我有一个涉及大量碰撞和爆炸的游戏。
基本上，敌人的射弹是从屏幕的右下角向左侧发射的。玩家可以使用他的武器拦截他们。
我希望每当“子弹”和射弹碰撞时，代码都会在撞击位置绘制预制粒子。 我的问题是，在实时碰撞中，粒子被很好地绘制，但它们永远不会停止。即使在碰撞后，粒子也会继续被拉伸。
现在，我使用回调机制通知渲染器某处发生了碰撞，并向我传递了碰撞的坐标（x，y）
这是我的渲染器代码。我从代码中删除了一些部分，只留下相关部分：
package com.david.gameworld;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.graphics.g2d.Sprite;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.math.Vector2;
import com.badlogic.gdx.physics.box2d.Body;
import com.badlogic.gdx.physics.box2d.Box2DDebugRenderer;
import com.badlogic.gdx.utils.Array;
import com.david.helpers.AssetsLoader;
import com.david.helpers.CollisionAndTouchCallbacks;
public class GameRenderer implements CollisionAndTouchCallbacks.DrawThings{
/* The GameRenderer class. Responsible for all the rendering work and graphics */
public static final float FLOOR_HEIGHT = 100.0f; // Public variable - The floor height
private static final float Pixels_To_Meters = 32.0f; // PTM Ration
public static float screenWidth; // Screen width
public static float screenHeight; // Screen height
public OrthographicCamera camera; // The orthographic camera
private GameWorld world; // The game world object, for rendering
private boolean drawTrajectory;
private boolean drawParticle;
private boolean isDrawnParticle;
private Box2DDebugRenderer debugRenderer; // Debug renderer, to see the positions and sizes of the bodies/fixtures
private SpriteBatch batch; // A sprite batch
private Array<Body> tempBodies; // An array that contains all the bodies of Box2D
private Array<Vector2> collisionPositions;
private float delta;
public GameRenderer(float screenWidth, float screenHeight, GameWorld world) {
this.world = world;
GameRenderer.screenHeight = screenHeight;
GameRenderer.screenWidth = screenWidth;
debugRenderer = new Box2DDebugRenderer();
batch = new SpriteBatch();
camera = new OrthographicCamera();
tempBodies = new Array<Body>();
collisionPositions = new Array<Vector2>();
drawTrajectory = false;
drawParticle = false;
isDrawnParticle = false;
}
public void render(float delta) {
Gdx.gl.glClearColor(1, 1, 1, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
this.delta = delta;
// Update the world
world.updateWorld();
batch.setProjectionMatrix(camera.combined);
// Get box2d World bodies
world.getBox2DWorld().getBodies(tempBodies);
// Draw the entire scene
batch.begin();
drawBodiesBox2D();
if(drawTrajectory)
drawTrajectory();
if(drawParticle) {
if(!isDrawnParticle) {
drawParticle();
isDrawnParticle = true;
} else {
if(AssetsLoader.explosion.isComplete()) {
drawParticle = false;
isDrawnParticle = false;
}
}
}
batch.end();
// Debug Renderer for box2d world
}
// If user is aiming, draw the trajectory of the acorn
public void drawTrajectory() {
Gdx.app.log("System Out Println!!!!!!!!!", "Draw projectile");
float t = 0.1f, x = world.getArrayAcorns().peek().getX(), y = world
.getArrayAcorns().peek().getY();
float width = AssetsLoader.orbit.getWidth() / 8 / Pixels_To_Meters;
float height = AssetsLoader.orbit.getHeight() / 8 / Pixels_To_Meters;
float timeSeparation = 0.08f;
for (int i = 0; i < 40; i++) {
x = world.getAcornEquation().getX(t);
y = world.getAcornEquation().getY(t);
batch.draw(AssetsLoader.orbit, x, y, width, height);
t += timeSeparation;
}
}
private void drawBodiesBox2D() {
for (Body body : tempBodies) {
if (body.getUserData() != null
&& body.getUserData() instanceof Sprite) {
Sprite sprite = (Sprite) body.getUserData();
if (!sprite.getTexture().equals(AssetsLoader.ground)) {
sprite.setPosition(body.getPosition().x - sprite.getWidth()
/ 2, body.getPosition().y - sprite.getHeight() / 2);
} else {
sprite.setSize(screenWidth, FLOOR_HEIGHT / Pixels_To_Meters);
}
sprite.setRotation((float) Math.toDegrees(body.getAngle()));
batch.draw(AssetsLoader.catapult_base1, 450 / Pixels_To_Meters,
(FLOOR_HEIGHT - 10) / Pixels_To_Meters,
AssetsLoader.catapult_base1.getWidth()
/ Pixels_To_Meters,
AssetsLoader.catapult_base1.getHeight()
/ Pixels_To_Meters);
sprite.draw(batch);
}
}
}
public void dispose() {
AssetsLoader.dispose();
batch.dispose();
world.dispose();
debugRenderer.dispose();
}
// Update method for the orthographic camera
public void updateCamera(int width, int height) {
camera.setToOrtho(false, width, height);
screenWidth = (float) width;
screenHeight = (float) height;
camera.update();
// Already Meters
}
public OrthographicCamera getCamera() {
return this.camera;
}
private void drawParticle() {
// TODO Auto-generated method stub
AssetsLoader.explosion.setPosition(collisionPositions.first().x,collisionPositions.first().y);
AssetsLoader.explosion.start();
AssetsLoader.explosion.draw(batch,delta);
AssetsLoader.explosion.allowCompletion();
}
@Override
public void signalToTrajectory(boolean flag) {
// TODO Auto-generated method stub
drawTrajectory = flag;
}
@Override
public void signalToParticle(boolean flag, Array<Vector2> positions) {
// TODO Auto-generated method stub
if(flag)
collisionPositions = positions;
drawParticle = flag;
}
}
如何绘制粒子效果一次，就是这样？
答案 0 :(得分：1)
您可以使用/优化我的粒子类，查看my post here
要绘制一次粒子效果并将其绘制成:(它在myparticle free方法中）：
ParticleEffect effect = new ParticleEffect();
Emitter emitter = effect.getControllers().first().emitter;
if (emitter instanceof RegularEmitter){
RegularEmitter reg = (RegularEmitter) emitter;
reg.setEmissionMode(RegularEmitter.EmissionMode.EnabledUntilCycleEnd);
//reg.durationValue.setLow(10f);
reg.dispose();
}
emitter.dispose();