| /* |
| * Copyright (C) 2008 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef SkPageFlipper_DEFINED |
| #define SkPageFlipper_DEFINED |
| |
| #include "SkRegion.h" |
| |
| /** SkPageFlipper manages alternating inval/dirty regions for a rectangular area |
| (like a bitmap). You call inval() to accumulate inval areas, and then when |
| you're ready to "flip" pages (i.e. draw into the one you've been |
| invalidating) you call update, which swaps the inval regions, and returns |
| two things to you: 1) the final inval region to be drawn into, and 2) the |
| region of pixels that should be copied from the "front" page onto the one |
| you're about to draw into. This copyBits region will be disjoint from the |
| inval region, so both need to be handled. |
| */ |
| class SkPageFlipper { |
| public: |
| SkPageFlipper(); |
| SkPageFlipper(int width, int height); |
| |
| int width() const { return fWidth; } |
| int height() const { return fHeight; } |
| |
| void resize(int width, int height); |
| |
| bool isDirty() const { return !fDirty1->isEmpty(); } |
| const SkRegion& dirtyRgn() const { return *fDirty1; } |
| |
| void inval(); |
| void inval(const SkIRect&); |
| void inval(const SkRegion&); |
| void inval(const SkRect&, bool antialias); |
| |
| /** When you're ready to write to the back page, call update. The returned |
| region is the invalidate are that needs to be drawn to. The copyBits |
| region (provided by the caller) is the area that should be copied from |
| the front page to the back page (will not intersect with the returned |
| inval region. |
| |
| Once this is called, the two internal regions are swapped, so the *new* |
| back inval region is ready to receive new inval calls. |
| */ |
| const SkRegion& update(SkRegion* copyBits); |
| |
| private: |
| SkRegion* fDirty0; |
| SkRegion* fDirty1; |
| SkRegion fDirty0Storage; |
| SkRegion fDirty1Storage; |
| int fWidth; |
| int fHeight; |
| }; |
| |
| #endif |
| |