skia2/include/core/SkPathEffect.h
reed@google.com 6bac947cd5 Add option in flattening to write factory names inline, as we are recording.
SkGPipe needs this, since it cannot (unlike SkPicture) see all of the factories
before it hands its data to the reader.

In this mode, the writer embedds the factory name the first time it sees it,
and then after that writes an index (referencing the fFactorySet). The reader
installs an empty array, and as it encounters names, appends them to that array
so that subsequent indices can be used to retrieve the previously named factory.

Some of the existing patheffects did not register their factory names, so those
changes are also part of this CL. Annoyingly, to register your factory using the
current scheme, it has to be in the public section of the class definition.




git-svn-id: http://skia.googlecode.com/svn/trunk@1663 2bbb7eff-a529-9590-31e7-b0007b416f81
2011-06-21 19:24:00 +00:00

144 lines
4.4 KiB
C++

/*
* Copyright (C) 2006 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 SkPathEffect_DEFINED
#define SkPathEffect_DEFINED
#include "SkFlattenable.h"
class SkPath;
/** \class SkPathEffect
SkPathEffect is the base class for objects in the SkPaint that affect
the geometry of a drawing primitive before it is transformed by the
canvas' matrix and drawn.
Dashing is implemented as a subclass of SkPathEffect.
*/
class SK_API SkPathEffect : public SkFlattenable {
public:
SkPathEffect() {}
/** Given a src path and a width value, return true if the patheffect
has produced a new path (dst) and a new width value. If false is returned,
ignore dst and width.
On input, width >= 0 means the src should be stroked
On output, width >= 0 means the dst should be stroked
*/
virtual bool filterPath(SkPath* dst, const SkPath& src, SkScalar* width) = 0;
private:
// illegal
SkPathEffect(const SkPathEffect&);
SkPathEffect& operator=(const SkPathEffect&);
};
/** \class SkPairPathEffect
Common baseclass for Compose and Sum. This subclass manages two pathEffects,
including flattening them. It does nothing in filterPath, and is only useful
for managing the lifetimes of its two arguments.
*/
class SkPairPathEffect : public SkPathEffect {
public:
SkPairPathEffect(SkPathEffect* pe0, SkPathEffect* pe1);
virtual ~SkPairPathEffect();
protected:
SkPairPathEffect(SkFlattenableReadBuffer&);
virtual void flatten(SkFlattenableWriteBuffer&);
// these are visible to our subclasses
SkPathEffect* fPE0, *fPE1;
private:
typedef SkPathEffect INHERITED;
};
/** \class SkComposePathEffect
This subclass of SkPathEffect composes its two arguments, to create
a compound pathEffect.
*/
class SkComposePathEffect : public SkPairPathEffect {
public:
/** Construct a pathEffect whose effect is to apply first the inner pathEffect
and the the outer pathEffect (e.g. outer(inner(path)))
The reference counts for outer and inner are both incremented in the constructor,
and decremented in the destructor.
*/
SkComposePathEffect(SkPathEffect* outer, SkPathEffect* inner)
: INHERITED(outer, inner) {}
// overrides
virtual bool filterPath(SkPath* dst, const SkPath& src, SkScalar* width);
static SkFlattenable* CreateProc(SkFlattenableReadBuffer& buffer) {
return SkNEW_ARGS(SkComposePathEffect, (buffer));
}
protected:
virtual Factory getFactory() { return CreateProc; }
private:
SkComposePathEffect(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {}
// illegal
SkComposePathEffect(const SkComposePathEffect&);
SkComposePathEffect& operator=(const SkComposePathEffect&);
typedef SkPairPathEffect INHERITED;
};
/** \class SkSumPathEffect
This subclass of SkPathEffect applies two pathEffects, one after the other.
Its filterPath() returns true if either of the effects succeeded.
*/
class SkSumPathEffect : public SkPairPathEffect {
public:
/** Construct a pathEffect whose effect is to apply two effects, in sequence.
(e.g. first(path) + second(path))
The reference counts for first and second are both incremented in the constructor,
and decremented in the destructor.
*/
SkSumPathEffect(SkPathEffect* first, SkPathEffect* second)
: INHERITED(first, second) {}
// overrides
virtual bool filterPath(SkPath* dst, const SkPath& src, SkScalar* width);
static SkFlattenable* CreateProc(SkFlattenableReadBuffer& buffer) {
return SkNEW_ARGS(SkSumPathEffect, (buffer));
}
protected:
virtual Factory getFactory() { return CreateProc; }
private:
SkSumPathEffect(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {}
// illegal
SkSumPathEffect(const SkSumPathEffect&);
SkSumPathEffect& operator=(const SkSumPathEffect&);
typedef SkPairPathEffect INHERITED;
};
#endif