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Diffstat (limited to 'samples/browseable/AccelerometerPlay/src/com.example.android.accelerometerplay/AccelerometerPlayActivity.java')
| -rw-r--r-- | samples/browseable/AccelerometerPlay/src/com.example.android.accelerometerplay/AccelerometerPlayActivity.java | 429 |
1 files changed, 0 insertions, 429 deletions
diff --git a/samples/browseable/AccelerometerPlay/src/com.example.android.accelerometerplay/AccelerometerPlayActivity.java b/samples/browseable/AccelerometerPlay/src/com.example.android.accelerometerplay/AccelerometerPlayActivity.java deleted file mode 100644 index b15685261..000000000 --- a/samples/browseable/AccelerometerPlay/src/com.example.android.accelerometerplay/AccelerometerPlayActivity.java +++ /dev/null @@ -1,429 +0,0 @@ -/* - * 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.example.android.accelerometerplay; - -import android.annotation.TargetApi; -import android.app.Activity; -import android.content.Context; -import android.graphics.Bitmap; -import android.graphics.Canvas; -import android.graphics.BitmapFactory.Options; -import android.hardware.Sensor; -import android.hardware.SensorEvent; -import android.hardware.SensorEventListener; -import android.hardware.SensorManager; -import android.os.Build; -import android.os.Bundle; -import android.os.PowerManager; -import android.os.PowerManager.WakeLock; -import android.util.AttributeSet; -import android.util.DisplayMetrics; -import android.view.Display; -import android.view.Surface; -import android.view.View; -import android.view.ViewGroup; -import android.view.WindowManager; -import android.widget.FrameLayout; - -/** - * This is an example of using the accelerometer to integrate the device's - * acceleration to a position using the Verlet method. This is illustrated with - * a very simple particle system comprised of a few iron balls freely moving on - * an inclined wooden table. The inclination of the virtual table is controlled - * by the device's accelerometer. - * - * @see SensorManager - * @see SensorEvent - * @see Sensor - */ - -public class AccelerometerPlayActivity extends Activity { - - private SimulationView mSimulationView; - private SensorManager mSensorManager; - private PowerManager mPowerManager; - private WindowManager mWindowManager; - private Display mDisplay; - private WakeLock mWakeLock; - - /** Called when the activity is first created. */ - @Override - public void onCreate(Bundle savedInstanceState) { - super.onCreate(savedInstanceState); - - // Get an instance of the SensorManager - mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE); - - // Get an instance of the PowerManager - mPowerManager = (PowerManager) getSystemService(POWER_SERVICE); - - // Get an instance of the WindowManager - mWindowManager = (WindowManager) getSystemService(WINDOW_SERVICE); - mDisplay = mWindowManager.getDefaultDisplay(); - - // Create a bright wake lock - mWakeLock = mPowerManager.newWakeLock(PowerManager.SCREEN_BRIGHT_WAKE_LOCK, getClass() - .getName()); - - // instantiate our simulation view and set it as the activity's content - mSimulationView = new SimulationView(this); - mSimulationView.setBackgroundResource(R.drawable.wood); - setContentView(mSimulationView); - } - - @Override - protected void onResume() { - super.onResume(); - /* - * when the activity is resumed, we acquire a wake-lock so that the - * screen stays on, since the user will likely not be fiddling with the - * screen or buttons. - */ - mWakeLock.acquire(); - - // Start the simulation - mSimulationView.startSimulation(); - } - - @Override - protected void onPause() { - super.onPause(); - /* - * When the activity is paused, we make sure to stop the simulation, - * release our sensor resources and wake locks - */ - - // Stop the simulation - mSimulationView.stopSimulation(); - - // and release our wake-lock - mWakeLock.release(); - } - - class SimulationView extends FrameLayout implements SensorEventListener { - // diameter of the balls in meters - private static final float sBallDiameter = 0.004f; - private static final float sBallDiameter2 = sBallDiameter * sBallDiameter; - - private final int mDstWidth; - private final int mDstHeight; - - private Sensor