src/core.py

from dataclasses import dataclass, field
from typing import List, Tuple, Optional, Iterable
import cadquery as cq
import math


Point2D = Tuple[float, float]


@dataclass
class PolyProfile:
    points: List[Point2D]


@dataclass
class CircleProfile:
    center: Point2D
    radius: float


@dataclass
class Contour:
    kind: str  # "poly" | "circle"
    points: List[Point2D]  # 閉ループ点列（最後は先頭と同じ）
    area_abs: float
    sample_point: Point2D   # なるべく内部点
    wire: Optional[cq.Wire] = None
    children: List["Contour"] = field(default_factory=list)
    parent: Optional["Contour"] = None
    depth: int = 0


def dedupe_sequential(pts: List[Point2D], eps: float = 1e-9) -> List[Point2D]:
    if not pts:
        return pts
    out = [pts[0]]
    for p in pts[1:]:
        if abs(p[0] - out[-1][0]) > eps or abs(p[1] - out[-1][1]) > eps:
            out.append(p)
    return out


def ensure_closed(pts: List[Point2D], eps: float = 1e-9) -> List[Point2D]:
    if not pts:
        return pts
    if abs(pts[0][0] - pts[-1][0]) > eps or abs(pts[0][1] - pts[-1][1]) > eps:
        return pts + [pts[0]]
    return pts


def signed_area_polygon(pts_closed: List[Point2D]) -> float:
    pts = pts_closed[:-1]
    a = 0.0
    n = len(pts)
    for i in range(n):
        x1, y1 = pts[i]
        x2, y2 = pts[(i + 1) % n]
        a += x1 * y2 - x2 * y1
    return 0.5 * a


def polygon_centroid(pts_closed: List[Point2D]) -> Point2D:
    """
    面積重心。退化時は頂点平均にフォールバック。
    """
    pts = pts_closed[:-1]
    area2 = 0.0
    cx = 0.0
    cy = 0.0
    n = len(pts)

    for i in range(n):
        x1, y1 = pts[i]
        x2, y2 = pts[(i + 1) % n]
        cross = x1 * y2 - x2 * y1
        area2 += cross
        cx += (x1 + x2) * cross
        cy += (y1 + y2) * cross

    if abs(area2) < 1e-12:
        sx = sum(x for x, _ in pts)
        sy = sum(y for _, y in pts)
        return (sx / len(pts), sy / len(pts))

    cx /= (3.0 * area2)
    cy /= (3.0 * area2)
    return (cx, cy)


def point_on_segment(pt: Point2D, a: Point2D, b: Point2D, eps: float = 1e-9) -> bool:
    px, py = pt
    ax, ay = a
    bx, by = b

    cross = (px - ax) * (by - ay) - (py - ay) * (bx - ax)
    if abs(cross) > eps:
        return False

    dot = (px - ax) * (bx - ax) + (py - ay) * (by - ay)
    if dot < -eps:
        return False

    sq_len = (bx - ax) ** 2 + (by - ay) ** 2
    if dot - sq_len > eps:
        return False

    return True


def point_in_polygon(pt: Point2D, poly_closed: List[Point2D], include_boundary: bool = True) -> bool:
    x, y = pt
    poly = poly_closed[:-1]
    inside = False
    n = len(poly)

    for i in range(n):
        p1 = poly[i]
        p2 = poly[(i + 1) % n]

        if include_boundary and point_on_segment(pt, p1, p2):
            return True

        x1, y1 = p1
        x2, y2 = p2

        intersects = ((y1 > y) != (y2 > y)) and (
            x < (x2 - x1) * (y - y1) / ((y2 - y1) + 1e-30) + x1
        )
        if intersects:
            inside = not inside

    return inside


def polygon_interior_sample_point(pts_closed: List[Point2D]) -> Point2D:
    """
    なるべく内部にある点を返す。
    まず重心を使い、内部でなければ最初の辺の中点を少し内側へ寄せる簡易フォールバック。
    """
    c = polygon_centroid(pts_closed)
    if point_in_polygon(c, pts_closed, include_boundary=False):
        return c

    pts = pts_closed[:-1]
    if len(pts) >= 3:
        x0, y0 = pts[0]
        x1, y1 = pts[1]
        mid = ((x0 + x1) * 0.5, (y0 + y1) * 0.5)

        cc = polygon_centroid(pts_closed)
        sx = mid[0] * 0.9 + cc[0] * 0.1
        sy = mid[1] * 0.9 + cc[1] * 0.1
        probe = (sx, sy)
        if point_in_polygon(probe, pts_closed, include_boundary=False):
            return probe

    return c


def contour_contains(a: Contour, b: Contour, eps: float = 1e-9) -> bool:
    """
    b の代表点が a の内部にあるかで判定。
    単純輪郭前提。
    """
    if a.kind == "poly":
        return point_in_polygon(b.sample_point, a.points, include_boundary=False)

    elif a.kind == "circle":
        cx, cy = a.sample_point
        rx = a.points[0][0] - cx
        ry = a.points[0][1] - cy
        r = math.hypot(rx, ry)
        bx, by = b.sample_point
        return math.hypot(bx - cx, by - cy) < (r - eps)

