前段时间项目中有用到OpenGLES进行开发的部分,因此花了2周的时间研究了下OpenGLES,写了个绘制2D图片的Demo,OpenGLES提供了android访问OpenGL的接口,也就是我们熟知的GLSurfaceView的使用,他实际上也是封装了JNI规范进行调用OpenGL的代码. 下面附完整Demo的代码
MainActivity.java
package com.example.draw2dimagedemo;import android.app.Activity;import android.opengl.GLSurfaceView;import android.os.Bundle;import android.view.Window;import android.view.WindowManager;import android.widget.RelativeLayout;public class MainActivity extends Activity { // Our OpenGL Surfaceview PRivate GLSurfaceView glSurfaceView; @Override protected void onCreate(Bundle savedInstanceState) { // Turn off the window's title bar requestWindowFeature(Window.FEATURE_NO_TITLE); // Super super.onCreate(savedInstanceState); // Fullscreen mode getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); // We create our Surfaceview for our OpenGL here. glSurfaceView = new GLSurf(this); // Set our view. setContentView(R.layout.activity_main); // Retrieve our Relative layout from our main layout we just set to our view. RelativeLayout layout = (RelativeLayout) findViewById(R.id.gamelayout); // Attach our surfaceview to our relative layout from our main layout. RelativeLayout.LayoutParams glParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT); layout.addView(glSurfaceView, glParams); } @Override protected void onPause() { super.onPause(); glSurfaceView.onPause(); } @Override protected void onResume() { super.onResume(); glSurfaceView.onResume(); }}MainActivity中需要注意的就是保持GlSurfaceView的生命周期和Activity的生命周期保持同步,也就是重写onPause()和onResume()方法去调用glsurfaceView的onPause()和onResume()方法.
GLSurf.java
package com.example.draw2dimagedemo;import android.content.Context;import android.opengl.GLSurfaceView;public class GLSurf extends GLSurfaceView { private final GLRenderer mRenderer; public GLSurf(Context context) { super(context); // Create an OpenGL ES 2.0 context. setEGLContextClientVersion(2); // Set the Renderer for drawing on the GLSurfaceView mRenderer = new GLRenderer(context); setRenderer(mRenderer); // Render the view only when there is a change in the drawing data setRenderMode(GLSurfaceView.RENDERMODE_CONTINUOUSLY); } @Override public void onPause() { super.onPause(); mRenderer.onPause(); } @Override public void onResume() { super.onResume(); mRenderer.onResume(); }}GLSurf中比较重要的一个方法是setRenderMode(),设置渲染模式,有两种模式 1.GLSurfaceView.RENDERMODE_CONTINUOUSLY GLSurfaceView以一定的时间不断渲染,这个是由GlsurfaceView内部控制的
2.GLSurfaceView.RENDERMODE_WHEN_DIRTY 当需要绘制的时候调用glSurfaceView.requestRender();去通知系统去更新渲染界面,实际上也就是去调用GLSurfaceView.Renderer中的onDrawFrame(GL10 gl10)方法.
