content: /*
   * Copyright (C) 2011 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  
  package android.filterfw;
  
  import android.filterfw.core.Filter;
  import android.filterfw.core.FilterFactory;
  import android.filterfw.core.FilterFunction;
  import android.filterfw.core.FrameManager;
  
  /**
   * A FilterFunctionEnvironment provides a simple functional front-end to manually executing
   * filters. Use this environment if a graph-based approach is not convenient for your case.
   * Typically, a FilterFunctionEnvironment is used as follows:
   *   1. Instantiate a new FilterFunctionEnvironment instance.
   *   2. Perform any configuration, such as setting a GL environment.
   *   3. Wrap Filters into FilterFunctions by calling createFunction().
   *   4. Execute FilterFunctions individually and use the results for further processing.
   * Additionally, there is a convenience method to execute a number of filters in sequence.
   * @hide
   */
  public class FilterFunctionEnvironment extends MffEnvironment {
  
      /**
       * Create a new FilterFunctionEnvironment with the default components.
       */
      public FilterFunctionEnvironment() {
          super(null);
      }
  
      /**
       * Create a new FilterFunctionEnvironment with a custom FrameManager. Pass null to auto-create
       * a FrameManager.
       *
       * @param frameManager The FrameManager to use, or null to auto-create one.
       */
      public FilterFunctionEnvironment(FrameManager frameManager) {
          super(frameManager);
      }
  
      /**
       * Create a new FilterFunction from a specific filter class. The function is initialized with
       * the given key-value list of parameters. Note, that this function uses the default shared
       * FilterFactory to create the filter instance.
       *
       * @param filterClass   The class of the filter to wrap. This must be a Filter subclass.
       * @param parameters    An argument list of alternating key-value filter parameters.
       * @return             A new FilterFunction instance.
       */
      public FilterFunction createFunction(Class filterClass, Object... parameters) {
          String filterName = "FilterFunction(" + filterClass.getSimpleName() + ")";
          Filter filter = FilterFactory.sharedFactory().createFilterByClass(filterClass, filterName);
          filter.initWithAssignmentList(parameters);
          return new FilterFunction(getContext(), filter);
      }
  
      /**
       * Convenience method to execute a sequence of filter functions. Note that every function in
       * the list MUST have one input and one output port, except the first filter (which must not
       * have any input ports) and the last filter (which may not have any output ports).
       *
       * @param functions A list of filter functions. The first filter must be a source filter.
       * @return         The result of the last filter executed, or null if the last filter did not
                          produce any output.
       *
      public Frame executeSequence(FilterFunction[] functions) {
          Frame oldFrame = null;
          Frame newFrame = null;
          for (FilterFunction filterFunction : functions) {
              if (oldFrame == null) {
                  newFrame = filterFunction.executeWithArgList();
              } else {
                  newFrame = filterFunction.executeWithArgList(oldFrame);
                  oldFrame.release();
              }
              oldFrame = newFrame;
          }
          if (oldFrame != null) {
              oldFrame.release();
          }
          return newFrame;
      }*/
  
  }
  