GLSurfaceView handles GL setup for you, which TextureView will not do. A
TextureView can be used as the native window when you create an EGL
surface. Here is an example (the interesting part is the call
to eglCreateWindowSurface()):
@Override
public void onSurfaceTextureAvailable(SurfaceTexture surface, int
width, int height) {
mRenderThread = new RenderThread(getResources(), surface);
mRenderThread.start();
}
private static class RenderThread extends Thread {
private static final String LOG_TAG = "GLTextureView";
static final int EGL_CONTEXT_CLIENT_VERSION = 0x3098;
static final int EGL_OPENGL_ES2_BIT = 4;
private volatile boolean mFinished;
private final Resources mResources;
private final SurfaceTexture mSurface;
private EGL10 mEgl;
private EGLDisplay mEglDisplay;
private EGLConfig mEglConfig;
private EGLContext mEglContext;
private EGLSurface mEglSurface;
private GL mGL;
RenderThread(Resources resources, SurfaceTexture surface) {
mResources = resources;
mSurface = surface;
}
private static final String sSimpleVS =
"attribute vec4 position;\n" +
"attribute vec2 texCoords;\n" +
"varying vec2 outTexCoords;\n" +
"\nvoid main(void) {\n" +
" outTexCoords = texCoords;\n" +
" gl_Position = position;\n" +
"}\n\n";
private static final String sSimpleFS =
"precision mediump float;\n\n" +
"varying vec2 outTexCoords;\n" +
"uniform sampler2D texture;\n" +
"\nvoid main(void) {\n" +
" gl_FragColor = texture2D(texture, outTexCoords);\n" +
"}\n\n";
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, 0.0f, 0.0f, 0.0f,
1.0f, -1.0f, 0.0f, 1.0f, 0.0f,
-1.0f, 1.0f, 0.0f, 0.0f, 1.0f,
1.0f, 1.0f, 0.0f, 1.0f, 1.0f,
};
@Override
public void run() {
initGL();
FloatBuffer triangleVertices =
ByteBuffer.allocateDirect(mTriangleVerticesData.length
*
FLOAT_SIZE_BYTES).order(ByteOrder.nativeOrder()).asFloatBuffer();
triangleVertices.put(mTriangleVerticesData).position(0);
int texture = loadTexture(R.drawable.large_photo);
int program = buildProgram(sSimpleVS, sSimpleFS);
int attribPosition = glGetAttribLocation(program, "position");
checkGlError();
int attribTexCoords = glGetAttribLocation(program, "texCoords");
checkGlError();
int uniformTexture = glGetUniformLocation(program, "texture");
checkGlError();
glBindTexture(GL_TEXTURE_2D, texture);
checkGlError();
glUseProgram(program);
checkGlError();
glEnableVertexAttribArray(attribPosition);
checkGlError();
glEnableVertexAttribArray(attribTexCoords);
checkGlError();
glUniform1i(uniformTexture, texture);
checkGlError();
while (!mFinished) {
checkCurrent();
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
checkGlError();
glClear(GL_COLOR_BUFFER_BIT);
checkGlError();
// drawQuad
triangleVertices.position(TRIANGLE_VERTICES_DATA_POS_OFFSET);
glVertexAttribPointer(attribPosition, 3, GL_FLOAT, false,
TRIANGLE_VERTICES_DATA_STRIDE_BYTES,
triangleVertices);
triangleVertices.position(TRIANGLE_VERTICES_DATA_UV_OFFSET);
glVertexAttribPointer(attribTexCoords, 3, GL_FLOAT, false,
TRIANGLE_VERTICES_DATA_STRIDE_BYTES,
triangleVertices);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
if (!mEgl.eglSwapBuffers(mEglDisplay, mEglSurface)) {
throw new RuntimeException("Cannot swap buffers");
}
checkEglError();
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
// Ignore
}
}
finishGL();
}
private int loadTexture(int resource) {
int[] textures = new int[1];
glActiveTexture(GL_TEXTURE0);
glGenTextures(1, textures, 0);
checkGlError();
int texture = textures[0];
glBindTexture(GL_TEXTURE_2D, texture);
checkGlError();
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,
GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,
GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T,
GL_CLAMP_TO_EDGE);
Bitmap bitmap = BitmapFactory.decodeResource(mResources,
resource);
GLUtils.texImage2D(GL_TEXTURE_2D, 0, GL_RGBA, bitmap,
GL_UNSIGNED_BYTE, 0);
checkGlError();
bitmap.recycle();
return texture;
}
private int buildProgram(String vertex, String fragment) {
int vertexShader = buildShader(vertex, GL_VERTEX_SHADER);
if (vertexShader == 0) return 0;
int fragmentShader = buildShader(fragment, GL_FRAGMENT_SHADER);
if (fragmentShader == 0) return 0;
int program = glCreateProgram();
glAttachShader(program, vertexShader);
checkGlError();
glAttachShader(program, fragmentShader);
checkGlError();
glLinkProgram(program);
checkGlError();
int[] status = new int[1];
glGetProgramiv(program, GL_LINK_STATUS, status, 0);
if (status[0] != GL_TRUE) {
String error = glGetProgramInfoLog(program);
Log.d(LOG_TAG, "Error while linking program:\n" + error);
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
glDeleteProgram(program);
return 0;
}
return program;
}
private int buildShader(String source, int type) {
int shader = glCreateShader(type);
glShaderSource(shader, source);
checkGlError();
glCompileShader(shader);
