feat(geom): update intersects(), support more shape types

- add IntersectOpts & as optional arg - update impl for ray-poly/ray-polyline - add support for new shape pairings: - line-polygon - line-polyline - ray-line - ray-group
thi-ng · Mar 20, 2024 · 21ce0d4 · 21ce0d4
1 parent cb18d3b
commit 21ce0d4
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diff --git a/packages/geom/src/intersects.ts b/packages/geom/src/intersects.ts
@@ -1,25 +1,40 @@
-import type { MultiFn2 } from "@thi.ng/defmulti";
+import { isNumber } from "@thi.ng/checks/is-number";
+import type { MultiFn2O } from "@thi.ng/defmulti";
 import { defmulti } from "@thi.ng/defmulti/defmulti";
-import type { IntersectionResult, IShape, PCLike } from "@thi.ng/geom-api";
+import type { IShape, IntersectionResult, PCLike } from "@thi.ng/geom-api";
 import { IntersectionType } from "@thi.ng/geom-api/isec";
+import { NONE } from "@thi.ng/geom-isec/api";
 import { intersectCircleCircle } from "@thi.ng/geom-isec/circle-circle";
 import { intersectLineLine } from "@thi.ng/geom-isec/line-line";
+import { intersectLinePolylineAll } from "@thi.ng/geom-isec/line-poly";
 import { intersectPlanePlane } from "@thi.ng/geom-isec/plane-plane";
 import { intersectRayCircle } from "@thi.ng/geom-isec/ray-circle";
 import { intersectRayPlane } from "@thi.ng/geom-isec/ray-plane";
-import { intersectRayPolyline } from "@thi.ng/geom-isec/ray-poly";
+import {
+	intersectRayPolyline,
+	intersectRayPolylineAll,
+} from "@thi.ng/geom-isec/ray-poly";
 import { intersectRayAABB, intersectRayRect } from "@thi.ng/geom-isec/ray-rect";
 import { testRectCircle } from "@thi.ng/geom-isec/rect-circle";
 import { testAabbAabb, testRectRect } from "@thi.ng/geom-isec/rect-rect";
+import { dist2, type Vec } from "@thi.ng/vectors";
 import type { AABB } from "./api/aabb.js";
 import type { Circle } from "./api/circle.js";
+import type { Group } from "./api/group.js";
 import type { Line } from "./api/line.js";
 import type { Plane } from "./api/plane.js";
 import type { Ray } from "./api/ray.js";
 import type { Rect } from "./api/rect.js";
 import type { Sphere } from "./api/sphere.js";
 import { __dispatch2 } from "./internal/dispatch.js";
 
+export interface IntersectOpts {
+	/**
+	 * Force returning all intersections, if possible (and supported).
+	 */
+	all: boolean;
+}
+
 /**
  * Performs intersection tests on given 2 shapes and returns
  * [`IntersectionResult`](https://docs.thi.ng/umbrella/geom-api/interfaces/IntersectionResult.html).
@@ -29,9 +44,12 @@ import { __dispatch2 } from "./internal/dispatch.js";
  *
  * - {@link Circle} / {@link Circle}
  * - {@link Line} / {@link Line}
+ * - {@link Line} / {@link Polygon}
+ * - {@link Line} / {@link Polyline}
  * - {@link Plane} / {@link Plane}
  * - {@link Ray} / {@link AABB}
  * - {@link Ray} / {@link Circle}
+ * - {@link Ray} / {@link Line}
  * - {@link Ray} / {@link Plane}
  * - {@link Ray} / {@link Polygon}
  * - {@link Ray} / {@link Polyline}
@@ -42,62 +60,117 @@ import { __dispatch2 } from "./internal/dispatch.js";
  * - {@link Rect} / {@link Rect}
  * - {@link Sphere} / {@link Sphere}
  *
+ * If {@link IntersectOpts.all} is enabled (default: false) and if the
+ * intersection pair supports it, all possible intersections will be returned
+ * (for some implementations this always the case anyway). Currently, this is
+ * option is only implemented for the following pairings:
+ *
+ * - {@link Ray} / {@link Polygon}
+ * - {@link Ray} / {@link Polyline}
+ *
  * @param a
  * @param b
+ * @param opts
  */
-export const intersects: MultiFn2<IShape, IShape, IntersectionResult> =
-	defmulti<any, any, IntersectionResult>(
-		__dispatch2,
-		{
-			"ray-sphere": "ray-circle",
-			"ray-quad": "ray-poly",
-			"ray-tri": "ray-poly",
-			"sphere-sphere": "circle-circle",
-		},
-		{
-			"aabb-aabb": (a: AABB, b: AABB) => ({
-				type: testAabbAabb(a.pos, a.size, b.pos, b.size)
-					? IntersectionType.INTERSECT
-					: IntersectionType.NONE,
-			}),
+export const intersects: MultiFn2O<
+	IShape,
+	IShape,
+	Partial<IntersectOpts>,
+	IntersectionResult
+> = defmulti<any, any, any, IntersectionResult>(
+	__dispatch2,
+	{
+		"ray-line": "ray-polyline",
+		"ray-sphere": "ray-circle",
+		"ray-quad": "ray-poly",
+		"ray-tri": "ray-poly",
+		"sphere-sphere": "circle-circle",
+	},
+	{
+		"aabb-aabb": (a: AABB, b: AABB) => ({
+			type: testAabbAabb(a.pos, a.size, b.pos, b.size)
+				? IntersectionType.INTERSECT
+				: IntersectionType.NONE,
+		}),
+
+		"circle-circle": (a: Circle, b: Circle) =>
+			intersectCircleCircle(a.pos, b.pos, a.r, b.r),
+
+		"line-line": ({ points: a }: Line, { points: b }: Line) =>
+			intersectLineLine(a[0], a[1], b[0], b[1]),
 
