Android视频处理之MediaCodec-6-给视频加水印
这篇文章一起来看下如果给一个视频文件加水印，然后新生成一个文件。方法其实很简单：解码视频->opengl绘制水印->编码视频->合成新视频。
通过前面的文章，其实我们都已经基本了解了这几个步骤的做法。
解码视频
MediaCodec(Decoder) 配置OutputSurface，解码视频到Surface，然后通过OpenGL去绘制这一帧数据
编码视频
MediaCodec(Encoder)配置InputSurface，编码OutputSurface绘制的帧数据。
合成视频
MediaMuxer合成MediaCodec(Encoder)编码过后的数据
所以本篇文章就主要是讲解怎么通过OpenGL去绘制水印，理论上MediaCodec自己就是编解码器，只有和OpenGL结合才能达到对视频处理的目的。
在android上，视频流和Camera使用输出的texture是一种特殊的格式，纹理类型是GL_TEXTURE_EXTERNAL_OES，而水印一般是图片，纹理类型是区别于它的我们经常使用的GL_TEXTURE_2D，专门针对2D图形绘制的。
因为我们是给视频帧加水印，而水印一般是一张小图，所以是需要知道水印的位置的。在绘制的时候需要调用glViewPort去设置水印位置。
GLES20.glViewport(bitmap.mOffX, bitmap.mOffY, bitmap.mWidth, bitmap.mHeight);绘制的shader也需要用2D类型的
private static final String FRAGMENT_2D_SHADER =
"precision mediump float;\n" + // highp here doesn't seem to matter
"varying vec2 vTextureCoord;\n" +
"uniform sampler2D sTexture;\n" +
"void main() {\n" +
" gl_FragColor = texture2D(sTexture, vTextureCoord);\n" +
"}\n";水印实际上是图片叠加，在OpenGL中专业名词叫做“混合”（Blend ），Blend 混合是将源色和目标色以某种方式混合生成特效的技术，常用来绘制透明或半透明的物体，所以这里我们需要启用混合功能
GLES20.glEnable(GLES20.GL_BLEND);然后通过texImage2D绘制图片
GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0);//让图片和纹理关联起来，加载到OpenGl空间中绘制水印完整代码如下：
/**
* Draws the external texture in SurfaceTexture onto the current EGL surface.
*/
public void drawFrame(SurfaceTexture st, boolean invert, Bitmap bitmap) {
checkGlError("onDrawFrame start");
st.getTransformMatrix(mSTMatrix);
if (invert) {
mSTMatrix[5] = -mSTMatrix[5];
mSTMatrix[13] = 1.0f - mSTMatrix[13];
}
GLES20.glUseProgram(mProgram);
checkGlError("glUseProgram");
GLES20.glEnable(GLES20.GL_BLEND);
GlUtil.checkGlError("glEnable");
GLES20.glBlendFunc(GLES20.GL_ONE, GLES20.GL_ONE_MINUS_SRC_ALPHA);
GlUtil.checkGlError("glBlendFunc");
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
GLES20.glBindTexture(mTargetTextureType, mTextureID);
mTriangleVertices.position(TRIANGLE_VERTICES_DATA_POS_OFFSET);
GLES20.glVertexAttribPointer(maPositionHandle, 3, GLES20.GL_FLOAT, false,
TRIANGLE_VERTICES_DATA_STRIDE_BYTES, mTriangleVertices);
checkGlError("glVertexAttribPointer maPosition");
GLES20.glEnableVertexAttribArray(maPositionHandle);
checkGlError("glEnableVertexAttribArray maPositionHandle");
mTriangleVertices.position(TRIANGLE_VERTICES_DATA_UV_OFFSET);
GLES20.glVertexAttribPointer(maTextureHandle, 2, GLES20.GL_FLOAT, false,
TRIANGLE_VERTICES_DATA_STRIDE_BYTES, mTriangleVertices);
checkGlError("glVertexAttribPointer maTextureHandle");
GLES20.glEnableVertexAttribArray(maTextureHandle);
checkGlError("glEnableVertexAttribArray maTextureHandle");
Matrix.setIdentityM(mMVPMatrix, 0);
GLES20.glUniformMatrix4fv(muMVPMatrixHandle, 1, false, mMVPMatrix, 0);
GLES20.glUniformMatrix4fv(muSTMatrixHandle, 1, false, mSTMatrix, 0);
if (bitmap != null) {
//上面是纹理贴图的取样方式，包括拉伸方式，取临近值和线性值
GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0);//让图片和纹理关联起来，加载到OpenGl空间中
}
GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
