Snapshot.h revision ae5575b3421c8fbe590ab046d7d5f2b36ecfd821
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_UI_SNAPSHOT_H 18#define ANDROID_UI_SNAPSHOT_H 19 20#include <GLES2/gl2.h> 21#include <GLES2/gl2ext.h> 22 23#include <utils/RefBase.h> 24 25#include <SkRegion.h> 26 27#include "Layer.h" 28#include "Matrix.h" 29#include "Rect.h" 30 31namespace android { 32namespace uirenderer { 33 34/** 35 * A snapshot holds information about the current state of the rendering 36 * surface. A snapshot is usually created whenever the user calls save() 37 * and discarded when the user calls restore(). Once a snapshot is created, 38 * it can hold information for deferred rendering. 39 * 40 * Each snapshot has a link to a previous snapshot, indicating the previous 41 * state of the renderer. 42 */ 43class Snapshot: public LightRefBase<Snapshot> { 44public: 45 Snapshot(): flags(0), previous(NULL), layer(NULL), fbo(0) { } 46 47 /** 48 * Copies the specified snapshot. Only the transform and clip rectangle 49 * are copied. The layer information is set to 0 and the transform is 50 * assumed to be dirty. The specified snapshot is stored as the previous 51 * snapshot. 52 */ 53 Snapshot(const sp<Snapshot>& s): 54 height(s->height), 55 transform(s->transform), 56 clipRect(s->clipRect), 57 flags(0), 58 previous(s), 59 layer(NULL), 60 fbo(s->fbo), 61 localClip(s->localClip) { 62 } 63 64 /** 65 * Various flags set on #flags. 66 */ 67 enum Flags { 68 /** 69 * Indicates that the clip region was modified. When this 70 * snapshot is restored so must the clip. 71 */ 72 kFlagClipSet = 0x1, 73 /** 74 * Indicates that this snapshot was created when saving 75 * a new layer. 76 */ 77 kFlagIsLayer = 0x2, 78 /** 79 * Indicates that this snapshot has changed the ortho matrix. 80 */ 81 kFlagDirtyOrtho = 0x4, 82 /** 83 * Indicates that the local clip should be recomputed. 84 */ 85 kFlagDirtyLocalClip = 0x8, 86 }; 87 88 /** 89 * Intersects the current clip with the new clip rectangle. 90 */ 91 bool clip(float left, float top, float right, float bottom, SkRegion::Op op) { 92 bool clipped = false; 93 94 Rect r(left, top, right, bottom); 95 transform.mapRect(r); 96 97 switch (op) { 98 case SkRegion::kDifference_Op: 99 break; 100 case SkRegion::kIntersect_Op: 101 clipped = clipRect.intersect(r); 102 break; 103 case SkRegion::kUnion_Op: 104 clipped = clipRect.unionWith(r); 105 break; 106 case SkRegion::kXOR_Op: 107 break; 108 case SkRegion::kReverseDifference_Op: 109 break; 110 case SkRegion::kReplace_Op: 111 clipRect.set(r); 112 clipped = true; 113 break; 114 } 115 116 if (clipped) { 117 flags |= Snapshot::kFlagClipSet | Snapshot::kFlagDirtyLocalClip; 118 } 119 120 return clipped; 121 } 122 123 /** 124 * Sets the current clip. 125 */ 126 void setClip(float left, float top, float right, float bottom) { 127 clipRect.set(left, top, right, bottom); 128 flags |= Snapshot::kFlagClipSet | Snapshot::kFlagDirtyLocalClip; 129 } 130 131 const Rect& getLocalClip() { 132 if (flags & Snapshot::kFlagDirtyLocalClip) { 133 mat4 inverse; 134 inverse.loadInverse(transform); 135 localClip.set(clipRect); 136 inverse.mapRect(localClip); 137 flags &= ~Snapshot::kFlagDirtyLocalClip; 138 } 139 return localClip; 140 } 141 142 /** 143 * Height of the framebuffer the snapshot is rendering into. 144 */ 145 int height; 146 147 /** 148 * Local transformation. Holds the current translation, scale and 149 * rotation values. 150 */ 151 mat4 transform; 152 153 /** 154 * Current clip region. The clip is stored in canvas-space coordinates, 155 * (screen-space coordinates in the regular case.) 156 */ 157 Rect clipRect; 158 159 /** 160 * Dirty flags. 161 */ 162 int flags; 163 164 /** 165 * Previous snapshot. 166 */ 167 sp<Snapshot> previous; 168 169 /** 170 * Only set when the flag kFlagIsLayer is set. 171 */ 172 Layer* layer; 173 GLuint fbo; 174 175 /** 176 * Contains the previous ortho matrix. 177 */ 178 mat4 orthoMatrix; 179 180private: 181 Rect localClip; 182 183}; // class Snapshot 184 185}; // namespace uirenderer 186}; // namespace android 187 188#endif // ANDROID_UI_SNAPSHOT_H 189