Java程序
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1160行
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/*
* Copyright (C) 2013 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.controllersample;
import com.example.inputmanagercompat.InputManagerCompat;
import com.example.inputmanagercompat.InputManagerCompat.InputDeviceListener;
import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.graphics.Path;
import android.os.Build;
import android.os.SystemClock;
import android.os.Vibrator;
import android.util.AttributeSet;
import android.util.SparseArray;
import android.view.InputDevice;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.View;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Random;
/*
* A trivial joystick based physics game to demonstrate joystick handling. If
* the game controller has a vibrator, then it is used to provide feedback when
* a bullet is fired or the ship crashes into an obstacle. Otherwise, the system
* vibrator is used for that purpose.
*/
@TargetApi(Build.VERSION_CODES.HONEYCOMB_MR1)
public class GameView extends View implements InputDeviceListener {
private static final int MAX_OBSTACLES = 12;
private static final int DPAD_STATE_LEFT = 1 << 0;
private static final int DPAD_STATE_RIGHT = 1 << 1;
private static final int DPAD_STATE_UP = 1 << 2;
private static final int DPAD_STATE_DOWN = 1 << 3;
private final Random mRandom;
/*
* Each ship is created as an event comes in from a new Joystick device
*/
private final SparseArray<Ship> mShips;
private final Map<String, Integer> mDescriptorMap;
private final List<Bullet> mBullets;
private final List<Obstacle> mObstacles;
private long mLastStepTime;
private final InputManagerCompat mInputManager;
private final float mBaseSpeed;
private final float mShipSize;
private final float mBulletSize;
private final float mMinObstacleSize;
private final float mMaxObstacleSize;
private final float mMinObstacleSpeed;
private final float mMaxObstacleSpeed;
public GameView(Context context, AttributeSet attrs) {
super(context, attrs);
mRandom = new Random();
mShips = new SparseArray<Ship>();
mDescriptorMap = new HashMap<String, Integer>();
mBullets = new ArrayList<Bullet>();
mObstacles = new ArrayList<Obstacle>();
setFocusable(true);
setFocusableInTouchMode(true);
float baseSize = getContext().getResources().getDisplayMetrics().density * 5f;
mBaseSpeed = baseSize * 3;
mShipSize = baseSize * 3;
mBulletSize = baseSize;
mMinObstacleSize = baseSize * 2;
mMaxObstacleSize = baseSize * 12;
mMinObstacleSpeed = mBaseSpeed;
mMaxObstacleSpeed = mBaseSpeed * 3;
mInputManager = InputManagerCompat.Factory.getInputManager(this.getContext());
mInputManager.registerInputDeviceListener(this, null);
}
// Iterate through the input devices, looking for controllers. Create a ship
// for every device that reports itself as a gamepad or joystick.
void findControllersAndAttachShips() {
int[] deviceIds = mInputManager.getInputDeviceIds();
for (int deviceId : deviceIds) {
InputDevice dev = mInputManager.getInputDevice(deviceId);
int sources = dev.getSources();
// if the device is a gamepad/joystick, create a ship to represent it
if (((sources & InputDevice.SOURCE_GAMEPAD) == InputDevice.SOURCE_GAMEPAD) ||
((sources & InputDevice.SOURCE_JOYSTICK) == InputDevice.SOURCE_JOYSTICK)) {
// if the device has a gamepad or joystick
getShipForId(deviceId);
}
}
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
int deviceId = event.getDeviceId();
if (deviceId != -1) {
Ship currentShip = getShipForId(deviceId);
if (currentShip.onKeyDown(keyCode, event)) {
step(event.getEventTime());
return true;
}
}
return super.onKeyDown(keyCode, event);
}
@Override
public boolean onKeyUp(int keyCode, KeyEvent event) {
int deviceId = event.getDeviceId();
if (deviceId != -1) {
Ship currentShip = getShipForId(deviceId);
if (currentShip.onKeyUp(keyCode, event)) {
step(event.getEventTime());
return true;
}
}
return super.onKeyUp(keyCode, event);
}
@Override
public boolean onGenericMotionEvent(MotionEvent event) {
mInputManager.onGenericMotionEvent(event);
// Check that the event came from a joystick or gamepad since a generic
// motion event could be almost anything. API level 18 adds the useful
// event.isFromSource() helper function.