GLRenderer.java
package com.example.draw2dimagedemo;import android.content.Context;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.opengl.GLES20;import android.opengl.GLSurfaceView.Renderer;import android.opengl.GLUtils;import android.opengl.Matrix;import java.nio.ByteBuffer;import java.nio.ByteOrder;import java.nio.FloatBuffer;import java.nio.ShortBuffer;import javax.microedition.khronos.egl.EGLConfig;import javax.microedition.khronos.opengles.GL10;public class GLRenderer implements Renderer { // Our matrices private final float[] mtrxProjection = new float[16]; private final float[] mtrxView = new float[16]; private final float[] mtrxProjectionAndView = new float[16]; // Geometric variables //第一张图片所对应的位置数组 public float vertices[] = new float[] //这里的适配问题需要dp和px的转化 {// 0.0f, 600f, 0.0f,// 0.0f, 0f, 0.0f,// 600f, 0f, 0.0f,// 600f, 600f, 0.0f, 0.0f,1184f,0.0f, 0.0f,928f,0.0f, 256f,928f,0.0f, 256f,1184f,0.0f, }; //第二张图片所对应的位置数组 public static float vertices1[] = new float[] {// 350f, 1184f, 0.0f,// 350f, 700f, 0.0f,// 720f, 700f, 0.0f,// 720f, 1184f, 0.0f, 256f,1184f,0.0f, 256f,928f,0.0f, 512f,928f,0.0f, 512f,1184f,0.0f, }; //第三张图片所对应的位置数组 public static float vertices2[] = new float[] {// 0f,700f,0.0f,// 0f,0f,0f,// 240f,0f,0f,// 240f,700f,0f 512f,1184f,0.0f, 512f,928f,0.0f, 768f,928f,0.0f, 768f,1184f,0.0f, }; //第四张图片所对应的位置数组 public static float vertices3[] = new float[] { 0.0f,928f,0.0f, 0.0f,672f,0.0f, 256f,672f,0.0f, 256f,928f,0.0f, }; //第五张图片所对应的位置数组 public static float vertices4[] = new float[] { 256f,928f,0.0f, 256f,672f,0.0f, 512f,672f,0.0f, 512f,928f,0.0f, }; //第六张图片所对应的位置数组 public static float vertices5[] = new float[] { 512f,928f,0.0f, 512f,672f,0.0f, 768f,672f,0.0f, 768f,928f,0.0f, }; //第7张图片所对应的位置数组 public static float vertices6[] = new float[] { 0f,672f,0.0f, 0f,416f,0.0f, 256f,416f,0.0f, 256f,672f,0.0f, }; //第8张图片所对应的位置数组 public static float vertices7[] = new float[] { 256f,672f,0.0f, 256f,416f,0.0f, 512f,416f,0.0f, 512f,672f,0.0f, }; //第9张图片所对应的位置数组 public static float vertices8[] = new float[] { 512f,672f,0.0f, 512f,416f,0.0f, 768f,416f,0.0f, 768f,672f,0.0f, }; //第10张图片所对应的位置数组 public static float vertices9[] = new float[] { 0.0f,416f,0.0f, 0.0f,160f,0.0f, 256f,160f,0.0f, 256f,416f,0.0f, }; //第11张图片所对应的位置数组 public static float vertices10[] = new float[] { 256f,416f,0.0f, 256f,160f,0.0f, 512f,160f,0.0f, 512f,416f,0.0f, }; //第12张图片所对应的位置数组 public static float vertices11[] = new float[] { 512f,416f,0.0f, 512f,160f,0.0f, 768f,160f,0.0f, 768f,416f,0.0f, }; //第13张图片所对应的位置数组 public static float vertices12[] = new float[] { 0.0f,160f,0.0f, 0.0f,-96f,0.0f, 256f,-96f,0.0f, 256f,160f,0.0f, }; //第14张图片所对应的位置数组 public static float vertices13[] = new float[] { 256f,160f,0.0f, 256f,-96f,0.0f, 512f,-96f,0.0f, 512f,160f,0.0f, }; //第15张图片所对应的位置数组 public static float vertices14[] = new float[] { 512f,160f,0.0f, 512f,-96f,0.0f, 768f,-96f,0.0f, 768f,160f,0.0f, }; public static short indices[]; // public static short indices1[];// public static float vertices1[]; public static float uvs[]; public FloatBuffer vertexBuffer; // public FloatBuffer vertexBuffer1; public ShortBuffer drawListBuffer; // public ShortBuffer