Develop Reference

TextureView cannot get context for EGL3 for Emulator

I'm having issues when trying to initialize the EGLContext only on Android emulators.
For a strange reason, when I try to get the EGL3 Config it doesn't find anything...
This is the logic that I'm using:
EGL14.eglInitialize(mEGLDisplay, version, 0, version, 1)
EGLConfig config = getConfig(flags, 3);
if (config != null) {
int[] attrib3_list = {
EGL14.EGL_CONTEXT_CLIENT_VERSION, 3,
EGL14.EGL_NONE
};
EGLContext context = EGL14.eglCreateContext(mEGLDisplay, config, sharedContext,
attrib3_list, 0);
if (EGL14.eglGetError() == EGL14.EGL_SUCCESS) {
//Log.d(TAG, "Got GLES 3 config");
mEGLConfig = config;
mEGLContext = context;
mGlVersion = 3;
}
}
And here is the getConfig method
/**
* Finds a suitable EGLConfig.
*
* #param flags Bit flags from constructor.
* #param version Must be 2 or 3.
*/
private EGLConfig getConfig(int flags, int version) {
int renderableType = EGL14.EGL_OPENGL_ES2_BIT;
if (version >= 3) {
renderableType |= EGLExt.EGL_OPENGL_ES3_BIT_KHR;
}
// The actual surface is generally RGBA or RGBX, so situationally omitting alpha
// doesn't really help. It can also lead to a huge performance hit on glReadPixels()
// when reading into a GL_RGBA buffer.
int[] attribList = {
EGL14.EGL_RED_SIZE, 8,
EGL14.EGL_GREEN_SIZE, 8,
EGL14.EGL_BLUE_SIZE, 8,
EGL14.EGL_ALPHA_SIZE, 8,
EGL14.EGL_SAMPLES, 4,
//EGL14.EGL_DEPTH_SIZE, 16,
//EGL14.EGL_STENCIL_SIZE, 8,
EGL14.EGL_RENDERABLE_TYPE, renderableType,
EGL14.EGL_NONE, 0, // placeholder for recordable [#-3]
EGL14.EGL_NONE
};
if ((flags & FLAG_RECORDABLE) != 0) {
attribList[attribList.length - 3] = EGL_RECORDABLE_ANDROID;
attribList[attribList.length - 2] = 1;
}
EGLConfig[] configs = new EGLConfig[1];
int[] numConfigs = new int[1];
if (!EGL14.eglChooseConfig(mEGLDisplay, attribList, 0, configs, 0, configs.length,
numConfigs, 0)) {
Log.w(TAG, "unable to find RGB8888 / " + version + " EGLConfig");
return null;
}
return configs[0];
}
The emulator it's already compatible with EGL3; since I'm getting the following log: D/EGL_emulation: eglMakeCurrent: 0xe7205360: ver 3 0 (tinfo 0xe72031f0)
I'm out of ideas here...

Finally! I was able to get a valid configuration. So the problem was given by the following if
if (!EGL14.eglChooseConfig(mEGLDisplay, attribList, 0, configs, 0, configs.length,
numConfigs, 0)) {
Log.w(TAG, "unable to find RGB8888 / " + version + " EGLConfig");
return null;
}
Only on emulators eglChooseConfig will always return false, even if it found a valid configuration...
So I ended up with the following logic:
EGL14.eglChooseConfig(mEGLDisplay, attribList, 0, configs, 0, configs.length,
numConfigs, 0);
if (EGL14.eglGetError() != EGL14.EGL_SUCCESS) {
Log.w(TAG, "unable to find RGB8888 / " + version + " EGLConfig " + EGL14.eglGetError());
return null;
}
I know it's a bit of a Hack, but for the time being "it works"