int eventSource = event.getSource();
if ((((eventSource & InputDevice.SOURCE_GAMEPAD) == InputDevice.SOURCE_GAMEPAD) ||
((eventSource & InputDevice.SOURCE_JOYSTICK) == InputDevice.SOURCE_JOYSTICK))
&& event.getAction() == MotionEvent.ACTION_MOVE) {
int id = event.getDeviceId();
if (-1 != id) {
Ship curShip = getShipForId(id);
if (curShip.onGenericMotionEvent(event)) {
return true;
}
}
}
return super.onGenericMotionEvent(event);
}
@Override
public void onWindowFocusChanged(boolean hasWindowFocus) {
// Turn on and off animations based on the window focus.
// Alternately, we could update the game state using the Activity
// onResume()
// and onPause() lifecycle events.
if (hasWindowFocus) {
mLastStepTime = SystemClock.uptimeMillis();
mInputManager.onResume();
} else {
int numShips = mShips.size();
for (int i = 0; i < numShips; i++) {
Ship currentShip = mShips.valueAt(i);
if (currentShip != null) {
currentShip.setHeading(0, 0);
currentShip.setVelocity(0, 0);
currentShip.mDPadState = 0;
}
}
mInputManager.onPause();
}
super.onWindowFocusChanged(hasWindowFocus);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
// Reset the game when the view changes size.
reset();
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
// Update the animation
animateFrame();
// Draw the ships.
int numShips = mShips.size();
for (int i = 0; i < numShips; i++) {
Ship currentShip = mShips.valueAt(i);
if (currentShip != null) {
currentShip.draw(canvas);
}
}
// Draw bullets.
int numBullets = mBullets.size();
for (int i = 0; i < numBullets; i++) {
final Bullet bullet = mBullets.get(i);
bullet.draw(canvas);
}
// Draw obstacles.
int numObstacles = mObstacles.size();
for (int i = 0; i < numObstacles; i++) {
final Obstacle obstacle = mObstacles.get(i);
obstacle.draw(canvas);
}
}
/**
* Uses the device descriptor to try to assign the same color to the same
* joystick. If there are two joysticks of the same type connected over USB,
* or the API is < API level 16, it will be unable to distinguish the two
* devices.
*
* @param shipID
* @return
*/
@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
private Ship getShipForId(int shipID) {
Ship currentShip = mShips.get(shipID);
if (null == currentShip) {
// do we know something about this ship already?
InputDevice dev = InputDevice.getDevice(shipID);
String deviceString = null;
Integer shipColor = null;
if (null != dev) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
deviceString = dev.getDescriptor();
} else {
deviceString = dev.getName();
}
shipColor = mDescriptorMap.get(deviceString);
}
if (null != shipColor) {
int color = shipColor;
int numShips = mShips.size();
// do we already have a ship with this color?
for (int i = 0; i < numShips; i++) {
if (mShips.valueAt(i).getColor() == color) {
shipColor = null;
// we won't store this value either --- if the first
// controller gets disconnected/connected, it will get
// the same color.
deviceString = null;
}
}
}
if (null != shipColor) {
currentShip = new Ship(shipColor);
if (null != deviceString) {
mDescriptorMap.remove(deviceString);
}
} else {
currentShip = new Ship(getNextShipColor());
}
mShips.append(shipID, currentShip);
currentShip.setInputDevice(dev);
if (null != deviceString) {
mDescriptorMap.put(deviceString, currentShip.getColor());
}
}
return currentShip;
}
/**
* Remove the ship from the array of active ships by ID.
