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#pragma once
18
19#include <GLES2/gl2.h>
20#include <GLES2/gl2ext.h>
21
22#include <utils/LinearAllocator.h>
23#include <utils/RefBase.h>
24#include <ui/Region.h>
25
26#include <SkClipOp.h>
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) = delete;
48    static void* operator new(size_t size, LinearAllocator& allocator) {
49        return allocator.alloc<RoundRectClipState>(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
66/**
67 * A snapshot holds information about the current state of the rendering
68 * surface. A snapshot is usually created whenever the user calls save()
69 * and discarded when the user calls restore(). Once a snapshot is created,
70 * it can hold information for deferred rendering.
71 *
72 * Each snapshot has a link to a previous snapshot, indicating the previous
73 * state of the renderer.
74 */
75class Snapshot {
76public:
77
78    Snapshot();
79    Snapshot(Snapshot* s, int saveFlags);
80
81    /**
82     * Various flags set on ::flags.
83     */
84    enum Flags {
85        /**
86         * Indicates that the clip region was modified. When this
87         * snapshot is restored so must the clip.
88         */
89        kFlagClipSet = 0x1,
90        /**
91         * Indicates that this snapshot was created when saving
92         * a new layer.
93         */
94        kFlagIsLayer = 0x2,
95        /**
96         * Indicates that this snapshot is a special type of layer
97         * backed by an FBO. This flag only makes sense when the
98         * flag kFlagIsLayer is also set.
99         *
100         * Viewport has been modified to fit the new Fbo, and must be
101         * restored when this snapshot is restored.
102         */
103        kFlagIsFboLayer = 0x4,
104    };
105
106    /**
107     * Modifies the current clip with the new clip rectangle and
108     * the specified operation. The specified rectangle is transformed
109     * by this snapshot's trasnformation.
110     */
111    void clip(const Rect& localClip, SkClipOp op);
112
113    /**
114     * Modifies the current clip with the new clip rectangle and
115     * the specified operation. The specified rectangle is considered
116     * already transformed.
117     */
118    void clipTransformed(const Rect& r, SkClipOp op = SkClipOp::kIntersect);
119
120    /**
121     * Modifies the current clip with the specified path and operation.
122     */
123    void clipPath(const SkPath& path, SkClipOp op);
124
125    /**
126     * Sets the current clip.
127     */
128    void setClip(float left, float top, float right, float bottom);
129
130    /**
131     * Returns the current clip in local coordinates. The clip rect is
132     * transformed by the inverse transform matrix.
133     */
134    ANDROID_API const Rect& getLocalClip();
135
136    /**
137     * Returns the current clip in render target coordinates.
138     */
139    const Rect& getRenderTargetClip() const { return mClipArea->getClipRect(); }
140
141    /*
142     * Accessor functions so that the clip area can stay private
143     */
144    bool clipIsEmpty() const { return mClipArea->isEmpty(); }
145    const SkRegion& getClipRegion() const { return mClipArea->getClipRegion(); }
146    bool clipIsSimple() const { return mClipArea->isSimple(); }
147    const ClipArea& getClipArea() const { return *mClipArea; }
148    ClipArea& mutateClipArea() { return *mClipArea; }
149
150    WARN_UNUSED_RESULT const ClipBase* serializeIntersectedClip(LinearAllocator& allocator,
151            const ClipBase* recordedClip, const Matrix4& recordedClipTransform);
152    void applyClip(const ClipBase* clip, const Matrix4& transform);
153
154    /**
155     * Resets the clip to the specified rect.
156     */
157    void resetClip(float left, float top, float right, float bottom);
158
159    void initializeViewport(int width, int height) {
160        mViewportData.initialize(width, height);
161        mClipAreaRoot.setViewportDimensions(width, height);
162    }
163
164    int getViewportWidth() const { return mViewportData.mWidth; }
165    int getViewportHeight() const { return mViewportData.mHeight; }
166    const Matrix4& getOrthoMatrix() const { return mViewportData.mOrthoMatrix; }
167
168    const Vector3& getRelativeLightCenter() const { return mRelativeLightCenter; }
169    void setRelativeLightCenter(const Vector3& lightCenter) { mRelativeLightCenter = lightCenter; }
170
171    /**
172     * Sets (and replaces) the current clipping outline
173     *
174     * If the current round rect clip is high priority, the incoming clip is ignored.
175     */
176    void setClippingRoundRect(LinearAllocator& allocator, const Rect& bounds,
177            float radius, bool highPriority);
178
179    /**
180     * Sets (and replaces) the current projection mask
181     */
182    void setProjectionPathMask(const SkPath* path);
183
184    /**
185     * Indicates whether the current transform has perspective components.
186     */
187    bool hasPerspectiveTransform() const;
188
189    /**
190     * Dirty flags.
191     */
192    int flags;
193
194    /**
195     * Previous snapshot.
196     */
197    Snapshot* previous;
198
199    /**
200     * A pointer to the currently active layer.
201     *
202     * This snapshot does not own the layer, this pointer must not be freed.
203     */
204    Layer* layer;
205
206    /**
207     * Target FBO used for rendering. Set to 0 when rendering directly
208     * into the framebuffer.
209     */
210    GLuint fbo;
211
212    /**
213     * Local transformation. Holds the current translation, scale and
214     * rotation values.
215     *
216     * This is a reference to a matrix owned by this snapshot or another
217     *  snapshot. This pointer must not be freed. See ::mTransformRoot.
218     */
219    mat4* transform;
220
221    /**
222     * Current alpha value. This value is 1 by default, but may be set by a DisplayList which
223     * has translucent rendering in a non-overlapping View. This value will be used by
224     * the renderer to set the alpha in the current color being used for ensuing drawing
225     * operations. The value is inherited by child snapshots because the same value should
226     * be applied to descendants of the current DisplayList (for example, a TextView contains
227     * the base alpha value which should be applied to the child DisplayLists used for drawing
228     * the actual text).
229     */
230    float alpha;
231
232    /**
233     * Current clipping round rect.
234     *
235     * Points to data not owned by the snapshot, and may only be replaced by subsequent RR clips,
236     * never modified.
237     */
238    const RoundRectClipState* roundRectClipState;
239
240    /**
241     * Current projection masking path - used exclusively to mask projected, tessellated circles.
242     */
243    const SkPath* projectionPathMask;
244
245    void dump() const;
246
247private:
248    struct ViewportData {
249        ViewportData() : mWidth(0), mHeight(0) {}
250        void initialize(int width, int height) {
251            mWidth = width;
252            mHeight = height;
253            mOrthoMatrix.loadOrtho(0, width, height, 0, -1, 1);
254        }
255
256        /*
257         * Width and height of current viewport.
258         *
259         * The viewport is always defined to be (0, 0, width, height).
260         */
261        int mWidth;
262        int mHeight;
263        /**
264         * Contains the current orthographic, projection matrix.
265         */
266        mat4 mOrthoMatrix;
267    };
268
269    mat4 mTransformRoot;
270
271    ClipArea mClipAreaRoot;
272    ClipArea* mClipArea;
273    Rect mLocalClip;
274
275    ViewportData mViewportData;
276    Vector3 mRelativeLightCenter;
277
278}; // class Snapshot
279
280}; // namespace uirenderer
281}; // namespace android
282