checkGlError("glDrawArrays");
GLES20.glFlush();
GLES20.glDisable(GLES20.GL_BLEND);
GLES20.glDisableVertexAttribArray(maPositionHandle);
GLES20.glDisableVertexAttribArray(maTextureHandle);
GLES20.glBindTexture(mTargetTextureType, 0);
GLES20.glUseProgram(0);
}当视频帧和水印都绘制到OpenGL空间中后，我们就可以通过encoder的InputSurface.swapBuffer去把数据刷新到InputSurface，然后encoder收到数据进行编码，Muxer进行合成，最终生成我们需要的加了水印视频文件。
转换代码
大家可以调用下面这种方式进行测试
new Mp4Converter().convert("/sdcard/test.mp4", "/sdcard/test_output.mp4");Mp4Converter.java
请参考《Android视频处理之MediaCodec-5-生成mp4视频》
绘制代码
CodecOutputSurface.java
package demo.mediacodec.xueting.com.mediacodecdemo;
import android.graphics.Bitmap;
import android.graphics.SurfaceTexture;
import android.opengl.EGL14;
import android.opengl.EGLConfig;
import android.opengl.EGLContext;
import android.opengl.EGLDisplay;
import android.opengl.EGLSurface;
import android.opengl.GLES11Ext;
import android.opengl.GLES20;
import android.opengl.GLUtils;
import android.opengl.Matrix;
import android.util.Log;
import android.view.Surface;
import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.util.ArrayList;
import java.util.List;
/**
* Holds state associated with a Surface used for MediaCodec decoder output.
* <p>
* The constructor for this class will prepare GL, create a SurfaceTexture,
* and then create a Surface for that SurfaceTexture. The Surface can be passed to
* MediaCodec.configure() to receive decoder output. When a frame arrives, we latch the
* texture with updateTexImage(), then render the texture with GL to a pbuffer.
* <p>
* By default, the Surface will be using a BufferQueue in asynchronous mode, so we
* can potentially drop frames.
*/
public class CodecOutputSurface
implements SurfaceTexture.OnFrameAvailableListener {
private static final String TAG = CodecOutputSurface.class.getSimpleName();
private static final boolean DEBUG = true;
private STextureRender mTextureRender;
private STextureRender mTextureRender2D;
private SurfaceTexture mSurfaceTexture;
private Surface mSurface;
private EGLDisplay mEGLDisplay = EGL14.EGL_NO_DISPLAY;
private EGLContext mEGLContext = EGL14.EGL_NO_CONTEXT;
private EGLSurface mEGLSurface = EGL14.EGL_NO_SURFACE;
int mWidth;
int mHeight;
private Object mFrameSyncObject = new Object(); // guards mFrameAvailable
private boolean mFrameAvailable;
private ByteBuffer mPixelBuf; // used by saveFrame()
private List<Texture2DBitmap> mExternalImgs;
/**
* Creates a CodecOutputSurface backed by a pbuffer with the specified dimensions. The
* new EGL context and surface will be made current. Creates a Surface that can be passed
* to MediaCodec.configure().
*/
public CodecOutputSurface(int width, int height) {
if (width <= 0 || height <= 0) {
throw new IllegalArgumentException();
}
mWidth = width;
mHeight = height;
eglSetup();
makeCurrent();
setup();
}
public CodecOutputSurface() {
setup();
}
/**
* Creates interconnected instances of TextureRender, SurfaceTexture, and Surface.
