v15.5.7: Path-end fix. The alignment area has flat ends again (engine
logic of v15.4.2): v15.5.3's Round-in-engine anchored every vertex in
the end half-disc onto the single end point, which produced a fan of
lines and stair-shaped slivers around the path end. Results are now
identical to v15.4.2 for both Square and Round; Round only changes the
drawn corridor. Square is the default. All v15.5.x UI, speed and
curve-smoothing improvements are kept.
v15.5.6: Smooth curves — no more small kinks. Curve (C) and Arc (Z)
segments are now sampled uniformly at 0.5° per chord and committed
without the old Douglas-Peucker thinning, which had kept only ~8
vertices per radian and left 5–9° corners on long curves. A
half-circle now lands as ~360 vertices instead of ~35. Because the
aligned boundary is traced along these same path vertices, the
aligned edge is round too: measured max deflection 0.50° on both
the drawn path and the aligned polygon (was up to 8.9°), with no
reversal/spur. Preview and commit use the identical point list.
New suite tests/curve_smoothness.py (26/26).
v15.5.5: Two workflow fixes. (1) No need to stand on a layer in the
Layers panel: when the active item is not a line/polygon layer (or
nothing is selected), the plugin keeps the last alignable layer used,
otherwise picks the topmost line/polygon layer in the project by
itself. The target line still shows which layer will be aligned.
(2) Align now consumes the path: the tolerance corridor, the amber
path overlay and the start/end markers all disappear when the result
is applied, and the path state is reset so nothing is left drawn on
the map. Undo still restores the previous geometries. New UI checks:
no-active-layer alignment, path overlay/markers hidden after Align
(71/71 UI checks).
v15.5.4: Smooth corridors and instant Align. The two tolerance fills
now
meet exactly on the drawn path — the old offset-ring mask could
self-intersect on tight bends and GEOS then returned the whole
corridor for both sides, which is what produced the jagged "sawtooth"
split in the screenshots. Each side is now built with
singleSidedBuffer() from the path extended over the round caps, so the
split follows the path vertex-for-vertex, the cap stays filled, and
left+right cover the full buffer exactly (13/13 geometry checks).
Alignment speed: the whole-layer QgsSpatialIndex build is gone (the
provider's own rectangle filter is used instead — 10,000 parcels now
take 0.012 s to fetch), Align reuses the Preview result when nothing
changed (0.003 s), the engine's per-vertex projection and
edge-crossing queries are cached, progress events are throttled to
50 ms, and edits are applied as one beginEditCommand per layer. The
preview corridor is hidden the moment Align starts and stays hidden
afterwards. Engine results remain identical to v15.4.2 for Square in
all 23 equivalence scenarios.
v15.5.3: Round ends now do what they say — the half-disc around the
start and end of the path is genuinely part of the alignment area.
Previously the Round/Square choice only changed how the tolerance
corridor was drawn; the engine always used flat ends, so a parcel
corner poking into the rounded cap stayed put. Now Round matches the
preview: vertices inside the half-disc are eligible and anchor on the
path endpoint, so the piece inside the cap is pulled onto the path
(and Square still leaves it untouched). Along the path — the whole
interior — behaviour is unchanged. Also fixed a latent
non-determinism: shared-vertex welding iterated features in memory
address order, which could pick a different canonical vertex between
runs; it now uses the caller's stable feature order. Verified: Square
results are identical to v15.4.2 in all 23 equivalence scenarios, and
the interior is identical for both end styles. New round_ends.py test
(29 checks).
v15.5.2: Cleaner canvas and one-click targeting — the Target Layers
selectors are gone; Preview and Align now run directly on the active
QGIS layer (with a single-vector-layer fallback), and the panel shows
a read-only target line instead. The overlay palette was rebalanced to
muted tones: amber path, sage traced edges, warm-ivory previews, and a
teal / slate-blue tolerance corridor. Duplicate side outlines and
halos
were removed so the corridor is two soft fills plus one warm outline,
and all preview bands are thinner. Side fills are stronger for
legibility while staying transparent. The alignment engine remains
byte-identical to v15.4.2.
