- 把shader代码写入raw里面
vertex_shader.glsl
attribute vec4 av_Position;//顶点位置
attribute vec2 af_Position;//纹理位置
varying vec2 v_texPo;//纹理位置 与fragment_shader交互
void main() {
v_texPo = af_Position;
gl_Position = av_Position;
}
fragment_shader.glsl
precision mediump float;//精度 为float
varying vec2 v_texPo;//纹理位置 接收于vertex_shader
uniform sampler2D sTexture;//纹理
void main() {
gl_FragColor=texture2D(sTexture, v_texPo);
}
- 写入数据,注意纹理映射
纹理坐标系
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.opengl.GLES20;
import android.opengl.GLUtils;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
//纹理 根据坐标系映射
public class BitmapTexture {
//顶点坐标
static float vertexData[] = { // in counterclockwise order:
-1f, -1f, 0.0f, // bottom left
1f, -1f, 0.0f, // bottom right
-1f, 1f, 0.0f, // top left
1f, 1f, 0.0f, // top right
};
//纹理坐标 对应顶点坐标 与之映射
static float textureData[] = { // in counterclockwise order:
0f, 1f, 0.0f, // bottom left
1f, 1f, 0.0f, // bottom right
0f, 0f, 0.0f, // top left
1f, 0f, 0.0f, // top right
};
//每一次取点的时候取几个点
static final int COORDS_PER_VERTEX = 3;
private final int vertexCount = vertexData.length / COORDS_PER_VERTEX;
//每一次取的总的点 大小
private final int vertexStride = COORDS_PER_VERTEX * 4; // 4 bytes per vertex
private Context context;
//位置
private FloatBuffer vertexBuffer;
//纹理
private FloatBuffer textureBuffer;
private int program;
private int avPosition;
//纹理位置
private int afPosition;
//纹理id
private int textureId;
public BitmapTexture(Context context) {
this.context = context;
vertexBuffer = ByteBuffer.allocateDirect(vertexData.length * 4)
.order(ByteOrder.nativeOrder())
.asFloatBuffer()
.put(vertexData);
vertexBuffer.position(0);
textureBuffer = ByteBuffer.allocateDirect(textureData.length * 4)
.order(ByteOrder.nativeOrder())
.asFloatBuffer()
.put(textureData);
textureBuffer.position(0);
}
public void onSurfaceCreated() {
String vertexSource = ShaderUtil.readRawTxt(context, R.raw.vertex_shader);
String fragmentSource = ShaderUtil.readRawTxt(context, R.raw.fragment_shader);
program = ShaderUtil.createProgram(vertexSource, fragmentSource);
if (program > 0) {
//获取顶点坐标字段
avPosition = GLES20.glGetAttribLocation(program, "av_Position");
//获取纹理坐标字段
afPosition = GLES20.glGetAttribLocation(program, "af_Position");
int[] textureIds = new int[1];
//创建纹理
GLES20.glGenTextures(1, textureIds, 0);
if (textureIds[0] == 0) {
return;
}
textureId = textureIds[0];
//绑定纹理
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureId);
//环绕（超出纹理坐标范围） （s==x t==y GL_REPEAT 重复）
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_REPEAT);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_REPEAT);
//过滤（纹理像素映射到坐标点） （缩小、放大：GL_LINEAR线性）
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);
Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), R.mipmap.bg);
if (bitmap == null) {
return;
}
//设置纹理为2d图片
GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0);
}
}
public void draw() {
//使用程序
GLES20.glUseProgram(program);
GLES20.glEnableVertexAttribArray(avPosition);
GLES20.glEnableVertexAttribArray(afPosition);
//设置顶点位置值
GLES20.glVertexAttribPointer(avPosition, COORDS_PER_VERTEX, GLES20.GL_FLOAT, false, vertexStride, vertexBuffer);
//设置纹理位置值
GLES20.glVertexAttribPointer(afPosition, COORDS_PER_VERTEX, GLES20.GL_FLOAT, false, vertexStride, textureBuffer);
//绘制 GLES20.GL_TRIANGLE_STRIP:复用坐标
GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, vertexCount);
GLES20.glDisableVertexAttribArray(avPosition);