*/
private void setup() {
mTextureRender = new STextureRender(STextureRender.SHADER_OES);
mTextureRender.surfaceCreated();
mTextureRender2D = new STextureRender(STextureRender.SHADER_2D);
mTextureRender2D.surfaceCreated();
if (DEBUG) Log.d(TAG, "textureID=" + mTextureRender.getTextureId());
mSurfaceTexture = new SurfaceTexture(mTextureRender.getTextureId());
// This doesn't work if this object is created on the thread that CTS started for
// these test cases.
//
// The CTS-created thread has a Looper, and the SurfaceTexture constructor will
// create a Handler that uses it. The "frame available" message is delivered
// there, but since we're not a Looper-based thread we'll never see it. For
// this to do anything useful, CodecOutputSurface must be created on a thread without
// a Looper, so that SurfaceTexture uses the main application Looper instead.
//
// Java language note: passing "this" out of a constructor is generally unwise,
// but we should be able to get away with it here.
mSurfaceTexture.setOnFrameAvailableListener(this);
mSurface = new Surface(mSurfaceTexture);
mPixelBuf = ByteBuffer.allocateDirect(mWidth * mHeight * 4);
mPixelBuf.order(ByteOrder.LITTLE_ENDIAN);
}
/**
* Prepares EGL. We want a GLES 2.0 context and a surface that supports pbuffer.
*/
private void eglSetup() {
mEGLDisplay = EGL14.eglGetDisplay(EGL14.EGL_DEFAULT_DISPLAY);
if (mEGLDisplay == EGL14.EGL_NO_DISPLAY) {
throw new RuntimeException("unable to get EGL14 display");
}
int[] version = new int[2];
if (!EGL14.eglInitialize(mEGLDisplay, version, 0, version, 1)) {
mEGLDisplay = null;
throw new RuntimeException("unable to initialize EGL14");
}
// Configure EGL for pbuffer and OpenGL ES 2.0, 24-bit RGB.
int[] attribList = {
EGL14.EGL_RED_SIZE, 8,
EGL14.EGL_GREEN_SIZE, 8,
EGL14.EGL_BLUE_SIZE, 8,
EGL14.EGL_ALPHA_SIZE, 8,
EGL14.EGL_RENDERABLE_TYPE, EGL14.EGL_OPENGL_ES2_BIT,
EGL14.EGL_SURFACE_TYPE, EGL14.EGL_PBUFFER_BIT,
EGL14.EGL_NONE
};
EGLConfig[] configs = new EGLConfig[1];
int[] numConfigs = new int[1];
if (!EGL14.eglChooseConfig(mEGLDisplay, attribList, 0, configs, 0, configs.length,
numConfigs, 0)) {
throw new RuntimeException("unable to find RGB888+recordable ES2 EGL config");
}
// Configure context for OpenGL ES 2.0.
int[] attrib_list = {
EGL14.EGL_CONTEXT_CLIENT_VERSION, 2,
EGL14.EGL_NONE
};
mEGLContext = EGL14.eglCreateContext(mEGLDisplay, configs[0], EGL14.EGL_NO_CONTEXT,
attrib_list, 0);
checkEglError("eglCreateContext");
if (mEGLContext == null) {
throw new RuntimeException("null context");
}
// Create a pbuffer surface.
int[] surfaceAttribs = {
EGL14.EGL_WIDTH, mWidth,
EGL14.EGL_HEIGHT, mHeight,
EGL14.EGL_NONE
};
mEGLSurface = EGL14.eglCreatePbufferSurface(mEGLDisplay, configs[0], surfaceAttribs, 0);
checkEglError("eglCreatePbufferSurface");
if (mEGLSurface == null) {
throw new RuntimeException("surface was null");
}
}
/**
* Discard all resources held by this class, notably the EGL context.
