fix(geom-isec): fix #269 update rayBox()

- fix Y/Z-axis handling - add tests
thi-ng · Dec 27, 2020 · 441cddb · 441cddb
1 parent 1c0e284
commit 441cddb
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Showing 2 changed files with 74 additions and 3 deletions.
diff --git a/packages/geom-isec/src/ray-rect.ts b/packages/geom-isec/src/ray-rect.ts
@@ -53,12 +53,12 @@ const rayBox: FnU4<ReadonlyVec, [number, number]> = (rpos, dir, bmin, bmax) => {
     d = 1 / dir[1];
     t1 = (bmin[1] - p) * d;
     t2 = (bmax[1] - p) * d;
+    tmin = max(tmin, min(t1, t2));
+    tmax = min(tmax, max(t1, t2));
     p = rpos[2];
     d = 1 / dir[2];
     t1 = (bmin[2] - p) * d;
     t2 = (bmax[2] - p) * d;
-    tmin = max(tmin, min(t1, t2));
-    tmax = min(tmax, max(t1, t2));
     return [max(tmin, min(t1, t2)), min(tmax, max(t1, t2))];
 };
 
@@ -73,9 +73,9 @@ const intersectWith = (
         ? inside
             ? {
                   type: IntersectionType.INTERSECT,
-                  inside,
                   isec: [maddN([], dir, tmax, rpos)],
                   alpha: tmax,
+                  inside,
               }
             : {
                   type: IntersectionType.INTERSECT,

diff --git a/packages/geom-isec/test/ray.ts b/packages/geom-isec/test/ray.ts
@@ -0,0 +1,71 @@
+import { eqDelta, maddN3, mulN3, normalize, Vec } from "@thi.ng/vectors";
+import * as assert from "assert";
+import { intersectRayAABB } from "../src";
+
+describe("ray intersection", () => {
+    it("rayBox inside", () => {
+        const dirs: Vec[] = [
+            [-1, -1, -1],
+            [-1, -1, 0],
+            [-1, -1, 1],
+            [-1, 0, -1],
+            [-1, 0, 0],
+            [-1, 0, 1],
+            [-1, 1, -1],
+            [-1, 1, 0],
+            [-1, 1, 1],
+            [0, -1, -1],
+            [0, -1, 0],
+            [0, -1, 1],
+            [0, 0, -1],
+            [0, 0, 1],
+            [0, 1, -1],
+            [0, 1, 0],
+            [0, 1, 1],
+            [1, -1, -1],
+            [1, -1, 0],
+            [1, -1, 1],
+            [1, 0, -1],
+            [1, 0, 0],
+            [1, 0, 1],
+            [1, 1, -1],
+            [1, 1, 0],
+            [1, 1, 1],
+        ];
+        for (let d of dirs) {
+            const n = normalize([], d);
+            const i = intersectRayAABB([5, 5, 5], n, [0, 0, 0], [10, 10, 10]);
+            const expected = maddN3([], n, i.alpha!, [5, 5, 5]);
+            assert(i.inside, `inside d=${d}`);
+            assert(
+                eqDelta(expected, <Vec>i.isec![0]),
+                `d=${d} isec=${i.isec}, exp=${expected}`
+            );
+        }
+    });
+
+    it("rayBox outside", () => {
+        const dirs: Vec[] = [
+            [1, 0, 0],
+            [0, 1, 0],
+            [0, 0, 1],
+        ];
+        for (let d of dirs) {
+            let o = mulN3([], d, -10);
+            let i = intersectRayAABB(o, d, [-5, -5, -5], [5, 5, 5]);
+            let expected = maddN3([], d, i.alpha!, o);
+            assert(
+                eqDelta(expected, <Vec>i.isec![0]),
+                `d=${d} isec=${i.isec}, exp=${expected}`
+            );
+            d = mulN3(d, d, -1);
+            o = mulN3([], d, -10);
+            i = intersectRayAABB(o, d, [-5, -5, -5], [5, 5, 5]);
+            expected = maddN3([], d, i.alpha!, o);
+            assert(
+                eqDelta(expected, <Vec>i.isec![0]),
+                `d=${d} isec=${i.isec}, exp=${expected}`
+            );
+        }
+    });
+});