REL: Version 3.1.0

[imikejackson]

Release Notes — EbsdLib 3.1.0

EbsdLib 3.1 is the "discrete pole figures + TSL-by-default" release. It builds
on the 3.0 MTEX-correctness work with a new vector-marker pole-figure renderer
and a switch of the public default hexagonal/trigonal basis back to X‖a
(TSL/EDAX). The two themes:

1. Discrete (vector-marker) pole figures. A new renderer draws each pole as
   a crisp, decimated vector marker instead of rasterizing it as pixels —
   sharper figures, controllable marker size, and a hard cap on overdraw for
   million-pole datasets.
2. X‖a (TSL) is the default convention again. 3.0 shipped X‖a* (MTEX) as
   the public default; 3.1 returns the default to X‖a to match legacy DREAM3D
   and the rest of EbsdLib. The internal canonical tables are unchanged
   (X‖a*); only the default the public APIs/structs select changed.

Detailed API reference: v3_api_reference.md.

Breaking changes

Default hexagonal/trigonal convention is now X‖a (TSL)

The default value of HexConvention flipped from XParallelAStar (3.0) to
XParallelA (3.1) in every public surface that selects it:

• LaueOps::generateIPFTriangleLegend(...) — the conv parameter, which was
  required in 3.0, now defaults to ebsdlib::HexConvention::XParallelA.
• PoleFigureConfiguration_t::hexConvention — now defaults to XParallelA.
• CompositePoleFigureConfiguration_t::hexConvention — now defaults to XParallelA.

Effect: hexagonal/trigonal pole-figure positions and legend/family labels
render in the TSL basis by default. IPF colors are unaffected (convention-
invariant). Callers that want the 3.0 behavior must now pass
HexConvention::XParallelAStar explicitly (e.g. to compare side-by-side with
MTEX). Cubic / tetragonal / orthorhombic / monoclinic / triclinic are unaffected.

Pole-figure family labels: brace notation, convention-independent

getDefaultPoleFigureNames() now returns plane-family brace notation —
{0001}, {10-10}, {11-20}, {001}, {011}, {111}, etc. — for every
Laue class, and the labels are identical under both conventions. The 3.0
behavior of switching the hexagonal a-family label (<10-10> ↔ <2-1-10>) with
the convention is removed; both conventions now report {11-20} for that family
(the family identity is convention-independent; only the on-figure dot positions
rotate by 30°). Downstream code that parsed the old angle-bracket strings, or
that relied on the per-convention label switch, must update.

Rendered-figure differences

Pole figures now render +Y-up by default (flipFinalImage), and discrete
figures use the vector-marker renderer rather than per-pixel stamping. Output is
not byte-identical to 3.0. Any pixel-level exemplars pinned against 3.0 pole
figures must be regenerated.

New features

Discrete vector-marker pole figure renderer

• DiscretePoleFigureCompositor renders discrete pole figures by stamping
  opaque marker sprites, with a MarkerOccupancyGrid that decimates
  overlapping markers (bounded overdraw for >1M-pole inputs).
• ebsdlib::GeneratePoleFigureComposite(config) is the dispatch entry point:
  it routes discrete && !discreteHeatMap figures to the vector-marker
  renderer and everything else to the raster PoleFigureCompositor. Prefer
  this over calling a compositor directly.
• CompositePoleFigureConfiguration_t gained a DiscreteMarkerStyle
  (markerStyle.radiusFraction) to control marker size.
• StereographicProjectUpperHemisphere(...) projection helper.
• Shared title / axis / info-block chrome extracted into a reusable
  PoleFigureChrome module.

IPF legends annotate their convention

Hexagonal and trigonal IPF triangle legends now print a small
Convention: X||a (TSL) (or X||a* (MTEX/Oxford)) sub-line under the title,
so a legend is self-documenting. Non-hex/trig classes are unchanged.

Apps that changed

App	Status
generate_ipf_legends	defaults to X‖a; prints the absolute output directory at start/finish; regenerates the per-class legend + pole-figure matrix as PNG
render_ebsd	--convention now defaults to x_a (TSL)

Validation evidence

• Strict IPF-color corners. LaueOpsTest::IPFColor_SSTCorners asserts the
  standard-stereographic-triangle corners render as pure primaries for every
  Laue class: apex ([0001]/[001]) = red, η-min edge = green, η-max edge =
  blue (exact primaries for cubic and hex 6/mmm; dominant-channel just inside the
  edge for the wider-wedge classes, which sit on a fold boundary).
• Discrete-render performance guard. A hidden test renders a >1M-pole
  discrete figure to bound decimation cost.
• MTEX positions still validated. PoleFigurePositionTest continues to pass
  against the MTEX golden (X‖a*). PoleFigureLaueComparisonTest now routes
  through GeneratePoleFigureComposite (vector markers) and pins X‖a* locally
  to stay aligned with its MTEX comparison script.