    return False


def make_poly_contour(points: List[Point2D], scale: float, min_area: float) -> Optional[Contour]:
    pts = [(x * scale, y * scale) for x, y in points]
    pts = dedupe_sequential(pts)
    pts = ensure_closed(pts)

    if len(pts) < 4:
        return None

    area = signed_area_polygon(pts)
    if abs(area) < min_area:
        return None

    wire = cq.Workplane("XY").polyline(pts[:-1]).close().wire().val()
    sample = polygon_interior_sample_point(pts)

    return Contour(
        kind="poly",
        points=pts,
        area_abs=abs(area),
        sample_point=sample,
        wire=wire,
    )


def make_circle_contour(center: Point2D, radius: float, scale: float, min_area: float) -> Optional[Contour]:
    cx, cy = center[0] * scale, center[1] * scale
    r = radius * scale
    area = math.pi * r * r

    if area < min_area or r <= 0:
        return None

    wire = cq.Workplane("XY").center(cx, cy).circle(r).wire().val()

    # points は半径推定用に保持
    pts = [
        (cx + r, cy),
        (cx, cy + r),
        (cx - r, cy),
        (cx, cy - r),
        (cx + r, cy),
    ]

    return Contour(
        kind="circle",
        points=pts,
        area_abs=area,
        sample_point=(cx, cy),
        wire=wire,
    )


def build_nesting(contours: List[Contour]) -> List[Contour]:
    """
    最小包含親を求めて木構造化。
    """
    for c in contours:
        c.children = []
        c.parent = None
        c.depth = 0

    contours_sorted = sorted(contours, key=lambda c: c.area_abs)

    for child in contours_sorted:
        parent_candidates = [
            cand for cand in contours_sorted
            if cand is not child
            and cand.area_abs > child.area_abs
            and contour_contains(cand, child)
        ]
        if parent_candidates:
            parent = min(parent_candidates, key=lambda c: c.area_abs)
            child.parent = parent
            parent.children.append(child)

    roots = [c for c in contours if c.parent is None]

    def assign_depth(node: Contour, depth: int):
        node.depth = depth
        for ch in node.children:
            assign_depth(ch, depth + 1)

    for r in roots:
        assign_depth(r, 0)

    return roots


def face_from_contour_tree(node: Contour) -> cq.Face:
    """
    depth 偶数: material
    depth 奇数: hole
    という偶奇規則を使う。
    1つの material ノードについて、その直下の hole を穴として face 化する。
    """
    if node.wire is None:
        raise ValueError("Contour has no wire")

    outer = node.wire
    holes = [ch.wire for ch in node.children if ch.wire is not None]
    return cq.Face.makeFromWires(outer, holes)


def collect_material_nodes(roots: List[Contour]) -> List[Contour]:
    out: List[Contour] = []

    def walk(n: Contour):
        if n.depth % 2 == 0:
            out.append(n)
        for ch in n.children:
            walk(ch)

    for r in roots:
        walk(r)

    return out


def union_workplanes(solids: List[cq.Workplane]) -> cq.Workplane:
    if not solids:
        raise ValueError("No solids to union")

    model = solids[0]
    for s in solids[1:]:
        model = model.union(s)
    return model


def build_solid(
    poly_profiles: Iterable[PolyProfile],
    circle_profiles: Iterable[CircleProfile],
    height: float,
    scale: float = 1.0,
    min_area: float = 1e-6,
) -> Optional[cq.Workplane]:
    """
    輪郭を正規化し、包含関係から outer / hole / island を解釈して
    Z方向に押し出したソリッドを生成する。

    仕様:
    - 単純閉曲線を想定
    - 自己交差輪郭は未対応
    - 偶奇規則で material / void を決定
    """
    if height <= 0:
        raise ValueError("height must be positive")

    contours: List[Contour] = []

    for prof in poly_profiles:
        c = make_poly_contour(prof.points, scale=scale, min_area=min_area)
        if c is not None:
            contours.append(c)

    for cprof in circle_profiles:
        c = make_circle_contour(
            center=cprof.center,
            radius=cprof.radius,
            scale=scale,
            min_area=min_area,
        )
        if c is not None:
            contours.append(c)

    if not contours:
        return None

    roots = build_nesting(contours)
    material_nodes = collect_material_nodes(roots)

    solids: List[cq.Workplane] = []
    for node in material_nodes:
        face = face_from_contour_tree(node)
        solid = cq.Solid.extrudeLinear(face, cq.Vector(0, 0, height))
        solids.append(cq.Workplane("XY").newObject([solid]))

    if not solids:
        return None

    model = union_workplanes(solids)
    print("completed!")
    return model


def export_step(model: cq.Workplane, path: str) -> None:
    cq.exporters.export(model, path)


def export_stl(model: cq.Workplane, path: str) -> None:
    cq.exporters.export(model, path)


if __name__ == "__main__":
    # 例1: 外形四角 + 中央穴円
    poly_profiles = [
        PolyProfile(points=[
            (0, 0),
            (100, 0),
            (100, 60),
            (0, 60),
        ])
    ]

    circle_profiles = [
        CircleProfile(center=(50, 30), radius=10)
    ]

    model = build_solid(
        poly_profiles=poly_profiles,
        circle_profiles=circle_profiles,
        height=8.0,
        scale=1.0,
        min_area=1e-6,
    )

    if model is not None:
        export_step(model, "output.step")
        export_stl(model, "output.stl")