drawListBuffer1; public FloatBuffer uvBuffer;// public FloatBuffer uvBuffer1;// private int program;// private int uColorLocation;// private int aPositionLocation;// private static final String U_COLOR = "u_Color";// private static final String A_POSITION = "a_Position"; // Our screenresolution float mScreenWidth = 1280; float mScreenHeight = 768; // Misc Context mContext; long mLastTime; int mProgram; private FloatBuffer mUvBuffer1; private FloatBuffer mVerticeBuffer; public GLRenderer(Context c) { mContext = c; mLastTime = System.currentTimeMillis() + 100; } public void onPause() { /* Do stuff to pause the renderer */ } public void onResume() { /* Do stuff to resume the renderer */ mLastTime = System.currentTimeMillis(); } @Override public void onDrawFrame(GL10 unused) { // Get the current time long now = System.currentTimeMillis(); // We should make sure we are valid and sane if (mLastTime > now) return; // Get the amount of time the last frame took. long elapsed = now - mLastTime; // Update our example // Render our example Render(mtrxProjectionAndView); // Save the current time to see how long it took :). mLastTime = now; } private void Render(float[] m) { // clear Screen and Depth Buffer, we have set the clear color as black. GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT); //绘制第一张图片的所有操作// // get handle to vertex shader's vPosition member int mPositionHandle = GLES20.glGetAttribLocation(riGraphicTools.sp_Image, "vPosition");//// // Enable generic vertex attribute array// GLES20.glEnableVertexAttribArray(mPositionHandle);//// // Prepare the triangle coordinate data// GLES20.glVertexAttribPointer(mPositionHandle, 3,// GLES20.GL_FLOAT, false,// 0, vertexBuffer);//// // Get handle to texture coordinates location int mTexCoordLoc = GLES20.glGetAttribLocation(riGraphicTools.sp_Image, "a_texCoord");//// // Enable generic vertex attribute array// GLES20.glEnableVertexAttribArray(mTexCoordLoc);//// // Prepare the texturecoordinates// GLES20.glVertexAttribPointer(mTexCoordLoc, 2, GLES20.GL_FLOAT,// false,// 0, mUvBuffer1);//// // Get handle to shape's transformation matrix// int mtrxhandle = GLES20.glGetUniformLocation(riGraphicTools.sp_Image, "uMVPMatrix");//// // Apply the projection and view transformation// GLES20.glUniformMatrix4fv(mtrxhandle, 1, false, m, 0);//// // Get handle to textures locations// int mSamplerLoc = GLES20.glGetUniformLocation(riGraphicTools.sp_Image, "s_texture"); // TODO// String vertexShaderSource = TextResourceReader// .readTextFileFromResource(mContext, R.raw.simple_vertex_shader);// String fragmentShaderSource = TextResourceReader// .readTextFileFromResource(mContext, R.raw.simple_fragment_shader);//// int vertexShader = ShaderHelper.compileVertexShader(vertexShaderSource);// int fragmentShader = ShaderHelper.compileFragmentShader(fragmentShaderSource);//// program = ShaderHelper.linkProgram(vertexShader, fragmentShader);//// if (LoggerConfig.ON) {// ShaderHelper.validateProgram(program);// }//// glUseProgram(program);//// uColorLocation = glGetUniformLocation(program, U_COLOR);//// aPositionLocation = glGetAttribLocation(program, A_POSITION); // Set the sampler texture unit to 0, where we have saved the texture.