-			"circle-circle": (a: Circle, b: Circle) =>
-				intersectCircleCircle(a.pos, b.pos, a.r, b.r),
+		"line-poly": ({ points: a }: Line, poly: PCLike) =>
+			intersectLinePolylineAll(a[0], a[1], poly.points, true),
 
-			"line-line": ({ points: a }: Line, { points: b }: Line) =>
-				intersectLineLine(a[0], a[1], b[0], b[1]),
+		"line-polyline": ({ points: a }: Line, poly: PCLike) =>
+			intersectLinePolylineAll(a[0], a[1], poly.points, false),
 
-			"plane-plane": (a: Plane, b: Plane) =>
-				intersectPlanePlane(a.normal, a.w, b.normal, b.w),
+		"plane-plane": (a: Plane, b: Plane) =>
+			intersectPlanePlane(a.normal, a.w, b.normal, b.w),
 
-			"ray-aabb": (ray: Ray, box: AABB) =>
-				intersectRayAABB(ray.pos, ray.dir, box.pos, box.max()),
+		"ray-aabb": (ray: Ray, box: AABB) =>
+			intersectRayAABB(ray.pos, ray.dir, box.pos, box.max()),
 
-			"ray-circle": (ray: Ray, sphere: Sphere) =>
-				intersectRayCircle(ray.pos, ray.dir, sphere.pos, sphere.r),
+		"ray-circle": (ray: Ray, sphere: Sphere) =>
+			intersectRayCircle(ray.pos, ray.dir, sphere.pos, sphere.r),
+
+		"ray-group": (ray: Ray, { children }: Group, opts?: IntersectOpts) => {
+			let minD = Infinity;
+			const points: Vec[] = [];
+			const all = opts?.all;
+			for (let child of children) {
+				let $res = intersects(ray, child, opts);
+				if ($res.type !== IntersectionType.INTERSECT) continue;
+				const single = isNumber($res.isec![0]);
+				const first = single ? <Vec>$res.isec : (<Vec[]>$res.isec)[0];
+				const alpha =
+					$res.alpha !== undefined
+						? $res.alpha
+						: dist2(ray.pos, first);
+				if (all) {
+					if (single) points.push(first);
+					else points.push(...(<Vec[]>$res.isec));
+					minD = Math.min(minD, alpha);
+				} else if (alpha < minD) {
+					minD = alpha;
+					points[0] = first;
+				}
+			}
+			return minD < Infinity
+				? {
+						type: IntersectionType.INTERSECT,
+						isec: points,
+						alpha: minD,
+				  }
+				: NONE;
+		},
 
-			"ray-plane": (ray: Ray, plane: Plane) =>
-				intersectRayPlane(ray.pos, ray.dir, plane.normal, plane.w),
+		"ray-plane": (ray: Ray, plane: Plane) =>
+			intersectRayPlane(ray.pos, ray.dir, plane.normal, plane.w),
 
-			"ray-poly": (ray: Ray, poly: PCLike) =>
-				intersectRayPolyline(ray.pos, ray.dir, poly.points, true),
+		"ray-poly": (ray: Ray, poly: PCLike, opts?: IntersectOpts) =>
+			opts?.all
+				? intersectRayPolylineAll(ray.pos, ray.dir, poly.points, true)
+				: intersectRayPolyline(ray.pos, ray.dir, poly.points, true),
 
-			"ray-polyline": (ray: Ray, poly: PCLike) =>
-				intersectRayPolyline(ray.pos, ray.dir, poly.points, false),
+		"ray-polyline": (ray: Ray, poly: PCLike, opts?: IntersectOpts) =>
+			opts?.all
+				? intersectRayPolylineAll(ray.pos, ray.dir, poly.points, false)
+				: intersectRayPolyline(ray.pos, ray.dir, poly.points, false),
 
-			"ray-rect": (ray: Ray, rect: Rect) =>
-				intersectRayRect(ray.pos, ray.dir, rect.pos, rect.max()),
+		"ray-rect": (ray: Ray, rect: Rect) =>
+			intersectRayRect(ray.pos, ray.dir, rect.pos, rect.max()),
 
-			"rect-circle": (rect: Rect, circle: Circle) => ({
-				type: testRectCircle(rect.pos, rect.size, circle.pos, circle.r)
-					? IntersectionType.INTERSECT
-					: IntersectionType.NONE,
-			}),
+		"rect-circle": (rect: Rect, circle: Circle) => ({
+			type: testRectCircle(rect.pos, rect.size, circle.pos, circle.r)
+				? IntersectionType.INTERSECT
+				: IntersectionType.NONE,
+		}),
 
-			"rect-rect": (a: Rect, b: Rect) => ({
-				type: testRectRect(a.pos, a.size, b.pos, b.size)
-					? IntersectionType.INTERSECT
-					: IntersectionType.NONE,
-			}),
-		}
-	);
+		"rect-rect": (a: Rect, b: Rect) => ({
+			type: testRectRect(a.pos, a.size, b.pos, b.size)
+				? IntersectionType.INTERSECT
+				: IntersectionType.NONE,
+		}),
+	}
+);
diff --git a/packages/geom/src/point-at.ts b/packages/geom/src/point-at.ts
@@ -45,6 +45,8 @@ import { vertices } from "./vertices.js";
  * - {@link Rect}
  * - {@link Triangle}
  *
+ * Note: For {@link Ray}, the `t` is interpreted as distance from the ray origin.
+ *
  * @param shape
  * @param t
  */