Add EGL call error checking.

static void printGLString(const char *name, GLenum s)

{

     fprintf(stderr, "printGLString %s, %d\n", name, s);

     const char *v = (const char *)glGetString(s);

     if (v)

         printf("GL %s = %s\n", name, v);

     int error = glGetError();

     fprintf(stderr, "glGetError() = %d, result of glGetString = %x\n", error,

         (unsigned int)v);

     if ((v < (const char*) 0) || (v > (const char*) 0x1000))

         fprintf(stderr, "GL %s = %s\n", name, v);

     else

         printf("GL %s = (null)\n", name);

         fprintf(stderr, "GL %s = (null)\n", name);

}

static const char* eglErrorToString[] = {

    "EGL_SUCCESS",      // 0x3000 12288

    "EGL_NOT_INITIALIZED",

    "EGL_BAD_ACCESS",   // 0x3002 12290

    "EGL_BAD_ALLOC",

    "EGL_BAD_ATTRIBUTE",

    "EGL_BAD_CONFIG",

    "EGL_BAD_CONTEXT",  // 0x3006 12294

    "EGL_BAD_CURRENT_SURFACE",

    "EGL_BAD_DISPLAY",

    "EGL_BAD_MATCH",

    "EGL_BAD_NATIVE_PIXMAP",

    "EGL_BAD_NATIVE_WINDOW",

    "EGL_BAD_PARAMETER",  // 0x300c 12300

    "EGL_BAD_SURFACE"

};

static void checkEglError(const char* op) {

    for(EGLint error = eglGetError();

		error != EGL_SUCCESS;

	error = eglGetError()) {

        const char* errorString = "unknown";

        if (error >= EGL_SUCCESS && error <= EGL_BAD_SURFACE) {

            errorString = eglErrorToString[error - EGL_SUCCESS];

        }

        fprintf(stderr, "%s() returned eglError %s (0x%x)\n", op,

            errorString, error);

    }

}

int main(int argc, char** argv)

     EGLNativeWindowType window = 0;

     window = android_createDisplaySurface();

     checkEglError("<init>");

     dpy = eglGetDisplay(EGL_DEFAULT_DISPLAY);

     checkEglError("eglGetDisplay");

     eglInitialize(dpy, &majorVersion, &minorVersion);

     checkEglError("eglInitialize");

     fprintf(stderr, "EGL version %d.%d\n", majorVersion, minorVersion);

     EGLUtils::selectConfigForNativeWindow(dpy, s_configAttribs, window, &config);

     fprintf(stderr, "Chosen config: 0x%08x\n", (unsigned long) config);

     checkEglError("EGLUtils::selectConfigForNativeWindow");

     surface = eglCreateWindowSurface(dpy, config, window, NULL);

     checkEglError("eglCreateWindowSurface");

     EGLint gl2_0Attribs[] = {EGL_CONTEXT_CLIENT_VERSION, 2, EGL_NONE};

     context = eglCreateContext(dpy, config, NULL, gl2_0Attribs);

     checkEglError("eglCreateContext");

     eglMakeCurrent(dpy, surface, surface, context);

     checkEglError("eglMakeCurrent");

     eglQuerySurface(dpy, surface, EGL_WIDTH, &w);

     checkEglError("eglQuerySurface");

     eglQuerySurface(dpy, surface, EGL_HEIGHT, &h);

     checkEglError("eglQuerySurface");

     GLint dim = w<h ? w : h;

     fprintf(stderr, "Window dimensions: %d x %d\n", w, h);

     printGLString("Version", GL_VERSION);

     printGLString("Vendor", GL_VENDOR);

     printGLString("Renderer", GL_RENDERER);