public final class EglCore {
private EGLDisplay mEGLDisplay = EGL14.EGL_NO_DISPLAY;
private EGLContext mEGLContext = EGL14.EGL_NO_CONTEXT;
private EGLConfig mEGLConfig = null;
private int mGlVersion = -1;
/**
* Prepares EGL display and context.
* @param sharedContext The context to share, or null if sharing is not desired.
* @param flags Configuration bit flags, e.g. FLAG_RECORDABLE.
*/
public EglCore(EGLContext sharedContext, int flags) {
...
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");
}
// Try to get a GLES3 context, if requested.
if ((flags & FLAG_TRY_GLES3) != 0) {
//Log.d(TAG, "Trying GLES 3");
EGLConfig config = getConfig(flags, 3);
...
}
if (mEGLContext == EGL14.EGL_NO_CONTEXT) { // GLES 2 only, or GLES 3 attempt failed
//Log.d(TAG, "Trying GLES 2");
EGLConfig config = getConfig(flags, 2);
if (config == null) {
throw new RuntimeException("Unable to find a suitable EGLConfig");
}
int[] attrib2_list = {
EGL14.EGL_CONTEXT_CLIENT_VERSION, 2,
EGL14.EGL_NONE
};
EGLContext context = EGL14.eglCreateContext(mEGLDisplay, config, sharedContext,
attrib2_list, 0);
checkEglError("eglCreateContext");
mEGLConfig = config;
mEGLContext = context;
mGlVersion = 2;
}
/**
* Finds a suitable EGLConfig.
*
* @param flags Bit flags from constructor.
* @param version Must be 2 or 3.
*/
private EGLConfig getConfig(int flags, int version) {
...
// 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_DEPTH_SIZE, 16,
//EGL14.EGL_STENCIL_SIZE, 8,
EGL14.EGL_RENDERABLE_TYPE, renderableType,
EGL14.EGL_NONE, 0, // placeholder for recordable [@-3]
EGL14.EGL_NONE
};
...
return configs[0];
}
/**
* Discards all resources held by this class, notably the EGL context. This must be
* called from the thread where the context was created.
* <p>
* On completion, no context will be current.
*/
public void release() {
if (mEGLDisplay != EGL14.EGL_NO_DISPLAY) {
// Android is unusual in that it uses a reference-counted EGLDisplay. So for
// every eglInitialize() we need an eglTerminate().
EGL14.eglMakeCurrent(mEGLDisplay, EGL14.EGL_NO_SURFACE, EGL14.EGL_NO_SURFACE,
EGL14.EGL_NO_CONTEXT);
EGL14.eglDestroyContext(mEGLDisplay, mEGLContext);
EGL14.eglReleaseThread();
EGL14.eglTerminate(mEGLDisplay);
}
mEGLDisplay = EGL14.EGL_NO_DISPLAY;
mEGLContext = EGL14.EGL_NO_CONTEXT;
mEGLConfig = null;
}
/**
* Creates an EGL surface associated with a Surface.
* <p>
* If this is destined for MediaCodec, the EGLConfig should have the "recordable" attribute.
*/
public EGLSurface createWindowSurface(Object surface) {
if (!(surface instanceof Surface) && !(surface instanceof SurfaceTexture)) {
throw new RuntimeException("invalid surface: " + surface);
}
// Create a window surface, and attach it to the Surface we received.
int[] surfaceAttribs = {
EGL14.EGL_NONE
};
EGLSurface eglSurface = EGL14.eglCreateWindowSurface(mEGLDisplay, mEGLConfig, surface,
surfaceAttribs, 0);
checkEglError("eglCreateWindowSurface");
if (eglSurface == null) {
throw new RuntimeException("surface was null");
}
return eglSurface;
}
/**
* Creates an EGL surface associated with an offscreen buffer.
*/
public EGLSurface createOffscreenSurface(int width, int height) {
int[] surfaceAttribs = {
EGL14.EGL_WIDTH, width,
EGL14.EGL_HEIGHT, height,
EGL14.EGL_NONE
};
EGLSurface eglSurface = EGL14.eglCreatePbufferSurface(mEGLDisplay, mEGLConfig,
surfaceAttribs, 0);
checkEglError("eglCreatePbufferSurface");
if (eglSurface == null) {
throw new RuntimeException("surface was null");
}
return eglSurface;
}
/**
* Makes our EGL context current, using the supplied surface for both "draw" and "read".
*/
public void makeCurrent(EGLSurface eglSurface) {
if (mEGLDisplay == EGL14.EGL_NO_DISPLAY) {
// called makeCurrent() before create?
Log.d(TAG, "NOTE: makeCurrent w/o display");
}
if (!EGL14.eglMakeCurrent(mEGLDisplay, eglSurface, eglSurface, mEGLContext)) {
throw new RuntimeException("eglMakeCurrent failed");
}
}
/**
* Calls eglSwapBuffers. Use this to "publish" the current frame.
*
* @return false on failure
*/
public boolean swapBuffers(EGLSurface eglSurface) {
return EGL14.eglSwapBuffers(mEGLDisplay, eglSurface);
}
}
