When graphics module is destroyed, stop XR session;

Terrible, but better.

src/modules/graphics/graphics.c

@@ -640,6 +640,14 @@ bool lovrGraphicsInit(GraphicsConfig* config) {
 
 void lovrGraphicsDestroy() {
   if (!state.initialized) return;
+#ifndef LOVR_DISABLE_HEADSET
+  // If there's an active headset session it needs to be stopped so it can clean up its Pass and
+  // swapchain textures before gpu_destroy is called.  This is really hacky and should be solved
+  // with module-level refcounting in the future.
+  if (lovrHeadsetInterface && lovrHeadsetInterface->stop) {
+    lovrHeadsetInterface->stop();
+  }
+#endif
   for (Readback* readback = state.oldestReadback; readback; readback = readback->next) {
     lovrRelease(readback, lovrReadbackDestroy);
   }

src/modules/headset/headset.h

@@ -112,6 +112,7 @@ typedef enum {
 // Notes:
 // - init is called immediately, the graphics module may not exist yet
 // - start is called after the graphics module is initialized, can be used to set up textures etc.
+// - graphics module currently calls stop when it's destroyed, which is hacky and should be improved
 // - getDisplayFrequency may return 0.f if the information is unavailable.
 // - For isDown, changed can be set to false if change information is unavailable or inconvenient.
 // - getAxis may write 4 floats to the output value.  The expected number is a constant (see axisCounts in l_headset).
@@ -124,6 +125,7 @@ typedef struct HeadsetInterface {
   uint32_t (*createVulkanDevice)(void* instance, void* deviceCreateInfo, void* allocator, uintptr_t device, void* getInstanceProcAddr);
   bool (*init)(HeadsetConfig* config);
   void (*start)(void);
+  void (*stop)(void);
   void (*destroy)(void);
   bool (*getName)(char* name, size_t length);
   HeadsetOrigin (*getOriginType)(void);

src/modules/headset/headset_openxr.c

@@ -1035,20 +1035,24 @@ static void openxr_start(void) {
   }
 }
 
-static void openxr_destroy(void) {
+static void openxr_stop(void) {
+  if (!state.session) {
+    return;
+  }
+
+  lovrRelease(state.pass, lovrPassDestroy);
+
   for (uint32_t i = 0; i < 2; i++) {
     for (uint32_t j = 0; j < state.textureCount[i]; j++) {
       lovrRelease(state.textures[i][j], lovrTextureDestroy);
     }
   }
 
-  lovrRelease(state.pass, lovrPassDestroy);
+  if (state.swapchain[COLOR]) xrDestroySwapchain(state.swapchain[COLOR]);
+  if (state.swapchain[DEPTH]) xrDestroySwapchain(state.swapchain[DEPTH]);
 
-  for (size_t i = 0; i < MAX_ACTIONS; i++) {
-    if (state.actions[i]) {
-      xrDestroyAction(state.actions[i]);
-    }
-  }
+  if (state.handTrackers[0]) xrDestroyHandTrackerEXT(state.handTrackers[0]);
+  if (state.handTrackers[1]) xrDestroyHandTrackerEXT(state.handTrackers[1]);
 
   for (size_t i = 0; i < MAX_DEVICES; i++) {
     if (state.spaces[i]) {
@@ -1056,13 +1060,15 @@ static void openxr_destroy(void) {
     }
   }
 
-  if (state.handTrackers[0]) xrDestroyHandTrackerEXT(state.handTrackers[0]);
-  if (state.handTrackers[1]) xrDestroyHandTrackerEXT(state.handTrackers[1]);
-  if (state.actionSet) xrDestroyActionSet(state.actionSet);
-  if (state.swapchain[COLOR]) xrDestroySwapchain(state.swapchain[COLOR]);
-  if (state.swapchain[DEPTH]) xrDestroySwapchain(state.swapchain[DEPTH]);
   if (state.referenceSpace) xrDestroySpace(state.referenceSpace);
   if (state.session) xrDestroySession(state.session);
+  state.session = NULL;
+}
+
+static void openxr_destroy(void) {
+  openxr_stop();
+
+  if (state.actionSet) xrDestroyActionSet(state.actionSet);
   if (state.instance) xrDestroyInstance(state.instance);
   memset(&state, 0, sizeof(state));
 }
@@ -1967,6 +1973,7 @@ HeadsetInterface lovrHeadsetOpenXRDriver = {
   .createVulkanDevice = openxr_createVulkanDevice,
   .init = openxr_init,
   .start = openxr_start,
+  .stop = openxr_stop,
   .destroy = openxr_destroy,
   .getName = openxr_getName,
   .getOriginType = openxr_getOriginType,