@Override
public MC_TYPE at(int x, int y, Aggregates<? extends Boolean> aggregates) {
int code = 0;
if (aggregates.get(x - 1, y - 1)) {
code = code | DOWN_INDEX_LEFT;
}
if (aggregates.get(x, y - 1)) {
code = code | DOWN_INDEX_RIGHT;
}
if (aggregates.get(x - 1, y)) {
code = code | UP_INDEX_LEFT;
}
if (aggregates.get(x, y)) {
code = code | UP_INDEX_RIGHT;
}
return MC_TYPE.get(code);
}
/**
* An iso level can be made of multiple regions with holes in them. This builds one path (into
* the passed GeneralPath) that represents one connected contour.
*
* @param isoData Marching-cubes classification at each cell
* @param isoDivided The boolean above/below classification for each cell (to disambiguate
* saddles)
* @param iso The path to build into
*/
public static void stichContour(
Aggregates<MC_TYPE> isoData,
Aggregates<Boolean> isoDivided,
GeneralPath iso,
int startX,
int startY) {
int x = startX, y = startY;
SIDE prevSide = SIDE.NONE;
// Found an unambiguous iso line at [r][c], so start there.
MC_TYPE startCell = isoData.get(x, y);
Point2D nextPoint = startCell.firstSide(prevSide).nextPoint(x, y);
iso.moveTo(nextPoint.getX(), nextPoint.getY());
prevSide = isoData.get(x, y).secondSide(prevSide, isoDivided.get(x, y));
// System.out.printf("-------------------\n);
do {
// Process current cell
MC_TYPE curCell = isoData.get(x, y);
nextPoint = curCell.secondSide(prevSide, isoDivided.get(x, y)).nextPoint(x, y);
// System.out.printf("%d,%d: %s\n",x,y,curCell.secondSide(prevSide, isoDivided.get(x,y)));
iso.lineTo(nextPoint.getX(), nextPoint.getY());
SIDE nextSide = curCell.secondSide(prevSide, isoDivided.get(x, y));
isoData.set(x, y, curCell.clearWith()); // Erase this marching cube line entry
// Advance for next cell
prevSide = nextSide;
switch (nextSide) {
case LEFT:
x -= 1;
break;
case RIGHT:
x += 1;
break;
case BOTTOM:
y += 1;
break;
case TOP:
y -= 1;
break;
case NONE:
throw new IllegalArgumentException(
"Encountered side NONE after starting contour line.");
}
} while (x != startX || y != startY);
iso.closePath();
}
