static int vertical_coincident(const SkDLine& line, double x) {
double min = line[0].fX;
double max = line[1].fX;
if (min > max) {
SkTSwap(min, max);
}
if (!precisely_between(min, x, max)) {
return 0;
}
if (AlmostEqualUlps(min, max)) {
return 2;
}
return 1;
}
int SkIntersections::vertical(const SkDLine& line, double x) {
double min = line[0].fX;
double max = line[1].fX;
if (min > max) {
SkTSwap(min, max);
}
if (!precisely_between(min, x, max)) {
return fUsed = 0;
}
if (AlmostEqualUlps(min, max)) {
fT[0][0] = 0;
fT[0][1] = 1;
return fUsed = 2;
}
fT[0][0] = (x - line[0].fX) / (line[1].fX - line[0].fX);
return fUsed = 1;
}
int SkIntersections::vertical(const SkDLine& line, double top, double bottom,
double x, bool flipped) {
int result = vertical(line, x);
switch (result) {
case 0:
break;
case 1: {
double yIntercept = line[0].fY + fT[0][0] * (line[1].fY - line[0].fY);
if (!precisely_between(top, yIntercept, bottom)) {
return fUsed = 0;
}
fT[1][0] = (yIntercept - top) / (bottom - top);
break;
}
case 2:
double a0 = line[0].fY;
double a1 = line[1].fY;
double b0 = flipped ? bottom : top;
double b1 = flipped ? top : bottom;
// FIXME: share common code above
double at0 = (a0 - b0) / (a0 - a1);
double at1 = (a0 - b1) / (a0 - a1);
if ((at0 < 0 && at1 < 0) || (at0 > 1 && at1 > 1)) {
return fUsed = 0;
}
fT[0][0] = SkTMax(SkTMin(at0, 1.0), 0.0);
fT[0][1] = SkTMax(SkTMin(at1, 1.0), 0.0);
int bIn = (a0 - a1) * (b0 - b1) < 0;
fT[1][bIn] = SkTMax(SkTMin((b0 - a0) / (b0 - b1), 1.0), 0.0);
fT[1][!bIn] = SkTMax(SkTMin((b0 - a1) / (b0 - b1), 1.0), 0.0);
bool second = fabs(fT[0][0] - fT[0][1]) > FLT_EPSILON;
SkASSERT((fabs(fT[1][0] - fT[1][1]) <= FLT_EPSILON) ^ second);
return computePoints(line, 1 + second);
}
if (flipped) {
// OPTIMIZATION: instead of swapping, pass original line, use [1].fY - [0].fY
for (int index = 0; index < result; ++index) {
fT[1][index] = 1 - fT[1][index];
}
}
return computePoints(line, result);
}
int SkIntersections::horizontal(const SkDLine& line, double left, double right,
double y, bool flipped) {
int result = horizontal(line, y);
switch (result) {
case 0:
break;
case 1: {
double xIntercept = line[0].fX + fT[0][0] * (line[1].fX - line[0].fX);
if (!precisely_between(left, xIntercept, right)) {
return fUsed = 0;
}
fT[1][0] = (xIntercept - left) / (right - left);
break;
}
case 2:
double a0 = line[0].fX;
double a1 = line[1].fX;
double b0 = flipped ? right : left;
double b1 = flipped ? left : right;
// FIXME: share common code below
double at0 = (a0 - b0) / (a0 - a1);
double at1 = (a0 - b1) / (a0 - a1);
if ((at0 < 0 && at1 < 0) || (at0 > 1 && at1 > 1)) {
return fUsed = 0;
}
fT[0][0] = SkTMax(SkTMin(at0, 1.0), 0.0);
fT[0][1] = SkTMax(SkTMin(at1, 1.0), 0.0);
int bIn = (a0 - a1) * (b0 - b1) < 0;
fT[1][bIn] = SkTMax(SkTMin((b0 - a0) / (b0 - b1), 1.0), 0.0);
fT[1][!bIn] = SkTMax(SkTMin((b0 - a1) / (b0 - b1), 1.0), 0.0);
bool second = fabs(fT[0][0] - fT[0][1]) > FLT_EPSILON;
SkASSERT((fabs(fT[1][0] - fT[1][1]) <= FLT_EPSILON) ^ second);
return computePoints(line, 1 + second);
}
if (flipped) {
// OPTIMIZATION: instead of swapping, pass original line, use [1].fX - [0].fX
for (int index = 0; index < result; ++index) {
fT[1][index] = 1 - fT[1][index];
}
}
return computePoints(line, result);
}
int SkIntersections::vertical(const SkDLine& line, double top, double bottom,
double x, bool flipped) {
// see if end points intersect the opposite line
double t;
if (checkEndPoint(x, top, line, &t, false)) {
insert(t, flipped, x, top);
}
if (top != bottom) {
if (checkEndPoint(x, bottom,line, &t, false)) {
insert(t, !flipped, x, bottom);
}
for (int index = 0; index < 2; ++index) {
if (!checkEndPointV(line[index], top, bottom, x, flipped, &t)) {
continue;
}
insert( index, t, line[index]);
}
}
if (used() > 0) {
SkASSERT(fUsed <= 2);
return used(); // coincident lines are returned here
}
int result = vertical(line, x);
if (!result) {
return 0;
}
SkASSERT(result == 1);
double yIntercept = line[0].fY + fT[0][0] * (line[1].fY - line[0].fY);
if (!precisely_between(top, yIntercept, bottom)) {
return fUsed = 0;
}
fT[1][0] = (yIntercept - top) / (bottom - top);
if (flipped) {
// OPTIMIZATION: instead of swapping, pass original line, use [1].fY - [0].fY
for (int index = 0; index < result; ++index) {
fT[1][index] = 1 - fT[1][index];
}
}
return computePoints(line, result);
}
int SkIntersections::horizontal(const SkDLine& line, double left, double right,
double y, bool flipped) {
// see if end points intersect the opposite line
double t;
if (checkEndPoint(left, y, line, &t, true)) {
insert(t, flipped, left, y);
}
if (left != right) {
if (checkEndPoint(right, y, line, &t, true)) {
insert(t, !flipped, right, y);
}
for (int index = 0; index < 2; ++index) {
if (!checkEndPointH(line[index], left, right, y, flipped, &t)) {
continue;
}
insert(index, t, line[index]);
}
}
if (used() > 0) {
SkASSERT(fUsed <= 2);
return used(); // coincident lines are returned here
}
int result = horizontal(line, y);
if (!result) {
return 0;
}
SkASSERT(result == 1);
double xIntercept = line[0].fX + fT[0][0] * (line[1].fX - line[0].fX);
if (!precisely_between(left, xIntercept, right)) {
return fUsed = 0;
}
fT[1][0] = (xIntercept - left) / (right - left);
if (flipped) {
// OPTIMIZATION: ? instead of swapping, pass original line, use [1].fX - [0].fX
for (int index = 0; index < result; ++index) {
fT[1][index] = 1 - fT[1][index];
}
}
return computePoints(line, result);
}
bool SkDCubic::monotonicInY() const {
return precisely_between(fPts[0].fY, fPts[1].fY, fPts[3].fY)
&& precisely_between(fPts[0].fY, fPts[2].fY, fPts[3].fY);
}