*/
public void release() {
if (mEGLDisplay != EGL14.EGL_NO_DISPLAY) {
EGL14.eglDestroySurface(mEGLDisplay, mEGLSurface);
EGL14.eglDestroyContext(mEGLDisplay, mEGLContext);
EGL14.eglReleaseThread();
EGL14.eglTerminate(mEGLDisplay);
}
mEGLDisplay = EGL14.EGL_NO_DISPLAY;
mEGLContext = EGL14.EGL_NO_CONTEXT;
mEGLSurface = EGL14.EGL_NO_SURFACE;
mSurface.release();
// this causes a bunch of warnings that appear harmless but might confuse someone:
// W BufferQueue: [unnamed-3997-2] cancelBuffer: BufferQueue has been abandoned!
//mSurfaceTexture.release();
mTextureRender = null;
mTextureRender2D = null;
mSurface = null;
mSurfaceTexture = null;
//release external bitmap
if (mExternalImgs != null && !mExternalImgs.isEmpty()) {
for (Texture2DBitmap bitmap : mExternalImgs) {
if (bitmap.mBitmap != null && !bitmap.mBitmap.isRecycled()) {
bitmap.mBitmap.recycle();
}
}
}
mExternalImgs = null;
}
/**
* Makes our EGL context and surface current.
*/
public void makeCurrent() {
if (!EGL14.eglMakeCurrent(mEGLDisplay, mEGLSurface, mEGLSurface, mEGLContext)) {
throw new RuntimeException("eglMakeCurrent failed");
}
}
/**
* Returns the Surface.
*/
public Surface getSurface() {
return mSurface;
}
/**
* Latches the next buffer into the texture. Must be called from the thread that created
* the CodecOutputSurface object. (More specifically, it must be called on the thread
* with the EGLContext that contains the GL texture object used by SurfaceTexture.)
*/
public void awaitNewImage() {
final int TIMEOUT_MS = 2500;
synchronized (mFrameSyncObject) {
while (!mFrameAvailable) {
try {
// Wait for onFrameAvailable() to signal us. Use a timeout to avoid
// stalling the test if it doesn't arrive.
mFrameSyncObject.wait(TIMEOUT_MS);
if (!mFrameAvailable) {
// TODO: if "spurious wakeup", continue while loop
throw new RuntimeException("frame wait timed out");
}
} catch (InterruptedException ie) {
// shouldn't happen
throw new RuntimeException(ie);
}
}
mFrameAvailable = false;
}
// Latch the data.
mTextureRender.checkGlError("before updateTexImage");
mSurfaceTexture.updateTexImage();
}
/**
* Draws the data from SurfaceTexture onto the current EGL surface.
*
* @param invert if set, render the image with Y inverted (0,0 in top left)
*/
public void drawImage(boolean invert) {
GLES20.glViewport(0, 0, mWidth, mHeight);
mTextureRender.drawFrame(mSurfaceTexture, invert,null);
drawExternalImage(invert);
}
// SurfaceTexture callback
@Override
public void onFrameAvailable(SurfaceTexture st) {
if (DEBUG) Log.d(TAG, "new frame available");
synchronized (mFrameSyncObject) {
if (mFrameAvailable) {
throw new RuntimeException("mFrameAvailable already set, frame could be dropped");
}
mFrameAvailable = true;
mFrameSyncObject.notifyAll();
}
}
/**
* Saves the current frame to disk as a PNG image.
*/
public void saveFrame(String filename) throws IOException {
// glReadPixels gives us a ByteBuffer filled with what is essentially big-endian RGBA
// data (i.e. a byte of red, followed by a byte of green...). To use the Bitmap
// constructor that takes an int[] array with pixel data, we need an int[] filled
// with little-endian ARGB data.
//
// If we implement this as a series of buf.get() calls, we can spend 2.5 seconds just
// copying data around for a 720p frame. It's better to do a bulk get() and then
// rearrange the data in memory. (For comparison, the PNG compress takes about 500ms
// for a trivial frame.)
