// both the outer outline and the outline of a hole are called a "trace" // should return outer outline first and then outline of holes // seems to return first point again at the end sometimes srecord noeq RegionBorder_innerPoints_v2(IImageRegion region) extends AbstractSteppable { event newTrace(bool isHole); event foundPoint(Pt p); event traceDone; settable bool includeHoles = true; int w, x, y, dir; Iterator<Pt> it; byte[] reachedInDirections; // bits 0 to 3 bool tracing; int nTrace; // 1 for outline, 2+ for hole // directions (0 = right, 1 = down, 2 = left, 3 = up) static Pt[] directions = { pt(1, 0), pt(0, 1), pt(-1, 0), pt(0, -1) // r, d, l, u }; void init { var image = region.image(); w = image.w(); reachedInDirections = new byte[w*image.h()]; it = region.pixelIterator(); } public bool step() { if (reachedInDirections == null) init(); if (tracing) ret walkOnePixel(); else ret findFirstPixel(); } bool walkOnePixel() { int pos = y*w+x; if ((reachedInDirections[pos] & (1 << dir)) != 0) { traceDone(); tracing = false; ret includeHoles; } reachedInDirections[pos] |= (byte) 1 << dir; foundPoint(x, y); for (int turn = 3; turn <= 6; turn++) { // try left, straight, right, back int newDir = (dir+turn) & 3; Pt d = directions[newDir]; int x2 = x+d.x, y2 = y+d.y; bool b = region.contains(x2, y2); ifdef RegionBorder_innerPoints_debug printVars(+x, +y, +dir, +turn, +newDir, +x2, +y2, +b); endifdef if (b) { x = x2; y = y2; dir = newDir; true; } } true; // no black pixels found in any direction - region must be a single pixel } bool findFirstPixel() { // search for first border pixel if (!it.hasNext()) false; // done Pt p = it.next(); x = p.x; y = p.y; if (reachedInDirections[y*w+x] != 0) true; // seen pixel before // if pixel above is empty, walk to the right if (!region.contains(x, y-1)) ret true with startTrace(0); // if pixel on the left is empty, walk upwards if (!region.contains(x-1, y)) ret true with startTrace(3); // if pixel on the right is empty, walk downwards if (!region.contains(x+1, y)) ret true with startTrace(1); // if pixel below is empty, walk left if (!region.contains(x, y+1)) ret true with startTrace(2); // not a border pixel, continue search true; } void startTrace(int dir) { this.dir = dir; // mark point reached from all directions in next step reachedInDirections[y*w+x] = (byte) (15 & ~(1 << dir)); set tracing; newTrace(++nTrace > 1); } void foundPoint(int x, int y) { foundPoint(pt(x, y)); } // get all points as list simplyCached L<Pt> allPoints() { new PtBuffer l; onFoundPoint(p -> l.add(p)); run(); ret l; } // get outline as OnePath simplyCached OnePath onePath() { includeHoles(false); ret new OnePath(allPoints(), true); } // or as OnePathWithOrigin simplyCached OnePathWithOrigin onePathWithOrigin() { includeHoles(false); ret new OnePathWithOrigin(allPoints(), true); } // for debugging void runAndPrint { onNewTrace(hole -> print(!hole ? "new outline" : "new hole")); onTraceDone(-> print("traceDone")); onFoundPoint(p -> print("foundPoint " + p)); stepMaxWithStats(this, 10000); } bool tracingHole() { ret nTrace > 1; } }
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Snippet ID: | #1034966 |
Snippet name: | RegionBorder_innerPoints_v2 backup |
Eternal ID of this version: | #1034966/1 |
Text MD5: | 9bfd6f2269893dc5a1501dd1c370646f |
Author: | stefan |
Category: | javax |
Type: | JavaX fragment (include) |
Public (visible to everyone): | Yes |
Archived (hidden from active list): | No |
Created/modified: | 2022-03-18 22:15:10 |
Source code size: | 3741 bytes / 141 lines |
Pitched / IR pitched: | No / No |
Views / Downloads: | 131 / 138 |
Referenced in: | -