OpenGL es2.0 创建颜色线圆

ゞ浴缸里的玫瑰 2022-08-06 13:14 98阅读 0赞

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);
    	}
    	
    }

二、片源着色器：

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;
    }

三、顶多着色器：

uniform mat4 uMVPMatrix;
    attribute vec3 aPosition;
    
    void main(){
        gl_Position=uMVPMatrix*vec4(aPosition,1); 
    }