Android native activity, GLES 3.0 shader compilations fails

I wanted to experiment with Native Activity and GLES 3.0, for a personal project, until I hit this roadblock: The shaders won't load and/or compile, I'm not really sure, as OPENGL's logs are non-existent.
Here are both of my shaders:
static const char glVertexShader[] =
"#version 300 es\n"
"in vec4 vPosition;\n"
"void main()\n"
"{\n"
" gl_Position = vPosition;\n"
"}\n\0";
static const char glFragmentShader[] =
"#version 300 es\n"
"precision mediump float;\n"
"void main()\n"
"{\n"
" gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);\n"
"}\n\0";
And here are my shader loading and program creation functions:
GLuint loadShader(GLenum shaderType, const char* shaderSource)
{
GLuint shader = glCreateShader(shaderType);
if (shader)
{
glShaderSource(shader, 1, &shaderSource, NULL);
glCompileShader(shader);
GLint compiled = 0;
glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled);
if (!compiled)
{
GLint infoLen = 0;
glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &infoLen);
if (infoLen)
{
char * buf = new char[infoLen];
if (buf)
{
glGetShaderInfoLog(shader, infoLen, NULL, buf);
log.log_error("Could not Compile Shader %d:\n%s\n", shaderType, buf);
delete[] buf;
}
glDeleteShader(shader);
shader = 0;
}
}
}
return shader;
}
GLuint createProgram(const char* vertexSource, const char * fragmentSource)
{
log.log_info("Loading vertex shader");
GLuint vertexShader = loadShader(GL_VERTEX_SHADER, vertexSource);
if (!vertexShader)
{
log.log_info("Vertex shader load failure!");
return 0;
}
log.log_info("Loading fragment shader");
GLuint fragmentShader = loadShader(GL_FRAGMENT_SHADER, fragmentSource);
if (!fragmentShader)
{
log.log_info("Fragment shader load failure!");
return 0;
}
GLuint program = glCreateProgram();
if (program)
{
glAttachShader(program, vertexShader);
glAttachShader(program, fragmentShader);
glLinkProgram(program);
GLint linkStatus = GL_FALSE;
glGetProgramiv(program, GL_LINK_STATUS, &linkStatus);
if (linkStatus != GL_TRUE)
{
GLint bufLength = 0;
glGetProgramiv(program, GL_INFO_LOG_LENGTH, &bufLength);
if (bufLength)
{
char* buf = new char[bufLength];
if (buf)
{
glGetProgramInfoLog(program, bufLength, NULL, buf);
log.log_error("Could not link program:\n%s\n", buf);
delete[] buf;
}
}
glDeleteProgram(program);
program = 0;
}
}
return program;
}
I'll also include my setup code and drawing code below:
Setup code:
GLuint simpleTriangleProgram;
GLuint vPosition;
bool setupGraphics(int w, int h)
{
simpleTriangleProgram = createProgram(glVertexShader, glFragmentShader);
if (!simpleTriangleProgram)
{
log.log_error("Could not create program");
return false;
}
vPosition = glGetAttribLocation(simpleTriangleProgram, "vPosition");
glViewport(0, 0, w, h);
return true;
}
Drawing code:
//-------------------------------
const GLfloat triangleVertices[] = {
0.0f, 1.0f,
-1.0f, -1.0f,
1.0f, -1.0f
};
//-------------------------------
/**
* Just the current frame in the display.
*/
static void engine_draw_frame(struct engine* engine) {
if (engine->display == NULL) {
// No display.
return;
}
// Just fill the screen with a color.
glClearColor(((float)engine->state.x) / engine->width, engine->state.angle,
((float)engine->state.y) / engine->height, 1);
glClear(GL_COLOR_BUFFER_BIT);
//---------------------------------------------------
