private static void renderHull(PtEntry pt) {
Inf inf = Inf.create();
int count = 30;
PtEntry ptStart = pt;
do {
inf.update();
if (pt.prev(true) != null) {
boolean valley = false;
valley =
(pt.prev(true).source() == pt.source() && pt.prev(true).orig().next(true) != pt.orig());
V.pushColor(MyColor.cBLUE);
V.pushStroke(valley ? STRK_RUBBERBAND : STRK_THICK);
V.drawLine(pt.prev(true), pt);
V.pop(2);
}
V.pushColor(MyColor.cDARKGREEN);
V.mark(pt, MARK_DISC, .6);
V.pop();
if (Editor.withLabels(true)) {
StringBuilder sb = new StringBuilder();
sb.append(" #" + pt.id());
if (pt.source() != null) sb.append(" <" + pt.source() + ">");
V.pushScale(.6);
V.draw(sb.toString(), MyMath.ptOnCircle(pt, MyMath.radians(30), 3), TX_FRAME | TX_BGND);
V.pop();
}
pt = pt.next(true);
if (count-- == 0) V.draw("too many points rendering!", 50, 50, TX_CLAMP);
} while (pt != ptStart && count > 0);
}
/**
* Calculate possible hull of a pair of polygons
*
* @param a
* @param b
* @return possible hull
*/
private static EdPolygon calcPHull(EdPolygon aPoly, EdPolygon bPoly) {
final boolean db = true;
if (db && T.update())
T.msg(
"calc possible hull of two polygons"
+ T.show(aPoly, MyColor.cBLUE, STRK_THICK, -1)
+ T.show(bPoly, MyColor.cDARKGREEN, STRK_THICK, -1));
PtEntry a = PtEntry.buildFrom(aPoly);
PtEntry b = PtEntry.buildFrom(bPoly);
PtEntry aHull = PtEntry.convexHull(a);
PtEntry bHull = PtEntry.convexHull(b);
inf = Inf.create();
if (db && T.update()) {
T.msg(
"convex hulls"
+ T.show(aHull.toPolygon(), MyColor.cBLUE, STRK_THICK, -1)
+ T.show(bHull.toPolygon(), MyColor.cDARKGREEN, STRK_THICK, -1));
}
PtEntry ph = hullOfPolygons(a, b, aHull, bHull);
traceHullPt = ph;
insertValleys(ph, a.source(), b.source());
expandHull(ph, aHull, bHull, true);
expandHull(ph, aHull, bHull, false);
return ph.toPolygon();
}
private static void OLDexpandHull(
PtEntry convHullEntry, PtEntry aHull, PtEntry bHull, boolean ccw) {
boolean db__OLD = C.vb(DB_HULLEXPAND);
if (db__OLD && T.update()) T.msg("expandHull" + T.show(convHullEntry) + " ccw=" + ccw);
PtEntry[] opp = new PtEntry[2];
opp[0] = aHull;
opp[1] = bHull;
PtEntry old____hEnt = convHullEntry;
boolean advanced = false;
do {
if (old____hEnt != convHullEntry) advanced = true;
inf.update();
if (old____hEnt.source() == null) {
if (db__OLD && T.update())
T.msg("expandHull, source unknown, guaranteed not convex" + T.show(old____hEnt));
old____hEnt = old____hEnt.next(ccw);
continue;
}
int w = (old____hEnt.source() == opp[0].source()) ? 1 : 0;
PtEntry oppEnt = opp[w];
boolean isTangent =
!COper3.right(old____hEnt, oppEnt, oppEnt.next(true), ccw)
&& !COper3.right(old____hEnt, oppEnt, oppEnt.prev(true), ccw);
if (!isTangent) {
if (db__OLD && T.update())
T.msg(
"expandHull, advance tangent line"
+ T.show(oppEnt.toPolygon(), MyColor.cDARKGRAY, -1, MARK_X)
+ T.show(old____hEnt)
+ tl(old____hEnt, oppEnt));
opp[w] = oppEnt.next(ccw);
continue;
}
if (COper3.left(old____hEnt, oppEnt, old____hEnt.next(ccw), ccw)
&& COper3.left(old____hEnt, oppEnt, old____hEnt.prev(ccw), ccw)) {
DArray dispPts = new DArray();
// delete points until cross tangent line
PtEntry next = old____hEnt.next(ccw);
while (true) {
PtEntry prev = next;
dispPts.add(prev);
next = prev.delete(ccw);
inf.update();
if (COper3.right(old____hEnt, oppEnt, next, ccw)) {
FPoint2 cross = MyMath.linesIntersection(old____hEnt, oppEnt, prev, next, null);
old____hEnt = old____hEnt.insert(new PtEntry(cross), ccw);
if (db__OLD && T.update())
T.msg(
"expandHull, clipped to shadow region"
+ tl(old____hEnt, oppEnt)
+ T.show(old____hEnt)
+ T.show(dispPts));
break;
}
}
} else {
if (db__OLD && T.update())
T.msg(
"expandHull, not dipping into shadow region"
+ T.show(old____hEnt.next(ccw))
+ tl(old____hEnt, oppEnt));
}
old____hEnt = old____hEnt.next(ccw);
} while (!advanced || old____hEnt != convHullEntry);
}
private static void insertValleys(