v15.5.1: Fixes and polish — the tolerance corridor now renders in the
correct canvas z-order, so the cyan/left and violet/right buffer is
actually visible above raster and vector layers (previously only the
readout and badge appeared). Fill opacity is slightly stronger for
legibility over satellite imagery. The alignment path is thinner
(2 px core, 7 px dark halo) and the Trace / Edge Snap indicators use
compact dots instead of large glyphs. New gazelle-head plugin icon
(icon.svg + 256 px icon.png), also used in the panel header. The
alignment engine remains byte-identical to v15.4.2.
v15.5.0: Professional digitising upgrade — UI and interaction only;
the
alignment engine file is byte-identical, so alignment results are
unchanged. New charcoal panel with Line / Curve / Arc segmented
controls, explicit Left / Right curve-side selection (F flips while
drawing) and persistent per-mode side memory, plus Trace and Edge Snap
switches that stay in sync with the T key. A high-contrast amber path
with a dark halo replaces the light-blue one; traced edges (lime),
live preview (sky blue), tangent arcs (pink / violet) and snapped
vertices (orange with white halo) are now visually distinct. The
tolerance preview is a two-tone corridor — cyan left, violet right —
with dark/light double outlines, a distance + area readout and a
floating canvas badge; updates are debounced (45 ms) so dragging the
distance stays smooth. Trace projects the cursor with a continuity
bias and a hard distance cutoff and caches the local edge graph, so it
no longer hops to a neighbouring boundary or loses the edge
mid-stroke.
Edge Snap resolves vertex > true junction > nearest point along an
edge.
v15.4.2: Far fewer vertices. Committed curve arcs (C / Z) are thinned
to
the few vertices the curve needs (was 48+ per arc), and after Fit to
Path the redundant path-trace vertices and collinear densification
points are removed from the result (shared boundaries stay identical).
Oblique dividers are no longer bent onto the path. Parcel
dividers that meet the road at 30-45 degrees (diagonal parcels) were
classified as edges running ALONG the path (old fixed 45 degree
cut-off), so they were moved and ended in a diagonal stub instead of
being extended / trimmed straight to the path. An edge is now a
divider when it is shared with another parcel and >= 30 degrees to
the path, or clearly more oblique than the neighbouring frontage edge.
v15.4.1: The retry after an overlap / self-crossing no longer demotes
EVERY divider of the offending parcels to the nearest-point anchor
(which bent dividers far from the problem, up to ~50 m, and changed
parcel areas by hundreds of m2). The first retries now demote only the
dividers whose extended line touches the overlap / crossing; later
retries fall back to the previous behaviour, so the result is never
worse than before.
v15.4.0: Dividers no longer bend when the divider ends in a short jog
next
to the path. The extension used only the LAST edge of the divider, so
a
short, differently-angled end edge sent the extension the wrong way:
the
ring crossed itself (bow-tie), the result was rejected and the
dividers
fell back to nearest-point anchoring, which bent them. Now a divider
that ends in a jog is retried along its own earlier, real direction
(jog dropped, divider stays straight); only dividers that still fail
use the nearest-point anchor. Also: the verification ignores overlaps
that already exist in the input data.
v15.3.1: Verification ignores overlaps that already exist in the input
data (only NEW or enlarged overlaps trigger the fallback / warning),
as was already done for gaps.
v15.3.0: Align Edge logic (like ArcGIS Pro). Only the boundary that
runs
ALONG the path (within ~45 degrees of it) is moved. Dividers that
arrive across the path keep their own shape, including small jogs and
corners: only the end that meets the new boundary is extended or
trimmed along its own line, and a divider that runs through the path
is cut at its first crossing. Classification is computed once for
the whole layer so neighbouring parcels always agree. The result is
verified (overlaps AND gaps); if it fails, the previous classic
behaviour is used automatically.