// GLES20.glUniform1i(mSamplerLoc, 0); //设置绘制平面图形的颜色 //GLES20.glUniform4f(uColorLocation,1.0f,1.0f,1.0f,1.0f);// GLES20.glUniform4f(mtrxhandle,1.0f,1.0f,1.0f,1.0f); // Draw the triangle// GLES20.glDrawElements(GLES20.GL_TRIANGLES, indices.length,// GLES20.GL_UNSIGNED_SHORT, drawListBuffer);//// // Disable vertex array// GLES20.glDisableVertexAttribArray(mPositionHandle);// GLES20.glDisableVertexAttribArray(mTexCoordLoc); //绘制第二张图片 // get handle to vertex shader's vPosition member //拼接图片 one // Create the triangles mVerticeBuffer = setupTriangle(vertices); // Create the image information mUvBuffer1 = setupImage(R.drawable.mapa1); drawBitmap(m, mPositionHandle, mTexCoordLoc, mVerticeBuffer, mUvBuffer1, indices); FloatBuffer VertexPositionBuffer20 = setupTriangle(vertices); FloatBuffer uvBuffer20 = setupImage(R.drawable.mapb1); drawBitmap(m, mPositionHandle, mTexCoordLoc, VertexPositionBuffer20, uvBuffer20, indices); //拼接图片 two FloatBuffer VertexPositionBuffer1 = setupTriangle(vertices1); FloatBuffer uvBuffer1 = setupImage(R.drawable.mapa1); drawBitmap(m, mPositionHandle, mTexCoordLoc, VertexPositionBuffer1, uvBuffer1, indices); //拼接图片 three FloatBuffer VertexPositionBuffer2 = setupTriangle(vertices2); FloatBuffer uvBuffer2 = setupImage(R.drawable.mapa3); drawBitmap(m, mPositionHandle, mTexCoordLoc, VertexPositionBuffer2, uvBuffer2, indices); //拼接图片 four FloatBuffer VertexPositionBuffer3 = setupTriangle(vertices3); FloatBuffer uvBuffer3 = setupImage(R.drawable.mapa4); drawBitmap(m, mPositionHandle, mTexCoordLoc, VertexPositionBuffer3, uvBuffer3, indices); //拼接图片 five FloatBuffer VertexPositionBuffer4 = setupTriangle(vertices4); FloatBuffer uvBuffer4 = setupImage(R.drawable.mapa5); drawBitmap(m, mPositionHandle, mTexCoordLoc, VertexPositionBuffer4, uvBuffer4, indices); //拼接图片 six FloatBuffer VertexPositionBuffer5 = setupTriangle(vertices5); FloatBuffer uvBuffer5 = setupImage(R.drawable.mapa1); drawBitmap(m, mPositionHandle, mTexCoordLoc, VertexPositionBuffer5, uvBuffer5, indices); //拼接图片 7 FloatBuffer VertexPositionBuffer6 = setupTriangle(vertices6); FloatBuffer uvBuffer6 = setupImage(R.drawable.mapa1); drawBitmap(m, mPositionHandle, mTexCoordLoc, VertexPositionBuffer6, uvBuffer6, indices); //拼接图片 8 FloatBuffer VertexPositionBuffer7 = setupTriangle(vertices7); FloatBuffer uvBuffer7 = setupImage(R.drawable.mapa1); drawBitmap(m, mPositionHandle, mTexCoordLoc, VertexPositionBuffer7, uvBuffer7, indices); //拼接图片 9 FloatBuffer VertexPositionBuffer8 = setupTriangle(vertices8); FloatBuffer uvBuffer8 = setupImage(R.drawable.mapa1); drawBitmap(m, mPositionHandle, mTexCoordLoc, VertexPositionBuffer8, uvBuffer8, indices); //拼接图片 10 FloatBuffer VertexPositionBuffer9 = setupTriangle(vertices9); FloatBuffer uvBuffer9 = setupImage(R.drawable.mapa1); drawBitmap(m, mPositionHandle, mTexCoordLoc, VertexPositionBuffer9, uvBuffer9, indices); //拼接图片 11 FloatBuffer VertexPositionBuffer10 = setupTriangle(vertices10); FloatBuffer uvBuffer10 = setupImage(R.drawable.mapa1); drawBitmap(m, mPositionHandle, mTexCoordLoc, VertexPositionBuffer10, uvBuffer10, indices); //拼接图片 12 FloatBuffer VertexPositionBuffer11 = setupTriangle(vertices11); FloatBuffer uvBuffer11 = setupImage(R.drawable.mapa1); drawBitmap(m, mPositionHandle, mTexCoordLoc, VertexPositionBuffer11, uvBuffer11, indices); //拼接图片 13 FloatBuffer VertexPositionBuffer12 = setupTriangle(vertices12); FloatBuffer uvBuffer12 = setupImage(R.drawable.mapb1); drawBitmap(m, mPositionHandle, mTexCoordLoc, VertexPositionBuffer12, uvBuffer12, indices); //拼接图片 14 FloatBuffer VertexPositionBuffer13 = setupTriangle(vertices13); FloatBuffer uvBuffer13 = setupImage(R.drawable.mapb1); drawBitmap(m, mPositionHandle, mTexCoordLoc, VertexPositionBuffer13, uvBuffer13, indices); //拼接图片 15 FloatBuffer VertexPositionBuffer14 = setupTriangle(vertices14); FloatBuffer uvBuffer14 = setupImage(R.drawable.mapb1); drawBitmap(m, mPositionHandle, mTexCoordLoc, VertexPositionBuffer14, uvBuffer14, indices); } private void drawBitmap(float[] m, int mPositionHandle, int mTexCoordLoc, FloatBuffer vertexBufferPosition, FloatBuffer uvBuffer1, short[] shortsIndices) { int mPositionHandle1 = GLES20.glGetAttribLocation(riGraphicTools.sp_Image, "vPosition"); // Enable generic vertex attribute array GLES20.glEnableVertexAttribArray(mPositionHandle1); // Prepare the triangle coordinate data 绘制了两个三角形 GLES20.glVertexAttribPointer(mPositionHandle, 3, GLES20.GL_FLOAT, false, 0, vertexBufferPosition); // Get handle to texture coordinates location int mTexCoordLoc1 = GLES20.glGetAttribLocation(riGraphicTools.sp_Image, "a_texCoord"); // Enable generic vertex attribute array GLES20.glEnableVertexAttribArray(mTexCoordLoc1); // Prepare the texturecoordinates GLES20.glVertexAttribPointer(mTexCoordLoc, 2, GLES20.GL_FLOAT, false, 0, uvBuffer1); // Get handle to shape's transformation matrix int mtrxhandle1 = GLES20.glGetUniformLocation(riGraphicTools.sp_Image, "uMVPMatrix"); // Apply the projection and view transformation GLES20.glUniformMatrix4fv(mtrxhandle1, 1, false, m, 0); // Get handle to textures locations int mSamplerLoc1 = GLES20.glGetUniformLocation(riGraphicTools.sp_Image, "s_texture"); // Set the sampler texture unit to 0, where we have saved the texture. GLES20.glUniform1i(mSamplerLoc1, 0); // Draw the triangle GLES20.glDrawElements(GLES20.GL_TRIANGLES, shortsIndices.length, GLES20.GL_UNSIGNED_SHORT, drawListBuffer); // Disable vertex array GLES20.glDisableVertexAttribArray(mPositionHandle); GLES20.glDisableVertexAttribArray(mTexCoordLoc); } @Override public void onSurfaceChanged(GL10 gl, int width, int height) { // We need to know the current width and height. mScreenWidth = width; mScreenHeight = height; // Redo the Viewport, making it fullscreen. GLES20.glViewport(0, 0, (int) width, (int) height); // Clear our matrices for (int i = 0; i < 16; i++) { mtrxProjection[i] = 0.0f; mtrxView[i] = 0.0f; mtrxProjectionAndView[i] = 0.0f; } //矩阵的偏移 // Setup our screen width and height for normal sprite translation. Matrix.orthoM(mtrxProjection, 0, 0f, mScreenWidth, 0.0f, mScreenHeight, 0, 50); // Set the camera position (View matrix) Matrix.setLookAtM(mtrxView, 0, 0f, 0f, 1f, 0f, 0f, 0f, 0f, 1.0f, 0.0f); // Calculate the projection and view transformation Matrix.multiplyMM(mtrxProjectionAndView, 0, mtrxProjection, 