform transform) { if (fixture.getType() == Type.Circle) { CircleShape shape = (CircleShape) fixture.getShape(); float radius = shape.getRadius(); vertices[0].set(shape.getPosition()); transform.mul(vertices[0]); lower.set(vertices[0].x - radius, vertices[0].y - radius); upper.set(vertices[0].x + radius, vertices[0].y + radius); // define vertices in ccw fashion... vertices[0].set(lower.x, lower.y); vertices[1].set(upper.x, lower.y); vertices[2].set(upper.x, upper.y); vertices[3].set(lower.x, upper.y); drawSolidPolygon(vertices, 4, AABB_COLOR, true); } else if (fixture.getType() == Type.Polygon) { PolygonShape shape = (PolygonShape) fixture.getShape(); int vertexCount = shape.getVertexCount(); shape.getVertex(0, vertices[0]); lower.set(transform.mul(vertices[0])); upper.set(lower); for (int i = 1; i < vertexCount; i++) { shape.getVertex(i, vertices[i]); transform.mul(vertices[i]); lower.x = Math.min(lower.x, vertices[i].x); lower.y = Math.min(lower.y, vertices[i].y); upper.x = Math.max(upper.x, vertices[i].x); upper.y = Math.max(upper.y, vertices[i].y); } // define vertices in ccw fashion... vertices[0].set(lower.x, lower.y); vertices[1].set(upper.x, lower.y); vertices[2].set(upper.x, upper.y); vertices[3].set(lower.x, upper.y); drawSolidPolygon(vertices, 4, AABB_COLOR, true); } } private static Vector2 t = new Vector2(); private static Vector2 axis = new Vector2(); private void drawShape(Fixture fixture, Transform transform, Color color) { if (fixture.getType() == Type.Circle) { CircleShape circle = (CircleShape) fixture.getShape(); t.set(circle.getPosition()); transform.mul(t); drawSolidCircle(t, circle.getRadius(), axis.set(transform.vals[Transform.COS], transform.vals[Transform.SIN]), color); } if (fixture.getType() == Type.Edge) { EdgeShape edge = (EdgeShape) fixture.getShape(); edge.getVertex1(vertices[0]); edge.getVertex2(vertices[1]); transform.mul(vertices[0]); transform.mul(vertices[1]); drawSolidPolygon(vertices, 2, color, true); } if (fixture.getType() == Type.Polygon) { PolygonShape chain = (PolygonShape) fixture.getShape(); int vertexCount = chain.getVertexCount(); for (int i = 0; i < vertexCount; i++) { chain.getVertex(i, vertices[i]); transform.mul(vertices[i]); } drawSolidPolygon(vertices, vertexCount, color, true); } if (fixture.getType() == Type.Chain) { ChainShape chain = (ChainShape) fixture.getShape(); int vertexCount = chain.getVertexCount(); for (int i = 0; i < vertexCount; i++) { chain.getVertex(i, vertices[i]); transform.mul(vertices[i]); } drawSolidPolygon(vertices, vertexCount, color, chain.isLooped()); } } private final Vector2 f = new Vector2(); private final Vector2 v = new Vector2(); private final Vector2 lv = new Vector2(); private void drawSolidCircle(Vector2 center, float radius, Vector2 axis, Color color) { float angle = 0; float angleInc = 2 * (float) Math.PI / 20; renderer.setColor(color.r, color.g, color.b, color.a); for (int i = 0; i < 20; i++, angle += angleInc) { v.set((float) Math.cos(angle) * radius + center.x, (float) Math.sin(angle) * radius + center.y); if (i == 0) { lv.set(v); f.set(v); continue; } renderer.line(lv.x, lv.y, v.x, v.y); lv.set(v); } renderer.line(f.x, f.y, lv.x, lv.y); renderer.line(center.x, center.y, 0, center.x + axis.x * radius, center.y + axis.y * radius, 0); } private void drawSolidPolygon(Vector2[] vertices, int vertexCount, Color color, boolean closed) { renderer.setColor(color.r, color.g, color.b, color.a); for (int i = 0; i < vertexCount; i++) { Vector2 v = vertices[i]; if (i == 0) { lv.set(v); f.set(v); continue; } renderer.line(lv.x, lv.y, v.x, v.y); lv.set(v); } if (closed) renderer.line(f.x, f.y, lv.x, lv.y); } private void drawJoint(Joint joint) { Body bodyA = joint.getBodyA(); Body bodyB = joint.getBodyB(); Transform xf1 = bodyA.getTransform(); Transform xf2 = bodyB.getTransform(); Vector2 x1 = xf1.getPosition(); Vector2 x2 = xf2.getPosition(); Vector2 p1 = joint.getAnchorA(); Vector2 p2 = joint.getAnchorB(); if (joint.getType() == JointType.DistanceJoint) { drawSegment(p1, p2, JOINT_COLOR); } else if (joint.getType() == JointType.PulleyJoint) { PulleyJoint pulley = (PulleyJoint) joint; Vector2 s1 = pulley.getGroundAnchorA(); Vector2 s2 = pulley.getGroundAnchorB(); drawSegment(s1, p1, JOINT_COLOR); drawSegment(s2, p2, JOINT_COLOR); drawSegment(s1, s2, JOINT_COLOR); } else if (joint.getType() == JointType.MouseJoint) { drawSegment(joint.getAnchorA(), joint.getAnchorB(), JOINT_COLOR); } else { drawSegment(x1, p1, JOINT_COLOR); drawSegment(p1, p2, JOINT_COLOR); drawSegment(x2, p2, JOINT_COLOR); } } private void drawSegment(Vector2 x1, Vector2 x2, Color color) { renderer.setColor(color); renderer.line(x1.x, x1.y, x2.x, x2.y); } private void drawContact(Contact contact) { WorldManifold worldManifold = contact.getWorldManifold(); if (worldManifold.getNumberOfContactPoints() == 0) return; Vector2 point = worldManifold.getPoints()[0]; renderer.point(point.x, point.y, 0); } public boolean isDrawBodies() { return drawBodies; } public void setDrawBodies(boolean drawBodies) { this.drawBodies = drawBodies; } public boolean isDrawJoints() { return drawJoints; } public void setDrawJoints(boolean drawJoints) { this.drawJoints = drawJoints; } public boolean isDrawAABBs() { return drawAABBs; } public void setDrawAABBs(boolean drawAABBs) { this.drawAABBs = drawAABBs; } public boolean isDrawInactiveBodies() { return drawInactiveBodies; } public void setDrawInactiveBodies(boolean drawInactiveBodies) { this.drawInactiveBodies = drawInactiveBodies; } public boolean isDrawVelocities() { return drawVelocities; } public void setDrawVelocities(boolean drawVelocities) { this.drawVelocities = drawVelocities; } public boolean isDrawContacts() { return drawContacts; } public void setDrawContacts(boolean drawContacts) { this.drawContacts = drawContacts; } public static Vector2 getAxis() { return axis; } public static void setAxis(Vector2 axis) { Box2DDebugRenderer.axis = axis; } public void dispose() { batch.dispose(); } }