mAccelerometer; - private long mLastT; - - private float mXDpi; - private float mYDpi; - private float mMetersToPixelsX; - private float mMetersToPixelsY; - private float mXOrigin; - private float mYOrigin; - private float mSensorX; - private float mSensorY; - private float mHorizontalBound; - private float mVerticalBound; - private final ParticleSystem mParticleSystem; - /* - * Each of our particle holds its previous and current position, its - * acceleration. for added realism each particle has its own friction - * coefficient. - */ - class Particle extends View { - private float mPosX = (float) Math.random(); - private float mPosY = (float) Math.random(); - private float mVelX; - private float mVelY; - - public Particle(Context context) { - super(context); - } - - public Particle(Context context, AttributeSet attrs) { - super(context, attrs); - } - - public Particle(Context context, AttributeSet attrs, int defStyleAttr) { - super(context, attrs, defStyleAttr); - } - - @TargetApi(Build.VERSION_CODES.LOLLIPOP) - public Particle(Context context, AttributeSet attrs, int defStyleAttr, - int defStyleRes) { - super(context, attrs, defStyleAttr, defStyleRes); - } - - public void computePhysics(float sx, float sy, float dT) { - - final float ax = -sx/5; - final float ay = -sy/5; - - mPosX += mVelX * dT + ax * dT * dT / 2; - mPosY += mVelY * dT + ay * dT * dT / 2; - - mVelX += ax * dT; - mVelY += ay * dT; - } - - /* - * Resolving constraints and collisions with the Verlet integrator - * can be very simple, we simply need to move a colliding or - * constrained particle in such way that the constraint is - * satisfied. - */ - public void resolveCollisionWithBounds() { - final float xmax = mHorizontalBound; - final float ymax = mVerticalBound; - final float x = mPosX; - final float y = mPosY; - if (x > xmax) { - mPosX = xmax; - mVelX = 0; - } else if (x < -xmax) { - mPosX = -xmax; - mVelX = 0; - } - if (y > ymax) { - mPosY = ymax; - mVelY = 0; - } else if (y < -ymax) { - mPosY = -ymax; - mVelY = 0; - } - } - } - - /* - * A particle system is just a collection of particles - */ - class ParticleSystem { - static final int NUM_PARTICLES = 5; - private Particle mBalls[] = new Particle[NUM_PARTICLES]; - - ParticleSystem() { - /* - * Initially our particles have no speed or acceleration - */ - for (int i = 0; i < mBalls.length; i++) { - mBalls[i] = new Particle(getContext()); - mBalls[i].setBackgroundResource(R.drawable.ball); - mBalls[i].setLayerType(LAYER_TYPE_HARDWARE, null); - addView(mBalls[i], new ViewGroup.LayoutParams(mDstWidth, mDstHeight)); - } - } - - /* - * Update the position of each particle in the system using the - * Verlet integrator. - */ - private void updatePositions(float sx, float sy, long timestamp) { - final long t = timestamp; - if (mLastT != 0) { - final float dT = (float) (t - mLastT) / 1000.f /** (1.0f / 1000000000.0f)*/; - final int count = mBalls.length; - for (int i = 0; i < count; i++) { - Particle ball = mBalls[i]; - ball.computePhysics(sx, sy, dT); - } - } - mLastT = t; - } - - /* - * Performs one iteration of the simulation. First updating the - * position of all the particles and resolving the constraints and - * collisions. - */ - public void update(float sx, float sy, long now) { - // update the system's positions - updatePositions(sx, sy, now); - - // We do no more than a limited number of iterations - final int NUM_MAX_ITERATIONS = 10; - - /* - * Resolve collisions, each particle is tested against every - * other particle for collision. If a collision is detected the - * particle is moved away using a virtual spring of infinite - * stiffness. - */ - boolean more = true; - final int count = mBalls.length; - for (int k = 0; k < NUM_MAX_ITERATIONS && more; k++) { - more = false; - for (int i = 0; i < count; i++) { - Particle curr = mBalls[i]; - for (int j = i + 1; j < count; j++) { - Particle ball = mBalls[j]; - float dx = ball.mPosX - curr.mPosX; - float dy = ball.mPosY - curr.mPosY; - float dd = dx * dx + dy * dy; - // Check for collisions - if (dd <= sBallDiameter2) { - /* - * add a little bit of entropy, after nothing is - * perfect in the universe. - */ - dx += ((float) Math.random() - 0.5f) * 0.0001f; - dy += ((float) Math.random() - 0.5f) * 