xyz.luan.geometry.de.lighti.clipper.Edge Maven / Gradle / Ivy
package xyz.luan.geometry.de.lighti.clipper;
import java.util.logging.Logger;
import xyz.luan.geometry.OpType;
import xyz.luan.geometry.Point;
import xyz.luan.geometry.de.lighti.clipper.Clipper.Direction;
import xyz.luan.geometry.de.lighti.clipper.Clipper.PolyFillType;
import xyz.luan.geometry.de.lighti.clipper.Clipper.PolyType;
class Edge {
static enum Side {
LEFT, RIGHT
}
static boolean doesE2InsertBeforeE1(Edge e1, Edge e2) {
if (e2.current.getX() == e1.current.getX()) {
if (e2.top.getY() > e1.top.getY()) {
return e2.top.getX() < topX(e1, e2.top.getY());
} else {
return e1.top.getX() > topX(e2, e1.top.getY());
}
} else {
return e2.current.getX() < e1.current.getX();
}
}
static boolean slopesEqual(Edge e1, Edge e2) {
return e1.getDelta().getY() * e2.getDelta().getX() == e1.getDelta().getX() * e2.getDelta().getY();
}
static void swapPolyIndexes(Edge edge1, Edge edge2) {
final int outIdx = edge1.outIdx;
edge1.outIdx = edge2.outIdx;
edge2.outIdx = outIdx;
}
static void swapSides(Edge edge1, Edge edge2) {
final Edge.Side side = edge1.side;
edge1.side = edge2.side;
edge2.side = side;
}
static double topX(Edge edge, double currentY) {
if (currentY == edge.getTop().getY()) {
return edge.getTop().getX();
}
return (edge.getBot().getX() + Math.round(edge.deltaX * (currentY - edge.getBot().getY())));
}
private final Point bot;
private final Point current;
private final Point top;
private final Point delta;
double deltaX;
PolyType polyTyp;
Edge.Side side;
int windDelta; // 1 or -1 depending on winding direction
int windCnt;
int windCnt2; // winding count of the opposite polytype
int outIdx;
Edge next;
Edge prev;
Edge nextInLML;
Edge nextInAEL;
Edge prevInAEL;
Edge nextInSEL;
Edge prevInSEL;
protected final static int SKIP = -2;
protected final static int UNASSIGNED = -1;
protected final static double HORIZONTAL = -3.4E+38;
private final static Logger LOGGER = Logger.getLogger(Edge.class.getName());
public Edge() {
delta = new Point();
top = new Point();
bot = new Point();
current = new Point();
}
public Edge findNextLocMin() {
Edge e = this;
Edge e2;
for (;;) {
while (!e.bot.equals(e.prev.bot) || e.current.equals(e.top)) {
e = e.next;
}
if (e.deltaX != Edge.HORIZONTAL && e.prev.deltaX != Edge.HORIZONTAL) {
break;
}
while (e.prev.deltaX == Edge.HORIZONTAL) {
e = e.prev;
}
e2 = e;
while (e.deltaX == Edge.HORIZONTAL) {
e = e.next;
}
if (e.top.getY() == e.prev.bot.getY()) {
continue; // ie just an intermediate horz.
