Fix hang when switching kart in selection screen for vulkan

lib/graphics_engine/include/ge_main.hpp

@@ -17,6 +17,7 @@ bool m_disable_npot_texture;
 bool m_convert_irrlicht_mesh;
 bool m_texture_compression;
 bool m_vulkan_fullscreen_desktop;
+bool m_enable_draw_call_cache;
 std::unordered_set<std::string> m_ondemand_load_texture_paths;
 float m_render_scale;
 };

lib/graphics_engine/include/ge_vulkan_driver.hpp

@@ -23,8 +23,9 @@ using namespace video;
 
 namespace GE
 {
-    class GEVulkanFBOTexture;
     class GEVulkanDepthTexture;
+    class GEVulkanDrawCall;
+    class GEVulkanFBOTexture;
     class GEVulkanMeshCache;
     class GEVulkanTextureDescriptor;
     enum GEVulkanSampler : unsigned
@@ -359,6 +360,9 @@ namespace GE
         void handleDeletedTextures();
         void addRTTPolyCount(unsigned count)       { m_rtt_polycount += count; }
         SDL_Window* getSDLWindow() const                    { return m_window; }
+        void clearDrawCallsCache();
+        void addDrawCallToCache(std::unique_ptr<GEVulkanDrawCall>& dc);
+        std::unique_ptr<GEVulkanDrawCall> getDrawCallFromCache();
     private:
         struct SwapChainSupportDetails
         {
@@ -501,6 +505,8 @@ namespace GE
         GEVulkanFBOTexture* m_separate_rtt_texture;
         u32 m_rtt_polycount;
 
+        std::vector<std::unique_ptr<GEVulkanDrawCall> > m_draw_calls_cache;
+
         void createInstance(SDL_Window* window);
         void findPhysicalDevice();
         bool checkDeviceExtensions(VkPhysicalDevice device);

lib/graphics_engine/src/ge_main.cpp

@@ -12,6 +12,7 @@ GEConfig g_config =
     false,
     false,
     true,
+    false,
     {},
     1.0f
 };

lib/graphics_engine/src/ge_vulkan_driver.cpp

@@ -2430,6 +2430,7 @@ void GEVulkanDriver::updateRenderScale(float value)
         return;
     waitIdle();
     setDisableWaitIdle(true);
+    clearDrawCallsCache();
     destroySwapChainRelated(false/*handle_surface*/);
     getGEConfig()->m_render_scale = value;
     createSwapChainRelated(false/*handle_surface*/);
@@ -2442,6 +2443,29 @@ void GEVulkanDriver::updateRenderScale(float value)
     setDisableWaitIdle(false);
 }   // updateRenderScale
 
+// ----------------------------------------------------------------------------
+void GEVulkanDriver::clearDrawCallsCache()
+{
+    m_draw_calls_cache.clear();
+}   // clearDrawCallsCache
+
+// ----------------------------------------------------------------------------
+void GEVulkanDriver::addDrawCallToCache(std::unique_ptr<GEVulkanDrawCall>& dc)
+{
+    if (getGEConfig()->m_enable_draw_call_cache)
+        m_draw_calls_cache.push_back(std::move(dc));
+}   // addDrawCallToCache
+
+// ----------------------------------------------------------------------------
+std::unique_ptr<GEVulkanDrawCall> GEVulkanDriver::getDrawCallFromCache()
+{
+    if (!getGEConfig()->m_enable_draw_call_cache || m_draw_calls_cache.empty())
+        return std::unique_ptr<GEVulkanDrawCall>(new GEVulkanDrawCall);
+    auto dc = std::move(m_draw_calls_cache.back());
+    m_draw_calls_cache.pop_back();
+    return dc;
+}   // getDrawCallFromCache
+
 }
 
 namespace irr

lib/graphics_engine/src/ge_vulkan_scene_manager.cpp

@@ -286,12 +286,18 @@ irr::u32 GEVulkanSceneManager::registerNodeForRendering(
 // ----------------------------------------------------------------------------
 void GEVulkanSceneManager::addDrawCall(GEVulkanCameraSceneNode* cam)
 {
-    m_draw_calls[cam] = std::unique_ptr<GEVulkanDrawCall>(new GEVulkanDrawCall);
+    GEVulkanDriver* gevk = static_cast<GEVulkanDriver*>(getVideoDriver());
+    m_draw_calls[cam] = gevk->getDrawCallFromCache();
 }   // addDrawCall
 
 // ----------------------------------------------------------------------------
 void GEVulkanSceneManager::removeDrawCall(GEVulkanCameraSceneNode* cam)
 {
+    if (m_draw_calls.find(cam) == m_draw_calls.end())
+        return;
+    GEVulkanDriver* gevk = static_cast<GEVulkanDriver*>(getVideoDriver());
+    auto& dc = m_draw_calls.at(cam);
+    gevk->addDrawCallToCache(dc);
     m_draw_calls.erase(cam);
 }   // removeDrawCall
 

src/states_screens/kart_selection.cpp

@@ -48,6 +48,11 @@
 #include <IGUIEnvironment.h>
 #include <IGUIButton.h>
 
+#ifndef SERVER_ONLY
+#include <ge_main.hpp>
+#include <ge_vulkan_driver.hpp>
+#endif
+
 using namespace GUIEngine;
 using irr::core::stringw;
 
@@ -335,6 +340,9 @@ void KartSelectionScreen::beforeAddingWidget()
 
 void KartSelectionScreen::init()
 {
+#ifndef SERVER_ONLY
+    GE::getGEConfig()->m_enable_draw_call_cache = true;
+#endif
     m_instance_ptr = this;
     Screen::init();
     m_must_delete_on_back = false;
@@ -441,6 +449,12 @@ void KartSelectionScreen::init()
 
 void KartSelectionScreen::tearDown()
 {
+#ifndef SERVER_ONLY
+    GE::getGEConfig()->m_enable_draw_call_cache = false;
+    GE::GEVulkanDriver* gevk = GE::getVKDriver();
+    if (gevk)
+        gevk->clearDrawCallsCache();
+#endif
 #ifdef MOBILE_STK
     if (m_multiplayer)
         MessageQueue::discardStatic();