Android实现粒子爆炸效果的方法
作者：红薯
这篇文章主要介绍了Android实现粒子爆炸效果的方法,实例分析了Android动画特效的实现技巧,需要的朋友可以参考下
本文实例讲述了Android实现粒子爆炸效果的方法。分享给大家供大家参考。具体如下：
1. Explosion.java文件：
package net.obviam.particles.model;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.util.Log;
public class Explosion {
private static final String TAG = Explosion.class.getSimpleName();
public static final int STATE_ALIVE = 0;
// at least 1 particle is alive
public static final int STATE_DEAD = 1;
// all particles are dead
private Particle[] particles;
// particles in the explosion
private int x, y;
// the explosion's origin
private float gravity;
// the gravity of the explosion (+ upward, - down)
private float wind;
// speed of wind on horizontal
private int size; // number of particles
private int state; // whether it's still active or not
public Explosion(int particleNr, int x, int y) {
Log.d(TAG, "Explosion created at " + x + "," + y);
this.state = STATE_ALIVE;
this.particles = new Particle[particleNr];
for (int i = 0; i < this.particles.length; i++) {
Particle p = new Particle(x, y);
this.particles[i] = p;
}
this.size = particleNr;
}
public Particle[] getParticles() {
return particles;
}
public void setParticles(Particle[] particles) {
this.particles = particles;
}
public int getX() {
return x;
}
public void setX(int x) {
this.x = x;
}
public int getY() {
return y;
}
public void setY(int y) {
this.y = y;
}
public float getGravity() {
return gravity;
}
public void setGravity(float gravity) {
this.gravity = gravity;
}
public float getWind() {
return wind;
}
public void setWind(float wind) {
this.wind = wind;
}
public int getSize() {
return size;
}
public void setSize(int size) {
this.size = size;
}
public int getState() {
return state;
}
public void setState(int state) {
this.state = state;
}
// helper methods -------------------------
public boolean isAlive() {
return this.state == STATE_ALIVE;
}
public boolean isDead() {
return this.state == STATE_DEAD;
}
public void update() {
if (this.state != STATE_DEAD) {
boolean isDead = true;
for (int i = 0; i < this.particles.length; i++) {
if (this.particles[i].isAlive()) {
this.particles[i].update();
isDead = false;
}
}
if (isDead)
this.state = STATE_DEAD;
}
}
public void update(Rect container) {
if (this.state != STATE_DEAD) {
boolean isDead = true;
for (int i = 0; i < this.particles.length; i++) {
if (this.particles[i].isAlive()) {
this.particles[i].update(container);
// this.particles[i].update();
isDead = false;
}
}
if (isDead)
this.state = STATE_DEAD;
}
}
public void draw(Canvas canvas) {
for(int i = 0; i < this.particles.length; i++) {
if (this.particles[i].isAlive()) {
this.particles[i].draw(canvas);
}
}
}
}
2. Particle.java文件如下：
package net.obviam.particles.model;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
public class Particle {
public static final int STATE_ALIVE = 0; // particle is alive
public static final int STATE_DEAD = 1; // particle is dead
public static final int DEFAULT_LIFETIME = 200; // play with this
public static final int MAX_DIMENSION = 5; // the maximum width or height
public static final int MAX_SPEED = 10; // maximum speed (per update)
private int state; // particle is alive or dead
private float widht; // width of the particle
private float height; // height of the particle
private float x, y; // horizontal and vertical position
private double xv, yv; // vertical and horizontal velocity
private int age; // current age of the particle
private int lifetime; // particle dies when it reaches this value
private int color; // the color of the particle
private Paint paint; // internal use to avoid instantiation
public int getState() {
return state;
}
public void setState(int state) {
this.state = state;
}
public float getWidht() {
return widht;
}
public void setWidht(float widht) {
this.widht = widht;
}
public float getHeight() {
return height;
}
public void setHeight(float height) {
this.height = height;
}
public float getX() {
return x;
}
public void setX(float x) {
this.x = x;
}
public float getY() {
return y;
}
public void setY(float y) {
this.y = y;
}
public double getXv() {
return xv;
}
public void setXv(double xv) {
this.xv = xv;
}
public double getYv() {
return yv;
}
public void setYv(double yv) {
this.yv = yv;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public int getLifetime() {
return lifetime;
}
public void setLifetime(int lifetime) {
this.lifetime = lifetime;
}
public int getColor() {
return color;
}
public void setColor(int color) {
this.color = color;
}
// helper methods -------------------------
public boolean isAlive() {
return this.state == STATE_ALIVE;
}
public boolean isDead() {
return this.state == STATE_DEAD;
}
public Particle(int x, int y) {
this.x = x;
this.y = y;
this.state = Particle.STATE_ALIVE;
this.widht = rndInt(1, MAX_DIMENSION);
this.height = this.widht;
// this.height = rnd(1, MAX_DIMENSION);
this.lifetime = DEFAULT_LIFETIME;
this.age = 0;
this.xv = (rndDbl(0, MAX_SPEED * 2) - MAX_SPEED);
this.yv = (rndDbl(0, MAX_SPEED * 2) - MAX_SPEED);
// smoothing out the diagonal speed
if (xv * xv + yv * yv > MAX_SPEED * MAX_SPEED) {
xv *= 0.7;
yv *= 0.7;
}
this.color = Color.argb(255, rndInt(0, 255), rndInt(0, 255), rndInt(0, 255));
this.paint = new Paint(this.color);
}
/**
* Resets the particle
* @param x
* @param y
*/
public void reset(float x, float y) {
this.state = Particle.STATE_ALIVE;
this.x = x;
this.y = y;
this.age = 0;
}
// Return an integer that ranges from min inclusive to max inclusive.
static int rndInt(int min, int max) {
return (int) (min + Math.random() * (max - min + 1));
}
static double rndDbl(double min, double max) {
return min + (max - min) * Math.random();
}
public void update() {
if (this.state != STATE_DEAD) {
this.x += this.xv;
this.y += this.yv;
// extract alpha
int a = this.color >>> 24;
a -= 2; // fade by 5
if (a <= 0) { // if reached transparency kill the particle
this.state = STATE_DEAD;
} else {
this.color = (this.color & 0x00ffffff) + (a << 24); // set the new alpha
this.paint.setAlpha(a);
this.age++; // increase the age of the particle
// this.widht *= 1.05;
// this.height *= 1.05;
}
if (this.age >= this.lifetime) { // reached the end if its life
this.state = STATE_DEAD;
}
// http://lab.polygonal.de/2007/05/10/bitwise-gems-fast-integer-math/
//32bit
// var color:uint = 0xff336699;
// var a:uint = color >>> 24;
// var r:uint = color >>> 16 & 0xFF;
// var g:uint = color >>> 8 & 0xFF;
// var b:uint = color & 0xFF;
}
}
public void update(Rect container) {
// update with collision
if (this.isAlive()) {
if (this.x <= container.left || this.x >= container.right - this.widht) {
this.xv *= -1;
}
// Bottom is 480 and top is 0 !!!
if (this.y <= container.top || this.y >= container.bottom - this.height) {
this.yv *= -1;
}
}
update();
}
public void draw(Canvas canvas) {
// paint.setARGB(255, 128, 255, 50);
paint.setColor(this.color);
canvas.drawRect(this.x, this.y, this.x + this.widht, this.y + this.height, paint);
// canvas.drawCircle(x, y, widht, paint);
}
}
希望本文所述对大家的Android程序设计有所帮助。