}
if (e2.prev.bot.getX() < e.bot.getX()) {
e = e2;
}
break;
}
return e;
}
public Point getBot() {
return bot;
}
public Point getCurrent() {
return current;
}
public Point getDelta() {
return delta;
}
public Edge getMaximaPair() {
Edge result = null;
if (next.top.equals(top) && next.nextInLML == null) {
result = next;
} else if (prev.top.equals(top) && prev.nextInLML == null) {
result = prev;
}
if (result != null
&& (result.outIdx == Edge.SKIP || result.nextInAEL == result.prevInAEL && !result.isHorizontal())) {
return null;
}
return result;
}
public Edge getNextInAEL(Direction direction) {
return direction == Direction.LEFT_TO_RIGHT ? nextInAEL : prevInAEL;
}
public Point getTop() {
return top;
}
public boolean isContributing(PolyFillType clipFillType, PolyFillType subjFillType, OpType clipType) {
LOGGER.entering(Edge.class.getName(), "isContributing");
PolyFillType pft, pft2;
if (polyTyp == PolyType.SUBJECT) {
pft = subjFillType;
pft2 = clipFillType;
} else {
pft = clipFillType;
pft2 = subjFillType;
}
switch (pft) {
case EVEN_ODD:
// return false if a subj line has been flagged as inside a subj
// polygon
if (windDelta == 0 && windCnt != 1) {
return false;
}
break;
case NON_ZERO:
if (Math.abs(windCnt) != 1) {
return false;
}
break;
case POSITIVE:
if (windCnt != 1) {
return false;
}
break;
default: // PolyFillType.pftNegative
if (windCnt != -1) {
return false;
}
break;
}
switch (clipType) {
case INTERSECTION:
switch (pft2) {
case EVEN_ODD:
case NON_ZERO:
return windCnt2 != 0;
case POSITIVE:
return windCnt2 > 0;
default:
return windCnt2 < 0;
}
case UNION:
switch (pft2) {
case EVEN_ODD:
case NON_ZERO:
return windCnt2 == 0;
case POSITIVE:
return windCnt2 <= 0;
default:
return windCnt2 >= 0;
}
case DIFFERENCE:
if (polyTyp == PolyType.SUBJECT) {
switch (pft2) {
case EVEN_ODD:
case NON_ZERO:
return windCnt2 == 0;
case POSITIVE:
return windCnt2 <= 0;
default:
return windCnt2 >= 0;
}
} else {
switch (pft2) {
case EVEN_ODD:
case NON_ZERO:
return windCnt2 != 0;
case POSITIVE:
return windCnt2 > 0;
default:
return windCnt2 < 0;
}
}
case XOR:
if (windDelta == 0) {
switch (pft2) {
case EVEN_ODD:
case NON_ZERO:
return windCnt2 == 0;
case POSITIVE:
return windCnt2 <= 0;
default:
return windCnt2 >= 0;
}
} else {
return true;
}
}
return true;
}
public boolean isEvenOddAltFillType(PolyFillType clipFillType, PolyFillType subjFillType) {
if (polyTyp == PolyType.SUBJECT) {
return clipFillType == PolyFillType.EVEN_ODD;
} else {
return subjFillType == PolyFillType.EVEN_ODD;
}
}
public boolean isEvenOddFillType(PolyFillType clipFillType, PolyFillType subjFillType) {
if (polyTyp == PolyType.SUBJECT) {
return subjFillType == PolyFillType.EVEN_ODD;
} else {
return clipFillType == PolyFillType.EVEN_ODD;
}
}
public boolean isHorizontal() {
return delta.getY() == 0;
}
public boolean isIntermediate(double y) {
return top.getY() == y && nextInLML != null;
}
public boolean isMaxima(double Y) {
return top.getY() == Y && nextInLML == null;
}
public void reverseHorizontal() {
// swap horizontal edges' top and bottom x's so they follow the natural
// progression of the bounds - ie so their xbots will align with the
// adjoining lower edge. [Helpful in the ProcessHorizontal() method.]
double temp = top.getX();
top.setX(bot.getX());
bot.setX(temp);
}
public void setBot(Point bot) {
this.bot.set(bot);
}
public void setCurrent(Point current) {
this.current.set(current);
}
public void setTop(Point top) {
this.top.set(top);
}
@Override
public String toString() {
return "TEdge [Bot=" + bot + ", Curr=" + current + ", Top=" + top + ", Delta=" + delta + ", Dx=" + deltaX
+ ", PolyTyp=" + polyTyp + ", Side=" + side + ", WindDelta=" + windDelta + ", WindCnt=" + windCnt
+ ", WindCnt2=" + windCnt2 + ", OutIdx=" + outIdx + ", Next=" + next + ", Prev=" + prev + ", NextInLML="
+ nextInLML + ", NextInAEL=" + nextInAEL + ", PrevInAEL=" + prevInAEL + ", NextInSEL=" + nextInSEL
+ ", PrevInSEL=" + prevInSEL + "]";
}
public void updateDeltaX() {
delta.setX(top.getX() - bot.getX());
delta.setY(top.getY() - bot.getY());
if (delta.getY() == 0) {
deltaX = Edge.HORIZONTAL;
} else {
deltaX = (double) delta.getX() / delta.getY();
}
}
};
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