nav.ui

class ManualNavDialog(*args: Any, **kwargs: Any)

Bases: QDialog

Manual navigation dialog for overlaying image and combined model.

The viewport uses false color (image in red/blue, blend in green). Separate Image Stretch and Model Stretch groups each provide black/white/gamma and a display toggle. Model transparency and an optional binary mask overlay sit under model stretch.

run_modal() → tuple[bool, tuple[float, float] | None, float | None]

Run the dialog modally, creating a QApplication if necessary.

nav.ui.mosaic_viewer

Projection math for alternate 2-D display modes and the 3-D sphere view.

All projection functions operate in normalized display units. The conversion between normalized units and viewport pixels uses the linear transform:

viewport_x = normalized_x * scale + cx
viewport_y = normalized_y * scale + cy

where (cx, cy) is the projection centre in viewport pixels and scale is pixels per normalized unit. ProjectionParams carries these values.

Normalized-unit conventions per kind

• RECT – 1 unit = 1 degree. x = longitude [0, 360), y = -latitude. This projection is rendered by the existing body-sphere canvas path; these functions are used only for graticule overlays.

• POLAR_N – 1 unit = stereographic equatorial radius. r = 0 is the north pole, r = 1 is the equator. 0 deg longitude appears at the top (screen-y direction).

• POLAR_S – same as POLAR_N with latitude sign-flipped. r = 0 is the south pole, r = 1 is the equator.

• MOLLWEIDE – 1 unit = sqrt(2). The full-globe ellipse spans x in [-2*sqrt(2), 2*sqrt(2)] and y in [-sqrt(2), sqrt(2)].

• SPHERE_3D – 1 unit = sphere radius. The visible disk has r <= 1. The camera views from the +X direction; yaw/pitch define which geographic point faces the camera.

Coordinate system

Screen y increases downward (PyQt6 convention). Normalized y also increases downward to match, so vy = yn * scale + cy with no sign flip needed in the viewport transform.

class ProjectionKind(*values)

Bases: Enum

Available projection modes for the body mosaic viewer.

MOLLWEIDE = 'mollweide'

POLAR_N = 'polar_n'

POLAR_S = 'polar_s'

RECT = 'rect'

SPHERE_3D = 'sphere_3d'

class ProjectionParams(kind: ProjectionKind, cx: float, cy: float, scale: float, yaw_deg: float = 0.0, pitch_deg: float = 0.0)

Bases: object

Viewport geometry for a single projection frame.

Parameters:

• kind – Which projection to use.

• cx – Viewport X coordinate of the projection centre (pixels from left).

• cy – Viewport Y coordinate of the projection centre (pixels from top).

• scale – Pixels per normalized unit (see module docstring).

• yaw_deg – SPHERE_3D only – longitude at the centre of the view (deg).

• pitch_deg – SPHERE_3D only – latitude at the centre of the view (deg).

cx: float

cy: float

kind: ProjectionKind

pitch_deg: float = 0.0

scale: float

yaw_deg: float = 0.0

display_to_lonlat(vx: ndarray, vy: ndarray, params: ProjectionParams) → tuple[ndarray, ndarray, ndarray]

Map viewport pixel positions to geographic coordinates.

Parameters:

• vx – Viewport X pixel array.

• vy – Viewport Y pixel array.

• params – Current projection parameters.

Returns:

Tuple (lon_deg, lat_deg, valid) where valid is a bool mask (False for pixels outside the valid domain of the projection).

Raises:

ValueError – If params.kind is unknown or params.scale is zero / non-finite.

fit_scale(kind: ProjectionKind, vw: int, vh: int) → float

Return a scale (pixels per normalized unit) that fits the projection.

The result leaves a margin _FIT_SCALE_MARGIN (10 % inset) around the projection so it does not touch the viewport edge at the initial zoom level.

Parameters:

• kind – Projection kind.

• vw – Viewport width in pixels.

• vh – Viewport height in pixels.

Returns:

Scale in pixels per normalized unit.

Raises:

ValueError – If vw or vh is not strictly positive.

lonlat_to_display(lon_deg: ndarray, lat_deg: ndarray, params: ProjectionParams) → tuple[ndarray, ndarray, ndarray]

Map geographic coordinates to viewport pixel positions.

Parameters:

• lon_deg – Longitude array (deg), any range.

• lat_deg – Latitude array (deg), values in [-90, 90].

• params – Current projection parameters.

Returns:

Tuple (vx, vy, visible) where vx and vy are float64 arrays of viewport pixel coordinates and visible is a bool array (False for points not representable in this projection at params).

Raises:

ValueError – If params.kind is unknown or params.scale is zero / non-finite.

sphere_pixel_to_lonlat(vx: ndarray, vy: ndarray, params: ProjectionParams) → tuple[ndarray, ndarray, ndarray]

Ray-cast orthographic sphere: viewport pixels to (lon_deg, lat_deg, hit).

Points outside the sphere disk or on the back hemisphere return hit=False.

Parameters:

• vx – Viewport X pixel array.

• vy – Viewport Y pixel array.

• params – Projection parameters; kind must be SPHERE_3D.

Returns:

Tuple (lon_deg, lat_deg, hit).