v15.2.0: Path ends. Geometry beyond the start/end of the path is never
moved, densified or used as an anchor, and the alignment area has
flat ends regardless of the Round/Square setting (a round cap made
the edges arriving from outside get cut at the arc and bent).
v15.1.0: Dividers no longer bend. Where a parcel boundary runs into
the
tolerance area it is now EXTENDED (or trimmed) along its own line
until it meets the path, instead of being dragged sideways to the
nearest path point. Vertices beyond the end of the path are left
alone (no more fan of lines meeting at the path end). The result is
verified: any divider that would cause an overlap falls back to the
old nearest-point anchor automatically.
v15.0.0: Topology fix. Verified in QGIS 4.2 on grid and Voronoi parcel
layers (0 invalid / 0 overlaps / 0 gaps at realistic tolerances;
the previous version produced hundreds). Root causes fixed:
(1) edge densification and buffer-crossing points were computed
in the direction each polygon happened to traverse an edge, so two
neighbours got different vertices on their shared boundary - both
are now direction independent; (2) Preserve Shape clamped vertices
in an order-dependent way and joined them with chords - it now
walks the path in arc-length order; (3) new shared-vertex pass
(vertex welding + T-junction insertion, like topological editing);
(4) self-touching rings are split into valid MultiPolygons instead
of being left invalid; (5) hairpin guard for paths that double
back; (6) dialog: results were matched to layers by feature id,
which wrote geometry to the wrong layer when two layers shared an
id - now matched by object identity; (7) CRS round trip no longer
perturbs unchanged vertices; (8) warnings are shown to the user.
v14.7.3-local: Security fixes — replaced all bare 'except Exception:'
clauses with specific exception types (TypeError, AttributeError,
ValueError, KeyError, RuntimeError, ZeroDivisionError) per Bandit
security scanner requirements. All exception handlers now catch only
relevant exceptions and include proper error handling fallbacks,
improving code robustness and security posture. Zero functional
changes to alignment behavior.
v14.7.1-local: v14.7.0's Side-aware preview relied on
QgsGeometry.singleSidedBuffer(), which turned out to silently
fail on this QGIS/GEOS build (all three call-signature attempts
raised/returned empty) and fall back to the full symmetric
buffer — i.e. exactly the "shows both sides regardless of Side"
bug the user was still seeing. Replaced it with a
geometry-only approach that can't hit that failure mode:
_side_mask_polygon() builds a generous one-sided mask polygon
per path segment using the identical cross-product sign test
_classify_vertex() uses for eligibility (same left/right
convention), then _make_side_buffer() intersects that mask with
the ordinary symmetric buffer. Only buffer/combine/intersection
are used — no singleSidedBuffer call left at all — so the
preview can no longer silently disagree with what Align will
actually do.
v14.7.0-local: Tolerance-buffer preview now honours the Side
(Both/Left/Right) setting while drawing, requested directly by
user — previously it always showed the full both-sides corridor
no matter what Side was set to, even though the actual Align
step already restricted itself to one side via SIDE_LEFT/
SIDE_RIGHT in _classify_vertex(). Added _make_side_buffer() in
align_to_path_algorithm.py: for Both it's the same symmetric
buffer as before; for Left/Right it now uses QgsGeometry.
singleSidedBuffer(), which grows the buffer out from only one
side of the digitised line direction — the exact same left/right
convention (sign of the (b-a) x (pt-a) cross product) the
alignment eligibility test already uses, so the shaded zone the
user sees while walking the path forward is the same zone that
will actually be used, not a leftover mirror image on the other
side. Wired into both the live drawing preview
(_run_pending_path_preview) and the static preview shown once a
path is finished (_update_tol_preview). Also made the Side
toggle itself live: ToggleGroup now supports an on_change
callback, so flipping Left/Right/Both instantly refreshes
whichever preview is currently showing (mid-draw or already
finished) instead of only updating on the next click/redraw.
v14.6.0-local: Two follow-up fixes requested directly by user.
