openGL es2.0 粒子系统方式之球体爆炸

待我称王封你为后i 2022-08-07 00:18 151阅读 0赞

一、Java代码：

package com.gzdxid.particles;
    
    import java.nio.FloatBuffer;
    
    import com.gzdxid.utils.BufferUtil;
    import com.gzdxid.utils.MatrixState;
    
    import android.opengl.GLES20;
    
    public class GrainShooter {
    
    	int mProgram;
    	int muMVPMatrixHandle;
    	int uPointSizeHandle;
    	int uColorHandle;
    	int uTimeHandle;
    	int maVelocityHandle;
    
    	private FloatBuffer mVelocityBuffer;
    
    	private int vCount;
    	private float pointSize;
    	private float timeLive = 0;
    	private long timeStamp = 0;
    
    	public GrainShooter(float pointSize, int pointCount, int mProgram) {
    		// TODO Auto-generated constructor stub
    		this.vCount = pointCount;
    		this.pointSize = pointSize;
    		initVertex();
    		initShader(mProgram);
    	}
    
    	private void initVertex() {
    		float []velocity=new float[vCount*3];
    		for(int i=0;i<vCount;i++){
    			double hAngle=2*Math.random()*Math.PI;
    			double vAngle=0.35*Math.random()*Math.PI+0.15*Math.PI;
    			final double vTotal=1+1*Math.random();
    			double vx=vTotal*Math.cos(vAngle)*Math.sin(hAngle);
    			double vy=vTotal*Math.sin(vAngle);
    			double vz=vTotal*Math.cos(vAngle)*Math.cos(hAngle);
    			velocity[i*3]=(float) vx;
    			velocity[i*3+1]=(float) vy;
    			velocity[i*3+2]=(float) vz;
    		}
    		mVelocityBuffer=BufferUtil.getFloatBuffer(velocity);
    	}
    
    	private void initShader(int mProgram) {
    		this.mProgram=mProgram;
    		muMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
    		uPointSizeHandle = GLES20.glGetUniformLocation(mProgram, "uPointSize");
    		uColorHandle = GLES20.glGetUniformLocation(mProgram, "uColor");
    		uTimeHandle = GLES20.glGetUniformLocation(mProgram, "uTime");
    		maVelocityHandle = GLES20.glGetAttribLocation(mProgram, "aVelocity");
    	}
    
    	public void drawSelf() {
    		long currTimeStamp=System.nanoTime()/1000000;
    		if(currTimeStamp-timeStamp>=5){
    			timeLive+=0.02f;
    			timeStamp=currTimeStamp;
    		}
    		GLES20.glUseProgram(mProgram);
    		GLES20.glUniformMatrix4fv(muMVPMatrixHandle, 1, false, MatrixState.getFinalMatrix(), 0);
    		GLES20.glUniform1f(uPointSizeHandle, pointSize);
    		GLES20.glUniform1f(uTimeHandle, timeLive);
    		GLES20.glUniform3fv(uColorHandle, 1, new float[]{1,0,0}, 0);
    		GLES20.glVertexAttribPointer(maVelocityHandle, 3, GLES20.GL_FLOAT, false, 3*4, mVelocityBuffer);
    		GLES20.glEnableVertexAttribArray(maVelocityHandle);
    		GLES20.glDrawArrays(GLES20.GL_POINTS, 0, vCount);
    	}
    }

二、定点着色器：

uniform mat4 uMVPMatrix;
    uniform float uPointSize;
    uniform float uTime;
    attribute vec3 aVelocity;
    void main()
    {
       float currTime=mod(uTime,5);
       float px=aVelocity.x*currTime;
       float py=aVelocity.y*currTime-0.5*1.0*currTime*currTime;
       float pz=aVelocity.z*currTime;
       gl_Position=uMVPMatrix*vec4(px,py,pz,1);
       gl_PointSize=uPointSize;
    }

三、片源着色器：

precision mediump float;
    uniform vec3 uColor;
    void main()
    {
      gl_FragColor=vec4(uColor,1.0);
    }