checkGlError();
int[] status = new int[1];
glGetShaderiv(shader, GL_COMPILE_STATUS, status, 0);
if (status[0] != GL_TRUE) {
String error = glGetShaderInfoLog(shader);
Log.d(LOG_TAG, "Error while compiling shader:\n" + error);
glDeleteShader(shader);
return 0;
}
return shader;
}
private void checkEglError() {
int error = mEgl.eglGetError();
if (error != EGL10.EGL_SUCCESS) {
Log.w(LOG_TAG, "EGL error = 0x" +
Integer.toHexString(error));
}
}
private void checkGlError() {
int error = glGetError();
if (error != GL_NO_ERROR) {
Log.w(LOG_TAG, "GL error = 0x" +
Integer.toHexString(error));
}
}
private void finishGL() {
mEgl.eglDestroyContext(mEglDisplay, mEglContext);
mEgl.eglDestroySurface(mEglDisplay, mEglSurface);
}
private void checkCurrent() {
if (!mEglContext.equals(mEgl.eglGetCurrentContext()) ||
!mEglSurface.equals(mEgl.eglGetCurrentSurface(EGL10.EGL_DRAW))) {
if (!mEgl.eglMakeCurrent(mEglDisplay, mEglSurface,
mEglSurface, mEglContext)) {
throw new RuntimeException("eglMakeCurrent failed "
+
GLUtils.getEGLErrorString(mEgl.eglGetError()));
}
}
}
private void initGL() {
mEgl = (EGL10) EGLContext.getEGL();
mEglDisplay = mEgl.eglGetDisplay(EGL10.EGL_DEFAULT_DISPLAY);
if (mEglDisplay == EGL10.EGL_NO_DISPLAY) {
throw new RuntimeException("eglGetDisplay failed "
+ GLUtils.getEGLErrorString(mEgl.eglGetError()));
}
int[] version = new int[2];
if (!mEgl.eglInitialize(mEglDisplay, version)) {
throw new RuntimeException("eglInitialize failed " +
GLUtils.getEGLErrorString(mEgl.eglGetError()));
}
mEglConfig = chooseEglConfig();
if (mEglConfig == null) {
throw new RuntimeException("eglConfig not initialized");
}
mEglContext = createContext(mEgl, mEglDisplay, mEglConfig);
mEglSurface = mEgl.eglCreateWindowSurface(mEglDisplay,
mEglConfig, mSurface, null);
if (mEglSurface == null || mEglSurface == EGL10.EGL_NO_SURFACE)
{
int error = mEgl.eglGetError();
if (error == EGL10.EGL_BAD_NATIVE_WINDOW) {
Log.e(LOG_TAG, "createWindowSurface returned
EGL_BAD_NATIVE_WINDOW.");
return;
}
throw new RuntimeException("createWindowSurface failed "
+ GLUtils.getEGLErrorString(error));
}
if (!mEgl.eglMakeCurrent(mEglDisplay, mEglSurface, mEglSurface,
mEglContext)) {
throw new RuntimeException("eglMakeCurrent failed "
+ GLUtils.getEGLErrorString(mEgl.eglGetError()));
}
mGL = mEglContext.getGL();
}
EGLContext createContext(EGL10 egl, EGLDisplay eglDisplay,
EGLConfig eglConfig) {
int[] attrib_list = { EGL_CONTEXT_CLIENT_VERSION, 2,
EGL10.EGL_NONE };
return egl.eglCreateContext(eglDisplay, eglConfig,
EGL10.EGL_NO_CONTEXT, attrib_list);
}
private EGLConfig chooseEglConfig() {
int[] configsCount = new int[1];
EGLConfig[] configs = new EGLConfig[1];
int[] configSpec = getConfig();
if (!mEgl.eglChooseConfig(mEglDisplay, configSpec, configs, 1,
configsCount)) {
throw new IllegalArgumentException("eglChooseConfig failed
" +
GLUtils.getEGLErrorString(mEgl.eglGetError()));
} else if (configsCount[0] > 0) {
return configs[0];
}
return null;
}
private int[] getConfig() {
return new int[] {
EGL10.EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
EGL10.EGL_RED_SIZE, 8,
EGL10.EGL_GREEN_SIZE, 8,
EGL10.EGL_BLUE_SIZE, 8,
EGL10.EGL_ALPHA_SIZE, 8,
EGL10.EGL_DEPTH_SIZE, 0,
EGL10.EGL_STENCIL_SIZE, 0,
EGL10.EGL_NONE
};
}
void finish() {
mFinished = true;
}
}
On Wed, Nov 23, 2011 at 8:54 AM, plafayette <pierre.lafaye...@gmail.com>wrote:
> The TextureView documentation states that it can be used to render
> OpenGL content.
>
> In the blog post announcing TextureView, it states:
>
> A TextureView can just as easily be used to embed an OpenGL scene in
> your application. As of Android 4.0, eglCreateWindowSurface() can be
> used to render into a SurfaceTexture object.
>
> Which seems to imply that to use TextureView instead of GLSurfaceView,
> one would have to do all the EGL setup themselves and manage the
> EGLContext and the threading (since GLSurfaceView maintains a
> GLThread). There doesn't seem to be any sample code in the Android 4.0
> SDK that demonstrates how the "TextureView can just as easily be used
> to embed an OpenGL scene". TextureView seems to plug in more cleanly
> to the Camera preview (setPreviewTexture) and MediaPlayer
> (setSurface).
>
> Is it possible to use GLSurfaceView in conjunction with TextureView by
> using GLSurfaceView.setEGLWindowSurfaceFactory to make it render to
> the TextureView's SurfaceTexture?
>
> Again, it would be nice if there were some sample code.
>
> p.s. Posted on stackoverflow.com as well. Feel free to answer:
>
> http://stackoverflow.com/questions/8231978/how-to-replace-glsurfaceview-with-textureview-in-android-ice-cream-sandwich
>
> --
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--
Romain Guy
Android framework engineer
romain...@android.com
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