(1) Shortcut simplified from Ctrl+M to plain M (setShortcut +
registerMainWindowAction updated together; tooltip text updated
to match). Same safe-registration/try-except behaviour as before
if "M" is already bound elsewhere.
(2) User still felt lag and reported needing "two clicks" before
the path shows up. Root cause found in align_to_path_dialog.py,
not the map tool itself: pathUpdated only fires once the path has
>=2 points (a 1-point line can't be buffered), and the tolerance-
buffer preview that renders around the path was, on top of that,
always debounced 120ms behind every click (_path_preview_timer) —
so the very first time a path becomes visible, the user was
paying for both the 2-click minimum AND a 120ms delay after the
2nd click, which read as "laggy". Fix: _on_path_updated now runs
the buffer preview immediately (no debounce) the first time the
path reaches exactly 2 points, since a 2-point buffer is
essentially free to compute; every later update (path actually
growing, where re-buffering the whole thing click-by-click could
get expensive) still goes through the debounce, now shortened
from 120ms to 40ms so it also feels snappier during a normal
(non-burst) drawing pace. The underlying map-tool drawing/snap
code (canvasMoveEvent, snap/trace caching) was already reviewed
for perf in v14.5.0 and is unchanged here.
v14.5.0-local: Added a Ctrl+M keyboard shortcut to open/close the
panel
quickly, requested directly by user. Registered via
iface.registerMainWindowAction() (in addition to the action's own
setShortcut()) so it fires app-wide, not just when the toolbar
button has focus, and unregistered cleanly in unload(). If Ctrl+M
is already bound to something else, registration fails safely
(caught and logged) and the toolbar/menu entry keeps working
normally instead of the clash breaking plugin load. Also reviewed
for stability/perf per user report of the panel "feeling heavy":
no changes were needed there — the mouse-move handling, snap
lookups and trace-graph building were already reworked in
v14.0-14.4 to cache aggressively and skip sub-pixel jitter (see
canvasMoveEvent, _get_cached_snap_vertices, _get_cached_snap_segments,
_get_trace_graph), and every QGIS-version-sensitive Qt/PyQt import
already has a 3.x/4.x compatibility fallback. Confirmed all five
module files still compile cleanly.
v14.4.1-local: Z curve mode COMMIT-time exact-closure fix, requested
directly by user ("corners leave breaks that ruin the geometry").
Root cause: _arc_points_spiral()'s fallback (used whenever the
curvature-eased spiral solve can't reach the clicked point on the
current flip side) is _arc_points_true_round(), which applies a
140 deg anti-hook SWEEP CLAMP. That clamp is correct for the LIVE
PREVIEW (stops a dragged arc curling into a fish-hook) but was
being carried into the COMMITTED vertex list too, silently
landing the new vertex short of the point the user actually
clicked. The next segment then started from that short,
un-signalled position instead of from the clicked corner -- a
stray gap at exactly the corner the user was drawing.
Fix: on commit only, if the spiral (or its clamped fallback)
does not land on the clicked point within tolerance, re-solve
with the unclamped closed-form circular arc (_arc_points), which
always reaches the clicked point exactly for any non-degenerate
tangent/chord. The live preview is unchanged and still shows the
gentler clamped shape while dragging. Verified in isolation
(no QGIS) against a swept random sample of end points/flip
sides: every previously-short commit (e.g. a 0.13 map-unit gap
reproduced at pt=(-0.046,-0.505), flip=1 from tangent (1,0) at
origin) now closes to zero gap; every already-exact commit is
unaffected (identical output, since the fallback branch is
skipped when the spiral already lands on the point).
v14.4.0-local: New independent "Edge Snap Engine" (ArcGIS Pro-style
edge snapping), requested directly by user because QGIS's own
snapping felt vertex-only and inconsistent. Adds a new toggle
button/icon (🧲 Edge Snap) in the panel, ON by default, that
drives a snapping engine fully independent of QGIS's project
snapping config: the cursor now snaps to the nearest point
anywhere along a visible line/polygon edge, not only at its
vertices, with the whole matched edge highlighted in green while
hovering — matching ArcGIS Pro's snap feel. Vertices still take
priority over edges within the same tolerance. Switching the
toggle OFF restores the previous QgsSnappingUtils-based behaviour.
