Snapshot.h revision 8aef54fa17f2a3753d9a8f2027629bc480088f69 
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
17#ifndef ANDROID_UI_SNAPSHOT_H
18#define ANDROID_UI_SNAPSHOT_H
19
20#include <GLES2/gl2.h>
21#include <GLES2/gl2ext.h>
22
23#include <utils/RefBase.h>
24
25#include <SkCanvas.h>
26#include <SkRegion.h>
27
28#include "Layer.h"
29#include "Matrix.h"
30#include "Rect.h"
31
32namespace android {
33namespace uirenderer {
34
35/**
36 * A snapshot holds information about the current state of the rendering
37 * surface. A snapshot is usually created whenever the user calls save()
38 * and discarded when the user calls restore(). Once a snapshot is created,
39 * it can hold information for deferred rendering.
40 *
41 * Each snapshot has a link to a previous snapshot, indicating the previous
42 * state of the renderer.
43 */
44class Snapshot: public LightRefBase<Snapshot> {
45public:
46    Snapshot(): invisible(false), flags(0), previous(NULL), layer(NULL), fbo(0) {
47        transform = &mTransformRoot;
48        clipRect = &mClipRectRoot;
49    }
50
51    /**
52     * Copies the specified snapshot/ The specified snapshot is stored as
53     * the previous snapshot.
54     */
55    Snapshot(const sp<Snapshot>& s, int saveFlags):
56            height(s->height),
57            invisible(s->invisible),
58            flags(0),
59            previous(s),
60            layer(NULL),
61            fbo(s->fbo),
62            viewport(s->viewport) {
63        if (saveFlags & SkCanvas::kMatrix_SaveFlag) {
64            mTransformRoot.load(*s->transform);
65            transform = &mTransformRoot;
66        } else {
67            transform = s->transform;
68        }
69
70        if (saveFlags & SkCanvas::kClip_SaveFlag) {
71            mClipRectRoot.set(*s->clipRect);
72            clipRect = &mClipRectRoot;
73        } else {
74            clipRect = s->clipRect;
75        }
76
77        if ((s->flags & Snapshot::kFlagClipSet) &&
78                !(s->flags & Snapshot::kFlagDirtyLocalClip)) {
79            mLocalClip.set(s->mLocalClip);
80        } else {
81            flags |= Snapshot::kFlagDirtyLocalClip;
82        }
83    }
84
85    /**
86     * Various flags set on #flags.
87     */
88    enum Flags {
89        /**
90         * Indicates that the clip region was modified. When this
91         * snapshot is restored so must the clip.
92         */
93        kFlagClipSet = 0x1,
94        /**
95         * Indicates that this snapshot was created when saving
96         * a new layer.
97         */
98        kFlagIsLayer = 0x2,
99        /**
100         * Indicates that this snapshot has changed the ortho matrix.
101         */
102        kFlagDirtyOrtho = 0x4,
103        /**
104         * Indicates that the local clip should be recomputed.
105         */
106        kFlagDirtyLocalClip = 0x8,
107    };
108
109    /**
110     * Intersects the current clip with the new clip rectangle.
111     */
112    bool clip(float left, float top, float right, float bottom, SkRegion::Op op) {
113        bool clipped = false;
114
115        Rect r(left, top, right, bottom);
116        transform->mapRect(r);
117
118        switch (op) {
119            case SkRegion::kDifference_Op:
120                break;
121            case SkRegion::kIntersect_Op:
122                clipped = clipRect->intersect(r);
123                break;
124            case SkRegion::kUnion_Op:
125                clipped = clipRect->unionWith(r);
126                break;
127            case SkRegion::kXOR_Op:
128                break;
129            case SkRegion::kReverseDifference_Op:
130                break;
131            case SkRegion::kReplace_Op:
132                clipRect->set(r);
133                clipped = true;
134                break;
135        }
136
137        if (clipped) {
138            flags |= Snapshot::kFlagClipSet | Snapshot::kFlagDirtyLocalClip;
139        }
140
141        return clipped;
142    }
143
144    /**
145     * Sets the current clip.
146     */
147    void setClip(float left, float top, float right, float bottom) {
148        clipRect->set(left, top, right, bottom);
149        flags |= Snapshot::kFlagClipSet | Snapshot::kFlagDirtyLocalClip;
150    }
151
152    const Rect& getLocalClip() {
153        if (flags & Snapshot::kFlagDirtyLocalClip) {
154            mat4 inverse;
155            inverse.loadInverse(*transform);
156
157            mLocalClip.set(*clipRect);
158            inverse.mapRect(mLocalClip);
159
160            flags &= ~Snapshot::kFlagDirtyLocalClip;
161        }
162        return mLocalClip;
163    }
164
165    // TODO: Temporary
166    void resetTransform(float x, float y, float z) {
167        transform = &mTransformRoot;
168        transform->loadTranslate(x, y, z);
169    }
170
171    // TODO: Temporary
172    void resetClip(float left, float top, float right, float bottom) {
173        clipRect = &mClipRectRoot;
174        clipRect->set(left, top, right, bottom);
175        flags |= Snapshot::kFlagClipSet | Snapshot::kFlagDirtyLocalClip;
176    }
177
178    /**
179     * Height of the framebuffer the snapshot is rendering into.
180     */
181    int height;
182
183    /**
184     * If true, the layer won't be rendered.
185     */
186    bool invisible;
187
188    /**
189     * Dirty flags.
190     */
191    int flags;
192
193    /**
194     * Previous snapshot.
195     */
196    sp<Snapshot> previous;
197
198    /**
199     * Only set when the flag kFlagIsLayer is set.
200     */
201    Layer* layer;
202    GLuint fbo;
203
204    /**
205     * Current viewport.
206     */
207    Rect viewport;
208
209    /**
210     * Contains the previous ortho matrix.
211     */
212    mat4 orthoMatrix;
213
214    /**
215     * Local transformation. Holds the current translation, scale and
216     * rotation values.
217     */
218    mat4* transform;
219
220    /**
221     * Current clip region. The clip is stored in canvas-space coordinates,
222     * (screen-space coordinates in the regular case.)
223     */
224    Rect* clipRect;
225
226private:
227    mat4 mTransformRoot;
228    Rect mClipRectRoot;
229    Rect mLocalClip;
230
231}; // class Snapshot
232
233}; // namespace uirenderer
234}; // namespace android
235
236#endif // ANDROID_UI_SNAPSHOT_H
237