//
// So... we set the ByteBuffer to little-endian, which should turn the bulk IntBuffer
// get() into a straight memcpy on most Android devices. Our ints will hold ABGR data.
// Swapping B and R gives us ARGB. We need about 30ms for the bulk get(), and another
// 270ms for the color swap.
//
// We can avoid the costly B/R swap here if we do it in the fragment shader (see
// http://stackoverflow.com/questions/21634450/ ).
//
// Having said all that... it turns out that the Bitmap#copyPixelsFromBuffer()
// method wants RGBA pixels, not ARGB, so if we create an empty bitmap and then
// copy pixel data in we can avoid the swap issue entirely, and just copy straight
// into the Bitmap from the ByteBuffer.
//
// Making this even more interesting is the upside-down nature of GL, which means
// our output will look upside-down relative to what appears on screen if the
// typical GL conventions are used. (For ExtractMpegFrameTest, we avoid the issue
// by inverting the frame when we render it.)
//
// Allocating large buffers is expensive, so we really want mPixelBuf to be
// allocated ahead of time if possible. We still get some allocations from the
// Bitmap / PNG creation.
mPixelBuf.rewind();
GLES20.glReadPixels(0, 0, mWidth, mHeight, GLES20.GL_RGBA, GLES20.GL_UNSIGNED_BYTE,
mPixelBuf);
BufferedOutputStream bos = null;
try {
bos = new BufferedOutputStream(new FileOutputStream(filename));
Bitmap bmp = Bitmap.createBitmap(mWidth, mHeight, Bitmap.Config.ARGB_8888);
mPixelBuf.rewind();
bmp.copyPixelsFromBuffer(mPixelBuf);
bmp.compress(Bitmap.CompressFormat.PNG, 90, bos);
bmp.recycle();
} finally {
if (bos != null) bos.close();
}
if (DEBUG) {
Log.d(TAG, "Saved " + mWidth + "x" + mHeight + " frame as '" + filename + "'");
}
}
/**
* Saves the current frame to disk as a PNG image.
*/
public Bitmap genFrameBitmap() throws IOException {
// glReadPixels gives us a ByteBuffer filled with what is essentially big-endian RGBA
// data (i.e. a byte of red, followed by a byte of green...). To use the Bitmap
// constructor that takes an int[] array with pixel data, we need an int[] filled
// with little-endian ARGB data.
//
// If we implement this as a series of buf.get() calls, we can spend 2.5 seconds just
// copying data around for a 720p frame. It's better to do a bulk get() and then
// rearrange the data in memory. (For comparison, the PNG compress takes about 500ms
// for a trivial frame.)
//
// So... we set the ByteBuffer to little-endian, which should turn the bulk IntBuffer
// get() into a straight memcpy on most Android devices. Our ints will hold ABGR data.
// Swapping B and R gives us ARGB. We need about 30ms for the bulk get(), and another
// 270ms for the color swap.
//
// We can avoid the costly B/R swap here if we do it in the fragment shader (see
// http://stackoverflow.com/questions/21634450/ ).
//
// Having said all that... it turns out that the Bitmap#copyPixelsFromBuffer()
// method wants RGBA pixels, not ARGB, so if we create an empty bitmap and then
// copy pixel data in we can avoid the swap issue entirely, and just copy straight
// into the Bitmap from the ByteBuffer.
//
// Making this even more interesting is the upside-down nature of GL, which means
// our output will look upside-down relative to what appears on screen if the
// typical GL conventions are used. (For ExtractMpegFrameTest, we avoid the issue
// by inverting the frame when we render it.)
//
// Allocating large buffers is expensive, so we really want mPixelBuf to be
// allocated ahead of time if possible. We still get some allocations from the
// Bitmap / PNG creation.
mPixelBuf.rewind();
GLES20.glReadPixels(0, 0, mWidth, mHeight, GLES20.GL_RGBA, GLES20.GL_UNSIGNED_BYTE,
mPixelBuf);
Bitmap bmp = Bitmap.createBitmap(mWidth, mHeight, Bitmap.Config.ARGB_8888);
mPixelBuf.rewind();
bmp.copyPixelsFromBuffer(mPixelBuf);
return bmp;
}
/**
* Checks for EGL errors.
