/*
* 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;
}*/
}