PtEntry hullPt, Object aSrc, Object bSrc) { // pa, MyPolygon pb) {
boolean db = C.vb(DB_INSERTVALLEY);
PtEntry ent = hullPt;
if (db && T.update()) T.msg("insertValleys");
do {
PtEntry next = ent.next(true);
if (ent.source() == next.source()) {
PtEntry orig = ent.orig();
if (orig.next(true) != next.orig()) {
PtEntry vPeak0 = ent;
PtEntry vPeak1 = next;
EdPolygon opp = (EdPolygon) (vPeak0.source() == aSrc ? bSrc : aSrc);
FPoint2 kernelPt = opp.getPointMod(C.vi(KERNELVERT));
// construct a chain from the vertices of the valley
PtEntry handle = new PtEntry(vPeak0);
PtEntry hNext = handle;
PtEntry e = vPeak0.orig();
while (e != vPeak1.orig()) {
inf.update();
e = e.next(true);
hNext = hNext.insert(new PtEntry(e), true);
}
if (C.vb(SKIPCONTOUR)) {
PtEntry h0 = handle.next(true);
PtEntry h1 = hNext.prev(true);
PtEntry.join(vPeak0, h0);
PtEntry.join(h1, vPeak1);
if (db && T.update())
T.msg("inserted unmodified valley" + T.show(vPeak0) + T.show(vPeak1));
} else {
if (!C.vb(DB_CONTOUR)) T.disable();
PtEntry hull = COper3.buildHullForChain(handle, kernelPt);
if (!C.vb(DB_CONTOUR)) T.enable();
// find entries corresponding to start, end of hull
PtEntry peak0 = null, peak1 = null;
{
PtEntry hEnt = hull;
while (peak0 == null || peak1 == null) {
inf.update();
if (hEnt.orig() == vPeak0.orig()) peak0 = hEnt;
if (hEnt.orig() == vPeak1.orig()) peak1 = hEnt;
hEnt = hEnt.next(true);
}
}
PtEntry.join(vPeak0, peak0.next(true));
PtEntry.join(peak1.prev(true), vPeak1);
if (db && T.update())
T.msg("inserted monotonic valley" + T.show(vPeak0) + T.show(vPeak1));
}
}
}
ent = next;
} while (ent != hullPt);
}
/**
* Apply hull expansion procedure
*
* @param convHullEntry an entry of the hull (should be on the convex hull, so it is not deleted
* or replaced and is still valid for subsequent calls)
* @param aHull entry on convex hull of polygon A
* @param bHull entry on convex hull of polygon B
* @param ccw true to move in ccw direction, else cw
*/
private static void expandHull(PtEntry convHullEntry, PtEntry aHull, PtEntry bHull, boolean ccw) {
if (C.vb(OLDMETHOD)) {
OLDexpandHull(convHullEntry, aHull, bHull, ccw);
return;
}
boolean db = C.vb(DB_HULLEXPAND);
if (db && T.update()) T.msg("expandHull" + T.show(convHullEntry) + " ccw=" + ccw);
// tangent points for A, B
PtEntry[] tangentPoints = new PtEntry[2];
tangentPoints[0] = aHull;
tangentPoints[1] = bHull;
PtEntry hEnt = convHullEntry;
do {
inf.update();
// calculate tangent ray R
PtEntry tangentPt = null;
while (true) {
int tanIndex = (hEnt.source() == tangentPoints[0].source()) ? 1 : 0;
tangentPt = tangentPoints[tanIndex];
if (!COper3.right(hEnt, tangentPt, tangentPt.next(true), ccw)
&& !COper3.right(hEnt, tangentPt, tangentPt.prev(true), ccw)) break;
tangentPt = tangentPt.next(ccw);
if (db && T.update())
T.msg(
"expandHull, advance tangent line"
+ T.show(tangentPt.toPolygon(), MyColor.cDARKGRAY, -1, MARK_DISC)
+ T.show(hEnt)
+ tl(hEnt, tangentPt));
tangentPoints[tanIndex] = tangentPt;
}
if (COper3.left(hEnt, tangentPt, hEnt.next(ccw), ccw)) {
DArray dispPts = new DArray();
// delete points until cross tangent line
PtEntry next = hEnt.next(ccw);
while (true) {
PtEntry prev = next;
dispPts.add(prev);
next = prev.delete(ccw);
if (COper3.right(hEnt, tangentPt, next, ccw)) {
FPoint2 cross = MyMath.linesIntersection(hEnt, tangentPt, prev, next, null);
hEnt = hEnt.insert(new PtEntry(cross), ccw);
if (db && T.update())
T.msg(
"expandHull, clipped to shadow region"
+ tl(hEnt, tangentPt)
+ T.show(hEnt)
+ T.show(dispPts));
break;
}
}
} else {
if (db && T.update())
T.msg(
"expandHull, not dipping into shadow region"
+ T.show(hEnt.next(ccw))
+ tl(hEnt, tangentPt));
}
while (true) {
hEnt = hEnt.next(ccw);
if (COper3.left(hEnt.prev(ccw), hEnt, hEnt.next(ccw), ccw)) break;
if (db && T.update()) T.msg("skipping reflex vertex" + T.show(hEnt));
}
} while (hEnt != convHullEntry);
}