glUseProgram(simpleTriangleProgram);
glVertexAttribPointer(vPosition, 2, GL_FLOAT, GL_FALSE, 0, triangleVertices);
glEnableVertexAttribArray(vPosition);
glDrawArrays(GL_TRIANGLES, 0, 3);
//---------------------------------------------------
eglSwapBuffers(engine->display, engine->surface);
}
And yes, the GLES context is properly created. But let me know if I should post that code too.
Here's my context creation code:
/**
* Initialize an EGL context for the current display.
*/
static int engine_init_display(struct engine* engine) {
// initialize OpenGL ES and EGL
/*
* Here specify the attributes of the desired configuration.
* Below, we select an EGLConfig with at least 8 bits per color
* component compatible with on-screen windows
*/
const EGLint attribs[] = {
EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
EGL_BLUE_SIZE, 8,
EGL_GREEN_SIZE, 8,
EGL_RED_SIZE, 8,
EGL_NONE
};
EGLint w, h, format;
EGLint numConfigs;
EGLConfig config;
EGLSurface surface;
EGLContext context;
EGLDisplay display = eglGetDisplay(EGL_DEFAULT_DISPLAY);
eglInitialize(display, 0, 0);
/* Here, the application chooses the configuration it desires.
* find the best match if possible, otherwise use the very first one
*/
eglChooseConfig(display, attribs, NULL, 0, &numConfigs);
std::unique_ptr<EGLConfig[]> supportedConfigs(new EGLConfig[numConfigs]);
assert(supportedConfigs);
eglChooseConfig(display, attribs, supportedConfigs.get(), numConfigs, &numConfigs);
assert(numConfigs);
auto i = 0;
for (; i < numConfigs; i++) {
auto& cfg = supportedConfigs[i];
EGLint r, g, b, d;
if (eglGetConfigAttrib(display, cfg, EGL_RED_SIZE, &r) &&
eglGetConfigAttrib(display, cfg, EGL_GREEN_SIZE, &g) &&
eglGetConfigAttrib(display, cfg, EGL_BLUE_SIZE, &b) &&
eglGetConfigAttrib(display, cfg, EGL_DEPTH_SIZE, &d) &&
r == 8 && g == 8 && b == 8 && d == 0) {
config = supportedConfigs[i];
break;
}
}
if (i == numConfigs) {
config = supportedConfigs[0];
}
EGLint AttribList[] =
{
EGL_CONTEXT_CLIENT_VERSION, 3,
EGL_NONE
};
/* EGL_NATIVE_VISUAL_ID is an attribute of the EGLConfig that is
* guaranteed to be accepted by ANativeWindow_setBuffersGeometry().
* As soon as we picked a EGLConfig, we can safely reconfigure the
* ANativeWindow buffers to match, using EGL_NATIVE_VISUAL_ID. */
eglGetConfigAttrib(display, config, EGL_NATIVE_VISUAL_ID, &format);
surface = eglCreateWindowSurface(display, config, engine->app->window, NULL);
context = eglCreateContext(display, config, NULL, AttribList);
if (eglMakeCurrent(display, surface, surface, context) == EGL_FALSE) {
log.log_warning("Unable to eglMakeCurrent");
return -1;
}
eglQuerySurface(display, surface, EGL_WIDTH, &w);
eglQuerySurface(display, surface, EGL_HEIGHT, &h);
engine->display = display;
engine->context = context;
engine->surface = surface;
engine->width = w;
engine->height = h;
engine->state.angle = 0;
// Check openGL on the system
auto opengl_info = { GL_VENDOR, GL_RENDERER, GL_VERSION, GL_EXTENSIONS };
for (auto name : opengl_info) {
auto info = glGetString(name);
log.log_info("OpenGL Info: %s", info);
}
// Initialize GL state.
// glEnable(GL_CULL_FACE);
// glEnable(GL_DEPTH_TEST);
return 0;
}
Full log:
Log pic
Note: my logger class is just a wrapper for __android_log_vprint(). I didn't include it because it isn't relevant in the slightest.

