skia2/include/core/SkPictureRecorder.h
schenney eeff8bb8ff Allow reset of the SkPictureRecorder cull rect and other parameters during endRecording.
For some users of SkPictureRecorder, the cull rect is more efficiently
determined while drawing is in progress, rather than when recording starts.
The existing API requires the cull rect at start time, even though the
information is not used for any culling purpose until the end of recording.

This patch provides a means to reset the cull rect when recording ends,
allowing users to update the rect based on information learned during
drawing and for the new rect to be used as the culling bound. A valid
bound is still required on the beginRecording call because
it sizes the underlying canvas and sets the aspect ratio for any bounding
box hierarchy. The bounding box factory can also be specified and parameters
that control SkPicture creation.

R=mtklein, reed1
BUG=skia:3919

Review URL: https://codereview.chromium.org/1178673007
2015-07-07 14:27:10 -07:00

127 lines
4.9 KiB
C++

/*
* Copyright 2014 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkPictureRecorder_DEFINED
#define SkPictureRecorder_DEFINED
#include "../../src/core/SkMiniRecorder.h"
#include "SkBBHFactory.h"
#include "SkPicture.h"
#include "SkRefCnt.h"
#ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
namespace android {
class Picture;
};
#endif
class SkCanvas;
class SkDrawable;
class SkPictureRecord;
class SkRecord;
class SkRecorder;
class SK_API SkPictureRecorder : SkNoncopyable {
public:
SkPictureRecorder();
~SkPictureRecorder();
enum RecordFlags {
// This flag indicates that, if some BHH is being computed, saveLayer
// information should also be extracted at the same time.
kComputeSaveLayerInfo_RecordFlag = 0x01,
// If you call drawPicture() on the recording canvas, this flag forces
// that to use SkPicture::playback() immediately rather than (e.g.) reffing the picture.
kPlaybackDrawPicture_RecordFlag = 0x02,
};
/** Returns the canvas that records the drawing commands.
@param bounds the cull rect used when recording this picture. Any drawing the falls outside
of this rect is undefined, and may be drawn or it may not.
@param bbhFactory factory to create desired acceleration structure
@param recordFlags optional flags that control recording.
@return the canvas.
*/
SkCanvas* beginRecording(const SkRect& bounds,
SkBBHFactory* bbhFactory = NULL,
uint32_t recordFlags = 0);
SkCanvas* beginRecording(SkScalar width, SkScalar height,
SkBBHFactory* bbhFactory = NULL,
uint32_t recordFlags = 0) {
return this->beginRecording(SkRect::MakeWH(width, height), bbhFactory, recordFlags);
}
/** Returns the recording canvas if one is active, or NULL if recording is
not active. This does not alter the refcnt on the canvas (if present).
*/
SkCanvas* getRecordingCanvas();
/**
* Signal that the caller is done recording. This invalidates the canvas returned by
* beginRecording/getRecordingCanvas. Ownership of the object is passed to the caller, who
* must call unref() when they are done using it.
*
* The returned picture is immutable. If during recording drawables were added to the canvas,
* these will have been "drawn" into a recording canvas, so that this resulting picture will
* reflect their current state, but will not contain a live reference to the drawables
* themselves.
*/
SkPicture* SK_WARN_UNUSED_RESULT endRecordingAsPicture();
/**
* Signal that the caller is done recording, and update the cull rect to use for bounding
* box hierarchy (BBH) generation. The behavior is the same as calling
* endRecordingAsPicture(), except that this method updates the cull rect initially passed
* into beginRecording.
* @param cullRect the new culling rectangle to use as the overall bound for BBH generation
* and subsequent culling operations.
* @return the picture containing the recorded content.
*/
SkPicture* SK_WARN_UNUSED_RESULT endRecordingAsPicture(const SkRect& cullRect);
/**
* Signal that the caller is done recording. This invalidates the canvas returned by
* beginRecording/getRecordingCanvas. Ownership of the object is passed to the caller, who
* must call unref() when they are done using it.
*
* Unlike endRecordingAsPicture(), which returns an immutable picture, the returned drawable
* may contain live references to other drawables (if they were added to the recording canvas)
* and therefore this drawable will reflect the current state of those nested drawables anytime
* it is drawn or a new picture is snapped from it (by calling drawable->newPictureSnapshot()).
*/
SkDrawable* SK_WARN_UNUSED_RESULT endRecordingAsDrawable();
// Legacy API -- use endRecordingAsPicture instead.
SkPicture* SK_WARN_UNUSED_RESULT endRecording() { return this->endRecordingAsPicture(); }
private:
void reset();
/** Replay the current (partially recorded) operation stream into
canvas. This call doesn't close the current recording.
*/
#ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
friend class android::Picture;
#endif
friend class SkPictureRecorderReplayTester; // for unit testing
void partialReplay(SkCanvas* canvas) const;
bool fActivelyRecording;
uint32_t fFlags;
SkRect fCullRect;
SkAutoTUnref<SkBBoxHierarchy> fBBH;
SkAutoTUnref<SkRecorder> fRecorder;
SkAutoTUnref<SkRecord> fRecord;
SkMiniRecorder fMiniRecorder;
typedef SkNoncopyable INHERITED;
};
#endif