Set default render scale for VR to 0.8 on Quest and update related configurations

OPENXR.md

@@ -117,7 +117,8 @@ The old Eager Frame Heartbeat option has been removed and existing `eager_frame_
 settings are ignored. Completed rendering wakes the XR thread immediately. A 50 ms keep-alive
 still protects pauses and window dragging without eager repeats during rendering.
 
-`render_scale` scales the per-eye size recommended by the OpenXR runtime.
+`render_scale` scales the per-eye size recommended by the OpenXR runtime. It defaults to 1.0 on PC
+and 0.8 on the Quest, whose mobile GPU needs the headroom.
 `world_units_per_meter` controls the scale of headset translation in the game world.
 `hud_distance_meters` and `hud_width_meters` place and size the virtual screen. They are read at
 launch and govern both the menu screen and the in-race 2D screen, so 2D content keeps its place

android/app/src/main/java/org/wiicompiled/quest/GameStorage.kt

@@ -20,6 +20,8 @@ object GameStorage {
     const val DISC_DIRECTORY = "DATA"
     /** The Retro Rewind pack the modded product reads (`[paths] retro_rewind_root`). */
     const val MOD_DIRECTORY = "RetroRewind6"
+    /** `[vr] render_scale` until the player changes it; must match kVrRenderScaleDefault on Android. */
+    const val DEFAULT_RENDER_SCALE = 0.8
 
     enum class DiscStatus { Missing, Incomplete, Ready }
 
@@ -91,7 +93,7 @@ object GameStorage {
                 "",
                 "[vr]",
                 "enabled = true",
-                "render_scale = 1.0",
+                "render_scale = $DEFAULT_RENDER_SCALE",
             )
             config.writeText(lines.joinToString("\n", postfix = "\n"))
         } else {

android/app/src/main/java/org/wiicompiled/quest/launcher/SettingsPage.kt

@@ -161,7 +161,7 @@ class SettingsPage(
         section(R.string.section_vr_headset) {
             slider(
                 R.string.vr_render_scale, R.string.vr_render_scale_helper, 0.25, 2.0, 0.05,
-                read = { number(it, "vr", "render_scale", 0.25, 2.0, 1.0) },
+                read = { number(it, "vr", "render_scale", 0.25, 2.0, GameStorage.DEFAULT_RENDER_SCALE) },
                 format = { "%.2f×".format(it) },
                 write = { c, value -> c.setFloat("vr", "render_scale", value) },
             )

docs/quest-port.md

@@ -670,8 +670,9 @@ or `EndAccess` errors); a black mirror too points at Aurora itself.
 - **Performance.** The desktop product targets x86-64-v3; nothing has been
   profiled on the XR2. The first run compiles every bundled pipeline recipe
   (about half a minute); later runs load Dawn's pipeline cache from `Cache/`
-  next to `DATA`. Start with `render_scale` below 1.0 if the
-  compositor reports missed frames. `XR_FB_foveation` is not used yet.
+  next to `DATA`. `render_scale` defaults to 0.8 here (1.0 on
+  PC); lower it further if the compositor reports missed frames.
+  `XR_FB_foveation` is not used yet.
 - **Lifecycle.** Backgrounding (the Quest menu, guardian) pauses the session
   through the ordinary `STOPPING`/`READY` events; SDL's Android surface loss is
   handled by Aurora's existing Android paths. Neither has been exercised.

runtime/include/runtime_config.h

@@ -164,6 +164,17 @@ inline constexpr int kPortableSearchDepth = 4;
 inline constexpr uint32_t kPostProcessingBloomPath = 0x10u;
 inline constexpr uint32_t kDisabledPostProcessingPathsDefault = kPostProcessingBloomPath;
 
+// Headset eye size as a fraction of what the OpenXR runtime recommends. A
+// standalone headset renders on a mobile GPU, so the Quest starts below it;
+// the launcher's first Config.toml (GameStorage.kt) writes the same value.
+#if defined(__ANDROID__)
+inline constexpr float kVrRenderScaleDefault = 0.8f;
+#define MKW_VR_RENDER_SCALE_DEFAULT_TEXT "0.8"
+#else
+inline constexpr float kVrRenderScaleDefault = 1.0f;
+#define MKW_VR_RENDER_SCALE_DEFAULT_TEXT "1.0"
+#endif
+
 // First-person camera defaults and the range its head offsets accept, in one
 // place: the config getters, the on-disk template and the F10 bar's reset all
 // read them from here, so they cannot drift apart again.
@@ -427,7 +438,7 @@ inline void EnsureConfigFile() {
               "controller_mode = \"wii_remote\"\n"
               "# VR interpolation: 0 = Off, 1 = Auto, or 72/90/120 FPS. Live.\n"
               "frame_interpolation_fps = 0\n"
-              "render_scale = 1.0\n"
+              "render_scale = " MKW_VR_RENDER_SCALE_DEFAULT_TEXT "\n"
               "world_units_per_meter = 500.0\n"
               "hud_distance_meters = 2.0\n"
               "hud_width_meters = 2.4\n"
@@ -1307,7 +1318,7 @@ inline bool VrRequired(bool fallback = false) {
     return Get().vrRequired.value_or(fallback);
 }
 
-inline float VrRenderScale(float fallback = 1.0f) {
+inline float VrRenderScale(float fallback = kVrRenderScaleDefault) {
     return std::clamp(Get().vrRenderScale.value_or(fallback), 0.25f, 2.0f);
 }
 

runtime/src/vr/openxr_integration.cpp

@@ -365,7 +365,7 @@ public:
         config.application_name = aurora_config.appName != nullptr ? aurora_config.appName
                                                                     : "WiiCompiled";
         config.engine_name = "Aurora";
-        config.resolution_scale = RuntimeConfigFile::VrRenderScale(1.0f);
+        config.resolution_scale = RuntimeConfigFile::VrRenderScale();
 #if defined(_WIN32)
         config.required_extensions = {"XR_KHR_D3D12_enable"};
         config.optional_extensions = {"XR_KHR_win32_convert_performance_counter_time",