This:
#version 300 es
attribute vec4 vPosition;
void main()
{
gl_Position = vPosition;
}
... isn't a legal ESSL version 300 shader, so you should be getting a compile error log returned by the compiler on your platform. Do you not get anything from your log_info log channel?
To make the shader legal replace attribute with in.

Based on the log posted, glCreateShader is returning 0 which only happens when the context is not valid.
Looking at the time stamps in the log, you appear to be loading your shaders before you are creating the OpenGLES context.

Antialiasing in OpenGL ES 2.0?

Is there a way to implement Antialiasing technique in OpenGL ES 2.0? I have goggled and found few methods but there was no change in the output.
In the worst case, I've planned to implement multiple pass rendering, to smooth the edges in fragment shader, by displaying average colour of the pixels around every pixel, but it costs more GPU performance.
Any suggestions?

A lot of devices support MSAA (Multi-Sample Anti-Aliasing). To take advantage of this feature, you have to choose a EGLConfig that has multisampling.
On Android, if you use GLSurfaceView, you will have to implement your own EGLConfigChooser. You can then use EGL functions, particularly eglChooseConfig() to find a config you like.
The following code is untested, but it should at least sketch how this can be implemented. In the constructor of your GLSurfaceView derived class, before calling setRenderer(), add:
setEGLConfigChooser(new MyConfigChooser());
Then implement MyConfigChooser. You can make this a nested class inside your GLSurfaceView:
class MyConfigChooser implements GLSurfaceView.EGLConfigChooser {
#Override
public EGLConfig chooseConfig(EGL10 egl, EGLDisplay display) {
int attribs[] = {
EGL10.EGL_LEVEL, 0,
EGL10.EGL_RENDERABLE_TYPE, 4, // EGL_OPENGL_ES2_BIT
EGL10.EGL_COLOR_BUFFER_TYPE, EGL10.EGL_RGB_BUFFER,
EGL10.EGL_RED_SIZE, 8,
EGL10.EGL_GREEN_SIZE, 8,
EGL10.EGL_BLUE_SIZE, 8,
EGL10.EGL_DEPTH_SIZE, 16,
EGL10.EGL_SAMPLE_BUFFERS, 1,
EGL10.EGL_SAMPLES, 4, // This is for 4x MSAA.
EGL10.EGL_NONE
};
EGLConfig[] configs = new EGLConfig[1];
int[] configCounts = new int[1];
egl.eglChooseConfig(display, attribs, configs, 1, configCounts);
if (configCounts[0] == 0) {
// Failed! Error handling.
return null;
} else {
return configs[0];
}
}
}
You will obviously want to substitute the specific values you need for your configuration. In reality, it's much more robust to call eglChooseConfig() with a small set of strictly necessary attributes, let it enumerate all configs that match those attributes, and then implement your own logic to choose the best among them. The defined behavior of eglChooseConfig() is kind of odd already (see documentation), and there's no telling how GPU vendors implement it.
On iOS, you can set this property on your GLKView to enable 4x MSAA:
[view setDrawableMultisample: GLKViewDrawableMultisample4X];
There are other antialiasing approaches you can consider:
Supersampling: Render to a texture that is a multiple (typically twice) the size of your final render surface in each direction, and then downsample it. This uses a lot of memory, and the overhead is substantial. But if it meets your performance requirements, the quality will be excellent.
Old school: Render the frame multiple times with slight offsets, and average the frames. This was commonly done with the accumulation buffer in the early days of OpenGL. The accumulation buffer is obsolete, but you can do the same thing with FBOs. See the section "Scene Antialiasing" under "The Framebuffer" in the original Red Book for a description of the method.

