OpenGL es2.0 创建颜色线圆

一、Java代码：</span>

package com.gzdxid.utils;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.util.ArrayList;

import android.opengl.GLES20;

public class DrawCircleLine {

int mProgram;
int muMVPMatrixHandle;
int maPositionHandle;

int muColorRHandle;
int muColorGHandle;
int muColorBHandle;
int muColorAHandle;

FloatBuffer mVertexBuffer;
int vCount = 0;

float lineWidth=4;
int SPAN_NUM=36;

public DrawCircleLine(float radius,int mProgram) {
// TODO Auto-generated constructor stub
initVertex(radius);
initShader(mProgram);
}

private void initVertex(float radius) {
// TODO Auto-generated method stub
float angle=360f/SPAN_NUM;
ArrayList<Float>alv=new ArrayList<Float>();
for(int i=0;i<=SPAN_NUM;i++){
float x=(float) (radius*Math.cos(Math.toRadians(angle*i)));
float y=(float) (radius*Math.sin(Math.toRadians(angle*i)));
float z=0;
alv.add(x);alv.add(y);alv.add(z);
}
vCount=alv.size()/3;
int number=alv.size();
float vertices[]=new float[number];
for(int i=0;i<number;i++){
vertices[i]=alv.get(i);
}
ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length * 4);
vbb.order(ByteOrder.nativeOrder());
mVertexBuffer = vbb.asFloatBuffer();
mVertexBuffer.put(vertices);
mVertexBuffer.position(0);
}

private void initShader(int mProgram) {
this.mProgram=mProgram;
muMVPMatrixHandle=GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
maPositionHandle=GLES20.glGetAttribLocation(mProgram, "aPosition");
muColorRHandle=GLES20.glGetUniformLocation(mProgram, "uColorR");
muColorGHandle=GLES20.glGetUniformLocation(mProgram, "uColorG");
muColorBHandle=GLES20.glGetUniformLocation(mProgram, "uColorB");
muColorAHandle=GLES20.glGetUniformLocation(mProgram, "uColorA");
}

public void drawSelf(float r,float g,float b,float a){
GLES20.glUseProgram(mProgram);
GLES20.glUniformMatrix4fv(muMVPMatrixHandle, 1, false, MatrixState.getFinalMatrix(), 0);
GLES20.glUniform1f(muColorRHandle, r);
GLES20.glUniform1f(muColorGHandle, g);
GLES20.glUniform1f(muColorBHandle, b);
GLES20.glUniform1f(muColorAHandle, a);
GLES20.glVertexAttribPointer(maPositionHandle, 3, GLES20.GL_FLOAT, false, 3*4, mVertexBuffer);
GLES20.glEnableVertexAttribArray(maPositionHandle);
GLES20.glLineWidth(lineWidth);
GLES20.glDrawArrays(GLES20.GL_LINE_STRIP, 0, vCount);
}

}

precision mediump float;

uniform float uColorR;
uniform float uColorG;
uniform float uColorB;
uniform float uColorA;

void main(){
vec4 finalColor;
finalColor=vec4(uColorR,uColorG,uColorB,uColorA);
gl_FragColor=finalColor;
}

uniform mat4 uMVPMatrix;
attribute vec3 aPosition;

void main(){
gl_Position=uMVPMatrix*vec4(aPosition,1);
}