float MgEllipse::_hitTest(const Point2d& pt, float tol, MgHitResult& res) const
{
if (isCircle()) {
Point2d pt1(getCenter()), pt2(pt);
crossCircle(pt1, pt2, this);
float d1 = pt.distanceTo(pt1);
float d2 = pt.distanceTo(pt2);
res.nearpt = d1 < d2 ? pt1 : pt2;
return mgMin(d1, d2);
}
float distMin = _FLT_MAX;
const Box2d rect (pt, 2 * tol, 2 * tol);
Point2d ptTemp;
for (int i = 0; i < 4; i++) {
if (rect.isIntersect(Box2d(4, _bzpts + 3 * i))) {
mgnear::nearestOnBezier(pt, _bzpts + 3 * i, ptTemp);
float dist = pt.distanceTo(ptTemp);
if (dist <= tol && dist < distMin) {
distMin = dist;
res.nearpt = ptTemp;
res.segment = i;
}
}
}
return distMin;
}
float mgnear::cubicSplinesHit(
int n, const Point2d* knots, const Vector2d* knotvs, bool closed,
const Point2d& pt, float tol, Point2d& nearpt, int& segment, bool hermite)
{
Point2d ptTemp;
float dist, distMin = _FLT_MAX;
Point2d pts[4];
const Box2d rect (pt, 2 * tol, 2 * tol);
int n2 = (closed && n > 1) ? n + 1 : n;
segment = -1;
for (int i = 0; i + 1 < n2; i++) {
mgcurv::cubicSplineToBezier(n, knots, knotvs, i, pts, hermite);
if (rect.isIntersect(computeCubicBox(pts))) {
dist = mgnear::nearestOnBezier(pt, pts, ptTemp);
if (dist < distMin) {
distMin = dist;
nearpt = ptTemp;
segment = i;
}
}
}
return distMin;
}
float MgEllipse::_hitTest(const Point2d& pt, float tol,
Point2d& nearpt, int& segment) const
{
float distMin = _FLT_MAX;
const Box2d rect (pt, 2 * tol, 2 * tol);
Point2d ptTemp;
segment = -1;
for (int i = 0; i < 4; i++)
{
if (rect.isIntersect(Box2d(4, _bzpts + 3 * i)))
{
mgNearestOnBezier(pt, _bzpts + 3 * i, ptTemp);
float dist = pt.distanceTo(ptTemp);
if (dist <= tol && dist < distMin)
{
distMin = dist;
nearpt = ptTemp;
segment = i;
}
}
}
return distMin;
}
float mgnear::quadSplinesHit(int n, const Point2d* knots, bool closed,
const Point2d& pt, float tol, Point2d& nearpt, int& segment)
{
Point2d ptTemp;
float dist, distMin = _FLT_MAX;
Point2d pts[3 + 4];
const Box2d rect (pt, 2 * tol, 2 * tol);
segment = -1;
for (int i = 0; i < (closed ? n : n - 2); i++, pts[0] = pts[2]) {
if (i == 0) {
pts[0] = closed ? (knots[0] + knots[1]) / 2 : knots[0];
}
pts[1] = knots[(i+1) % n];
if (closed || i + 3 < n)
pts[2] = (knots[(i+1) % n] + knots[(i+2) % n]) / 2;
else
pts[2] = knots[i+2];
mgcurv::quadBezierToCubic(pts, pts + 3);
if (rect.isIntersect(computeCubicBox(pts + 3))) {
dist = mgnear::nearestOnBezier(pt, pts + 3, ptTemp);
if (dist < distMin) {
distMin = dist;
nearpt = ptTemp;
segment = i;
}
}
}
return distMin;
}
bool mgnear::beziersIntersectBox(
const Box2d& box, int count, const Point2d* points, bool closed)
{
for (int i = 0; i + 3 < count; i += 3) {
if (box.isIntersect(computeCubicBox(points + i))) {
return true;
}
}
if (closed && count > 3) {
if (box.isIntersect(computeCubicBox(points[count - 1],
points[count - 1] * 2 - points[count - 2].asVector(),
points[0] * 2 - points[1].asVector(), points[0])))
{
return true;
}
}
return false;
}
float mgnear::roundRectHit(
const Box2d& rect, float rx, float ry,
const Point2d& pt, float tol, Point2d& nearpt, int& segment)
{
rx = fabsf(rx);
if (ry < _MGZERO)