On Android platform, you can download this OpenGL demo apps source code from GDC 2011: it contains lots of best practices and show you how to do multisampling, including coverage antialiasing.
What you need to do is just customize GLSurfaceView.EGLConfigChooser and set this chooser:
// Set this chooser before calling setRenderer()
setEGLConfigChooser(new MultisampleConfigChooser());
setRenderer(mRenderer);
MultisampleConfigChooser.java sample code below:
package com.example.gdc11;
import javax.microedition.khronos.egl.EGL10;
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.egl.EGLDisplay;
import android.opengl.GLSurfaceView;
import android.util.Log;
// This class shows how to use multisampling. To use this, call
// myGLSurfaceView.setEGLConfigChooser(new MultisampleConfigChooser());
// before calling setRenderer(). Multisampling will probably slow down
// your app -- measure performance carefully and decide if the vastly
// improved visual quality is worth the cost.
public class MultisampleConfigChooser implements GLSurfaceView.EGLConfigChooser {
static private final String kTag = "GDC11";
#Override
public EGLConfig chooseConfig(EGL10 egl, EGLDisplay display) {
mValue = new int[1];
// Try to find a normal multisample configuration first.
int[] configSpec = {
EGL10.EGL_RED_SIZE, 5,
EGL10.EGL_GREEN_SIZE, 6,
EGL10.EGL_BLUE_SIZE, 5,
EGL10.EGL_DEPTH_SIZE, 16,
// Requires that setEGLContextClientVersion(2) is called on the view.
EGL10.EGL_RENDERABLE_TYPE, 4 /* EGL_OPENGL_ES2_BIT */,
EGL10.EGL_SAMPLE_BUFFERS, 1 /* true */,
EGL10.EGL_SAMPLES, 2,
EGL10.EGL_NONE
};
if (!egl.eglChooseConfig(display, configSpec, null, 0,
mValue)) {
throw new IllegalArgumentException("eglChooseConfig failed");
}
int numConfigs = mValue[0];
if (numConfigs <= 0) {
// No normal multisampling config was found. Try to create a
// converage multisampling configuration, for the nVidia Tegra2.
// See the EGL_NV_coverage_sample documentation.
final int EGL_COVERAGE_BUFFERS_NV = 0x30E0;
final int EGL_COVERAGE_SAMPLES_NV = 0x30E1;
configSpec = new int[]{
EGL10.EGL_RED_SIZE, 5,
EGL10.EGL_GREEN_SIZE, 6,
EGL10.EGL_BLUE_SIZE, 5,
EGL10.EGL_DEPTH_SIZE, 16,
EGL10.EGL_RENDERABLE_TYPE, 4 /* EGL_OPENGL_ES2_BIT */,
EGL_COVERAGE_BUFFERS_NV, 1 /* true */,
EGL_COVERAGE_SAMPLES_NV, 2, // always 5 in practice on tegra 2
EGL10.EGL_NONE
};
if (!egl.eglChooseConfig(display, configSpec, null, 0,
mValue)) {
throw new IllegalArgumentException("2nd eglChooseConfig failed");
}
numConfigs = mValue[0];
if (numConfigs <= 0) {
// Give up, try without multisampling.
configSpec = new int[]{
EGL10.EGL_RED_SIZE, 5,
EGL10.EGL_GREEN_SIZE, 6,
EGL10.EGL_BLUE_SIZE, 5,
EGL10.EGL_DEPTH_SIZE, 16,
EGL10.EGL_RENDERABLE_TYPE, 4 /* EGL_OPENGL_ES2_BIT */,
EGL10.EGL_NONE
};
if (!egl.eglChooseConfig(display, configSpec, null, 0,
mValue)) {
throw new IllegalArgumentException("3rd eglChooseConfig failed");
}
numConfigs = mValue[0];
if (numConfigs <= 0) {
throw new IllegalArgumentException("No configs match configSpec");
}
} else {
mUsesCoverageAa = true;
}
}
// Get all matching configurations.
EGLConfig[] configs = new EGLConfig[numConfigs];
if (!egl.eglChooseConfig(display, configSpec, configs, numConfigs,
mValue)) {
throw new IllegalArgumentException("data eglChooseConfig failed");
}
// CAUTION! eglChooseConfigs returns configs with higher bit depth
// first: Even though we asked for rgb565 configurations, rgb888
// configurations are considered to be "better" and returned first.
// You need to explicitly filter the data returned by eglChooseConfig!
int index = -1;
for (int i = 0; i < configs.length; ++i) {
if (findConfigAttrib(egl, display, configs[i], EGL10.EGL_RED_SIZE, 0) == 5) {
index = i;
break;
}
}
if (index == -1) {
Log.w(kTag, "Did not find sane config, using first");
}
EGLConfig config = configs.length > 0 ? configs[index] : null;
if (config == null) {
throw new IllegalArgumentException("No config chosen");
}
return config;
}
private int findConfigAttrib(EGL10 egl, EGLDisplay display,
EGLConfig config, int attribute, int defaultValue) {
if (egl.eglGetConfigAttrib(display, config, attribute, mValue)) {
return mValue[0];
}
return defaultValue;
}
public boolean usesCoverageAa() {
return mUsesCoverageAa;
}
private int[] mValue;
private boolean mUsesCoverageAa;
}
Before using this feature, you should known this will affect rendering efficiency, and may need to do a fully performance test.