GLES20.glDisableVertexAttribArray(afPosition);
}
}
ShaderUtil.java
import android.content.Context;
import android.opengl.GLES20;
import android.util.Log;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
public class ShaderUtil {
private static final String TAG = "ShaderUtil";
public static String readRawTxt(Context context, int rawId) {
InputStream inputStream = context.getResources().openRawResource(rawId);
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
StringBuffer sb = new StringBuffer();
String line;
try {
while ((line = reader.readLine()) != null) {
sb.append(line).append("\n");
}
reader.close();
} catch (Exception e) {
e.printStackTrace();
}
return sb.toString();
}
public static int loadShader(int shaderType, String source) {
// create a vertex shader type (GLES20.GL_VERTEX_SHADER)
// or a fragment shader type (GLES20.GL_FRAGMENT_SHADER)
int shader = GLES20.glCreateShader(shaderType);
if (shader != 0) {
//添加代码到shader
GLES20.glShaderSource(shader, source);
//编译shader
GLES20.glCompileShader(shader);
int[] compile = new int[1];
//检测是否编译成功
GLES20.glGetShaderiv(shader, GLES20.GL_COMPILE_STATUS, compile, 0);
if (compile[0] != GLES20.GL_TRUE) {
Log.d(TAG, "shader compile error");
GLES20.glDeleteShader(shader);
shader = 0;
}
}
return shader;
}
public static int createProgram(String vertexSource, String fragmentSource) {
//获取vertex shader
int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, vertexSource);
if (vertexShader == 0) {
return 0;
}
//获取fragment shader
int fragmentShader = loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentSource);
if (fragmentShader == 0) {
return 0;
}
//创建一个空的渲染程序
int program = GLES20.glCreateProgram();
if (program != 0) {
//添加vertexShader到渲染程序
GLES20.glAttachShader(program, vertexShader);
//添加fragmentShader到渲染程序
GLES20.glAttachShader(program, fragmentShader);
//关联为可执行渲染程序
GLES20.glLinkProgram(program);
int[] linsStatus = new int[1];
//检测是否关联成功
GLES20.glGetProgramiv(program, GLES20.GL_LINK_STATUS, linsStatus, 0);
if (linsStatus[0] != GLES20.GL_TRUE) {
Log.d(TAG, "link program error");
GLES20.glDeleteProgram(program);
program = 0;
}
}
return program;
}
}
- Render书写
MyRender.java
import android.content.Context;
import android.opengl.GLES20;
import android.opengl.GLSurfaceView;
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;
public class MyRender implements GLSurfaceView.Renderer {
private Context context;
private BitmapTexture bitmapTexture;
public MyRender(Context context) {
this.context = context;
}
@Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
bitmapTexture = new BitmapTexture(context);
bitmapTexture.onSurfaceCreated();
}
@Override
public void onSurfaceChanged(GL10 gl, int width, int height) {
//宽高
GLES20.glViewport(0, 0, width, height);
}
@Override
public void onDrawFrame(GL10 gl) {
//清空颜色
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
//设置背景颜色
// GLES20.glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
bitmapTexture.draw();
}
}
- GLSurfaceView引用Renderer
MyGLSurfaceView.java
import android.content.Context;
import android.opengl.GLSurfaceView;
import android.util.AttributeSet;
public class MyGLSurfaceView extends GLSurfaceView{
public MyGLSurfaceView(Context context) {
this(context, null);
}
public MyGLSurfaceView(Context context, AttributeSet attrs) {
super(context, attrs);
setEGLContextClientVersion(2);
setRenderer(new MyRender(context));
}
}
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