See AlignmentPathTool.set_edge_snap_enabled() /
_find_snap_point_edge_engine().
v14.3.0-local: STRUCTURAL SIMPLIFICATION, requested directly by user
after v14.2 still showed geometry corruption in "reshape"-style
edits. Root cause: v14.1's edge-angle classifier (FOLLOWING/
AMBIGUOUS/CROSSING/TOO_FAR/NOISE) was a SECOND, independent gate
on top of plain buffer containment — a vertex could sit plainly
inside the tolerance buffer and still be left raw, or only
partially warped by the run/sub-run splitting that classifier
needed, whenever its local edge angle didn't clear an adaptive
threshold. That is what produced unpredictable "reshape breaks
the geometry" behaviour even after the v14.2 arc-length fix,
which only fixed precision/ordering WITHIN that classifier's
gated regions, not the gating itself.
Fix: removed the entire angle-classification layer
(`_classify_edge`, `_smooth_edge_labels`, `_classify_edge_raw`,
`_edge_angle_to_tangent_deg`, `_adaptive_angle_threshold_deg`
and the FOLLOWING/AMBIGUOUS/CROSSING/TOO_FAR/NOISE labels — all
deleted). Eligibility is now the single, literal rule requested:
a vertex is eligible iff it lies inside the tolerance buffer of
the path (`_classify_vertex`, a real point-in-polygon test) —
full stop. `_process_ring` now finds maximal runs of consecutive
in-buffer vertices directly from that one test and replaces
(Fit) or re-anchors (Preserve) each run, with entry/exit
crossings computed on the immediate flanking edge. Densification
(`_densify_near_master`) dropped the same classifier call for
the same reason. This also deletes the whole "sandwiched raw
corner" special case from v14.1.7 — it cannot occur any more,
since a run is now defined purely by buffer membership, so a
run can never contain a non-eligible vertex to sandwich in the
first place.
Verified in isolation (no QGIS) against a synthetic polygon with
a transverse divider that pokes partway into the tolerance
buffer: the along-path stretches snap exactly onto the path,
the divider's in-buffer portion is pulled onto the path too
(the literal requested behaviour), its out-of-buffer portion is
left completely untouched, and no self-crossing or duplicate
vertices appear at either hand-off.
v14.2.0-local: ROOT-CAUSE FIX, not another patch. Every version
through
v14.1.7 computed the correct continuous nearest-path position
(segment + parameter t) for each vertex/crossing, then immediately
rounded it down to the nearest whole MASTER-PATH VERTEX
(`nearest_vertex_index`) before using it for anything — ordering,
anchoring, span-filling. That rounding was the actual source of
both the v14.1.6 "V spike on curves" bug (a rounded vertex index
is not a reliable stand-in for arc-length order on a bend) and,
separately, contributed to imprecise hand-off points generally.
v14.1.6/7 each patched one symptom (a monotonic clamp on indices;
dropping a sandwiched raw corner) without removing the rounding
step itself, so a new curve geometry could still expose a fresh
variant of the same root problem.
Fix: kept the exact continuous (seg_i, t) position, and its real
arc-length ("station"), all the way from projection through to
the emitted coordinate. Added `_MasterPath.point_at` /
`station_at` (true interpolated point / arc length instead of a
rounded vertex). `_master_span` now walks by real station order
— always monotonic on any path shape, curved or not — instead of
vertex-index comparison. Preserve Shape's monotonic clamp now
compares stations instead of indices, so it only fires on a
genuine backward jump, never on rounding noise. Verified in
isolation against a synthetic curved master path (21-vertex
bend): projected stations and a full `_master_span` walk across
the bend are confirmed monotonic with zero backward jumps.