glReadPixels when using PBuffers is failing in some android devices

I'm facing a problem with some opengl ES drivers, when calling glReadPixels for a Pbuffer some devices will just kill the app with no message at all. Others will give me the next trace and then freeze for around 10 seconds before killing the app.
Unable to Find Phys Addr for 0
So far the affected devices where the problem is reproducible are:
Galaxy Y, Galaxy Ace, Galaxy Mini, Galaxy Young
I've also tested the code in the next devices where it works correctly as expected, no problems at all:
Nexy 4, Nexus 7, Nexus Galaxy, SGI, SGII, SGIII, Motorola Mini-Defy, and some others more.
I've put together a quick test function which reproduces the problem. Maybe someone can spot the issue. Please this is only a test method, no reviews about it are necessary as I just put it together to allow testing the bug, if I missed something let me know.
private static void bugTest()
{
EGL10 egl = (EGL10)EGLContext.getEGL();
EGLDisplay eglDisplay = egl.eglGetDisplay(EGL10.EGL_DEFAULT_DISPLAY);
// Initialize
int[] version = new int[2];
egl.eglInitialize(eglDisplay, version);
// Query total number of configurations
int[] totalConfigurations = new int[1];
egl.eglGetConfigs(eglDisplay, null, 0, totalConfigurations);
EGLConfig[] configurationsList = new EGLConfig[totalConfigurations[0]];
int attribs[] = { EGL10.EGL_RENDERABLE_TYPE, 4 /* EGL_OPENGL_ES2_BIT */, EGL10.EGL_RED_SIZE, 1, EGL10.EGL_GREEN_SIZE, 1, EGL10.EGL_BLUE_SIZE, 1, EGL10.EGL_NONE };
if (egl.eglChooseConfig(eglDisplay, attribs, configurationsList, 1, totalConfigurations) == false)
{
Log.e(TAG, "Could not find config for GLES2");
egl.eglTerminate(eglDisplay);
return;
}
// Create the PBuffer
EGLSurface eglSurface = null;
final int surfaceWidth = 512;
final int surfaceHeight = 512;
try
{
int[] attribList = new int[] { EGL10.EGL_WIDTH, surfaceWidth, EGL10.EGL_HEIGHT, surfaceHeight, EGL10.EGL_NONE };
eglSurface = egl.eglCreatePbufferSurface(eglDisplay, configurationsList[0], attribList);
}
catch (Exception ex)
{
Log.e(TAG, "Failed to create surface");
egl.eglTerminate(eglDisplay);
return;
}
// BUG Test for glReadPixels
if (eglSurface != null)
{
// Create context
final int EGL_CONTEXT_CLIENT_VERSION = 0x3098;
final int GLES_VERSION = 2;
int[] attribList = { EGL_CONTEXT_CLIENT_VERSION, GLES_VERSION, EGL10.EGL_NONE };
EGLContext eglContext = egl.eglCreateContext(eglDisplay, configurationsList[0], EGL10.EGL_NO_CONTEXT, attribList);
if (eglContext != null)
{
// Attach context to surface
if (egl.eglMakeCurrent(eglDisplay, eglSurface, eglSurface, eglContext) == true)
{
// Perform the actual bug test
GL10 gl = (GL10)eglContext.getGL();
int buffer[] = new int[surfaceWidth * surfaceHeight];
IntBuffer wrappedBuffer = IntBuffer.wrap(buffer);
wrappedBuffer.position(0);
// BUG: Line of failure
gl.glReadPixels(0, 0, surfaceWidth, surfaceHeight, GL10.GL_RGB, GL10.GL_UNSIGNED_BYTE, wrappedBuffer);
// Also fails when using RGBA
//gl.glReadPixels(0, 0, surfaceWidth, surfaceHeight, GL10.GL_RGBA, GL10.GL_UNSIGNED_BYTE, wrappedBuffer);
}
egl.eglDestroyContext(eglDisplay, eglContext);
}
egl.eglDestroySurface(display, eglSurface);
}
egl.eglTerminate(eglDisplay);
}