*/
private void checkEglError(String msg) {
int error;
if ((error = EGL14.eglGetError()) != EGL14.EGL_SUCCESS) {
throw new RuntimeException(msg + ": EGL error: 0x" + Integer.toHexString(error));
}
}
/**
* 需要合成的贴图
*
* @param bitmap
*/
public void addExternalBitmaps(Texture2DBitmap bitmap) {
if (mExternalImgs == null) {
mExternalImgs = new ArrayList<>();
}
if (bitmap != null) {
mExternalImgs.add(bitmap);
}
}
//给视频帧数据贴额外的图片纹理
private void drawExternalImage(boolean invert) {
if (mExternalImgs != null && !mExternalImgs.isEmpty()) {
for (Texture2DBitmap bitmap : mExternalImgs) {
GLES20.glViewport(bitmap.mOffX, bitmap.mOffY, bitmap.mWidth, bitmap.mHeight);
mTextureRender2D.drawFrame(mSurfaceTexture, invert, bitmap.mBitmap);
}
}
}
/**
* Code for rendering a texture onto a surface using OpenGL ES 2.0.
*/
private static class STextureRender {
public static final int SHADER_OES = 0;
public static final int SHADER_2D = 1;
private static final int FLOAT_SIZE_BYTES = 4;
private static final int TRIANGLE_VERTICES_DATA_STRIDE_BYTES = 5 * FLOAT_SIZE_BYTES;
private static final int TRIANGLE_VERTICES_DATA_POS_OFFSET = 0;
private static final int TRIANGLE_VERTICES_DATA_UV_OFFSET = 3;
private final float[] mTriangleVerticesData = {
// X, Y, Z, U, V
-1.0f, -1.0f, 0, 0.f, 0.f,
1.0f, -1.0f, 0, 1.f, 0.f,
-1.0f, 1.0f, 0, 0.f, 1.f,
1.0f, 1.0f, 0, 1.f, 1.f,
};
private FloatBuffer mTriangleVertices;
private static final String VERTEX_SHADER =
"uniform mat4 uMVPMatrix;\n" +
"uniform mat4 uSTMatrix;\n" +
"attribute vec4 aPosition;\n" +
"attribute vec4 aTextureCoord;\n" +
"varying vec2 vTextureCoord;\n" +
"void main() {\n" +
" gl_Position = uMVPMatrix * aPosition;\n" +
" vTextureCoord = (uSTMatrix * aTextureCoord).xy;\n" +
"}\n";
private static final String FRAGMENT_SHADER =
"#extension GL_OES_EGL_image_external : require\n" +
"precision mediump float;\n" + // highp here doesn't seem to matter
"varying vec2 vTextureCoord;\n" +
"uniform samplerExternalOES sTexture;\n" +
"void main() {\n" +
" gl_FragColor = texture2D(sTexture, vTextureCoord);\n" +
"}\n";
private static final String FRAGMENT_2D_SHADER =
"precision mediump float;\n" + // highp here doesn't seem to matter
"varying vec2 vTextureCoord;\n" +
"uniform sampler2D sTexture;\n" +
"void main() {\n" +
" gl_FragColor = texture2D(sTexture, vTextureCoord);\n" +
"}\n";
private float[] mMVPMatrix = new float[16];
private float[] mSTMatrix = new float[16];
private int mProgram;
private int mTextureID = -12345;
private int muMVPMatrixHandle;
private int muSTMatrixHandle;
private int maPositionHandle;
private int maTextureHandle;
private int mTargetTextureType;
public STextureRender(int shaderType) {
mTargetTextureType = shaderType == SHADER_OES ? GLES11Ext.GL_TEXTURE_EXTERNAL_OES : GLES20.GL_TEXTURE_2D;
mTriangleVertices = ByteBuffer.allocateDirect(
mTriangleVerticesData.length * FLOAT_SIZE_BYTES)
.order(ByteOrder.nativeOrder()).asFloatBuffer();
mTriangleVertices.put(mTriangleVerticesData).position(0);
Matrix.setIdentityM(mSTMatrix, 0);
}
public int getTextureId() {
return mTextureID;
}
/**
* Draws the external texture in SurfaceTexture onto the current EGL surface.
