feat(geom-isec): add ray-plane, plane-plane fns, update readme

thi-ng · May 22, 2019 · 40a8bff · 40a8bff
1 parent 74dbcb0
commit 40a8bff
Show file tree

Hide file tree

Showing 5 changed files with 86 additions and 14 deletions.
diff --git a/packages/geom-isec/README.md b/packages/geom-isec/README.md
@@ -26,22 +26,23 @@ This project is part of the
 
 ### 2D tests
 
-| Type   | Circle | Line | Poly | Rect | Tri |
-|--------|:------:|:----:|:----:|:----:|:---:|
-| Circle |   ✓    |      |      |      |     |
-| Line   |        |  ✓   |      |      |     |
-| Point  |   ✓    |  ✓   |  ✓   |  ✓   |  ✓  |
-| Ray    |   ✓    |  ✓   |  ✓   |  ✓   |     |
-| Rect   |   ✓    |      |      |  ✓   |     |
+| Type   | Circle | Line | Poly | Ray | Rect | Tri |
+|--------|:------:|:----:|:----:|:---:|:----:|:---:|
+| Circle |   ✓    |      |      |     |      |     |
+| Line   |        |  ✓   |      |     |      |     |
+| Point  |   ✓    |  ✓   |  ✓   |     |  ✓   |  ✓  |
+| Ray    |   ✓    |  ✓   |  ✓   |     |  ✓   |     |
+| Rect   |   ✓    |      |      |     |  ✓   |     |
 
 ### 3D tests
 
-| Type   | AABB | Sphere |
-|--------|:----:|:------:|
-| AABB   |  ✓   |   ✓    |
-| Point  |  ✓   |   ✓    |
-| Ray    |  ✓   |   ✓    |
-| Sphere |      |   ✓    |
+| Type   | AABB | Plane | Point | Ray | Sphere |
+|--------|:----:|:-----:|:-----:|:---:|:------:|
+| AABB   |  ✓   |       |       |     |   ✓    |
+| Plane  |      |   ✓   |       |     |        |
+| Point  |  ✓   |       |       |     |   ✓    |
+| Ray    |  ✓   |   ✓   |       |     |   ✓    |
+| Sphere |      |       |       |     |   ✓    |
 
 ## Installation
 

diff --git a/packages/geom-isec/src/index.ts b/packages/geom-isec/src/index.ts
@@ -2,8 +2,10 @@ export * from "./point";
 
 export * from "./circle-circle";
 export * from "./line-line";
+export * from "./plane-plane";
 export * from "./ray-circle";
 export * from "./ray-line";
+export * from "./ray-plane";
 export * from "./ray-poly";
 export * from "./ray-rect";
 export * from "./rect-circle";

diff --git a/packages/geom-isec/src/plane-plane.ts b/packages/geom-isec/src/plane-plane.ts
@@ -0,0 +1,32 @@
+import { IntersectionType } from "@thi.ng/geom-api";
+import { eqDelta, eqDeltaFixed } from "@thi.ng/math";
+import {
+    add3,
+    cross3,
+    dot3,
+    mulN3,
+    ReadonlyVec
+} from "@thi.ng/vectors";
+import { NONE } from "./api";
+
+export const intersectPlanePlane = (
+    na: ReadonlyVec,
+    wa: number,
+    nb: ReadonlyVec,
+    wb: number
+) => {
+    const dn = dot3(na, nb);
+    if (eqDeltaFixed(dn, 1)) {
+        return eqDelta(wa, wb) ? { type: IntersectionType.COINCIDENT } : NONE;
+    }
+    const det = 1 / (1 - dn * dn);
+    const da = (wa - wb * dn) * det;
+    const db = (wb - wa * dn) * det;
+    return {
+        type: IntersectionType.INTERSECT,
+        isec: [
+            add3(null, mulN3([], na, da), mulN3([], nb, db)),
+            cross3([], na, nb)
+        ]
+    };
+};
diff --git a/packages/geom-isec/src/ray-line.ts b/packages/geom-isec/src/ray-line.ts
@@ -13,7 +13,7 @@ export const intersectRayLine = (
     const bay = b[1] - a[1];
     const d = dir[0] * bay - dir[1] * bax;
     if (eqDeltaFixed(d, 0)) {
-        return { type: IntersectionType.NONE };
+        return NONE;
     }
     const arx = a[0] - rpos[0];
     const ary = a[1] - rpos[1];

diff --git a/packages/geom-isec/src/ray-plane.ts b/packages/geom-isec/src/ray-plane.ts
@@ -0,0 +1,37 @@
+import { IntersectionType } from "@thi.ng/geom-api";
+import { EPS, sign } from "@thi.ng/math";
+import {
+    copy,
+    dot,
+    maddN,
+    mulN,
+    ReadonlyVec,
+    sub
+} from "@thi.ng/vectors";
+import { NONE } from "./api";
+
+export const intersectRayPlane = (
+    rpos: ReadonlyVec,
+    dir: ReadonlyVec,
+    normal: ReadonlyVec,
+    w: number,
+    eps = EPS
+) => {
+    const d = dot(normal, dir);
+    const cp = sign(dot(normal, rpos) - w, eps);
+    if ((d > eps && cp < 0) || (d < -eps && cp > 0)) {
+        const isec = sub(null, mulN([], normal, w), rpos);
+        const alpha = dot(normal, isec) / d;
+        return {
+            type: IntersectionType.INTERSECT,
+            isec: maddN(isec, rpos, dir, alpha),
+            alpha
+        };
+    }
+    return cp === 0
+        ? {
+              type: IntersectionType.COINCIDENT,
+              isec: copy(rpos)
+          }
+        : NONE;
+};