*
* @param shipID
*/
private void removeShipForID(int shipID) {
mShips.remove(shipID);
}
private void reset() {
mShips.clear();
mBullets.clear();
mObstacles.clear();
findControllersAndAttachShips();
}
private void animateFrame() {
long currentStepTime = SystemClock.uptimeMillis();
step(currentStepTime);
invalidate();
}
private void step(long currentStepTime) {
float tau = (currentStepTime - mLastStepTime) * 0.001f;
mLastStepTime = currentStepTime;
// Move the ships
int numShips = mShips.size();
for (int i = 0; i < numShips; i++) {
Ship currentShip = mShips.valueAt(i);
if (currentShip != null) {
currentShip.accelerate(tau);
if (!currentShip.step(tau)) {
currentShip.reincarnate();
}
}
}
// Move the bullets.
int numBullets = mBullets.size();
for (int i = 0; i < numBullets; i++) {
final Bullet bullet = mBullets.get(i);
if (!bullet.step(tau)) {
mBullets.remove(i);
i -= 1;
numBullets -= 1;
}
}
// Move obstacles.
int numObstacles = mObstacles.size();
for (int i = 0; i < numObstacles; i++) {
final Obstacle obstacle = mObstacles.get(i);
if (!obstacle.step(tau)) {
mObstacles.remove(i);
i -= 1;
numObstacles -= 1;
}
}
// Check for collisions between bullets and obstacles.
for (int i = 0; i < numBullets; i++) {
final Bullet bullet = mBullets.get(i);
for (int j = 0; j < numObstacles; j++) {
final Obstacle obstacle = mObstacles.get(j);
if (bullet.collidesWith(obstacle)) {
bullet.destroy();
obstacle.destroy();
break;
}
}
}
// Check for collisions between the ship and obstacles --- this could
// get slow
for (int i = 0; i < numObstacles; i++) {
final Obstacle obstacle = mObstacles.get(i);
for (int j = 0; j < numShips; j++) {
Ship currentShip = mShips.valueAt(j);
if (currentShip != null) {
if (currentShip.collidesWith(obstacle)) {
currentShip.destroy();
obstacle.destroy();
break;
}
}
}
}
// Spawn more obstacles offscreen when needed.
// Avoid putting them right on top of the ship.
int tries = MAX_OBSTACLES - mObstacles.size() + 10;
final float minDistance = mShipSize * 4;
while (mObstacles.size() < MAX_OBSTACLES && tries-- > 0) {
float size = mRandom.nextFloat() * (mMaxObstacleSize - mMinObstacleSize)
+ mMinObstacleSize;
float positionX, positionY;
int edge = mRandom.nextInt(4);
switch (edge) {
case 0:
positionX = -size;
positionY = mRandom.nextInt(getHeight());
break;
case 1:
positionX = getWidth() + size;
positionY = mRandom.nextInt(getHeight());
break;
case 2:
positionX = mRandom.nextInt(getWidth());
positionY = -size;
break;
default:
positionX = mRandom.nextInt(getWidth());
positionY = getHeight() + size;
break;
}
boolean positionSafe = true;
// If the obstacle is too close to any ships, we don't want to
// spawn it.