*/
public void drawFrame(SurfaceTexture st, boolean invert, Bitmap bitmap) {
checkGlError("onDrawFrame start");
st.getTransformMatrix(mSTMatrix);
if (invert) {
mSTMatrix[5] = -mSTMatrix[5];
mSTMatrix[13] = 1.0f - mSTMatrix[13];
}
GLES20.glUseProgram(mProgram);
checkGlError("glUseProgram");
GLES20.glEnable(GLES20.GL_BLEND);
GlUtil.checkGlError("glEnable");
GLES20.glBlendFunc(GLES20.GL_ONE, GLES20.GL_ONE_MINUS_SRC_ALPHA);
GlUtil.checkGlError("glBlendFunc");
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
GLES20.glBindTexture(mTargetTextureType, mTextureID);
mTriangleVertices.position(TRIANGLE_VERTICES_DATA_POS_OFFSET);
GLES20.glVertexAttribPointer(maPositionHandle, 3, GLES20.GL_FLOAT, false,
TRIANGLE_VERTICES_DATA_STRIDE_BYTES, mTriangleVertices);
checkGlError("glVertexAttribPointer maPosition");
GLES20.glEnableVertexAttribArray(maPositionHandle);
checkGlError("glEnableVertexAttribArray maPositionHandle");
mTriangleVertices.position(TRIANGLE_VERTICES_DATA_UV_OFFSET);
GLES20.glVertexAttribPointer(maTextureHandle, 2, GLES20.GL_FLOAT, false,
TRIANGLE_VERTICES_DATA_STRIDE_BYTES, mTriangleVertices);
checkGlError("glVertexAttribPointer maTextureHandle");
GLES20.glEnableVertexAttribArray(maTextureHandle);
checkGlError("glEnableVertexAttribArray maTextureHandle");
Matrix.setIdentityM(mMVPMatrix, 0);
GLES20.glUniformMatrix4fv(muMVPMatrixHandle, 1, false, mMVPMatrix, 0);
GLES20.glUniformMatrix4fv(muSTMatrixHandle, 1, false, mSTMatrix, 0);
if (bitmap != null) {
//上面是纹理贴图的取样方式，包括拉伸方式，取临近值和线性值
GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0);//让图片和纹理关联起来，加载到OpenGl空间中
}
GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
checkGlError("glDrawArrays");
GLES20.glFlush();
GLES20.glDisable(GLES20.GL_BLEND);
GLES20.glDisableVertexAttribArray(maPositionHandle);
GLES20.glDisableVertexAttribArray(maTextureHandle);
GLES20.glBindTexture(mTargetTextureType, 0);
GLES20.glUseProgram(0);
}
/**
* Initializes GL state. Call this after the EGL surface has been created and made current.
