From 07dd314e47c8169162735316c87d84437e9cba8a Mon Sep 17 00:00:00 2001
From: jesus luque <jesus.luque@lucab.co.uk>
Date: Tue, 6 Oct 2026 03:39:02 +0200
Subject: [PATCH 1/2] Fix SplatAccumulator: packed covSplats threw "Generator
 must be provided"

With covSplats and without extSplats, a stray check after the packed
covariance branch required a GsplatGenerator, so a covGenerator alone
(which that branch already handles) always threw. Remove it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JtbHkmUpoNeo1EwbHiLihG
---
 src/SplatAccumulator.ts            |  3 ---
 test/unit/SplatAccumulator.test.ts | 29 +++++++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 3 deletions(-)
 create mode 100644 test/unit/SplatAccumulator.test.ts

diff --git a/src/SplatAccumulator.ts b/src/SplatAccumulator.ts
index 5ca9fc23..44388c0f 100644
--- a/src/SplatAccumulator.ts
+++ b/src/SplatAccumulator.ts
@@ -309,9 +309,6 @@ export class SplatAccumulator {
               );
               roots.push(output);
             }
-            if (!generator) {
-              throw new Error("Generator must be provided");
-            }
           }
           if (generator) {
             const outputDepth = outputSplatDepth(
diff --git a/test/unit/SplatAccumulator.test.ts b/test/unit/SplatAccumulator.test.ts
new file mode 100644
index 00000000..1f99f81f
--- /dev/null
+++ b/test/unit/SplatAccumulator.test.ts
@@ -0,0 +1,29 @@
+import { expect, test } from "vitest";
+import { SplatAccumulator } from "../../src/SplatAccumulator";
+import type { CovSplatGenerator } from "../../src/SplatGenerator";
+import { Dyno, dynoBlock } from "../../src/dyno/base";
+import { CovSplat } from "../../src/dyno/splats";
+
+function covGenerator(): CovSplatGenerator {
+  return dynoBlock({ index: "int" }, { covsplat: CovSplat }, () => ({
+    covsplat: new Dyno({
+      outTypes: { covsplat: CovSplat },
+      statements: ({ outputs }) => [
+        `${outputs.covsplat}.flags = GSPLAT_FLAG_ACTIVE;`,
+      ],
+    }).outputs.covsplat,
+  }));
+}
+
+// The packed covariance accumulator (covSplats without extSplats) builds its
+// program from a covGenerator alone, as the extended one does.
+test("packed covSplats accumulator accepts a covGenerator alone", () => {
+  for (const extSplats of [false, true]) {
+    const accumulator = new SplatAccumulator({ extSplats, covSplats: true });
+    const { program } = accumulator.prepareProgramMaterial(
+      undefined,
+      covGenerator(),
+    );
+    expect(program).toBeTruthy();
+  }
+});

From fcd9e4fa666cc0ca318894dd920b8446cbfdc144 Mon Sep 17 00:00:00 2001
From: Oscar Lorentzon <oscarlorentzon@users.noreply.github.com>
Date: Sun, 18 Oct 2026 17:48:55 -0700
Subject: [PATCH 2/2] Split the covariance accumulator test by mode

The test ran the packed and the extended accumulator inside one case
named after the packed one. Each mode is now its own case, and the
generator declares only its input and output types.
---
 test/unit/SplatAccumulator.test.ts | 22 +++++++---------------
 1 file changed, 7 insertions(+), 15 deletions(-)

diff --git a/test/unit/SplatAccumulator.test.ts b/test/unit/SplatAccumulator.test.ts
index 1f99f81f..861cce2f 100644
--- a/test/unit/SplatAccumulator.test.ts
+++ b/test/unit/SplatAccumulator.test.ts
@@ -1,29 +1,21 @@
 import { expect, test } from "vitest";
 import { SplatAccumulator } from "../../src/SplatAccumulator";
 import type { CovSplatGenerator } from "../../src/SplatGenerator";
-import { Dyno, dynoBlock } from "../../src/dyno/base";
+import { dynoBlock } from "../../src/dyno/base";
 import { CovSplat } from "../../src/dyno/splats";
 
 function covGenerator(): CovSplatGenerator {
-  return dynoBlock({ index: "int" }, { covsplat: CovSplat }, () => ({
-    covsplat: new Dyno({
-      outTypes: { covsplat: CovSplat },
-      statements: ({ outputs }) => [
-        `${outputs.covsplat}.flags = GSPLAT_FLAG_ACTIVE;`,
-      ],
-    }).outputs.covsplat,
-  }));
+  return dynoBlock({ index: "int" }, { covsplat: CovSplat }, () => ({}));
 }
 
-// The packed covariance accumulator (covSplats without extSplats) builds its
-// program from a covGenerator alone, as the extended one does.
-test("packed covSplats accumulator accepts a covGenerator alone", () => {
-  for (const extSplats of [false, true]) {
+test.each([false, true])(
+  "covSplats accumulator with extSplats %s builds a program for a covSplats mesh",
+  (extSplats) => {
     const accumulator = new SplatAccumulator({ extSplats, covSplats: true });
     const { program } = accumulator.prepareProgramMaterial(
       undefined,
       covGenerator(),
     );
     expect(program).toBeTruthy();
-  }
-});
+  },
+);