CanvasState.h revision d9ee550888011a64fa3f35e666360ec8278597d8
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_CANVAS_STATE_H 18#define ANDROID_HWUI_CANVAS_STATE_H 19 20#include "Snapshot.h" 21 22#include <SkMatrix.h> 23#include <SkPath.h> 24#include <SkRegion.h> 25 26namespace android { 27namespace uirenderer { 28 29/** 30 * Abstract base class for any class containing CanvasState. 31 * Defines three mandatory callbacks. 32 */ 33class CanvasStateClient { 34public: 35 CanvasStateClient() { } 36 virtual ~CanvasStateClient() { } 37 38 /** 39 * Callback allowing embedder to take actions in the middle of a 40 * setViewport() call. 41 */ 42 virtual void onViewportInitialized() = 0; 43 44 /** 45 * Callback allowing embedder to take actions in the middle of a 46 * restore() call. May be called several times sequentially. 47 */ 48 virtual void onSnapshotRestored(const Snapshot& removed, const Snapshot& restored) = 0; 49 50 /** 51 * Allows subclasses to control what value is stored in snapshot's 52 * fbo field in * initializeSaveStack. 53 */ 54 virtual GLuint getTargetFbo() const = 0; 55 56}; // class CanvasStateClient 57 58/** 59 * Implements Canvas state methods on behalf of Renderers. 60 * 61 * Manages the Snapshot stack, implementing matrix, save/restore, and clipping methods in the 62 * Renderer interface. Drawing and recording classes that include a CanvasState will have 63 * different use cases: 64 * 65 * Drawing code maintaining canvas state (i.e. OpenGLRenderer) can query attributes (such as 66 * transform) or hook into changes (e.g. save/restore) with minimal surface area for manipulating 67 * the stack itself. 68 * 69 * Recording code maintaining canvas state (i.e. DisplayListCanvas) can both record and pass 70 * through state operations to CanvasState, so that not only will querying operations work 71 * (getClip/Matrix), but so that quickRejection can also be used. 72 */ 73 74class CanvasState { 75public: 76 CanvasState(CanvasStateClient& renderer); 77 ~CanvasState(); 78 79 /** 80 * Initializes the first snapshot, computing the projection matrix, 81 * and stores the dimensions of the render target. 82 */ 83 void initializeSaveStack(int viewportWidth, int viewportHeight, 84 float clipLeft, float clipTop, float clipRight, float clipBottom, 85 const Vector3& lightCenter); 86 87 bool hasRectToRectTransform() const { 88 return CC_LIKELY(currentTransform()->rectToRect()); 89 } 90 91 // Save (layer) 92 int getSaveCount() const { return mSaveCount; } 93 int save(int flags); 94 void restore(); 95 void restoreToCount(int saveCount); 96 97 // Save/Restore without side-effects 98 int saveSnapshot(int flags); 99 void restoreSnapshot(); 100 101 // Matrix 102 void getMatrix(SkMatrix* outMatrix) const; 103 void translate(float dx, float dy, float dz = 0.0f); 104 void rotate(float degrees); 105 void scale(float sx, float sy); 106 void skew(float sx, float sy); 107 108 void setMatrix(const SkMatrix& matrix); 109 void setMatrix(const Matrix4& matrix); // internal only convenience method 110 void concatMatrix(const SkMatrix& matrix); 111 void concatMatrix(const Matrix4& matrix); // internal only convenience method 112 113 // Clip 114 const Rect& getLocalClipBounds() const { return mSnapshot->getLocalClip(); } 115 const Rect& getRenderTargetClipBounds() const { return mSnapshot->getRenderTargetClip(); } 116 117 bool quickRejectConservative(float left, float top, float right, float bottom) const; 118 119 bool clipRect(float left, float top, float right, float bottom, SkRegion::Op op); 120 bool clipPath(const SkPath* path, SkRegion::Op op); 121 bool clipRegion(const SkRegion* region, SkRegion::Op op); 122 123 /** 124 * Sets a "clipping outline", which is independent from the regular clip. 125 * Currently only supports rectangles or rounded rectangles; passing in a 126 * more complicated outline fails silently. Replaces any previous clipping 127 * outline. 128 */ 129 void setClippingOutline(LinearAllocator& allocator, const Outline* outline); 130 void setClippingRoundRect(LinearAllocator& allocator, 131 const Rect& rect, float radius, bool highPriority = true); 132 void setProjectionPathMask(LinearAllocator& allocator, const SkPath* path); 133 134 /** 135 * Returns true if drawing in the rectangle (left, top, right, bottom) 136 * will be clipped out. Is conservative: might return false when subpixel- 137 * perfect tests would return true. 138 */ 139 bool calculateQuickRejectForScissor(float left, float top, float right, float bottom, 140 bool* clipRequired, bool* roundRectClipRequired, bool snapOut) const; 141 142 void setDirtyClip(bool opaque) { mDirtyClip = opaque; } 143 bool getDirtyClip() const { return mDirtyClip; } 144 145 void scaleAlpha(float alpha) { mSnapshot->alpha *= alpha; } 146 void setEmpty(bool value) { mSnapshot->empty = value; } 147 void setInvisible(bool value) { mSnapshot->invisible = value; } 148 149 inline const mat4* currentTransform() const { return currentSnapshot()->transform; } 150 inline const Rect& currentClipRect() const { return currentSnapshot()->getClipRect(); } 151 inline Region* currentRegion() const { return currentSnapshot()->region; } 152 inline int currentFlags() const { return currentSnapshot()->flags; } 153 const Vector3& currentLightCenter() const { return currentSnapshot()->getRelativeLightCenter(); } 154 inline bool currentlyIgnored() const { return currentSnapshot()->isIgnored(); } 155 int getViewportWidth() const { return currentSnapshot()->getViewportWidth(); } 156 int getViewportHeight() const { return currentSnapshot()->getViewportHeight(); } 157 int getWidth() const { return mWidth; } 158 int getHeight() const { return mHeight; } 159 bool clipIsSimple() const { return currentSnapshot()->clipIsSimple(); } 160 161 inline const Snapshot* currentSnapshot() const { return mSnapshot; } 162 inline Snapshot* writableSnapshot() { return mSnapshot; } 163 inline const Snapshot* firstSnapshot() const { return &mFirstSnapshot; } 164 165private: 166 Snapshot* allocSnapshot(Snapshot* previous, int savecount); 167 void freeSnapshot(Snapshot* snapshot); 168 void freeAllSnapshots(); 169 170 /// indicates that the clip has been changed since the last time it was consumed 171 bool mDirtyClip; 172 173 /// Dimensions of the drawing surface 174 int mWidth, mHeight; 175 176 /// Number of saved states 177 int mSaveCount; 178 179 /// Base state 180 Snapshot mFirstSnapshot; 181 182 /// Host providing callbacks 183 CanvasStateClient& mCanvas; 184 185 /// Current state 186 Snapshot* mSnapshot; 187 188 // Pool of allocated snapshots to re-use 189 // NOTE: The dtors have already been invoked! 190 Snapshot* mSnapshotPool = nullptr; 191 int mSnapshotPoolCount = 0; 192 193}; // class CanvasState 194 195}; // namespace uirenderer 196}; // namespace android 197 198#endif // ANDROID_HWUI_CANVAS_STATE_H 199