*/
public void surfaceCreated() {
mProgram = createProgram(VERTEX_SHADER, mTargetTextureType == GLES11Ext.GL_TEXTURE_EXTERNAL_OES ? FRAGMENT_SHADER : FRAGMENT_2D_SHADER);
if (mProgram == 0) {
throw new RuntimeException("failed creating program");
}
maPositionHandle = GLES20.glGetAttribLocation(mProgram, "aPosition");
checkLocation(maPositionHandle, "aPosition");
maTextureHandle = GLES20.glGetAttribLocation(mProgram, "aTextureCoord");
checkLocation(maTextureHandle, "aTextureCoord");
muMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
checkLocation(muMVPMatrixHandle, "uMVPMatrix");
muSTMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uSTMatrix");
checkLocation(muSTMatrixHandle, "uSTMatrix");
int[] textures = new int[1];
GLES20.glGenTextures(1, textures, 0);
mTextureID = textures[0];
GLES20.glBindTexture(mTargetTextureType, mTextureID);
checkGlError("glBindTexture mTextureID");
GLES20.glTexParameterf(mTargetTextureType, GLES20.GL_TEXTURE_MIN_FILTER,
GLES20.GL_NEAREST);
GLES20.glTexParameterf(mTargetTextureType, GLES20.GL_TEXTURE_MAG_FILTER,
GLES20.GL_LINEAR);
GLES20.glTexParameteri(mTargetTextureType, GLES20.GL_TEXTURE_WRAP_S,
GLES20.GL_CLAMP_TO_EDGE);
GLES20.glTexParameteri(mTargetTextureType, GLES20.GL_TEXTURE_WRAP_T,
GLES20.GL_CLAMP_TO_EDGE);
checkGlError("glTexParameter");
}
/**
* Replaces the fragment shader. Pass in null to reset to default.
*/
public void changeFragmentShader(String fragmentShader) {
if (fragmentShader == null) {
fragmentShader = FRAGMENT_SHADER;
}
GLES20.glDeleteProgram(mProgram);
mProgram = createProgram(VERTEX_SHADER, fragmentShader);
if (mProgram == 0) {
throw new RuntimeException("failed creating program");
}
}
private int loadShader(int shaderType, String source) {
int shader = GLES20.glCreateShader(shaderType);
checkGlError("glCreateShader type=" + shaderType);
GLES20.glShaderSource(shader, source);
GLES20.glCompileShader(shader);
int[] compiled = new int[1];
GLES20.glGetShaderiv(shader, GLES20.GL_COMPILE_STATUS, compiled, 0);
if (compiled[0] == 0) {
Log.e(TAG, "Could not compile shader " + shaderType + ":");
Log.e(TAG, " " + GLES20.glGetShaderInfoLog(shader));
GLES20.glDeleteShader(shader);
shader = 0;
}
return shader;
}
private int createProgram(String vertexSource, String fragmentSource) {
int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, vertexSource);
if (vertexShader == 0) {
return 0;
}
int pixelShader = loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentSource);
if (pixelShader == 0) {
return 0;
}
int program = GLES20.glCreateProgram();
if (program == 0) {
Log.e(TAG, "Could not create program");
}
GLES20.glAttachShader(program, vertexShader);
checkGlError("glAttachShader");
GLES20.glAttachShader(program, pixelShader);
checkGlError("glAttachShader");
GLES20.glLinkProgram(program);
int[] linkStatus = new int[1];
GLES20.glGetProgramiv(program, GLES20.GL_LINK_STATUS, linkStatus, 0);
if (linkStatus[0] != GLES20.GL_TRUE) {
Log.e(TAG, "Could not link program: ");
Log.e(TAG, GLES20.glGetProgramInfoLog(program));
GLES20.glDeleteProgram(program);
program = 0;
}
return program;
}
public void checkGlError(String op) {
int error;
while ((error = GLES20.glGetError()) != GLES20.GL_NO_ERROR) {
Log.e(TAG, op + ": glError " + error);
throw new RuntimeException(op + ": glError " + error);
}
}
public static void checkLocation(int location, String label) {
if (location < 0) {
throw new RuntimeException("Unable to locate '" + label + "' in program");
}
}
}
public class Texture2DBitmap {
public int mOffX = 0;
public int mOffY = 0;
public int mWidth;
public int mHeight;
public Bitmap mBitmap;
public Texture2DBitmap(int offX, int offY, int width, int height, Bitmap bitmap) {
mOffX = offX;
mOffY = offY;
mWidth = width;
mHeight = height;
mBitmap = bitmap;
}
}
}