Raises:

ValueError – If params.kind is not SPHERE_3D or params.scale is zero / non-finite.

Software renderer for non-rectangular body-mosaic projections.

render_to_image() converts a (lon_deg, lat_deg, valid) coordinate grid – produced by projections – into a QImage (Format_RGB888) using nearest-neighbour texture lookup, the same contrast-stretch pipeline as the existing rectangular render path, and optional per-pixel metadata tinting.

The function is intentionally stateless and side-effect-free so it can be called from any paint method without lock concerns.

render_to_image(image_ma: MaskedArray, *, lon_deg: ndarray, lat_deg: ndarray, valid: ndarray, lon_min_deg: float, lat_min_deg: float, d_lon_deg: float, d_lat_deg: float, lon_bin_to_dc: ndarray, n_full_lon: int, n_data_rows: int, n_data_cols: int, black: float, white: float, gamma: float, color_tint: ndarray | None) → QImage

Render a mosaic texture onto an arbitrary projection grid.

Parameters:

• image_ma – 2-D masked array (n_data_rows, n_data_cols) with the photometrically-corrected mosaic data.

• lon_deg – 2-D float64 array of longitudes (deg) for every output pixel, in [0, 360). After binning to k, any pixel with lon_bin_to_dc[k] == -1 has no data column and is off-grid (no-data when valid is True).

• lat_deg – 2-D float64 array of latitudes (deg), in [-90, 90]. Latitudes outside [lat_min_deg, lat_min_deg + n_data_rows * d_lat_deg) map to dr outside [0, n_data_rows) and are off-grid (no-data when valid is True).

• valid – 2-D bool array; False pixels are painted black (off-projection background). True pixels with no usable data (outside the file’s lat/lon extent or explicitly masked) are painted dark red.

• lon_min_deg – Geographic minimum longitude of the data grid (deg).

• lat_min_deg – Geographic minimum latitude of the data grid (deg).

• d_lon_deg – Longitude resolution of the data grid (deg/column).

• d_lat_deg – Latitude resolution of the data grid (deg/row).

• lon_bin_to_dc – 1-D int32 array mapping full-circle longitude bin index to data column index (-1 = absent).

• n_full_lon – Length of lon_bin_to_dc.

• n_data_rows – Number of rows in image_ma.

• n_data_cols – Number of columns in image_ma.

• black – Stretch black point.

• white – Stretch white point.

• gamma – Stretch gamma (applied as power).

• color_tint – Optional per-pixel RGB tint, shape (n_data_rows, n_data_cols, 3), float32 in [0, 1]. None = greyscale.

Returns:

A QImage in Format_RGB888 matching the shape of lon_deg / lat_deg.

Raises:

ValueError – If d_lon_deg or d_lat_deg is zero, if gamma is not positive, if len(lon_bin_to_dc) != n_full_lon, or if lon_deg, lat_deg, and valid do not share the same shape.

Lat/lon graticule polylines for non-rectangular body-mosaic projections.

graticule_polylines() samples parallels and meridians in geographic coordinates, projects them through the current ProjectionParams, and returns screen-space polyline segments ready for QPainter.drawPolyline.

Polylines are split wherever consecutive samples jump discontinuously (e.g. at the limb of a sphere or a map seam), so each returned segment is a continuous visible arc.

graticule_label_anchors(params: ProjectionParams, *, lat_step_deg: float, lon_step_deg: float) → tuple[list[tuple[float, float, str]], list[tuple[float, float, str]]]

Return label anchor positions for visible graticule lines.

Finds the best visible point along each parallel and meridian at which to draw a tick label. For parallels the anchor is the point closest to the screen centre along the line; for meridians similarly.

Parameters:

• params – Current projection parameters.

• lat_step_deg – Spacing of parallels (deg).

• lon_step_deg – Spacing of meridians (deg).

Returns:

Tuple (parallel_anchors, meridian_anchors). Each anchor is (vx, vy, label_text).

Raises:

• TypeError – If params is None.

• ValueError – If lat_step_deg or lon_step_deg is negative.

graticule_polylines(params: ProjectionParams, *, lat_step_deg: float, lon_step_deg: float, samples_per_line: int = 181, show_parallels: bool = True, show_meridians: bool = True) → tuple[list[list[tuple[float, float]]], list[list[tuple[float, float]]]]

Compute graticule screen-space polylines for the given projection.

Each “line” in the returned lists is a list of (vx, vy) tuples that can be drawn as a connected polyline. Lines are pre-split at discontinuities (sphere limb, map seam) so callers do not need to check for jumps.

Parameters:

• params – Current projection parameters. For RECT mode the caller should use the existing straight-line overlay path instead.

• lat_step_deg – Spacing of parallels (deg). Pass 0 to disable.

• lon_step_deg – Spacing of meridians (deg). Pass 0 to disable.

• samples_per_line – Number of sample points along each graticule line.

• show_parallels – Include parallel (constant-latitude) lines.

• show_meridians – Include meridian (constant-longitude) lines.

Returns:

Tuple (parallel_lines, meridian_lines) where each element is a list of polyline segments. A segment is a list of (vx, vy) float tuples.

Raises:

• TypeError – If params is None.

• ValueError – If lat_step_deg or lon_step_deg is negative, or if samples_per_line is less than 2.