Pbuffers are not supported on devices with Nvidia Tegra GPUs. The problem is their EGL driver, not your code. But there is really no good reason to use pbuffers anyway. They are obsolete. You should use FBOs instead, especially on Android. This article explains in detail why:
http://processors.wiki.ti.com/index.php/Render_to_Texture_with_OpenGL_ES
The best way to create an off-screen surface on Android is to construct a new SurfaceTexture() and pass that to eglCreateWindowSurface().

Android initialise openGL2.0 context with EGL

I want to do off-screen image processing on Android in native code, so I need create the openGL context in native code by EGL.
By EGL, we can create EGLSurface, I can see there are three choices there:
* EGL_WINDOW_BIT
* EGL_PIXMAP_BIT
* EGL_BUFFER_BIT
The first one is for on-screen processing, the second one is for off-screen, so I use EGL_PIXMAP_BIT like this:
// Step 1 - Get the default display.
EGLDisplay eglDisplay = eglGetDisplay((EGLNativeDisplayType) 0);
if ((eglDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY)) == EGL_NO_DISPLAY) {
LOGH("eglGetDisplay() returned error %d", eglGetError());
exit(-1);
}
// Step 2 - Initialize EGL.
if (!eglInitialize(eglDisplay, 0, 0)) {
LOGH("eglInitialize() returned error %d", eglGetError());
exit(-1);
}
// Step 3 - Make OpenGL ES the current API.
eglBindAPI(EGL_OPENGL_ES_API);
// Step 4 - Specify the required configuration attributes.
EGLint pi32ConfigAttribs[] = { EGL_SURFACE_TYPE, EGL_PIXMAP_BIT,
EGL_BLUE_SIZE, 8, EGL_GREEN_SIZE, 8, EGL_RED_SIZE, 8, EGL_NONE,
EGL_BIND_TO_TEXTURE_RGBA, EGL_TRUE };
// Step 5 - Find a config that matches all requirements.
int iConfigs;
EGLConfig eglConfig;
eglChooseConfig(eglDisplay, pi32ConfigAttribs, &eglConfig, 1, &iConfigs);
if (iConfigs != 1) {
LOGH(
"Error: eglChooseConfig(): config not found %d - %d.\n", eglGetError(), iConfigs);
exit(-1);
}
// Step 6 - Create a surface to draw to.
EGLSurface eglSurface = eglCreatePbufferSurface(eglDisplay, eglConfig,
NULL);
// Step 7 - Create a context.
EGLContext eglContext = eglCreateContext(eglDisplay, eglConfig, NULL,
ai32ContextAttribs);
// Step 8 - Bind the context to the current thread
eglMakeCurrent(eglDisplay, eglSurface, eglSurface, eglContext);
The code failed at step 5, it seems Android doesn't support off screen processing? EGL_PIXMAP_BIT type is not supported.!

