1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.gallery3d.photoeditor.filters;
18
19import android.media.effect.Effect;
20import android.media.effect.EffectContext;
21import android.os.Parcel;
22import android.os.Parcelable;
23
24import com.android.gallery3d.photoeditor.Photo;
25
26import java.util.HashMap;
27
28/**
29 * Image filter for photo editing; all of its methods must be called from a single GL thread.
30 */
31public abstract class Filter implements Parcelable {
32
33    // TODO: This should be set in MFF instead.
34    private static final int DEFAULT_TILE_SIZE = 640;
35
36    private static final HashMap<Filter, Effect> effects = new HashMap<Filter, Effect>();
37    private static EffectContext context;
38
39    /**
40     * Filter context should be released before the current GL context is lost.
41     */
42    public static void releaseContext() {
43        if (context != null) {
44            // Release all effects created with the releasing context.
45            for (Effect effect : effects.values()) {
46                effect.release();
47            }
48            effects.clear();
49            context.release();
50            context = null;
51        }
52    }
53
54    public void release() {
55        Effect effect = effects.remove(this);
56        if (effect != null) {
57            effect.release();
58        }
59    }
60
61    protected Effect getEffect(String name) {
62        Effect effect = effects.get(this);
63        if (effect == null) {
64            if (context == null) {
65                context = EffectContext.createWithCurrentGlContext();
66            }
67            effect = context.getFactory().createEffect(name);
68            effect.setParameter("tile_size", DEFAULT_TILE_SIZE);
69            effects.put(this, effect);
70        }
71        return effect;
72    }
73
74    /**
75     * Processes the source bitmap and matrix and output the destination bitmap and matrix.
76     *
77     * @param src source photo as the input.
78     * @param dst destination photo having the same dimension as source photo as the output.
79     */
80    public abstract void process(Photo src, Photo dst);
81
82    /**
83     * Instantiates CREATOR of subclasses for Parcelable implementations.
84     */
85    protected static <T extends Filter> Parcelable.Creator<T> creatorOf(Class<T> filterClass) {
86        return new FilterCreator<T>(filterClass);
87    }
88
89    /**
90     * Saves states for restoring filter later; subclasses can override this to persist states.
91     */
92    protected void writeToParcel(Parcel out) {
93    }
94
95    /**
96     * Restores filter from the saved states; subclasses can override this to persist states.
97     */
98    protected void readFromParcel(Parcel in) {
99    }
100
101    @Override
102    public int describeContents() {
103        return 0;
104    }
105
106    @Override
107    public void writeToParcel(Parcel dest, int flags) {
108        writeToParcel(dest);
109    }
110}
111