The Global Master Path Snapping guarantee (adjacent parcels
sharing a boundary get bitwise-identical coordinates) is
unaffected — it only ever relied on the pipeline being a
deterministic function of identical shared input geometry, never
on the coarseness of the snap.
v14.1.7-local: SECOND REAL BUG FIX (confirmed by user screenshots —
spike persisted after v14.1.6 even with Fit to Path). Distinct
root cause from v14.1.6: a ring corner sitting just outside the
tolerance buffer, flanked on both sides by FOLLOWING-classified
edges (typical right at the inside of a curved path bend, where
the buffer locally pinches), was split into two separate
sub-runs by _process_ring's outer loop — and the corner's own
RAW, unmoved coordinate was emitted between them. Since both
sub-runs' own anchors (exit_cross / entry_cross) already sit
right on the buffer edge near the curve, inserting the far-away
raw corner between them produced: aligned point -> raw corner ->
aligned point, i.e. the line visibly darted out to the old
corner position and back (the exact spike shape reported).
Verified the fix's branch logic in isolation against 6 run
patterns (sandwiched gap, leading-approach gap, trailing-approach
gap, all-eligible, all-ineligible, multiple gaps): the sandwiched
case now correctly drops the raw corner and bridges the two
sub-runs directly, while every other pattern (crucially, the
legitimate "long edge approaching the buffer from outside" case)
is untouched. Fix: in _process_ring's run-splitting loop, an
ineligible vertex with an eligible vertex before AND after it
within the same alignable run is no longer emitted at its raw
coordinate; it is dropped and the flanking sub-runs bridge the
gap via their own already-correct buffer-boundary anchors.
v14.1.6-local: REAL BUG FIX (confirmed by user-reported screenshots +
reproduced synthetically) — self-crossing "V" spike when a
near-parallel boundary edge is aligned against a CURVED stretch
of the master path (round-joined corridor). Root cause: per-vertex
snapping (_snap_mi via _classify_vertex -> master.project) picks
each point's globally-nearest master index independently, with no
awareness of path direction; on a bend, two adjacent boundary
vertices can have nearest-points that are OUT OF station order
(confirmed synthetically: raw indices [...,30,34,29,...] — a
forward-then-backward jump that manifests as the observed spike).
Reproduced in isolation with a mock curved master path + diagonal
crossing edge; index sequence was provably non-monotonic before
the fix and monotonic after. Fixed in _emit_subrun's Preserve
Shape branch: interior vertices are now clamped to progress
monotonically (in master-vertex-index terms) from the entry
anchor toward the exit anchor, never backward, matching the
path's own parameterisation. Fit to Path's _master_span was
already monotonic by construction and is unaffected structurally,
but entry/exit anchor selection on sharply curved paths uses the
same nearest-point search and has NOT yet been independently
re-verified against this class of bug — flagged as open follow-up.
v14.1.5-local: Verification pass over the v14.1
adaptive-classification
fix — confirmed by direct unit testing of the pure classifier
functions (_adaptive_angle_threshold_deg, _classify_edge_raw,
_smooth_edge_labels) against the documented threshold curve,
continuity rules and the old "1-following-edge-triggers-whole-ring"
failure mode (now correctly rejected). Static analysis (py_compile
+ pyflakes) run across all modules — zero syntax errors; removed
one dead/unused local variable in align_to_path_dialog.py
(result_map, never read). No behavioural change to alignment
output vs v14.1.4.
v14.1.0-local: Geometry engine fix — hard-coded 30° parallel cutoff
replaced with adaptive, distance/continuity-aware edge
classification (FOLLOWING/AMBIGUOUS/CROSSING/TOO_FAR/NOISE);
stricter evidence bar before a whole ring is fast-path snapped;
higher-fidelity curve linearisation tolerance. UI unchanged.
v14.0.1-local: محسّن للعمل محلي - تحسينات الثبات والأداء، دعم كامل لـ
QGIS 3.16-4.99
v14.0.0: Trace mode rebuilt on a local edge graph (_TraceGraph)

None