for (int i = 0; i < numShips; i++) {
Ship currentShip = mShips.valueAt(i);
if (currentShip != null) {
if (currentShip.distanceTo(positionX, positionY) < minDistance) {
// try to spawn again
positionSafe = false;
break;
}
}
}
// if the position is safe, add the obstacle and reset the retry
// counter
if (positionSafe) {
tries = MAX_OBSTACLES - mObstacles.size() + 10;
// we can add the obstacle now since it isn't close to any ships
float direction = mRandom.nextFloat() * (float) Math.PI * 2;
float speed = mRandom.nextFloat() * (mMaxObstacleSpeed - mMinObstacleSpeed)
+ mMinObstacleSpeed;
float velocityX = (float) Math.cos(direction) * speed;
float velocityY = (float) Math.sin(direction) * speed;
Obstacle obstacle = new Obstacle();
obstacle.setPosition(positionX, positionY);
obstacle.setSize(size);
obstacle.setVelocity(velocityX, velocityY);
mObstacles.add(obstacle);
}
}
}
private static float pythag(float x, float y) {
return (float) Math.hypot(x, y);
}
private static int blend(float alpha, int from, int to) {
return from + (int) ((to - from) * alpha);
}
private static void setPaintARGBBlend(Paint paint, float alpha,
int a1, int r1, int g1, int b1,
int a2, int r2, int g2, int b2) {
paint.setARGB(blend(alpha, a1, a2), blend(alpha, r1, r2),
blend(alpha, g1, g2), blend(alpha, b1, b2));
}
private static float getCenteredAxis(MotionEvent event, InputDevice device,
int axis, int historyPos) {
final InputDevice.MotionRange range = device.getMotionRange(axis, event.getSource());
if (range != null) {
final float flat = range.getFlat();
final float value = historyPos < 0 ? event.getAxisValue(axis)
: event.getHistoricalAxisValue(axis, historyPos);
// Ignore axis values that are within the 'flat' region of the
// joystick axis center.
// A joystick at rest does not always report an absolute position of
// (0,0).
if (Math.abs(value) > flat) {
return value;
}
}
return 0;
}
/**
* Any gamepad button + the spacebar or DPAD_CENTER will be used as the fire
* key.
*
* @param keyCode
* @return true of it's a fire key.
*/
private static boolean isFireKey(int keyCode) {
return KeyEvent.isGamepadButton(keyCode)
|| keyCode == KeyEvent.KEYCODE_DPAD_CENTER
|| keyCode == KeyEvent.KEYCODE_SPACE;
}
private abstract class Sprite {
protected float mPositionX;
protected float mPositionY;
protected float mVelocityX;
protected float mVelocityY;
protected float mSize;
protected boolean mDestroyed;
protected float mDestroyAnimProgress;
public void setPosition(float x, float y) {
mPositionX = x;
mPositionY = y;
}
public void setVelocity(float x, float y) {
mVelocityX = x;
mVelocityY = y;
}
public void setSize(float size) {
mSize = size;
}
public float distanceTo(float x, float y) {
return pythag(mPositionX - x, mPositionY - y);
}
public float distanceTo(Sprite other) {
return distanceTo(other.mPositionX, other.mPositionY);
}
public boolean collidesWith(Sprite other) {
// Really bad collision detection.
return !mDestroyed && !other.mDestroyed
&& distanceTo(other) <= Math.max(mSize, other.mSize)
+ Math.min(mSize, other.mSize) * 0.5f;
}
public boolean isDestroyed() {
return mDestroyed;
}
/**
* Moves the sprite based on the elapsed time defined by tau.
*
* @param tau the elapsed time in seconds since the last step
* @return false if the sprite is to be removed from the display
*/
public boolean step(float tau) {
mPositionX += mVelocityX * tau;
mPositionY += mVelocityY * tau;
if (mDestroyed) {
mDestroyAnimProgress += tau / getDestroyAnimDuration();
if (mDestroyAnimProgress >= getDestroyAnimCycles()) {
return false;
}
}
return true;
}
/**
* Draws the sprite.
*
* @param canvas the Canvas upon which to draw the sprite.
*/
public abstract void draw(Canvas canvas);
/**
* Returns the duration of the destruction animation of the sprite in
* seconds.
*
* @return the float duration in seconds of the destruction animation
*/
public abstract float getDestroyAnimDuration();
/**
* Returns the number of cycles to play the destruction animation. A
* destruction animation has a duration and a number of cycles to play
* it for, so we can have an extended death sequence when a ship or
* object is destroyed.
