Snapshot.h revision d27977d1a91d5a6b3cc9fa7664ac7e835e7bd895
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 "Layer.h" 26#include "Matrix.h" 27#include "Rect.h" 28 29namespace android { 30namespace uirenderer { 31 32/** 33 * A snapshot holds information about the current state of the rendering 34 * surface. A snapshot is usually created whenever the user calls save() 35 * and discarded when the user calls restore(). Once a snapshot is created, 36 * it can hold information for deferred rendering. 37 * 38 * Each snapshot has a link to a previous snapshot, indicating the previous 39 * state of the renderer. 40 */ 41class Snapshot: public LightRefBase<Snapshot> { 42public: 43 Snapshot(): layer(NULL), fbo(0) { } 44 45 /** 46 * Copies the specified snapshot. Only the transform and clip rectangle 47 * are copied. The layer information is set to 0 and the transform is 48 * assumed to be dirty. The specified snapshot is stored as the previous 49 * snapshot. 50 */ 51 Snapshot(const sp<Snapshot> s): 52 height(s->height), 53 transform(s->transform), 54 clipRect(s->clipRect), 55 flags(kFlagDirtyTransform), 56 previous(s), 57 layer(NULL), 58 fbo(s->fbo) { 59 mappedClip.set(s->clipRect); 60 transform.mapRect(mappedClip); 61 } 62 63 /** 64 * Various flags set on #flags. 65 */ 66 enum Flags { 67 /** 68 * Indicates that the clip region was modified. When this 69 * snapshot is restored so must the clip. 70 */ 71 kFlagClipSet = 0x1, 72 /** 73 * Indicates that the snapshot holds new transform 74 * information. 75 */ 76 kFlagDirtyTransform = 0x2, 77 /** 78 * Indicates that this snapshot was created when saving 79 * a new layer. 80 */ 81 kFlagIsLayer = 0x4, 82 /** 83 * Indicates that this snapshot has changed the ortho matrix. 84 */ 85 kFlagDirtyOrtho = 0x8, 86 }; 87 88 /** 89 * Returns the current clip region mapped by the current transform. 90 */ 91 const Rect& getMappedClip() { 92 return mappedClip; 93 } 94 95 /** 96 * Intersects the current clip with the new clip rectangle. 97 */ 98 bool clip(float left, float top, float right, float bottom) { 99 bool clipped = clipRect.intersect(left, top, right, bottom); 100 if (flags & kFlagDirtyTransform) { 101 flags &= ~kFlagDirtyTransform; 102 mappedClip.set(clipRect); 103 transform.mapRect(mappedClip); 104 } 105 return clipped; 106 } 107 108 /** 109 * Sets the current clip. 110 */ 111 void setClip(float left, float top, float right, float bottom) { 112 clipRect.set(left, top, right, bottom); 113 if (flags & kFlagDirtyTransform) { 114 flags &= ~kFlagDirtyTransform; 115 mappedClip.set(clipRect); 116 transform.mapRect(mappedClip); 117 } 118 } 119 120 /** 121 * Height of the framebuffer the snapshot is rendering into. 122 */ 123 int height; 124 125 /** 126 * Local transformation. Holds the current translation, scale and 127 * rotation values. 128 */ 129 mat4 transform; 130 131 /** 132 * Current clip region. 133 */ 134 Rect clipRect; 135 136 /** 137 * Dirty flags. 138 */ 139 int flags; 140 141 /** 142 * Previous snapshot. 143 */ 144 sp<Snapshot> previous; 145 146 /** 147 * Only set when the flag kFlagIsLayer is set. 148 */ 149 Layer* layer; 150 GLuint fbo; 151 152 /** 153 * Contains the previous ortho matrix. 154 */ 155 mat4 orthoMatrix; 156 157private: 158 // Clipping rectangle mapped with the transform 159 Rect mappedClip; 160}; // class Snapshot 161 162}; // namespace uirenderer 163}; // namespace android 164 165#endif // ANDROID_UI_SNAPSHOT_H 166