Snapshot.h revision fca52b7583d1e5f5ff8ed06554875d2a30ef56fa 
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_HWUI_SNAPSHOT_H
18#define ANDROID_HWUI_SNAPSHOT_H
19
20#include <GLES2/gl2.h>
21#include <GLES2/gl2ext.h>
22
23#include <utils/LinearAllocator.h>
24#include <utils/RefBase.h>
25#include <ui/Region.h>
26
27#include <SkRegion.h>
28
29#include "ClipArea.h"
30#include "Layer.h"
31#include "Matrix.h"
32#include "Outline.h"
33#include "Rect.h"
34#include "utils/Macros.h"
35
36namespace android {
37namespace uirenderer {
38
39/**
40 * Temporary structure holding information for a single outline clip.
41 *
42 * These structures are treated as immutable once created, and only exist for a single frame, which
43 * is why they may only be allocated with a LinearAllocator.
44 */
45class RoundRectClipState {
46public:
47    /** static void* operator new(size_t size); PURPOSELY OMITTED, allocator only **/
48    static void* operator new(size_t size, LinearAllocator& allocator) {
49        return allocator.alloc(size);
50    }
51
52    bool areaRequiresRoundRectClip(const Rect& rect) const {
53        return rect.intersects(dangerRects[0])
54                || rect.intersects(dangerRects[1])
55                || rect.intersects(dangerRects[2])
56                || rect.intersects(dangerRects[3]);
57    }
58
59    bool highPriority;
60    Matrix4 matrix;
61    Rect dangerRects[4];
62    Rect innerRect;
63    float radius;
64};
65
66class ProjectionPathMask {
67public:
68    /** static void* operator new(size_t size); PURPOSELY OMITTED, allocator only **/
69    static void* operator new(size_t size, LinearAllocator& allocator) {
70        return allocator.alloc(size);
71    }
72
73    const SkPath* projectionMask;
74    Matrix4 projectionMaskTransform;
75};
76
77/**
78 * A snapshot holds information about the current state of the rendering
79 * surface. A snapshot is usually created whenever the user calls save()
80 * and discarded when the user calls restore(). Once a snapshot is created,
81 * it can hold information for deferred rendering.
82 *
83 * Each snapshot has a link to a previous snapshot, indicating the previous
84 * state of the renderer.
85 */
86class Snapshot: public LightRefBase<Snapshot> {
87public:
88
89    Snapshot();
90    Snapshot(const sp<Snapshot>& s, int saveFlags);
91
92    /**
93     * Various flags set on ::flags.
94     */
95    enum Flags {
96        /**
97         * Indicates that the clip region was modified. When this
98         * snapshot is restored so must the clip.
99         */
100        kFlagClipSet = 0x1,
101        /**
102         * Indicates that this snapshot was created when saving
103         * a new layer.
104         */
105        kFlagIsLayer = 0x2,
106        /**
107         * Indicates that this snapshot is a special type of layer
108         * backed by an FBO. This flag only makes sense when the
109         * flag kFlagIsLayer is also set.
110         *
111         * Viewport has been modified to fit the new Fbo, and must be
112         * restored when this snapshot is restored.
113         */
114        kFlagIsFboLayer = 0x4,
115        /**
116         * Indicates that this snapshot or an ancestor snapshot is
117         * an FBO layer.
118         */
119        kFlagFboTarget = 0x8,
120    };
121
122    /**
123     * Modifies the current clip with the new clip rectangle and
124     * the specified operation. The specified rectangle is transformed
125     * by this snapshot's trasnformation.
126     */
127    bool clip(float left, float top, float right, float bottom,
128            SkRegion::Op op = SkRegion::kIntersect_Op);
129
130    /**
131     * Modifies the current clip with the new clip rectangle and
132     * the specified operation. The specified rectangle is considered
133     * already transformed.
134     */
135    bool clipTransformed(const Rect& r, SkRegion::Op op = SkRegion::kIntersect_Op);
136
137    /**
138     * Modifies the current clip with the specified region and operation.
139     * The specified region is considered already transformed.
140     */
141    bool clipRegionTransformed(const SkRegion& region, SkRegion::Op op);
142
143    /**
144     * Modifies the current clip with the specified path and operation.
145     */
146    bool clipPath(const SkPath& path, SkRegion::Op op);
147
148    /**
149     * Sets the current clip.
150     */
151    void setClip(float left, float top, float right, float bottom);
152
153    /**
154     * Returns the current clip in local coordinates. The clip rect is
155     * transformed by the inverse transform matrix.
156     */
157    ANDROID_API const Rect& getLocalClip();
158
159    /**
160     * Returns the current clip in render target coordinates.
161     */
162    const Rect& getRenderTargetClip() { return mClipArea->getClipRect(); }
163
164    /*
165     * Accessor functions so that the clip area can stay private
166     */
167    bool clipIsEmpty() const { return mClipArea->isEmpty(); }
168    const Rect& getClipRect() const { return mClipArea->getClipRect(); }
169    const SkRegion& getClipRegion() const { return mClipArea->getClipRegion(); }
170    bool clipIsSimple() const { return mClipArea->isSimple(); }
171    const ClipArea& getClipArea() const { return *mClipArea; }
172
173    /**
174     * Resets the clip to the specified rect.