*
* @return the float number of cycles to play the destruction animation
*/
public abstract float getDestroyAnimCycles();
protected boolean isOutsidePlayfield() {
final int width = GameView.this.getWidth();
final int height = GameView.this.getHeight();
return mPositionX < 0 || mPositionX >= width
|| mPositionY < 0 || mPositionY >= height;
}
protected void wrapAtPlayfieldBoundary() {
final int width = GameView.this.getWidth();
final int height = GameView.this.getHeight();
while (mPositionX <= -mSize) {
mPositionX += width + mSize * 2;
}
while (mPositionX >= width + mSize) {
mPositionX -= width + mSize * 2;
}
while (mPositionY <= -mSize) {
mPositionY += height + mSize * 2;
}
while (mPositionY >= height + mSize) {
mPositionY -= height + mSize * 2;
}
}
public void destroy() {
mDestroyed = true;
step(0);
}
}
private static int sShipColor = 0;
/**
* Returns the next ship color in the sequence. Very simple. Does not in any
* way guarantee that there are not multiple ships with the same color on
* the screen.
*
* @return an int containing the index of the next ship color
*/
private static int getNextShipColor() {
int color = sShipColor & 0x07;
if (0 == color) {
color++;
sShipColor++;
}
sShipColor++;
return color;
}
/*
* Static constants associated with Ship inner class
*/
private static final long[] sDestructionVibratePattern = new long[] {
0, 20, 20, 40, 40, 80, 40, 300
};
private class Ship extends Sprite {
private static final float CORNER_ANGLE = (float) Math.PI * 2 / 3;
private static final float TO_DEGREES = (float) (180.0 / Math.PI);
private final float mMaxShipThrust = mBaseSpeed * 0.25f;
private final float mMaxSpeed = mBaseSpeed * 12;
// The ship actually determines the speed of the bullet, not the bullet
// itself
private final float mBulletSpeed = mBaseSpeed * 12;
private final Paint mPaint;
private final Path mPath;
private final int mR, mG, mB;
private final int mColor;
// The current device that is controlling the ship
private InputDevice mInputDevice;
private float mHeadingX;
private float mHeadingY;
private float mHeadingAngle;
private float mHeadingMagnitude;
private int mDPadState;
/**
* The colorIndex is used to create the color based on the lower three
* bits of the value in the current implementation.
*
* @param colorIndex
*/
public Ship(int colorIndex) {
mPaint = new Paint();
mPaint.setStyle(Style.FILL);
setPosition(getWidth() * 0.5f, getHeight() * 0.5f);
setVelocity(0, 0);
setSize(mShipSize);
mPath = new Path();
mPath.moveTo(0, 0);
mPath.lineTo((float) Math.cos(-CORNER_ANGLE) * mSize,
(float) Math.sin(-CORNER_ANGLE) * mSize);
mPath.lineTo(mSize, 0);
mPath.lineTo((float) Math.cos(CORNER_ANGLE) * mSize,
(float) Math.sin(CORNER_ANGLE) * mSize);
mPath.lineTo(0, 0);
mR = (colorIndex & 0x01) == 0 ? 63 : 255;
mG = (colorIndex & 0x02) == 0 ? 63 : 255;
mB = (colorIndex & 0x04) == 0 ? 63 : 255;
mColor = colorIndex;
}
public boolean onKeyUp(int keyCode, KeyEvent event) {
// Handle keys going up.
boolean handled = false;
switch (keyCode) {
case KeyEvent.KEYCODE_DPAD_LEFT:
setHeadingX(0);
mDPadState &= ~DPAD_STATE_LEFT;
handled = true;
break;
case KeyEvent.KEYCODE_DPAD_RIGHT:
setHeadingX(0);
mDPadState &= ~DPAD_STATE_RIGHT;
handled = true;
break;
case KeyEvent.KEYCODE_DPAD_UP:
setHeadingY(0);
mDPadState &= ~DPAD_STATE_UP;
handled = true;
break;
case KeyEvent.KEYCODE_DPAD_DOWN:
setHeadingY(0);
mDPadState &= ~DPAD_STATE_DOWN;
handled = true;
break;
default:
if (isFireKey(keyCode)) {
handled = true;
}
break;
}
return handled;
}
/*
* Firing is a unique case where a ship creates a bullet. A bullet needs
* to be created with a position near the ship that is firing with a
* velocity that is based upon the speed of the ship.
