Android Open Source - opengl-particles Black Smoke

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Back to project page opengl-particles.

License

The source code is released under:

Apache License

Java Source Code

package com.kennethmaffei.particles;
/*  ww  w  .ja va 2  s  . c om*/
import javax.microedition.khronos.opengles.GL10;

import android.opengl.GLES11;

public class BlackSmoke extends ParticleSystem {

  @Override
  void InitializeParticle(int index) {
    Particle p = particles.get(index);
    p.colorR = p.colorG = p.colorB = p.colorA = 1.0f;
    
    p.lifeTime = p.life = lifeTime + Globals.random()*lifeTimeVar;
    p.deltaColorR = -(p.colorR)/p.life;
    p.deltaColorG = -(p.colorG)/p.life;
    p.deltaColorB = -(p.colorB)/p.life;
    p.deltaColorA = -1.0f/p.life;
    
    p.position.x = origin.x + (2.0f*Globals.random() - 1.0f)*width/2.0f;
    p.position.y = origin.y + (2.0f*Globals.random() - 1.0f)*depth/2.0f;
    p.position.z = origin.z + (2.0f*Globals.random() - 1.0f)*height/2.0f;
    
    p.velocity.x = velocity.x + (2.0f*Globals.random() - 1.0f)*velocityVariation.x;
    p.velocity.y = velocity.y + (2.0f*Globals.random() - 1.0f)*velocityVariation.y;
    p.velocity.z = velocity.z + (2.0f*Globals.random() - 1.0f)*velocityVariation.z;
    
    p.acceleration.copy(acceleration);
    
    p.size.x = startSize.x;
    p.size.y = startSize.y;
    
    p.deltaSize.x = (endSize.x - startSize.x)/p.life;
    p.deltaSize.y = (endSize.y - startSize.y)/p.life;
    
    //Now that the particle attributes are set, initialize the quad
    p.initializeQuad(startSize, glTexture[0], facing);
    
    //Now that the particle attributes are set, initialize the quad
    p.initializeQuad(startSize, glTexture[0], facing);
  }
  
  @Override
  void update(float elapsedTime) {
    if(!started)
      return;

    timeBeforeStartTime+= elapsedTime;
    if(timeBeforeStartTime < startTime)
      return;

    accumulatedTime+= elapsedTime;

    /* Frustum culling (NOT IMPLEMENTED HERE)
    * If you are doing frustum culling, then check here.
    * For example:
    *   
    *   //If the system is outside the frustion, don't draw it.
    *   //However, depending on what the system is, you may still
    *   //want to update it. For example, transient systems like
    *   //an explosion should still be updated, while fixed system
    *   //like mist or fire would not need to be updated.
    *   if(!frustum->sphereInFrustum(origin, rEff)) {
    *     draw = false;
    *    return; (Optional)
    *  }
    *
    */

    //Iterate over all the particles and update their attributes
    for(int i=0; i < numParticles; ) {
      Particle p = particles.get(i);
        //Update the particle's position based on the elapsed time and velocity
        p.position.x+= p.velocity.x * elapsedTime;
        p.position.y+= p.velocity.y * elapsedTime;
        p.position.z+= p.velocity.z * elapsedTime;
        p.velocity.x+= p.acceleration.x * elapsedTime;
        p.velocity.y+= p.acceleration.y * elapsedTime;
        p.velocity.z+= p.acceleration.z * elapsedTime;
    
      p.life -= 2*elapsedTime;
    
        p.size.x+= p.deltaSize.x * 2*elapsedTime;
      p.size.y+= p.deltaSize.y * 2*elapsedTime;
      
      p.colorA+= p.deltaColorA * 2*elapsedTime;
        p.colorG+= p.deltaColorG * 2*elapsedTime;
    
      p.colorR+= p.deltaColorR * 2*elapsedTime;
      p.colorB+= p.deltaColorB * 2*elapsedTime;
        
        //Kill the particle if it's been around long enough
        if(p.life <= 0.0) {
        //Swap the last particle with the current position, and decrease the count
        Particle dead = particles.get(i);
        particles.set(i, particles.get(numParticles - 1));
        particles.set(numParticles - 1, dead);
        numParticles--;
        }
        else {
        p.updateQuad();
        i++;
        }
    }
    
    if(accumulatedTime < duration || fixed) {
      float numParticlesThisFrame = elapsedTime*particlesPerSec;
      float numNewParticles = numParticlesThisFrame + numParticlesHeldOver;
      int numParticlesToEmit = (int) Math.floor(numNewParticles);
      numParticlesHeldOver = numNewParticles - numParticlesToEmit;
      updateSystem(numParticlesToEmit, elapsedTime);
      
      return;
    }
    else
      destroying = true;
  }
  
  @Override
  void draw(GL10 gl) {
    GLES11.glDepthMask(false);
    GLES11.glEnable(GLES11.GL_BLEND);
    GLES11.glTexEnvi(GLES11.GL_TEXTURE_ENV, GLES11.GL_TEXTURE_ENV_MODE, GLES11.GL_MODULATE);
    GLES11.glBlendFunc(GLES11.GL_ZERO, GLES11.GL_ONE_MINUS_SRC_COLOR); //Special blend mode for Black Smoke!
    
    GLES11.glBindTexture(GLES11.GL_TEXTURE_2D, glTexture[0]);
    
    GLES11.glPushMatrix();
    //No need for translation, it's done per particle when they are created
    //We don't translate an already-emitted particle's origin as the the emitter moves
    GLES11.glRotatef(rotate.x, 0, 0, 1);
    GLES11.glRotatef(rotate.y, 0, 1, 0);
    GLES11.glRotatef(rotate.x, 1, 0, 0);
    GLES11.glScalef(scale.x, scale.y, scale.z);
    
    for(int i=0; i<numParticles; i++)
      particles.get(i).quad.draw(gl);
    
    GLES11.glPopMatrix();
    
    GLES11.glDepthMask(true);
  }
}

Java Source Code List

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