+typedef struct _tdm_func_hwc {
+ /**
+ * @brief Create a new window on the given hwc.
+ * @param[in] hwc A hwc object
+ * @param[out] error #TDM_ERROR_NONE if success. Otherwise, error value.
+ * @return A created window object
+ * @since 2.0.0
+ */
+ tdm_hwc_window *(*hwc_create_window)(tdm_hwc *hwc, tdm_error *error);
+
+ /**
+ * @brief Get the supported format array for the hwc windows of a hwc object.
+ * @param[in] hwc A hwc object
+ * @param[out] formats The available format array
+ * @param[out] count The count of formats
+ * @return #TDM_ERROR_NONE if success. Otherwise, error value.
+ */
+ tdm_error (*hwc_get_supported_formats)(tdm_hwc *hwc, const tbm_format **formats,
+ int *count);
+
+
+ /**
+ * @brief Get the available property array of a hwc object.
+ * @param[in] hwc A hwc object
+ * @param[out] props The available property array
+ * @param[out] count The count of properties
+ * @return #TDM_ERROR_NONE if success. Otherwise, error value.
+ */
+ tdm_error (*hwc_get_available_properties)(tdm_hwc *hwc, const tdm_prop **props,
+ int *count);
+
+ /**
+ * @brief Get a target buffer queue
+ * @param[in] hwc A hwc object
+ * @param[out] error #TDM_ERROR_NONE if success. Otherwise, error value.
+ * @return A buffer queue
+ * @since 2.0.0
+ */
+ tbm_surface_queue_h (*hwc_get_client_target_buffer_queue)(tdm_hwc *hwc,
+ tdm_error *error);
+
+ /**
+ * @brief Set the client(relative to the TDM) target buffer
+ * @details Sets the buffer which will receive the hwc of client composition.
+ * Window marked as TDM_COMPOSITION_CLIENT or TDM_COMPOSITION_DEVICE_CANDIDATE
+ * will be composited into this buffer prior to the call to hwc_commit(),
+ * and windows not marked as TDM_COMPOSITION_CLIENT and
+ * TDM_COMPOSITION_DEVICE_CANDIDATE should be composited with this buffer by the
+ * device.
+ *
+ * The buffer handle provided may be null if no windows are being composited by
+ * the client. This must not result in an error (unless an invalid display
+ * handle is also provided).
+ *
+ * The damage parameter describes a buffer damage region as defined in the
+ * description of hwc_window_set_buffer_damage().
+ *
+ * Will be called before hwc_commit() if any of the layers are marked as
+ * TDM_COMPOSITION_CLIENT or TDM_COMPOSITION_DEVICE_CANDIDATE. If no layers are
+ * so marked, then it is not necessary to call this function. It is not necessary
+ * to call hwc_validate() after changing the target through this function.
+ * @param[in] hwc A hwc object
+ * @param[in] target The new target buffer
+ * @param[in] damage The buffer damage region
+ * @param[in] composited_wnds The array of composited hwc_wnds
+ * @param[in] num_wnds The size of #composited_wnds array
+ * @return #TDM_ERROR_NONE if success. Otherwise, error value.
+ * @since 2.0.0
+ */
+ tdm_error (*hwc_set_client_target_buffer)(tdm_hwc *hwc,
+ tbm_surface_h target_buffer,
+ tdm_region damage);
+
+ /**
+ * @brief Validate the hwc
+ * @details Instructs the device to inspect all of the layer state and
+ * determine if there are any composition type changes necessary before
+ * presenting the hwc. Permitted changes are described in the definition
+ * of tdm_composition_t above.
+ * @param[in] hwc A hwc object
+ * @param[out] num_types The number of composition type changes required by
+ * the device; if greater than 0, the client must either set and validate new
+ * types, or call hwc_accept_changes() to accept the changes returned by
+ * hwc_get_changed_composition_types(); must be the same as the number of
+ * changes returned by hwc_get_changed_composition_types (see the
+ * declaration of that function for more information); pointer will be non-NULL
+ * @return #TDM_ERROR_NONE if success. Otherwise, error value.
+ * @since 2.0.0
+ */
+ tdm_error (*hwc_validate)(tdm_hwc *hwc, tdm_hwc_window **composited_wnds,
+ uint32_t num_wnds, uint32_t *num_types);
+
+ /**
+ * @brief Get changed composition types
+ * @details Retrieves the windows for which the device requires a different
+ * composition type than had been set prior to the last call to hwc_validate().
+ * The client will either update its state with these types and call
+ * hwc_accept_changes, or will set new types and attempt to validate the
+ * display again.
+ * layers and types may be NULL to retrieve the number of elements which
+ * will be returned. The number of elements returned must be the same as the
+ * value returned in num_types from the last call to hwc_validate().
+ * @param[in] hwc A hwc object
+ * @param[out] num_elements If windows or types were NULL, the number of layers
+ * and types which would have been returned; if both were non-NULL, the
+ * number of elements returned in layers and types, which must not exceed
+ * the value stored in num_elements prior to the call; pointer will be
+ * non-NULL
+ * @param[out] windows An array of windows
+ * @param[out] composition_types An array of composition types, each
+ * corresponding to an element of windows
+ * @return #TDM_ERROR_NONE if success. Otherwise, error value.
+ * @since 2.0.0
+ */
+ tdm_error (*hwc_get_changed_composition_types)(tdm_hwc *hwc, uint32_t *num_elements,
+ tdm_hwc_window **hwc_window,
+ tdm_hwc_window_composition *composition_types);
+ /**
+ * @brief Accepts the changes required by the device
+ * @details Accepts the changes required by the device from the previous
+ * hwc_validate() call (which may be queried using
+ * hwc_get_chaged_composition_types()) and revalidates the display. This
+ * function is equivalent to requesting the changed types from
+ * hwc_get_chaged_composition_types(), setting those types on the
+ * corresponding windows, and then calling hwc_validate again.
+ * After this call it must be valid to present this display. Calling this after
+ * hwc_validate() returns 0 changes must succeed with TDM_ERROR_NONE, but
+ * should have no other effect.
+ * @param[in] hwc A hwc object
+ * @return #TDM_ERROR_NONE if success. Otherwise, error value.
+ * @since 2.0.0
+ */
+ tdm_error (*hwc_accept_changes)(tdm_hwc *hwc);
+
+ /**
+ * @brief Commit changes for a output object
+ * @param[in] hwc A hwc object
+ * @param[in] sync 0: asynchronous, 1:synchronous
+ * @param[in] user_data The user data
+ * @return #TDM_ERROR_NONE if success. Otherwise, error value.
+ * @see hwc_set_commit_handler, tdm_hwc_commit_handler
+ * @remark
+ * When this function is called, a backend module @b SHOULD apply the all
+ * changes of the given output object to screen as well as the layer changes
+ * of this output.
+ * If this function returns TDM_ERROR_NONE, a backend module @b SHOULD call
+ * a user commit handler with the user data of this function after all
+ * changes of the given output object are applied.
+ */
+ tdm_error (*hwc_commit)(tdm_hwc *hwc, int sync, void *user_data);
+
+ /**
+ * @brief Set a user commit handler
+ * @param[in] hwc A hwc object
+ * @param[in] func A user commit handler
+ * @return #TDM_ERROR_NONE if success. Otherwise, error value.
+ */
+ tdm_error (*hwc_set_commit_handler)(tdm_output *hwc, tdm_hwc_commit_handler func);
+} tdm_func_hwc;
+