*/
private void fire() {
if (!isDestroyed()) {
Bullet bullet = new Bullet();
bullet.setPosition(getBulletInitialX(), getBulletInitialY());
bullet.setVelocity(getBulletVelocityX(),
getBulletVelocityY());
mBullets.add(bullet);
vibrateController(20);
}
}
public boolean onKeyDown(int keyCode, KeyEvent event) {
// Handle DPad keys and fire button on initial down but not on
// auto-repeat.
boolean handled = false;
if (event.getRepeatCount() == 0) {
switch (keyCode) {
case KeyEvent.KEYCODE_DPAD_LEFT:
setHeadingX(-1);
mDPadState |= DPAD_STATE_LEFT;
handled = true;
break;
case KeyEvent.KEYCODE_DPAD_RIGHT:
setHeadingX(1);
mDPadState |= DPAD_STATE_RIGHT;
handled = true;
break;
case KeyEvent.KEYCODE_DPAD_UP:
setHeadingY(-1);
mDPadState |= DPAD_STATE_UP;
handled = true;
break;
case KeyEvent.KEYCODE_DPAD_DOWN:
setHeadingY(1);
mDPadState |= DPAD_STATE_DOWN;
handled = true;
break;
default:
if (isFireKey(keyCode)) {
fire();
handled = true;
}
break;
}
}
return handled;
}
/**
* Gets the vibrator from the controller if it is present. Note that it
* would be easy to get the system vibrator here if the controller one
* is not present, but we don't choose to do it in this case.
*
* @return the Vibrator for the controller, or null if it is not
* present. or the API level cannot support it
*/
@SuppressLint("NewApi")
private final Vibrator getVibrator() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN &&
null != mInputDevice) {
return mInputDevice.getVibrator();
}
return null;
}
private void vibrateController(int time) {
Vibrator vibrator = getVibrator();
if (null != vibrator) {
vibrator.vibrate(time);
}
}
private void vibrateController(long[] pattern, int repeat) {
Vibrator vibrator = getVibrator();
if (null != vibrator) {
vibrator.vibrate(pattern, repeat);
}
}
/**
* The ship directly handles joystick input.
*
* @param event
* @param historyPos
*/
private void processJoystickInput(MotionEvent event, int historyPos) {
// Get joystick position.
// Many game pads with two joysticks report the position of the
// second
// joystick
// using the Z and RZ axes so we also handle those.
// In a real game, we would allow the user to configure the axes
// manually.
if (null == mInputDevice) {
mInputDevice = event.getDevice();
}
float x = getCenteredAxis(event, mInputDevice, MotionEvent.AXIS_X, historyPos);
if (x == 0) {
x = getCenteredAxis(event, mInputDevice, MotionEvent.AXIS_HAT_X, historyPos);
}
if (x == 0) {
x = getCenteredAxis(event, mInputDevice, MotionEvent.AXIS_Z, historyPos);
}
float y = getCenteredAxis(event, mInputDevice, MotionEvent.AXIS_Y, historyPos);
if (y == 0) {
y = getCenteredAxis(event, mInputDevice, MotionEvent.AXIS_HAT_Y, historyPos);
}
if (y == 0) {
y = getCenteredAxis(event, mInputDevice, MotionEvent.AXIS_RZ, historyPos);
}
// Set the ship heading.
setHeading(x, y);
GameView.this.step(historyPos < 0 ? event.getEventTime() : event
.getHistoricalEventTime(historyPos));
}
public boolean onGenericMotionEvent(MotionEvent event) {
if (0 == mDPadState) {
// Process all historical movement samples in the batch.
final int historySize = event.getHistorySize();
for (int i = 0; i < historySize; i++) {
processJoystickInput(event, i);
}
// Process the current movement sample in the batch.
processJoystickInput(event, -1);
}
return true;
}
/**
* Set the game controller to be used to control the ship.
