openGL es2.0 创建纹理球

野性酷女 2022-08-06 13:21 183阅读 0赞

一、Java代码：

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 DrawBallTexture {
    
    	int mProgram;
    	int muMVPMatrixHandle;
    	int maPositionHandle;
    	int maTexCoorHandle;
    
    	FloatBuffer mVertexBuffer;
    	FloatBuffer mTexCoorBuffer;
    
    	int vCount = 0;
    	final float UNIT_SIZE = 1f;
    	final float angleSpan = 10f;
    	float R = 0;
    	
    	public float roateX;
    	public float roateY;
    
    	public DrawBallTexture(float r, int mProgram) {
    		// TODO Auto-generated constructor stub
    		initVertex(r);
    		initShader(mProgram);
    	}
    
    	private void initVertex(float r) {
    		// TODO Auto-generated method stub
    		R = r;
    		ArrayList<Float> alVertix = new ArrayList<Float>();
    		for (float vAngle = 90; vAngle > -90; vAngle -= angleSpan) {
    			for (float hAngle = 360; hAngle > 0; hAngle -= angleSpan) {
    				float x1 = getCoor(0, vAngle, hAngle);
    				float y1 = getCoor(1, vAngle, hAngle);
    				float z1 = getCoor(2, vAngle, hAngle);
    
    				float x2 = getCoor(0, vAngle - angleSpan, hAngle);
    				float y2 = getCoor(1, vAngle - angleSpan, hAngle);
    				float z2 = getCoor(2, vAngle - angleSpan, hAngle);
    
    				float x3 = getCoor(0, vAngle - angleSpan, hAngle - angleSpan);
    				float y3 = getCoor(1, vAngle - angleSpan, hAngle - angleSpan);
    				float z3 = getCoor(2, vAngle - angleSpan, hAngle - angleSpan);
    
    				float x4 = getCoor(0, vAngle, hAngle - angleSpan);
    				float y4 = getCoor(1, vAngle, hAngle - angleSpan);
    				float z4 = getCoor(2, vAngle, hAngle - angleSpan);
    
    				alVertix.add(x1);
    				alVertix.add(y1);
    				alVertix.add(z1);
    				alVertix.add(x2);
    				alVertix.add(y2);
    				alVertix.add(z2);
    				alVertix.add(x4);
    				alVertix.add(y4);
    				alVertix.add(z4);
    				// 构建第二三角形
    				alVertix.add(x4);
    				alVertix.add(y4);
    				alVertix.add(z4);
    				alVertix.add(x2);
    				alVertix.add(y2);
    				alVertix.add(z2);
    				alVertix.add(x3);
    				alVertix.add(y3);
    				alVertix.add(z3);
    			}
    		}
    		
    		vCount = alVertix.size() / 3;
    		
    		float vertices[] = new float[vCount * 3];
    		for (int i = 0; i < alVertix.size(); i++) {
    			vertices[i] = alVertix.get(i);
    		}
    		ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length * 4);
    		vbb.order(ByteOrder.nativeOrder());
    		mVertexBuffer = vbb.asFloatBuffer();
    		mVertexBuffer.put(vertices);
    		mVertexBuffer.position(0);
    
    		float[] texCoor = generateTexCoor(// 获取切分整图的纹理数组
    				(int) (360 / angleSpan), // 纹理图切分的列数
    				(int) (180 / angleSpan) // 纹理图切分的行数
    		);
    		ByteBuffer llbb = ByteBuffer.allocateDirect(texCoor.length * 4);
    		llbb.order(ByteOrder.nativeOrder());// 设置字节顺序
    		mTexCoorBuffer = llbb.asFloatBuffer();
    		mTexCoorBuffer.put(texCoor);
    		mTexCoorBuffer.position(0);
    	}
    
    	private void initShader(int mProgram) {
    		// TODO Auto-generated method stub
    		this.mProgram = mProgram;
    		muMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
    		maPositionHandle = GLES20.glGetAttribLocation(mProgram, "aPosition");
    		maTexCoorHandle = GLES20.glGetAttribLocation(mProgram, "aTexCoor");
    	}
    
    	public void drawSelf(int texId) {
    		MatrixState.rotate(roateX, 1, 0, 0);
    		MatrixState.rotate(roateY, 0, 1, 0);
    		
    		GLES20.glUseProgram(mProgram);
    		GLES20.glUniformMatrix4fv(muMVPMatrixHandle, 1, false, MatrixState.getFinalMatrix(), 0);
    		GLES20.glVertexAttribPointer(maPositionHandle, 3, GLES20.GL_FLOAT, false, 3 * 4, mVertexBuffer);
    		GLES20.glVertexAttribPointer(maTexCoorHandle, 2, GLES20.GL_FLOAT, false, 2 * 4, mTexCoorBuffer);
    		GLES20.glEnableVertexAttribArray(maPositionHandle);
    		GLES20.glEnableVertexAttribArray(maTexCoorHandle);
    		GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
    		GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, texId);
    		GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, vCount);
    	}
    
    	private float getCoor(int which, float vAngle, float hAngle) {
    		switch (which) {
    		case 0:// x
    			return (float) (R * UNIT_SIZE * Math.cos(Math.toRadians(vAngle)) * Math.cos(Math.toRadians(hAngle)));
    		case 1:// y
    			return (float) (R * UNIT_SIZE * Math.sin(Math.toRadians(vAngle)));
    		case 2:// z
    			return (float) (R * UNIT_SIZE * Math.cos(Math.toRadians(vAngle)) * Math.sin(Math.toRadians(hAngle)));
    		}
    		return 0;
    	}
    
    	// 自动切分纹理产生纹理数组的方法
    	public float[] generateTexCoor(int bw, int bh) {
    		float[] result = new float[bw * bh * 6 * 2];
    		float sizew = 1.0f / bw;// 列数
    		float sizeh = 1.0f / bh;// 行数
    		int c = 0;
    		for (int i = 0; i < bh; i++) {
    			for (int j = 0; j < bw; j++) {
    				// 每行列一个矩形，由两个三角形构成，共六个点，12个纹理坐标
    				float s = j * sizew;
    				float t = i * sizeh;
    				result[c++] = s;
    				result[c++] = t;
    				result[c++] = s;
    				result[c++] = t + sizeh;
    				result[c++] = s + sizew;
    				result[c++] = t;
    				result[c++] = s + sizew;
    				result[c++] = t;
    				result[c++] = s;
    				result[c++] = t + sizeh;
    				result[c++] = s + sizew;
    				result[c++] = t + sizeh;
    			}
    		}
    		return result;
    	}
    
    }

二、顶点着色器：

uniform mat4 uMVPMatrix;
    attribute vec3 aPosition;
    attribute vec2 aTexCoor;
    varying vec2 vTextureCoord;
    
    void main(){
        gl_Position=uMVPMatrix*vec4(aPosition,1); 
        vTextureCoord=aTexCoor;
    }

三、片源着色器：

precision mediump float;
    
    varying vec2 vTextureCoord;
    uniform sampler2D sTexture;
    
    void main(){
        gl_FragColor=texture2D(sTexture,vTextureCoord);
    }