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/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "src/pathops/SkPathOpsCurve.h"
#include "include/private/base/SkTemplates.h"
#include "src/pathops/SkPathOpsBounds.h"
#include "src/pathops/SkPathOpsRect.h"
#include <algorithm>
#include <cfloat>
// this cheats and assumes that the perpendicular to the point is the closest ray to the curve
// this case (where the line and the curve are nearly coincident) may be the only case that counts
double SkDCurve::nearPoint(SkPath::Verb verb, const SkDPoint& xy, const SkDPoint& opp) const {
int count = SkPathOpsVerbToPoints(verb);
double minX = fCubic.fPts[0].fX;
double maxX = minX;
for (int index = 1; index <= count; ++index) {
minX = std::min(minX, fCubic.fPts[index].fX);
maxX = std::max(maxX, fCubic.fPts[index].fX);
}
if (!AlmostBetweenUlps(minX, xy.fX, maxX)) {
return -1;
}
double minY = fCubic.fPts[0].fY;
double maxY = minY;
for (int index = 1; index <= count; ++index) {
minY = std::min(minY, fCubic.fPts[index].fY);
maxY = std::max(maxY, fCubic.fPts[index].fY);
}
if (!AlmostBetweenUlps(minY, xy.fY, maxY)) {
return -1;
}
SkIntersections i;
SkDLine perp = {{ xy, { xy.fX + opp.fY - xy.fY, xy.fY + xy.fX - opp.fX }}};
(*CurveDIntersectRay[verb])(*this, perp, &i);
int minIndex = -1;
double minDist = FLT_MAX;
for (int index = 0; index < i.used(); ++index) {
double dist = xy.distance(i.pt(index));
if (minDist > dist) {
minDist = dist;
minIndex = index;
}
}
if (minIndex < 0) {
return -1;
}
double largest = std::max(std::max(maxX, maxY), -std::min(minX, minY));
if (!AlmostEqualUlps_Pin(largest, largest + minDist)) { // is distance within ULPS tolerance?
return -1;
}
return SkPinT(i[0][minIndex]);
}
void SkDCurve::setConicBounds(const SkPoint curve[3], SkScalar curveWeight,
double tStart, double tEnd, SkPathOpsBounds* bounds) {
SkDConic dCurve;
dCurve.set(curve, curveWeight);
SkDRect dRect;
dRect.setBounds(dCurve, fConic, tStart, tEnd);
bounds->setLTRB(SkDoubleToScalar(dRect.fLeft), SkDoubleToScalar(dRect.fTop),
SkDoubleToScalar(dRect.fRight), SkDoubleToScalar(dRect.fBottom));
}
void SkDCurve::setCubicBounds(const SkPoint curve[4], SkScalar ,
double tStart, double tEnd, SkPathOpsBounds* bounds) {
SkDCubic dCurve;
dCurve.set(curve);
SkDRect dRect;
dRect.setBounds(dCurve, fCubic, tStart, tEnd);
bounds->setLTRB(SkDoubleToScalar(dRect.fLeft), SkDoubleToScalar(dRect.fTop),
SkDoubleToScalar(dRect.fRight), SkDoubleToScalar(dRect.fBottom));
}
void SkDCurve::setQuadBounds(const SkPoint curve[3], SkScalar ,
double tStart, double tEnd, SkPathOpsBounds* bounds) {
SkDQuad dCurve;
dCurve.set(curve);
SkDRect dRect;
dRect.setBounds(dCurve, fQuad, tStart, tEnd);
bounds->setLTRB(SkDoubleToScalar(dRect.fLeft), SkDoubleToScalar(dRect.fTop),
SkDoubleToScalar(dRect.fRight), SkDoubleToScalar(dRect.fBottom));
}
void SkDCurveSweep::setCurveHullSweep(SkPath::Verb verb) {
fOrdered = true;
fSweep[0] = fCurve[1] - fCurve[0];
if (SkPath::kLine_Verb == verb) {
fSweep[1] = fSweep[0];
fIsCurve = false;
return;
}
fSweep[1] = fCurve[2] - fCurve[0];
// OPTIMIZE: I do the following float check a lot -- probably need a
// central place for this val-is-small-compared-to-curve check
double maxVal = 0;
for (int index = 0; index <= SkPathOpsVerbToPoints(verb); ++index) {
maxVal = std::max(maxVal, std::max(SkTAbs(fCurve[index].fX),
SkTAbs(fCurve[index].fY)));
}
{
if (SkPath::kCubic_Verb != verb) {
if (roughly_zero_when_compared_to(fSweep[0].fX, maxVal)
&& roughly_zero_when_compared_to(fSweep[0].fY, maxVal)) {
fSweep[0] = fSweep[1];
}
goto setIsCurve;
}
SkDVector thirdSweep = fCurve[3] - fCurve[0];
if (fSweep[0].fX == 0 && fSweep[0].fY == 0) {
fSweep[0] = fSweep[1];
fSweep[1] = thirdSweep;
if (roughly_zero_when_compared_to(fSweep[0].fX, maxVal)
&& roughly_zero_when_compared_to(fSweep[0].fY, maxVal)) {
fSweep[0] = fSweep[1];
fCurve[1] = fCurve[3];
}
goto setIsCurve;
}
double s1x3 = fSweep[0].crossCheck(thirdSweep);
double s3x2 = thirdSweep.crossCheck(fSweep[1]);
if (s1x3 * s3x2 >= 0) { // if third vector is on or between first two vectors
goto setIsCurve;
}
double s2x1 = fSweep[1].crossCheck(fSweep[0]);
// FIXME: If the sweep of the cubic is greater than 180 degrees, we're in trouble
// probably such wide sweeps should be artificially subdivided earlier so that never happens
SkASSERT(s1x3 * s2x1 < 0 || s1x3 * s3x2 < 0);
if (s3x2 * s2x1 < 0) {
SkASSERT(s2x1 * s1x3 > 0);
fSweep[0] = fSweep[1];
fOrdered = false;
}
fSweep[1] = thirdSweep;
}
setIsCurve:
fIsCurve = fSweep[0].crossCheck(fSweep[1]) != 0;
}
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