Snapshot.h revision 6fe991e5e76f9af9dab960100d5768d96d5f4daa 
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 {
87public:
88
89    Snapshot();
90    Snapshot(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    void clip(float left, float top, float right, float bottom, SkRegion::Op op);
128
129    /**
130     * Modifies the current clip with the new clip rectangle and
131     * the specified operation. The specified rectangle is considered
132     * already transformed.
133     */
134    void clipTransformed(const Rect& r, SkRegion::Op op = SkRegion::kIntersect_Op);
135
136    /**
137     * Modifies the current clip with the specified region and operation.
138     * The specified region is considered already transformed.
139     */
140    void clipRegionTransformed(const SkRegion& region, SkRegion::Op op);
141
142    /**
143     * Modifies the current clip with the specified path and operation.
144     */
145    void clipPath(const SkPath& path, SkRegion::Op op);
146
147    /**
148     * Sets the current clip.
149     */
150    void setClip(float left, float top, float right, float bottom);
151
152    /**
153     * Returns the current clip in local coordinates. The clip rect is
154     * transformed by the inverse transform matrix.
155     */
156    ANDROID_API const Rect& getLocalClip();
157
158    /**
159     * Returns the current clip in render target coordinates.
160     */
161    const Rect& getRenderTargetClip() const { return mClipArea->getClipRect(); }
162
163    /*
164     * Accessor functions so that the clip area can stay private
165     */
166    bool clipIsEmpty() const { return mClipArea->isEmpty(); }
167    const SkRegion& getClipRegion() const { return mClipArea->getClipRegion(); }
168    bool clipIsSimple() const { return mClipArea->isSimple(); }
169    const ClipArea& getClipArea() const { return *mClipArea; }
170
171    /**
172     * Resets the clip to the specified rect.
173     */
174    void resetClip(float left, float top, float right, float bottom);
175
176    /**
177     * Resets the current transform to a pure 3D translation.
178     */
179    void resetTransform(float x, float y, float z);
180
181    void initializeViewport(int width, int height) {
182        mViewportData.initialize(width, height);
183        mClipAreaRoot.setViewportDimensions(width, height);
184    }
185
186    int getViewportWidth() const { return mViewportData.mWidth; }
187    int getViewportHeight() const { return mViewportData.mHeight; }
188    const Matrix4& getOrthoMatrix() const { return mViewportData.mOrthoMatrix; }
189
190    const Vector3& getRelativeLightCenter() const { return mRelativeLightCenter; }
191    void setRelativeLightCenter(const Vector3& lightCenter) { mRelativeLightCenter = lightCenter; }
192
193    /**
194     * Sets (and replaces) the current clipping outline
195     *
196     * If the current round rect clip is high priority, the incoming clip is ignored.
197     */
198    void setClippingRoundRect(LinearAllocator& allocator, const Rect& bounds,
199            float radius, bool highPriority);
200
201    /**
202     * Sets (and replaces) the current projection mask
203     */
204    void setProjectionPathMask(LinearAllocator& allocator, const SkPath* path);
205
206    /**
207     * Indicates whether this snapshot should be ignored. A snapshot
208     * is typically ignored if its layer is invisible or empty.
209     */
210    bool isIgnored() const;
211
212    /**
213     * Indicates whether the current transform has perspective components.
214     */
215    bool hasPerspectiveTransform() const;
216
217    /**
218     * Fills outTransform with the current, total transform to screen space,
219     * across layer boundaries.
220     */
221    void buildScreenSpaceTransform(Matrix4* outTransform) const;
222
223    /**
224     * Dirty flags.
225     */
226    int flags;
227
228    /**
229     * Previous snapshot.
230     */
231    Snapshot* previous;
232
233    /**
234     * A pointer to the currently active layer.
235     *
236     * This snapshot does not own the layer, this pointer must not be freed.
237     */
238    Layer* layer;
239
240    /**
241     * Target FBO used for rendering. Set to 0 when rendering directly
242     * into the framebuffer.
243     */
244    GLuint fbo;
245
246    /**
247     * Indicates that this snapshot is invisible and nothing should be drawn
248     * inside it. This flag is set only when the layer clips drawing to its
249     * bounds and is passed to subsequent snapshots.
250     */
251    bool invisible;
252
253    /**
254     * If set to true, the layer will not be composited. This is similar to
255     * invisible but this flag is not passed to subsequent snapshots.
256     */
257    bool empty;
258
259    /**
260     * Local transformation. Holds the current translation, scale and
261     * rotation values.
262     *
263     * This is a reference to a matrix owned by this snapshot or another
264     *  snapshot. This pointer must not be freed. See ::mTransformRoot.
265     */
266    mat4* transform;
267
268    /**
269     * The ancestor layer's dirty region.
270     *
271     * This is a reference to a region owned by a layer. This pointer must
272     * not be freed.
273     */
274    Region* region;
275
276    /**
277     * Current alpha value. This value is 1 by default, but may be set by a DisplayList which
278     * has translucent rendering in a non-overlapping View. This value will be used by
279     * the renderer to set the alpha in the current color being used for ensuing drawing
280     * operations. The value is inherited by child snapshots because the same value should
281     * be applied to descendants of the current DisplayList (for example, a TextView contains
282     * the base alpha value which should be applied to the child DisplayLists used for drawing
283     * the actual text).
284     */
285    float alpha;
286
287    /**
288     * Current clipping round rect.
289     *
290     * Points to data not owned by the snapshot, and may only be replaced by subsequent RR clips,
291     * never modified.
292     */
293    const RoundRectClipState* roundRectClipState;
294
295    /**
296     * Current projection masking path - used exclusively to mask tessellated circles.
297     */
298    const ProjectionPathMask* projectionPathMask;
299
300    void dump() const;
301
302private:
303    struct ViewportData {
304        ViewportData() : mWidth(0), mHeight(0) {}
305        void initialize(int width, int height) {
306            mWidth = width;
307            mHeight = height;
308            mOrthoMatrix.loadOrtho(0, width, height, 0, -1, 1);
309        }
310
311        /*
312         * Width and height of current viewport.
313         *
314         * The viewport is always defined to be (0, 0, width, height).
315         */
316        int mWidth;
317        int mHeight;
318        /**
319         * Contains the current orthographic, projection matrix.
320         */
321        mat4 mOrthoMatrix;
322    };
323
324    mat4 mTransformRoot;
325
326    ClipArea mClipAreaRoot;
327    ClipArea* mClipArea;
328    Rect mLocalClip;
329
330    ViewportData mViewportData;
331    Vector3 mRelativeLightCenter;
332
333}; // class Snapshot
334
335}; // namespace uirenderer
336}; // namespace android
337
338#endif // ANDROID_HWUI_SNAPSHOT_H
339