fix(geom-sdf): fix rect size handling

thi-ng · Jun 20, 2022 · cc72bab · cc72bab
1 parent f50e292
commit cc72bab
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Showing 2 changed files with 8 additions and 5 deletions.
diff --git a/packages/geom-sdf/src/as-sdf.ts b/packages/geom-sdf/src/as-sdf.ts
@@ -14,7 +14,8 @@ import type {
 } from "@thi.ng/geom";
 import type { Attribs, IShape } from "@thi.ng/geom-api";
 import { __dispatch } from "@thi.ng/geom/internal/dispatch";
-import { maddN2 } from "@thi.ng/vectors/maddn";
+import { add2 } from "@thi.ng/vectors/add";
+import { mulN2 } from "@thi.ng/vectors/muln";
 import type { SDFAttribs, SDFn } from "./api.js";
 import {
     difference,
@@ -119,8 +120,10 @@ export const asSDF: MultiFn1<IShape, SDFn> = defmulti<any, SDFn>(
         quadratic: ({ points: [a, b, c], attribs }: Quadratic) =>
             quadratic2(a, b, c, __sdfAttribs(attribs)),
 
-        rect: ({ pos, size, attribs }: Rect) =>
-            box2(maddN2([], size, 0.5, pos), size, __sdfAttribs(attribs)),
+        rect: ({ pos, size, attribs }: Rect) => {
+            const s = mulN2([], size, 0.5);
+            return box2(add2([], s, pos), s, __sdfAttribs(attribs));
+        },
     }
 );
 

diff --git a/packages/geom-sdf/src/dist.ts b/packages/geom-sdf/src/dist.ts
@@ -21,8 +21,8 @@ const mag2 = (v: ReadonlyVec) => Math.sqrt(magSq2(v));
 
 export const distCircle2 = (p: ReadonlyVec, radius: number) => mag2(p) - radius;
 
-export const distBox2 = (p: ReadonlyVec, size: ReadonlyVec) => {
-    const d = sub2(null, abs2([], p), size);
+export const distBox2 = (p: ReadonlyVec, halfSize: ReadonlyVec) => {
+    const d = sub2(null, abs2([], p), halfSize);
     return Math.min(Math.max(d[0], d[1]), 0) + mag2(max2(null, d, ZERO2));
 };