support for "Add an ANativeWindow API for SurfaceFlinger to suggest an optimal buffer orientation"

     * likely be removed in the near future.

     */

    NATIVE_WINDOW_CONCRETE_TYPE = 5,

    /*

     * Default width and height of the ANativeWindow, these are the dimensions

     * of the window irrespective of the NATIVE_WINDOW_SET_BUFFERS_DIMENSIONS

     * call.

     */

    NATIVE_WINDOW_DEFAULT_WIDTH = 6,

    NATIVE_WINDOW_DEFAULT_HEIGHT = 7,

    /*

     * transformation that will most-likely be applied to buffers. This is only

     * a hint, the actual transformation applied might be different.

     *

     * INTENDED USE:

     *

     * The transform hint can be used by a producer, for instance the GLES

     * driver, to pre-rotate the rendering such that the final transformation

     * in the composer is identity. This can be very useful when used in

     * conjunction with the h/w composer HAL, in situations where it

     * cannot handle arbitrary rotations.

     *

     * 1. Before dequeuing a buffer, the GL driver (or any other ANW client)

     *    queries the ANW for NATIVE_WINDOW_TRANSFORM_HINT.

     *

     * 2. The GL driver overrides the width and height of the ANW to

     *    account for NATIVE_WINDOW_TRANSFORM_HINT. This is done by querying

     *    NATIVE_WINDOW_DEFAULT_{WIDTH | HEIGHT}, swapping the dimensions

     *    according to NATIVE_WINDOW_TRANSFORM_HINT and calling

     *    native_window_set_buffers_dimensions().

     *

     * 3. The GL driver dequeues a buffer of the new pre-rotated size.

     *

     * 4. The GL driver renders to the buffer such that the image is

     *    already transformed, that is applying NATIVE_WINDOW_TRANSFORM_HINT

     *    to the rendering.

     *

     * 5. The GL driver calls native_window_set_transform to apply

     *    inverse transformation to the buffer it just rendered.

     *    In order to do this, the GL driver needs

     *    to calculate the inverse of NATIVE_WINDOW_TRANSFORM_HINT, this is

     *    done easily:

     *

     *        int hintTransform, inverseTransform;

     *        query(..., NATIVE_WINDOW_TRANSFORM_HINT, &hintTransform);

     *        inverseTransform = hintTransform;

     *        if (hintTransform & HAL_TRANSFORM_ROT_90)

     *            inverseTransform ^= HAL_TRANSFORM_ROT_180;

     *

     *

     * 6. The GL driver queues the pre-transformed buffer.

     *

     * 7. The composer combines the buffer transform with the display

     *    transform.  If the buffer transform happens to cancel out the

     *    display transform then no rotation is needed.

     *

     */

    NATIVE_WINDOW_TRANSFORM_HINT = 8,

};

/* valid operations for the (*perform)() hook */