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/*
* Copyright 2012 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "Simplify.h"
namespace Op {
#include "Simplify.cpp"
static bool windingIsActive(int winding, int spanWinding, int oppWinding,
const ShapeOp op) {
return winding * spanWinding <= 0 && abs(winding) <= abs(spanWinding)
&& (!winding || !spanWinding || winding == -spanWinding);
}
static void bridgeOp(SkTDArray<Contour*>& contourList, const ShapeOp op,
const int aXorMask, const int bXorMask, SkPath& simple) {
bool firstContour = true;
do {
Segment* topStart = findTopContour(contourList);
if (!topStart) {
break;
}
// Start at the top. Above the top is outside, below is inside.
// follow edges to intersection by changing the index by direction.
int index, endIndex;
Segment* current = topStart->findTop(index, endIndex);
int contourWinding;
if (firstContour) {
contourWinding = 0;
firstContour = false;
} else {
int sumWinding = current->windSum(SkMin32(index, endIndex));
// FIXME: don't I have to adjust windSum to get contourWinding?
if (sumWinding == SK_MinS32) {
sumWinding = current->computeSum(index, endIndex);
}
if (sumWinding == SK_MinS32) {
contourWinding = innerContourCheck(contourList, current,
index, endIndex);
} else {
contourWinding = sumWinding;
int spanWinding = current->spanSign(index, endIndex);
bool inner = useInnerWinding(sumWinding - spanWinding, sumWinding);
if (inner) {
contourWinding -= spanWinding;
}
#if DEBUG_WINDING
SkDebugf("%s sumWinding=%d spanWinding=%d sign=%d inner=%d result=%d\n", __FUNCTION__,
sumWinding, spanWinding, SkSign32(index - endIndex),
inner, contourWinding);
#endif
}
#if DEBUG_WINDING
// SkASSERT(current->debugVerifyWinding(index, endIndex, contourWinding));
SkDebugf("%s contourWinding=%d\n", __FUNCTION__, contourWinding);
#endif
}
SkPoint lastPt;
int winding = contourWinding;
int spanWinding = current->spanSign(index, endIndex);
int oppWinding = current->oppSign(index, endIndex);
bool active = windingIsActive(winding, spanWinding, oppWinding, op);
SkTDArray<Span*> chaseArray;
bool unsortable = false;
do {
#if DEBUG_WINDING
SkDebugf("%s active=%s winding=%d spanWinding=%d\n",
__FUNCTION__, active ? "true" : "false",
winding, spanWinding);
#endif
const SkPoint* firstPt = NULL;
do {
SkASSERT(!current->done());
int nextStart = index;
int nextEnd = endIndex;
Segment* next = current->findNextOp(chaseArray, active,
nextStart, nextEnd, winding, spanWinding, unsortable, op,
aXorMask, bXorMask);
if (!next) {
// FIXME: if unsortable, allow partial paths to be later
// assembled
SkASSERT(!unsortable);
if (active && firstPt && current->verb() != SkPath::kLine_Verb && *firstPt != lastPt) {
lastPt = current->addCurveTo(index, endIndex, simple, true);
SkASSERT(*firstPt == lastPt);
}
break;
}
if (!firstPt) {
firstPt = ¤t->addMoveTo(index, simple, active);
}
lastPt = current->addCurveTo(index, endIndex, simple, active);
current = next;
index = nextStart;
endIndex = nextEnd;
} while (*firstPt != lastPt && (active || !current->done()));
if (firstPt && active) {
#if DEBUG_PATH_CONSTRUCTION
SkDebugf("%s close\n", __FUNCTION__);
#endif
simple.close();
}
current = findChase(chaseArray, index, endIndex, contourWinding);
#if DEBUG_ACTIVE_SPANS
debugShowActiveSpans(contourList);
#endif
if (!current) {
break;
}
int lesser = SkMin32(index, endIndex);
spanWinding = current->spanSign(index, endIndex);
winding = current->windSum(lesser);
bool inner = useInnerWinding(winding - spanWinding, winding);
#if DEBUG_WINDING
SkDebugf("%s id=%d t=%1.9g spanWinding=%d winding=%d sign=%d"
" inner=%d result=%d\n",
__FUNCTION__, current->debugID(), current->t(lesser),
spanWinding, winding, SkSign32(index - endIndex),
useInnerWinding(winding - spanWinding, winding),
inner ? winding - spanWinding : winding);
#endif
if (inner) {
winding -= spanWinding;
}
int oppWinding = current->oppSign(index, endIndex);
active = windingIsActive(winding, spanWinding, oppWinding, op);
} while (true);
} while (true);
}
} // end of Op namespace
void operate(const SkPath& one, const SkPath& two, ShapeOp op, SkPath& result) {
result.reset();
result.setFillType(SkPath::kEvenOdd_FillType);
// turn path into list of segments
SkTArray<Op::Contour> contours;
// FIXME: add self-intersecting cubics' T values to segment
Op::EdgeBuilder builder(one, contours);
const int aXorMask = builder.xorMask();
builder.addOperand(two);
const int bXorMask = builder.xorMask();
builder.finish();
SkTDArray<Op::Contour*> contourList;
makeContourList(contours, contourList);
Op::Contour** currentPtr = contourList.begin();
if (!currentPtr) {
return;
}
Op::Contour** listEnd = contourList.end();
// find all intersections between segments
do {
Op::Contour** nextPtr = currentPtr;
Op::Contour* current = *currentPtr++;
Op::Contour* next;
do {
next = *nextPtr++;
} while (addIntersectTs(current, next) && nextPtr != listEnd);
} while (currentPtr != listEnd);
// eat through coincident edges
coincidenceCheck(contourList);
fixOtherTIndex(contourList);
// construct closed contours
bridgeOp(contourList, op, aXorMask, bXorMask, result);
}
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