0, mtrxView, 0); } @Override public void onSurfaceCreated(GL10 gl, EGLConfig config) { // Set the clear color to black GLES20.glClearColor(1.0f, 1.0f, 1.0f, 1); // Create the shaders, solid color int vertexShader = riGraphicTools.loadShader(GLES20.GL_VERTEX_SHADER, riGraphicTools.vs_SolidColor); int fragmentShader = riGraphicTools.loadShader(GLES20.GL_FRAGMENT_SHADER, riGraphicTools.fs_SolidColor); riGraphicTools.sp_SolidColor = GLES20.glCreateProgram(); // create empty OpenGL ES Program GLES20.glAttachShader(riGraphicTools.sp_SolidColor, vertexShader); // add the vertex shader to program GLES20.glAttachShader(riGraphicTools.sp_SolidColor, fragmentShader); // add the fragment shader to program GLES20.glLinkProgram(riGraphicTools.sp_SolidColor); // creates OpenGL ES program executables // Create the shaders, images vertexShader = riGraphicTools.loadShader(GLES20.GL_VERTEX_SHADER, riGraphicTools.vs_Image); fragmentShader = riGraphicTools.loadShader(GLES20.GL_FRAGMENT_SHADER, riGraphicTools.fs_Image); riGraphicTools.sp_Image = GLES20.glCreateProgram(); // create empty OpenGL ES Program GLES20.glAttachShader(riGraphicTools.sp_Image, vertexShader); // add the vertex shader to program GLES20.glAttachShader(riGraphicTools.sp_Image, fragmentShader); // add the fragment shader to program GLES20.glLinkProgram(riGraphicTools.sp_Image); // creates OpenGL ES program executables // Set our shader programm GLES20.glUseProgram(riGraphicTools.sp_Image); } public FloatBuffer setupImage(int id) { // Create our UV coordinates. //这里是干嘛的? 很关键 uvs = new float[]{ 0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f, 0.0f }; // The texture buffer ByteBuffer bb = ByteBuffer.allocateDirect(uvs.length * 4); bb.order(ByteOrder.nativeOrder()); uvBuffer = bb.asFloatBuffer(); uvBuffer.put(uvs); uvBuffer.position(0); // Generate Textures, if more needed, alter these numbers. int[] texturenames = new int[1]; GLES20.glGenTextures(1, texturenames, 0); // Retrieve our image from resources.// int id = mContext.getResources().getIdentifier("drawable/mapa1", null, mContext.getPackageName()); // Temporary create a bitmap //通过options改变图片的参数 BitmapFactory.Options opts = new BitmapFactory.Options(); opts.inPreferredConfig = Bitmap.Config.ARGB_8888; Bitmap bmp = BitmapFactory.decodeResource(mContext.getResources(), id,opts); // Bind texture to texturename GLES20.glActiveTexture(GLES20.GL_TEXTURE0); GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, texturenames[0]); // Set filtering 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); // Load the bitmap into the bound texture. GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bmp, 0); //开启gl的两个功能 使图片变成透明的 GLES20.glBlendFunc(GLES20.GL_SRC_ALPHA,GLES20.GL_ONE_MINUS_SRC_ALPHA); GLES20.glEnable(GLES20.GL_BLEND); // We are done using the bitmap so we should recycle it. bmp.recycle(); return uvBuffer; } public FloatBuffer setupTriangle(float[] verticesPosition) { // We have to create the vertices of our triangle.