71 lines
2.4 KiB
C++
71 lines
2.4 KiB
C++
/*
|
|
* 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
|
|
|