Route VR lifecycle through platform services

src/app.h

@@ -198,6 +198,8 @@ public:
     void display_file(std::string path);
     void share_file(std::string path);
     void request_app_close();
+    [[nodiscard]] bool start_platform_vr_mode();
+    void stop_platform_vr_mode();
     void attach_ui_thread();
     void detach_ui_thread();
     void acquire_render_context();

src/app_events.cpp

@@ -264,6 +264,16 @@ void App::request_app_close()
     active_platform_services().request_app_close();
 }
 
+bool App::start_platform_vr_mode()
+{
+    return active_platform_services().start_vr_mode();
+}
+
+void App::stop_platform_vr_mode()
+{
+    active_platform_services().stop_vr_mode();
+}
+
 void App::attach_ui_thread()
 {
     active_platform_services().attach_ui_thread();

src/app_vr.cpp

@@ -7,11 +7,6 @@
 #include "shape.h"
 #include "renderer_gl/opengl_capabilities.h"
 
-#ifdef _WIN32
-bool win32_vr_start();
-void win32_vr_stop();
-#endif
-
 namespace {
 
 void set_active_texture_unit(std::uint32_t unit_index)
@@ -104,18 +99,12 @@ Sphere controller_ray;
 
 bool App::vr_start()
 {
-#ifdef _WIN32
-    return win32_vr_start();
-#else
-    return false;
-#endif
+    return start_platform_vr_mode();
 }
 
 void App::vr_stop()
 {
-#ifdef _WIN32
-    win32_vr_stop();
-#endif
+    stop_platform_vr_mode();
 }
 
 void App::vr_draw_ui()

src/platform_api/platform_services.h

@@ -59,6 +59,8 @@ public:
     virtual void display_file(std::string_view path) = 0;
     virtual void share_file(std::string_view path) = 0;
     virtual void request_app_close() = 0;
+    [[nodiscard]] virtual bool start_vr_mode() = 0;
+    virtual void stop_vr_mode() = 0;
     virtual void pick_image(PickedPathCallback callback) = 0;
     virtual void pick_file(std::vector<std::string> file_types, PickedPathCallback callback) = 0;
     virtual void pick_save_file(std::vector<std::string> file_types, PickedPathCallback callback) = 0;

src/platform_legacy/legacy_platform_services.cpp

@@ -587,6 +587,15 @@ public:
 #endif
     }
 
+    [[nodiscard]] bool start_vr_mode() override
+    {
+        return false;
+    }
+
+    void stop_vr_mode() override
+    {
+    }
+
     void save_prepared_file(
         std::string_view path,
         std::string_view suggested_name,

src/platform_windows/windows_platform_services.cpp

@@ -21,6 +21,8 @@ void win32_renderdoc_frame_end();
 void win32_update_fps(int frames);
 void win32_update_stylus(float dt);
 void win32_save_window_state();
+bool win32_vr_start();
+void win32_vr_stop();
 
 namespace {
 
@@ -423,6 +425,16 @@ public:
         destroy_window();
     }
 
+    [[nodiscard]] bool start_vr_mode() override
+    {
+        return win32_vr_start();
+    }
+
+    void stop_vr_mode() override
+    {
+        win32_vr_stop();
+    }
+
     void pick_image(pp::platform::PickedPathCallback callback) override
     {
         const std::string path = open_file("Image Files (*.jpg, *.png)\0*.jpg;*.png");