You are trying to use EGL options that just don't work on Android and pbuffers only work on some GPUs - not Nvidia Tegra. pi32ConfigAttribs[] should look like this regardless of whether it will be on-screen or off-screen:
EGLint pi32ConfigAttribs[] =
{
EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
EGL_RED_SIZE, 8,
EGL_GREEN_SIZE, 8,
EGL_BLUE_SIZE, 8,
EGL_ALPHA_SIZE, 8,
EGL_DEPTH_SIZE, 0,
EGL_STENCIL_SIZE, 0,
EGL_NONE
};
Android is very inflexible in how they support off-screen EGLSurfaces. They defined their own pixmap type named EGL_NATIVE_BUFFER_ANDROID.
To create an EGL surface that is off-screen on Android, construct a SurfaceTexture and pass that to eglCreateWindowSurface(). You should also look at using the EGL Image Extension and EGL_NATIVE_BUFFER_ANDROID, as discussed here:
http://software.intel.com/en-us/articles/using-opengl-es-to-accelerate-apps-with-legacy-2d-guis
http://software.intel.com/en-us/articles/porting-opengl-games-to-android-on-intel-atom-processors-part-1
UPDATE:
Here is some sample code that creates an off-screen surface:
private EGL10 mEgl;
private EGLConfig[] maEGLconfigs;
private EGLDisplay mEglDisplay = null;
private EGLContext mEglContext = null;
private EGLSurface mEglSurface = null;
private EGLSurface[] maEglSurfaces = new EGLSurface[MAX_SURFACES];
#Override
public void onSurfaceTextureAvailable(SurfaceTexture surfaceTexture, int width, int height)
{
InitializeEGL();
CreateSurfaceEGL(surfaceTexture, width, height);
}
private void InitializeEGL()
{
mEgl = (EGL10)EGLContext.getEGL();
mEglDisplay = mEgl.eglGetDisplay(EGL10.EGL_DEFAULT_DISPLAY);
if (mEglDisplay == EGL10.EGL_NO_DISPLAY)
throw new RuntimeException("Error: eglGetDisplay() Failed " + GLUtils.getEGLErrorString(mEgl.eglGetError()));
int[] version = new int[2];
if (!mEgl.eglInitialize(mEglDisplay, version))
throw new RuntimeException("Error: eglInitialize() Failed " + GLUtils.getEGLErrorString(mEgl.eglGetError()));
maEGLconfigs = new EGLConfig[1];
int[] configsCount = new int[1];
int[] configSpec = 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
};
if ((!mEgl.eglChooseConfig(mEglDisplay, configSpec, maEGLconfigs, 1, configsCount)) || (configsCount[0] == 0))
throw new IllegalArgumentException("Error: eglChooseConfig() Failed " + GLUtils.getEGLErrorString(mEgl.eglGetError()));
if (maEGLconfigs[0] == null)
throw new RuntimeException("Error: eglConfig() not Initialized");
int[] attrib_list = { EGL_CONTEXT_CLIENT_VERSION, 2, EGL10.EGL_NONE };
mEglContext = mEgl.eglCreateContext(mEglDisplay, maEGLconfigs[0], EGL10.EGL_NO_CONTEXT, attrib_list);
}
private void CreateSurfaceEGL(SurfaceTexture surfaceTexture, int width, int height)
{
surfaceTexture.setDefaultBufferSize(width, height);
mEglSurface = mEgl.eglCreateWindowSurface(mEglDisplay, maEGLconfigs[0], surfaceTexture, null);
if (mEglSurface == null || mEglSurface == EGL10.EGL_NO_SURFACE)
{
int error = mEgl.eglGetError();
if (error == EGL10.EGL_BAD_NATIVE_WINDOW)
{
Log.e(LOG_TAG, "Error: createWindowSurface() Returned EGL_BAD_NATIVE_WINDOW.");
return;
}
throw new RuntimeException("Error: createWindowSurface() Failed " + GLUtils.getEGLErrorString(error));
}
if (!mEgl.eglMakeCurrent(mEglDisplay, mEglSurface, mEglSurface, mEglContext))
throw new RuntimeException("Error: eglMakeCurrent() Failed " + GLUtils.getEGLErrorString(mEgl.eglGetError()));
int[] widthResult = new int[1];
int[] heightResult = new int[1];
mEgl.eglQuerySurface(mEglDisplay, mEglSurface, EGL10.EGL_WIDTH, widthResult);
mEgl.eglQuerySurface(mEglDisplay, mEglSurface, EGL10.EGL_HEIGHT, heightResult);
Log.i(LOG_TAG, "EGL Surface Dimensions:" + widthResult[0] + " " + heightResult[0]);
}
private void DeleteSurfaceEGL(EGLSurface eglSurface)
{
if (eglSurface != EGL10.EGL_NO_SURFACE)
mEgl.eglDestroySurface(mEglDisplay, eglSurface);
}