skia2/src/effects/SkCornerPathEffect.cpp
reed 9fa60daad4 Simplify flattening to just write enough to call the factory/public-constructor for the class. We want to *not* rely on private constructors, and not rely on calling through the inheritance hierarchy for either flattening or unflattening(CreateProc).
Refactoring pattern:

1. guard the existing constructor(readbuffer) with the legacy build-flag
2. If you are a instancable subclass, implement CreateProc(readbuffer) to create a new instances from the buffer params (or return NULL).

If you're a shader subclass
1. You must read/write the local matrix if your class accepts that in its factory/constructor, else ignore it.

R=robertphillips@google.com, mtklein@google.com, senorblanco@google.com, senorblanco@chromium.org, sugoi@chromium.org

Author: reed@google.com

Review URL: https://codereview.chromium.org/395603002
2014-08-21 07:59:51 -07:00

144 lines
4.3 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.
*/
#include "SkCornerPathEffect.h"
#include "SkPath.h"
#include "SkPoint.h"
#include "SkReadBuffer.h"
#include "SkWriteBuffer.h"
SkCornerPathEffect::SkCornerPathEffect(SkScalar radius) : fRadius(radius) {}
SkCornerPathEffect::~SkCornerPathEffect() {}
static bool ComputeStep(const SkPoint& a, const SkPoint& b, SkScalar radius,
SkPoint* step) {
SkScalar dist = SkPoint::Distance(a, b);
step->set(b.fX - a.fX, b.fY - a.fY);
if (dist <= radius * 2) {
step->scale(SK_ScalarHalf);
return false;
} else {
step->scale(SkScalarDiv(radius, dist));
return true;
}
}
bool SkCornerPathEffect::filterPath(SkPath* dst, const SkPath& src,
SkStrokeRec*, const SkRect*) const {
if (0 == fRadius) {
return false;
}
SkPath::Iter iter(src, false);
SkPath::Verb verb, prevVerb = (SkPath::Verb)-1;
SkPoint pts[4];
bool closed;
SkPoint moveTo, lastCorner;
SkVector firstStep, step;
bool prevIsValid = true;
// to avoid warnings
moveTo.set(0, 0);
firstStep.set(0, 0);
lastCorner.set(0, 0);
for (;;) {
switch (verb = iter.next(pts, false)) {
case SkPath::kMove_Verb:
// close out the previous (open) contour
if (SkPath::kLine_Verb == prevVerb) {
dst->lineTo(lastCorner);
}
closed = iter.isClosedContour();
if (closed) {
moveTo = pts[0];
prevIsValid = false;
} else {
dst->moveTo(pts[0]);
prevIsValid = true;
}
break;
case SkPath::kLine_Verb: {
bool drawSegment = ComputeStep(pts[0], pts[1], fRadius, &step);
// prev corner
if (!prevIsValid) {
dst->moveTo(moveTo + step);
prevIsValid = true;
} else {
dst->quadTo(pts[0].fX, pts[0].fY, pts[0].fX + step.fX,
pts[0].fY + step.fY);
}
if (drawSegment) {
dst->lineTo(pts[1].fX - step.fX, pts[1].fY - step.fY);
}
lastCorner = pts[1];
prevIsValid = true;
break;
}
case SkPath::kQuad_Verb:
// TBD - just replicate the curve for now
if (!prevIsValid) {
dst->moveTo(pts[0]);
prevIsValid = true;
}
dst->quadTo(pts[1], pts[2]);
lastCorner = pts[2];
firstStep.set(0, 0);
break;
case SkPath::kCubic_Verb:
if (!prevIsValid) {
dst->moveTo(pts[0]);
prevIsValid = true;
}
// TBD - just replicate the curve for now
dst->cubicTo(pts[1], pts[2], pts[3]);
lastCorner = pts[3];
firstStep.set(0, 0);
break;
case SkPath::kClose_Verb:
if (firstStep.fX || firstStep.fY) {
dst->quadTo(lastCorner.fX, lastCorner.fY,
lastCorner.fX + firstStep.fX,
lastCorner.fY + firstStep.fY);
}
dst->close();
break;
case SkPath::kConic_Verb:
SkASSERT(0);
break;
case SkPath::kDone_Verb:
goto DONE;
}
if (SkPath::kMove_Verb == prevVerb) {
firstStep = step;
}
prevVerb = verb;
}
DONE:
return true;
}
SkFlattenable* SkCornerPathEffect::CreateProc(SkReadBuffer& buffer) {
return SkCornerPathEffect::Create(buffer.readScalar());
}
void SkCornerPathEffect::flatten(SkWriteBuffer& buffer) const {
buffer.writeScalar(fRadius);
}
#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
SkCornerPathEffect::SkCornerPathEffect(SkReadBuffer& buffer) {
fRadius = buffer.readScalar();
}
#endif