skia2/include/core/SkPathEffect.h
Mike Reed ec9d0e865d Move patheffect details to (private) base subclass
bug: skia:11957
Change-Id: Iceaa0ac1d7a3f049d2725629d78c755ad03a2862
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/411302
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
2021-05-22 01:55:43 +00:00

97 lines
3.3 KiB
C++

/*
* Copyright 2006 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkPathEffect_DEFINED
#define SkPathEffect_DEFINED
#include "include/core/SkFlattenable.h"
#include "include/core/SkScalar.h"
// not needed, but some of our clients need it (they don't IWYU)
#include "include/core/SkPath.h"
class SkPath;
struct SkRect;
class SkStrokeRec;
/** \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:
/**
* Returns a patheffect that apples each effect (first and second) to the original path,
* and returns a path with the sum of these.
*
* result = first(path) + second(path)
*
*/
static sk_sp<SkPathEffect> MakeSum(sk_sp<SkPathEffect> first, sk_sp<SkPathEffect> second);
/**
* Returns a patheffect that applies the inner effect to the path, and then applies the
* outer effect to the result of the inner's.
*
* result = outer(inner(path))
*/
static sk_sp<SkPathEffect> MakeCompose(sk_sp<SkPathEffect> outer, sk_sp<SkPathEffect> inner);
static SkFlattenable::Type GetFlattenableType() {
return kSkPathEffect_Type;
}
// move to base?
enum DashType {
kNone_DashType, //!< ignores the info parameter
kDash_DashType, //!< fills in all of the info parameter
};
struct DashInfo {
DashInfo() : fIntervals(nullptr), fCount(0), fPhase(0) {}
DashInfo(SkScalar* intervals, int32_t count, SkScalar phase)
: fIntervals(intervals), fCount(count), fPhase(phase) {}
SkScalar* fIntervals; //!< Length of on/off intervals for dashed lines
// Even values represent ons, and odds offs
int32_t fCount; //!< Number of intervals in the dash. Should be even number
SkScalar fPhase; //!< Offset into the dashed interval pattern
// mod the sum of all intervals
};
DashType asADash(DashInfo* info) const;
/**
* Given a src path (input) and a stroke-rec (input and output), apply
* this effect to the src path, returning the new path in dst, and return
* true. If this effect cannot be applied, return false and ignore dst
* and stroke-rec.
*
* The stroke-rec specifies the initial request for stroking (if any).
* The effect can treat this as input only, or it can choose to change
* the rec as well. For example, the effect can decide to change the
* stroke's width or join, or the effect can change the rec from stroke
* to fill (or fill to stroke) in addition to returning a new (dst) path.
*
* If this method returns true, the caller will apply (as needed) the
* resulting stroke-rec to dst and then draw.
*/
bool filterPath(SkPath* dst, const SkPath& src, SkStrokeRec*, const SkRect* cullR) const;
private:
SkPathEffect() = default;
friend class SkPathEffectBase;
using INHERITED = SkFlattenable;
};
#endif