make Discord's auto gain control toggle actually work

src/renderer/patches/fixAutoGainToggle.ts

@@ -0,0 +1,51 @@
+/*
+ * Vesktop, a desktop app aiming to give you a snappier Discord Experience
+ * Copyright (c) 2025 Vendicated and Vesktop contributors
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+import { Logger } from "@vencord/types/utils";
+import { MediaEngineStore } from "renderer/common";
+
+const logger = new Logger("FixAutoGain");
+
+function fixTrackConstraints(constraint: MediaTrackConstraints) {
+    const target = constraint.advanced?.find(opt => Object.hasOwn(opt, "autoGainControl")) ?? constraint;
+
+    target.autoGainControl = MediaEngineStore.getAutomaticGainControl();
+}
+
+function fixStreamConstraints(constraints: MediaStreamConstraints | undefined) {
+    if (!constraints?.audio) return;
+
+    if (typeof constraints.audio !== "object") {
+        constraints.audio = {};
+    }
+
+    fixTrackConstraints(constraints.audio);
+}
+
+const originalGetUserMedia = navigator.mediaDevices.getUserMedia;
+navigator.mediaDevices.getUserMedia = function (constraints) {
+    try {
+        fixStreamConstraints(constraints);
+        logger.debug("Fixed getUserMedia constraints", constraints);
+    } catch (e) {
+        logger.error("Failed to fix getUserMedia constraints", e);
+    }
+
+    return originalGetUserMedia.call(this, constraints);
+};
+
+const originalApplyConstraints = MediaStreamTrack.prototype.applyConstraints;
+MediaStreamTrack.prototype.applyConstraints = function (constraints) {
+    if (constraints) {
+        try {
+            fixTrackConstraints(constraints);
+            logger.debug("Fixed applyConstraints constraints", constraints);
+        } catch (e) {
+            logger.error("Failed to fix applyConstraints constraints", e);
+        }
+    }
+    return originalApplyConstraints.call(this, constraints);
+};

src/renderer/patches/index.ts

@@ -16,3 +16,4 @@ import "./windowsTitleBar";
 import "./streamerMode";
 import "./windowMethods";
 import "./hideDownloadAppsButton";
+import "./fixAutoGainToggle";