ry = rx;
rx = mgMin(rx, rect.width() * 0.5f);
ry = mgMin(ry, rect.height() * 0.5f);
segment = -1;
Point2d ptTemp, ptTemp2;
float dist, distMin = _FLT_MAX;
Point2d pts[8];
const Box2d rectTol (pt, 2 * tol, 2 * tol);
// 顶边上的两个圆弧切点，左，右
pts[0] = RoundRectTan(0, 1, rect, rx);
pts[1] = RoundRectTan(1, 0, rect, rx);
// 右边上的两个圆弧切点，上，下
pts[2] = RoundRectTan(1, 2, rect, ry);
pts[3] = RoundRectTan(2, 1, rect, ry);
// 底边上的两个圆弧切点，右，左
pts[4] = RoundRectTan(2, 3, rect, rx);
pts[5] = RoundRectTan(3, 2, rect, rx);
// 左边上的两个圆弧切点，下，上
pts[6] = RoundRectTan(3, 0, rect, ry);
pts[7] = RoundRectTan(0, 3, rect, ry);
for (int i = 0; i < 4; i++)
{
Box2d rcLine (pts[2 * i], pts[2 * i + 1]);
if (rcLine.isEmpty() || rectTol.isIntersect(rcLine))
{
dist = mglnrel::ptToLine(pts[2 * i], pts[2 * i + 1], pt, ptTemp);
if (dist <= tol && dist < distMin)
{
distMin = dist;
nearpt = ptTemp;
segment = 4 + i;
}
}
}
if (rx > _MGZERO && ry > _MGZERO)
{
_RoundRectHit(rect, rx, ry, pt, tol,
rectTol, pts, distMin, nearpt, segment);
}
return distMin;
}
float mgnear::linesHit(
int n, const Point2d* points, bool closed,
const Point2d& pt, float tol, Point2d& nearpt, int& segment,
bool* inside, int* hitType)
{
Point2d ptTemp;
float dist, distMin = _FLT_MAX;
const Box2d rect (pt, 2 * tol, 2 * tol);
int n2 = (closed && n > 1) ? n + 1 : n;
int type = mglnrel::ptInArea(pt, n, points, segment, Tol(tol), closed);
if (inside) {
*inside = (closed && type == mglnrel::kPtInArea);
}
if (hitType) {
*hitType = type;
}
if (type == mglnrel::kPtAtVertex) {
nearpt = points[segment];
distMin = nearpt.distanceTo(pt);
return distMin;
}
if (type == mglnrel::kPtOnEdge) {
distMin = mglnrel::ptToLine(points[segment], points[(segment+1)%n], pt, nearpt);
return distMin;
}
if (!closed || type != mglnrel::kPtInArea) {
return distMin;
}
for (int i = 0; i + 1 < n2; i++)
{
const Point2d& pt2 = points[(i + 1) % n];
if (closed || rect.isIntersect(Box2d(points[i], pt2)))
{
dist = mglnrel::ptToLine(points[i], pt2, pt, ptTemp);
if (distMin > 1e10f || (dist <= tol && dist < distMin))
{
distMin = dist;
nearpt = ptTemp;
if (dist <= tol)
segment = i;
}
}
}
return distMin;
}
static void _RoundRectHit(
const Box2d& rect, float rx, float ry,
const Point2d& pt, float tol, const Box2d &rectTol,
Point2d* pts, float& distMin,
Point2d& nearpt, int& segment)
{
Point2d ptsBezier[13], ptTemp;
Vector2d vec;
float dx = rect.width() * 0.5f - rx;
float dy = rect.height() * 0.5f - ry;
// 按逆时针方向从第一象限到第四象限连接的四段
mgcurv::ellipseToBezier(ptsBezier, rect.center(), rx, ry);
pts[3] = ptsBezier[0];
for (int i = 0; i < 4; i++)
{
pts[0] = pts[3];
pts[1] = ptsBezier[3 * i];
pts[2] = ptsBezier[3 * i + 1];
pts[3] = ptsBezier[3 * i + 2];
switch (i)
{
case 0: vec.set(dx, dy); break;
case 1: vec.set(-dx, dy); break;
case 2: vec.set(-dx, -dy); break;
case 3: vec.set(dx, -dy); break;
}
for (int j = 0; j < 4; j++)
pts[j] += vec;
if (rectTol.isIntersect(Box2d(4, pts)))
{
mgnear::nearestOnBezier(pt, pts, ptTemp);
float dist = pt.distanceTo(ptTemp);
if (dist <= tol && dist < distMin)
{
distMin = dist;
nearpt = ptTemp;
segment = (5 - i) % 4;
}
}
pts[3] -= vec;
}
}