// vertices = new float[]// { 400.0f, 300f, 0.0f,// 400.0f, 200f, 0.0f,// 500f, 200f, 0.0f,// 500f, 300f, 0.0f,// };// 0.0f, 0.0f, 0.0f,// 0f, 1280f, 0.0f,// 720f, 1280f, 0.0f,// 7200f, 0.0f, 0.0f, indices = new short[]{0, 1, 2, 0, 2, 3}; // The order of vertexrendering. // The vertex buffer. ByteBuffer bb = ByteBuffer.allocateDirect(verticesPosition.length * 4); bb.order(ByteOrder.nativeOrder()); vertexBuffer = bb.asFloatBuffer(); vertexBuffer.put(verticesPosition); vertexBuffer.position(0); // initialize byte buffer for the draw list ByteBuffer dlb = ByteBuffer.allocateDirect(indices.length * 2); dlb.order(ByteOrder.nativeOrder()); drawListBuffer = dlb.asShortBuffer(); drawListBuffer.put(indices); drawListBuffer.position(0); // We have to create the vertices of our triangle.// vertices1 = new float[]// { 600.0f, 200f, 0.0f,// 600.0f, 100f, 0.0f,// 700f, 100f, 0.0f,// 700f, 200f, 0.0f,// };//// indices1 = new short[]{0, 1, 2, 0, 2, 3}; // The order of vertexrendering.//// // The vertex buffer.// ByteBuffer bb1 = ByteBuffer.allocateDirect(vertices1.length * 4);// bb1.order(ByteOrder.nativeOrder());// vertexBuffer1 = bb1.asFloatBuffer();// vertexBuffer1.put(vertices1);// vertexBuffer1.position(0);//// // initialize byte buffer for the draw list// ByteBuffer dlb1 = ByteBuffer.allocateDirect(indices1.length * 2);// dlb1.order(ByteOrder.nativeOrder());// drawListBuffer1 = dlb.asShortBuffer();// drawListBuffer1.put(indices1);// drawListBuffer1.position(0); return vertexBuffer; }}GLRenderer类中重要的方法有三个 1.onSurfaceChanged(),创建Render时调用的方法 2.onSurfaceChanged(),当Surface改变尺寸的时候 3.onDrawFrame(),渲染时调用的方法
其他重要方法代码中都有详细注释,自行查看
riGraphicTools.java
package com.example.draw2dimagedemo;import android.opengl.GLES20;public class riGraphicTools { // Program variables public static int sp_SolidColor; public static int sp_Image; /* SHADER Solid * * This shader is for rendering a colored primitive. * */ public static final String vs_SolidColor = "uniform mat4 uMVPMatrix;" + "attribute vec4 vPosition;" + "void main() {" + " gl_Position = uMVPMatrix * vPosition;" + "}"; public static final String fs_SolidColor = "precision mediump float;" + "void main() {" + " gl_FragColor = vec4(0.5,0,0,1);" + "}"; /* SHADER Image * * This shader is for rendering 2D images straight from a texture * No additional effects. * */ public static final String vs_Image = "uniform mat4 uMVPMatrix;" + "attribute vec4 vPosition;" + "attribute vec2 a_texCoord;" + "varying vec2 v_texCoord;" + "void main() {" + " gl_Position = uMVPMatrix * vPosition;" + " v_texCoord = a_texCoord;" + "}"; public static final String fs_Image = "precision mediump float;" + "varying vec2 v_texCoord;" + "uniform sampler2D s_texture;" + "void main() {" + " gl_FragColor = texture2D( s_texture, v_texCoord );" + "}"; public static int loadShader(int type, String shaderCode){ // create a vertex shader type (GLES20.GL_VERTEX_SHADER) // or a fragment shader type (GLES20.GL_FRAGMENT_SHADER) int shader = GLES20.glCreateShader(type); // add the source code to the shader and compile it GLES20.glShaderSource(shader, shaderCode); GLES20.glCompileShader(shader); // return the shader return shader; }}riGraphicTools这个类替代了shader着色语言的作用,当然你也可以自己写shader语句 另外两个重要的概念就是Position数组和color数组.根据代码注释可看出来这两个数组的重要性.代码中需要的图片资源可以自行替换.
如有不足之处请指正,谢谢!
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