Android example source code file (Game.java)

This example Android source code file (Game.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, camera_move_speed, camera_orbit_speed, game, interruptedexception, landtilemap, object, os, runnable, simpleglrenderer, vector3, viewer_height

The Game.java Android example source code

/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * 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.android.heightmapprofiler;

import android.os.SystemClock;

// Very simple game runtime.  Implements basic movement and collision detection with the landscape.
public class Game implements Runnable {

	private Vector3 mCameraPosition = new Vector3(100.0f, 128.0f, 400.0f);
    private Vector3 mTargetPosition = new Vector3(350.0f, 128.0f, 650.0f);
    private Vector3 mWorkVector = new Vector3();
    private float mCameraXZAngle;
    private float mCameraYAngle;
    private float mCameraLookAtDistance = (float)Math.sqrt(mTargetPosition.distance2(mCameraPosition));
    private boolean mCameraDirty = true;
    private boolean mRunning = true;
    private boolean mPaused = false;
    private Object mPauseLock = new Object();
    private LandTileMap mTileMap;
    
    private final static float CAMERA_ORBIT_SPEED = 0.3f;
    private final static float CAMERA_MOVE_SPEED = 5.0f;
    private final static float VIEWER_HEIGHT = 15.0f;
    
    private SimpleGLRenderer mSimpleRenderer;
    
	public Game(SimpleGLRenderer renderer, LandTileMap tiles) {
		mSimpleRenderer = renderer;
		mTileMap = tiles;
	}

	public void run() {
		while (mRunning) {
			ProfileRecorder.sSingleton.start(ProfileRecorder.PROFILE_SIM);
			long startTime = SystemClock.uptimeMillis();
			
			if (mCameraDirty) {
				// snap the camera to the floor
				float height = mTileMap.getHeight(mCameraPosition.x, mCameraPosition.z);
				mCameraPosition.y = height + VIEWER_HEIGHT;
				updateCamera();
			}
			
			long endTime = SystemClock.uptimeMillis();
			ProfileRecorder.sSingleton.stop(ProfileRecorder.PROFILE_SIM);
			
			if (endTime - startTime < 16) { 
				// we're running too fast!  sleep for a bit to let the render thread do some work.
				try {
					Thread.sleep(16 - (endTime - startTime));
				} catch (InterruptedException e) {
					// Interruptions are not a big deal here.
				}
			}
			synchronized(mPauseLock) {
				if (mPaused) {
					while (mPaused) {
						try {
							mPauseLock.wait();
						} catch (InterruptedException e) {
							// OK if this is interrupted.
						}
					}
				}
			}
		}
	}
	
	synchronized private void updateCamera() {
		mWorkVector.set((float)Math.cos(mCameraXZAngle), (float)Math.sin(mCameraYAngle), (float)Math.sin(mCameraXZAngle));
		mWorkVector.multiply(mCameraLookAtDistance);
		mWorkVector.add(mCameraPosition);
    	
    	mTargetPosition.set(mWorkVector);
		mSimpleRenderer.setCameraPosition(mCameraPosition.x, mCameraPosition.y, mCameraPosition.z);
		mSimpleRenderer.setCameraLookAtPosition(mTargetPosition.x, mTargetPosition.y, mTargetPosition.z);
		mCameraDirty = false;
	}
	
	synchronized public void rotate(float x, float y) {
		if (x != 0.0f) {
			mCameraXZAngle += x * CAMERA_ORBIT_SPEED;
			mCameraDirty = true;
		}
		
		if (y != 0.0f) {
			mCameraYAngle += y * CAMERA_ORBIT_SPEED;
			mCameraDirty = true;
		}
	}

	synchronized public void move(float amount) {
		mWorkVector.set(mTargetPosition);
		mWorkVector.subtract(mCameraPosition);
		mWorkVector.normalize();
		mWorkVector.multiply(amount * CAMERA_MOVE_SPEED);
		mCameraPosition.add(mWorkVector);
		mTargetPosition.add(mWorkVector);
		mCameraDirty = true;
	}
	
	public void pause() {
		synchronized(mPauseLock) {
			mPaused = true;
		}
	}
	
	public void resume() {
		synchronized(mPauseLock) {
			mPaused = false;
            mPauseLock.notifyAll();
		}
	}

}