1/*
2 * Copyright (C) 2014 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_STATEFUL_BASE_RENDERER_H
18#define ANDROID_HWUI_STATEFUL_BASE_RENDERER_H
19
20#include <utils/RefBase.h>
21
22#include "Renderer.h"
23#include "Snapshot.h"
24
25namespace android {
26namespace uirenderer {
27
28/**
29 * Abstract Renderer subclass, which implements Canvas state methods.
30 *
31 * Manages the Snapshot stack, implementing matrix, save/restore, and clipping methods in the
32 * Renderer interface. Drawing and recording classes that extend StatefulBaseRenderer will have
33 * different use cases:
34 *
35 * Drawing subclasses (i.e. OpenGLRenderer) can query attributes (such as transform) or hook into
36 * changes (e.g. save/restore) with minimal surface area for manipulating the stack itself.
37 *
38 * Recording subclasses (i.e. DisplayListRenderer) can both record and pass through state operations
39 * to StatefulBaseRenderer, so that not only will querying operations work (getClip/Matrix), but so
40 * that quickRejection can also be used.
41 */
42class StatefulBaseRenderer : public Renderer {
43public:
44    StatefulBaseRenderer();
45
46    virtual status_t prepare(bool opaque) {
47        return prepareDirty(0.0f, 0.0f, mWidth, mHeight, opaque);
48    }
49
50    /**
51     * Initialize the first snapshot, computing the projection matrix, and stores the dimensions of
52     * the render target.
53     */
54    virtual void setViewport(int width, int height);
55    void initializeSaveStack(float clipLeft, float clipTop, float clipRight, float clipBottom,
56            const Vector3& lightCenter);
57
58    // getters
59    bool hasRectToRectTransform() const {
60        return CC_LIKELY(currentTransform()->rectToRect());
61    }
62
63    // Save (layer)
64    virtual int getSaveCount() const { return mSaveCount; }
65    virtual int save(int flags);
66    virtual void restore();
67    virtual void restoreToCount(int saveCount);
68    //virtual int saveLayer(float left, float top, float right, float bottom,
69    //        int alpha, SkXfermode::Mode mode, int flags);
70
71    // Matrix
72    virtual void getMatrix(SkMatrix* outMatrix) const;
73    virtual void translate(float dx, float dy, float dz = 0.0f);
74    virtual void rotate(float degrees);
75    virtual void scale(float sx, float sy);
76    virtual void skew(float sx, float sy);
77
78    virtual void setMatrix(const SkMatrix& matrix);
79    void setMatrix(const Matrix4& matrix); // internal only convenience method
80    virtual void concatMatrix(const SkMatrix& matrix);
81    void concatMatrix(const Matrix4& matrix); // internal only convenience method
82
83    // Clip
84    virtual const Rect& getLocalClipBounds() const { return mSnapshot->getLocalClip(); }
85
86    virtual bool quickRejectConservative(float left, float top, float right, float bottom) const;
87
88    virtual bool clipRect(float left, float top, float right, float bottom, SkRegion::Op op);
89    virtual bool clipPath(const SkPath* path, SkRegion::Op op);
90    virtual bool clipRegion(const SkRegion* region, SkRegion::Op op);
91
92    /**
93     * Does not support different clipping Ops (that is, every call to setClippingOutline is
94     * effectively using SkRegion::kReplaceOp)
95     *
96     * The clipping outline is independent from the regular clip.
97     */
98    void setClippingOutline(LinearAllocator& allocator, const Outline* outline);
99    void setClippingRoundRect(LinearAllocator& allocator,
100            const Rect& rect, float radius, bool highPriority = true);
101
102    inline const mat4* currentTransform() const {
103        return mSnapshot->transform;
104    }
105
106protected:
107    const Rect& getRenderTargetClipBounds() const { return mSnapshot->getRenderTargetClip(); }
108
109    int getWidth() { return mWidth; }
110    int getHeight() { return mHeight; }
111
112    // Save
113    int saveSnapshot(int flags);
114    void restoreSnapshot();
115
116    // allows subclasses to control what value is stored in snapshot's fbo field in
117    // initializeSaveStack
118    virtual GLuint getTargetFbo() const {
119        return -1;
120    }
121
122    // Clip
123    bool calculateQuickRejectForScissor(float left, float top, float right, float bottom,
124            bool* clipRequired, bool* roundRectClipRequired, bool snapOut) const;
125
126    /**
127     * Called just after a restore has occurred. The 'removed' snapshot popped from the stack,
128     * 'restored' snapshot has become the top/current.
129     *
130     * Subclasses can override this method to handle layer restoration
131     */
132    virtual void onSnapshotRestored(const Snapshot& removed, const Snapshot& restored) {};
133
134    virtual void onViewportInitialized() {};
135
136    inline const Rect* currentClipRect() const {
137        return mSnapshot->clipRect;
138    }
139
140    inline const Snapshot* currentSnapshot() const {
141        return mSnapshot != NULL ? mSnapshot.get() : mFirstSnapshot.get();
142    }
143
144    inline const Snapshot* firstSnapshot() const {
145        return mFirstSnapshot.get();
146    }
147
148    // indicites that the clip has been changed since the last time it was consumed
149    bool mDirtyClip;
150
151private:
152    // Dimensions of the drawing surface
153    int mWidth, mHeight;
154
155    // Number of saved states
156    int mSaveCount;
157
158    // Base state
159    sp<Snapshot> mFirstSnapshot;
160
161protected:
162    // Current state
163    // TODO: should become private, once hooks needed by OpenGLRenderer are added
164    sp<Snapshot> mSnapshot;
165}; // class StatefulBaseRenderer
166
167}; // namespace uirenderer
168}; // namespace android
169
170#endif // ANDROID_HWUI_STATEFUL_BASE_RENDERER_H
171