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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.
*/
#ifndef Intersections_DEFINE
#define Intersections_DEFINE
#include <algorithm> // for std::min
class Intersections {
public:
Intersections()
: fUsed(0)
, fUsed2(0)
, fCoincidentUsed(0)
, fSwap(0)
, fFlip(0)
{
// OPTIMIZE: don't need to be initialized in release
bzero(fT, sizeof(fT));
bzero(fCoincidentT, sizeof(fCoincidentT));
}
void add(double one, double two) {
for (int index = 0; index < fUsed; ++index) {
if (approximately_equal(fT[fSwap][index], one)
&& approximately_equal(fT[fSwap ^ 1][index], two)) {
return;
}
}
assert(fUsed < 9);
fT[fSwap][fUsed] = one;
fT[fSwap ^ 1][fUsed] = two;
++fUsed;
}
// start if index == 0 : end if index == 1
void addCoincident(double one, double two) {
for (int index = 0; index < fCoincidentUsed; ++index) {
if (approximately_equal(fCoincidentT[fSwap][index], one)
&& approximately_equal(fCoincidentT[fSwap ^ 1][index], two)) {
return;
}
}
assert(fCoincidentUsed < 9);
fCoincidentT[fSwap][fCoincidentUsed] = one;
fCoincidentT[fSwap ^ 1][fCoincidentUsed] = two;
++fCoincidentUsed;
}
void addCoincident(double s1, double e1, double s2, double e2) {
assert((fCoincidentUsed & 1) != 1);
for (int index = 0; index < fCoincidentUsed; index += 2) {
double cs1 = fCoincidentT[fSwap][index];
double ce1 = fCoincidentT[fSwap][index + 1];
bool s1in = approximately_between(cs1, s1, ce1);
bool e1in = approximately_between(cs1, e1, ce1);
double cs2 = fCoincidentT[fSwap ^ 1][index];
double ce2 = fCoincidentT[fSwap ^ 1][index + 1];
bool s2in = approximately_between(cs2, s2, ce2);
bool e2in = approximately_between(cs2, e2, ce2);
if ((s1in | e1in) & (s2in | e2in)) {
double lesser1 = std::min(cs1, ce1);
index += cs1 > ce1;
if (s1in < lesser1) {
fCoincidentT[fSwap][index] = s1in;
} else if (e1in < lesser1) {
fCoincidentT[fSwap][index] = e1in;
}
index ^= 1;
double greater1 = fCoincidentT[fSwap][index];
if (s1in > greater1) {
fCoincidentT[fSwap][index] = s1in;
} else if (e1in > greater1) {
fCoincidentT[fSwap][index] = e1in;
}
index &= ~1;
double lesser2 = std::min(cs2, ce2);
index += cs2 > ce2;
if (s2in < lesser2) {
fCoincidentT[fSwap ^ 1][index] = s2in;
} else if (e2in < lesser2) {
fCoincidentT[fSwap ^ 1][index] = e2in;
}
index ^= 1;
double greater2 = fCoincidentT[fSwap ^ 1][index];
if (s2in > greater2) {
fCoincidentT[fSwap ^ 1][index] = s2in;
} else if (e2in > greater2) {
fCoincidentT[fSwap ^ 1][index] = e2in;
}
return;
}
}
assert(fCoincidentUsed < 9);
fCoincidentT[fSwap][fCoincidentUsed] = s1;
fCoincidentT[fSwap ^ 1][fCoincidentUsed] = s2;
++fCoincidentUsed;
fCoincidentT[fSwap][fCoincidentUsed] = e1;
fCoincidentT[fSwap ^ 1][fCoincidentUsed] = e2;
++fCoincidentUsed;
}
// FIXME: this is necessary because curve/curve intersections are noisy
// remove once curve/curve intersections are improved
void cleanUp();
int coincidentUsed() {
return fCoincidentUsed;
}
void offset(int base, double start, double end) {
for (int index = base; index < fUsed; ++index) {
double val = fT[fSwap][index];
val *= end - start;
val += start;
fT[fSwap][index] = val;
}
}
void insert(double one, double two) {
assert(fUsed <= 1 || fT[0][0] < fT[0][1]);
int index;
for (index = 0; index < fUsed; ++index) {
if (approximately_equal(fT[0][index], one)
&& approximately_equal(fT[1][index], two)) {
return;
}
if (fT[0][index] > one) {
break;
}
}
assert(fUsed < 9);
int remaining = fUsed - index;
if (remaining > 0) {
memmove(&fT[0][index + 1], &fT[0][index], sizeof(fT[0][0]) * remaining);
memmove(&fT[1][index + 1], &fT[1][index], sizeof(fT[1][0]) * remaining);
}
fT[0][index] = one;
fT[1][index] = two;
++fUsed;
}
// FIXME: all callers should be moved to regular insert. Failures are likely
// if two separate callers differ on whether ts are equal or not
void insertOne(double t, int side) {
int used = side ? fUsed2 : fUsed;
assert(used <= 1 || fT[side][0] < fT[side][1]);
int index;
for (index = 0; index < used; ++index) {
if (approximately_equal(fT[side][index], t)) {
return;
}
if (fT[side][index] > t) {
break;
}
}
assert(used < 9);
int remaining = used - index;
if (remaining > 0) {
memmove(&fT[side][index + 1], &fT[side][index], sizeof(fT[side][0]) * remaining);
}
fT[side][index] = t;
side ? ++fUsed2 : ++fUsed;
}
bool intersected() const {
return fUsed > 0;
}
bool insertBalanced() const {
return fUsed == fUsed2;
}
void swap() {
fSwap ^= 1;
}
bool swapped() {
return fSwap;
}
int used() {
return fUsed;
}
double fT[2][9];
double fCoincidentT[2][9];
int fUsed;
int fUsed2;
int fCoincidentUsed;
int fFlip;
private:
int fSwap;
};
#endif
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