*
* @param dev the input device that will be controlling the ship
*/
public void setInputDevice(InputDevice dev) {
mInputDevice = dev;
}
/**
* Sets the X component of the joystick heading value, defined by the
* platform as being from -1.0 (left) to 1.0 (right). This function is
* generally used to change the heading in response to a button-style
* DPAD event.
*
* @param x the float x component of the joystick heading value
*/
public void setHeadingX(float x) {
mHeadingX = x;
updateHeading();
}
/**
* Sets the Y component of the joystick heading value, defined by the
* platform as being from -1.0 (top) to 1.0 (bottom). This function is
* generally used to change the heading in response to a button-style
* DPAD event.
*
* @param y the float y component of the joystick heading value
*/
public void setHeadingY(float y) {
mHeadingY = y;
updateHeading();
}
/**
* Sets the heading as floating point values returned by a joystick.
* These values are normalized by the Android platform to be from -1.0
* (left, top) to 1.0 (right, bottom)
*
* @param x the float x component of the joystick heading value
* @param y the float y component of the joystick heading value
*/
public void setHeading(float x, float y) {
mHeadingX = x;
mHeadingY = y;
updateHeading();
}
/**
* Converts the heading values from joystick devices to the polar
* representation of the heading angle if the magnitude of the heading
* is significant (> 0.1f).
*/
private void updateHeading() {
mHeadingMagnitude = pythag(mHeadingX, mHeadingY);
if (mHeadingMagnitude > 0.1f) {
mHeadingAngle = (float) Math.atan2(mHeadingY, mHeadingX);
}
}
/**
* Bring our ship back to life, stopping the destroy animation.
*/
public void reincarnate() {
mDestroyed = false;
mDestroyAnimProgress = 0.0f;
}
private float polarX(float radius) {
return (float) Math.cos(mHeadingAngle) * radius;
}
private float polarY(float radius) {
return (float) Math.sin(mHeadingAngle) * radius;
}
/**
* Gets the initial x coordinate for the bullet.
*
* @return the x coordinate of the bullet adjusted for the position and
* direction of the ship
*/
public float getBulletInitialX() {
return mPositionX + polarX(mSize);
}
/**
* Gets the initial y coordinate for the bullet.
*
* @return the y coordinate of the bullet adjusted for the position and
* direction of the ship
*/
public float getBulletInitialY() {
return mPositionY + polarY(mSize);
}
/**
* Returns the bullet speed Y component.
*
* @return adjusted Y component bullet speed for the velocity and
* direction of the ship
*/
public float getBulletVelocityY() {
return mVelocityY + polarY(mBulletSpeed);
}
/**
* Returns the bullet speed X component
*
* @return adjusted X component bullet speed for the velocity and
* direction of the ship
*/
public float getBulletVelocityX() {
return mVelocityX + polarX(mBulletSpeed);
}
/**
* Uses the heading magnitude and direction to change the acceleration
* of the ship. In theory, this should be scaled according to the
* elapsed time.