175     */
176    void resetClip(float left, float top, float right, float bottom);
177
178    /**
179     * Resets the current transform to a pure 3D translation.
180     */
181    void resetTransform(float x, float y, float z);
182
183    void initializeViewport(int width, int height) {
184        mViewportData.initialize(width, height);
185        mClipAreaRoot.setViewportDimensions(width, height);
186    }
187
188    int getViewportWidth() const { return mViewportData.mWidth; }
189    int getViewportHeight() const { return mViewportData.mHeight; }
190    const Matrix4& getOrthoMatrix() const { return mViewportData.mOrthoMatrix; }
191
192    const Vector3& getRelativeLightCenter() const { return mRelativeLightCenter; }
193    void setRelativeLightCenter(const Vector3& lightCenter) { mRelativeLightCenter = lightCenter; }
194
195    /**
196     * Sets (and replaces) the current clipping outline
197     *
198     * If the current round rect clip is high priority, the incoming clip is ignored.
199     */
200    void setClippingRoundRect(LinearAllocator& allocator, const Rect& bounds,
201            float radius, bool highPriority);
202
203    /**
204     * Sets (and replaces) the current projection mask
205     */
206    void setProjectionPathMask(LinearAllocator& allocator, const SkPath* path);
207
208    /**
209     * Indicates whether this snapshot should be ignored. A snapshot
210     * is typically ignored if its layer is invisible or empty.
211     */
212    bool isIgnored() const;
213
214    /**
215     * Indicates whether the current transform has perspective components.
216     */
217    bool hasPerspectiveTransform() const;
218
219    /**
220     * Fills outTransform with the current, total transform to screen space,
221     * across layer boundaries.
222     */
223    void buildScreenSpaceTransform(Matrix4* outTransform) const;
224
225    /**
226     * Dirty flags.
227     */
228    int flags;
229
230    /**
231     * Previous snapshot.
232     */
233    sp<Snapshot> previous;
234
235    /**
236     * A pointer to the currently active layer.
237     *
238     * This snapshot does not own the layer, this pointer must not be freed.
239     */
240    Layer* layer;
241
242    /**
243     * Target FBO used for rendering. Set to 0 when rendering directly
244     * into the framebuffer.
245     */
246    GLuint fbo;
247
248    /**
249     * Indicates that this snapshot is invisible and nothing should be drawn
250     * inside it. This flag is set only when the layer clips drawing to its
251     * bounds and is passed to subsequent snapshots.
252     */
253    bool invisible;
254
255    /**
256     * If set to true, the layer will not be composited. This is similar to
257     * invisible but this flag is not passed to subsequent snapshots.
258     */
259    bool empty;
260
261    /**
262     * Local transformation. Holds the current translation, scale and
263     * rotation values.
264     *
265     * This is a reference to a matrix owned by this snapshot or another
266     *  snapshot. This pointer must not be freed. See ::mTransformRoot.
267     */
268    mat4* transform;
269
270    /**
271     * The ancestor layer's dirty region.
272     *
273     * This is a reference to a region owned by a layer. This pointer must
274     * not be freed.
275     */
276    Region* region;
277
278    /**
279     * Current alpha value. This value is 1 by default, but may be set by a DisplayList which
280     * has translucent rendering in a non-overlapping View. This value will be used by
281     * the renderer to set the alpha in the current color being used for ensuing drawing
282     * operations. The value is inherited by child snapshots because the same value should
283     * be applied to descendants of the current DisplayList (for example, a TextView contains
284     * the base alpha value which should be applied to the child DisplayLists used for drawing
285     * the actual text).
286     */
287    float alpha;
288
289    /**
290     * Current clipping round rect.
291     *
292     * Points to data not owned by the snapshot, and may only be replaced by subsequent RR clips,
293     * never modified.
294     */
295    const RoundRectClipState* roundRectClipState;
296
297    /**
298     * Current projection masking path - used exclusively to mask tessellated circles.
299     */
300    const ProjectionPathMask* projectionPathMask;
301
302    void dump() const;
303
304private:
305    struct ViewportData {
306        ViewportData() : mWidth(0), mHeight(0) {}
307        void initialize(int width, int height) {
308            mWidth = width;
309            mHeight = height;
310            mOrthoMatrix.loadOrtho(0, width, height, 0, -1, 1);
311        }
312
313        /*
314         * Width and height of current viewport.
315         *
316         * The viewport is always defined to be (0, 0, width, height).
317         */
318        int mWidth;
319        int mHeight;
320        /**
321         * Contains the current orthographic, projection matrix.
322         */
323        mat4 mOrthoMatrix;
324    };
325
326    mat4 mTransformRoot;
327
328    ClipArea mClipAreaRoot;
329    ClipArea* mClipArea;
330    Rect mLocalClip;
331
332    ViewportData mViewportData;
333    Vector3 mRelativeLightCenter;
334
335}; // class Snapshot
336
337}; // namespace uirenderer
338}; // namespace android
339
340#endif // ANDROID_HWUI_SNAPSHOT_H
341