0.0001f; - dd = dx * dx + dy * dy; - // simulate the spring - final float d = (float) Math.sqrt(dd); - final float c = (0.5f * (sBallDiameter - d)) / d; - final float effectX = dx * c; - final float effectY = dy * c; - curr.mPosX -= effectX; - curr.mPosY -= effectY; - ball.mPosX += effectX; - ball.mPosY += effectY; - more = true; - } - } - curr.resolveCollisionWithBounds(); - } - } - } - - public int getParticleCount() { - return mBalls.length; - } - - public float getPosX(int i) { - return mBalls[i].mPosX; - } - - public float getPosY(int i) { - return mBalls[i].mPosY; - } - } - - public void startSimulation() { - /* - * It is not necessary to get accelerometer events at a very high - * rate, by using a slower rate (SENSOR_DELAY_UI), we get an - * automatic low-pass filter, which "extracts" the gravity component - * of the acceleration. As an added benefit, we use less power and - * CPU resources. - */ - mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_GAME); - } - - public void stopSimulation() { - mSensorManager.unregisterListener(this); - } - - public SimulationView(Context context) { - super(context); - mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER); - - DisplayMetrics metrics = new DisplayMetrics(); - getWindowManager().getDefaultDisplay().getMetrics(metrics); - mXDpi = metrics.xdpi; - mYDpi = metrics.ydpi; - mMetersToPixelsX = mXDpi / 0.0254f; - mMetersToPixelsY = mYDpi / 0.0254f; - - // rescale the ball so it's about 0.5 cm on screen - mDstWidth = (int) (sBallDiameter * mMetersToPixelsX + 0.5f); - mDstHeight = (int) (sBallDiameter * mMetersToPixelsY + 0.5f); - mParticleSystem = new ParticleSystem(); - - Options opts = new Options(); - opts.inDither = true; - opts.inPreferredConfig = Bitmap.Config.RGB_565; - } - - @Override - protected void onSizeChanged(int w, int h, int oldw, int oldh) { - // compute the origin of the screen relative to the origin of - // the bitmap - mXOrigin = (w - mDstWidth) * 0.5f; - mYOrigin = (h - mDstHeight) * 0.5f; - mHorizontalBound = ((w / mMetersToPixelsX - sBallDiameter) * 0.5f); - mVerticalBound = ((h / mMetersToPixelsY - sBallDiameter) * 0.5f); - } - - @Override - public void onSensorChanged(SensorEvent event) { - if (event.sensor.getType() != Sensor.TYPE_ACCELEROMETER) - return; - /* - * record the accelerometer data, the event's timestamp as well as - * the current time. The latter is needed so we can calculate the - * "present" time during rendering. In this application, we need to - * take into account how the screen is rotated with respect to the - * sensors (which always return data in a coordinate space aligned - * to with the screen in its native orientation). - */ - - switch (mDisplay.getRotation()) { - case Surface.ROTATION_0: - mSensorX = event.values[0]; - mSensorY = event.values[1]; - break; - case Surface.ROTATION_90: - mSensorX = -event.values[1]; - mSensorY = event.values[0]; - break; - case Surface.ROTATION_180: - mSensorX = -event.values[0]; - mSensorY = -event.values[1]; - break; - case Surface.ROTATION_270: - mSensorX = event.values[1]; - mSensorY = -event.values[0]; - break; - } - } - - @Override - protected void onDraw(Canvas canvas) { - /* - * Compute the new position of our object, based on accelerometer - * data and present time. - */ - final ParticleSystem particleSystem = mParticleSystem; - final long now = System.currentTimeMillis(); - final float sx = mSensorX; - final float sy = mSensorY; - - particleSystem.update(sx, sy, now); - - final float xc = mXOrigin; - final float yc = mYOrigin; - final float xs = mMetersToPixelsX; - final float ys = mMetersToPixelsY; - final int count = particleSystem.getParticleCount(); - for (int i = 0; i < count; i++) { - /* - * We transform the canvas so that the coordinate system matches - * the sensors coordinate system with the origin in the center - * of the screen and the unit is the meter. - */ - final float x = xc + particleSystem.getPosX(i) * xs; - final float y = yc - particleSystem.getPosY(i) * ys; - particleSystem.mBalls[i].setTranslationX(x); - particleSystem.mBalls[i].setTranslationY(y); - } - - // and make sure to redraw asap - invalidate(); - } - - @Override - public void onAccuracyChanged(Sensor sensor, int accuracy) { - } - } -} |