*
* @param tau the elapsed time in seconds between the last step
*/
public void accelerate(float tau) {
final float thrust = mHeadingMagnitude * mMaxShipThrust;
mVelocityX += polarX(thrust) * tau * mMaxSpeed / 4;
mVelocityY += polarY(thrust) * tau * mMaxSpeed / 4;
final float speed = pythag(mVelocityX, mVelocityY);
if (speed > mMaxSpeed) {
final float scale = mMaxSpeed / speed;
mVelocityX = mVelocityX * scale * scale;
mVelocityY = mVelocityY * scale * scale;
}
}
@Override
public boolean step(float tau) {
if (!super.step(tau)) {
return false;
}
wrapAtPlayfieldBoundary();
return true;
}
@Override
public void draw(Canvas canvas) {
setPaintARGBBlend(mPaint, mDestroyAnimProgress - (int) (mDestroyAnimProgress),
255, mR, mG, mB,
0, 255, 0, 0);
canvas.save(Canvas.MATRIX_SAVE_FLAG);
canvas.translate(mPositionX, mPositionY);
canvas.rotate(mHeadingAngle * TO_DEGREES);
canvas.drawPath(mPath, mPaint);
canvas.restore();
}
@Override
public float getDestroyAnimDuration() {
return 1.0f;
}
@Override
public void destroy() {
super.destroy();
vibrateController(sDestructionVibratePattern, -1);
}
@Override
public float getDestroyAnimCycles() {
return 5.0f;
}
public int getColor() {
return mColor;
}
}
private static final Paint mBulletPaint;
static {
mBulletPaint = new Paint();
mBulletPaint.setStyle(Style.FILL);
}
private class Bullet extends Sprite {
public Bullet() {
setSize(mBulletSize);
}
@Override
public boolean step(float tau) {
if (!super.step(tau)) {
return false;
}
return !isOutsidePlayfield();
}
@Override
public void draw(Canvas canvas) {
setPaintARGBBlend(mBulletPaint, mDestroyAnimProgress,
255, 255, 255, 0,
0, 255, 255, 255);
canvas.drawCircle(mPositionX, mPositionY, mSize, mBulletPaint);
}
@Override
public float getDestroyAnimDuration() {
return 0.125f;
}
@Override
public float getDestroyAnimCycles() {
return 1.0f;
}
}
private static final Paint mObstaclePaint;
static {
mObstaclePaint = new Paint();
mObstaclePaint.setARGB(255, 127, 127, 255);
mObstaclePaint.setStyle(Style.FILL);
}
private class Obstacle extends Sprite {
@Override
public boolean step(float tau) {
if (!super.step(tau)) {
return false;
}
wrapAtPlayfieldBoundary();
return true;
}
@Override
public void draw(Canvas canvas) {
setPaintARGBBlend(mObstaclePaint, mDestroyAnimProgress,
255, 127, 127, 255,
0, 255, 0, 0);
canvas.drawCircle(mPositionX, mPositionY,
mSize * (1.0f - mDestroyAnimProgress), mObstaclePaint);
}
@Override
public float getDestroyAnimDuration() {
return 0.25f;
}
@Override
public float getDestroyAnimCycles() {
return 1.0f;
}
}
/*
* When an input device is added, we add a ship based upon the device.
* @see
* com.example.inputmanagercompat.InputManagerCompat.InputDeviceListener
* #onInputDeviceAdded(int)
*/
@Override
public void onInputDeviceAdded(int deviceId) {
getShipForId(deviceId);
}
/*
* This is an unusual case. Input devices don't typically change, but they
* certainly can --- for example a device may have different modes. We use
* this to make sure that the ship has an up-to-date InputDevice.
* @see
* com.example.inputmanagercompat.InputManagerCompat.InputDeviceListener
* #onInputDeviceChanged(int)
*/
@Override
public void onInputDeviceChanged(int deviceId) {
Ship ship = getShipForId(deviceId);
ship.setInputDevice(InputDevice.getDevice(deviceId));
}
/*
* Remove any ship associated with the ID.
* @see
* com.example.inputmanagercompat.InputManagerCompat.InputDeviceListener
* #onInputDeviceRemoved(int)
*/
@Override
public void onInputDeviceRemoved(int deviceId) {
removeShipForID(deviceId);
}
}