Modified rendering framework to support surface size of 0 width and 0 height (this can occur on Windows when window gets minimized). In such situation, swapchain is not created and rendering function is not called. Instead, rendering loop waits for 1/10 of a second.

Project/Common/OperatingSystem.cpp

@@ -8,6 +8,8 @@
 // Intel does not assume any responsibility for any errors which may appear in this software
 // nor any responsibility to update it.
 
+#include <thread>
+#include <chrono>
 #include "OperatingSystem.h"
 
 namespace ApiWithoutSecrets {
@@ -94,6 +96,7 @@ namespace ApiWithoutSecrets {
       MSG message;
       bool loop = true;
       bool resize = false;
+      bool result = true;
 
       while( loop ) {
         if( PeekMessage( &message, NULL, 0, 0, PM_REMOVE ) ) {
@@ -115,16 +118,22 @@ namespace ApiWithoutSecrets {
           if( resize ) {
             resize = false;
             if( !tutorial.OnWindowSizeChanged() ) {
-              loop = false;
+              result = false;
+              break;
             }
           }
-          if( !tutorial.Draw() ) {
-            loop = false;
+          if( tutorial.ReadyToDraw() ) {
+            if( !tutorial.Draw() ) {
+              result = false;
+              break;
+            }
+          } else {
+            std::this_thread::sleep_for( std::chrono::milliseconds( 100 ) );
           }
         }
       }
 
-      return true;
+      return result;
     }
 
 #elif defined(VK_USE_PLATFORM_XCB_KHR)
@@ -203,6 +212,7 @@ namespace ApiWithoutSecrets {
       xcb_generic_event_t *event;
       bool loop = true;
       bool resize = false;
+      bool result = true;
 
       while( loop ) {
         event = xcb_poll_for_event( Parameters.Connection );
@@ -241,16 +251,22 @@ namespace ApiWithoutSecrets {
           if( resize ) {
             resize = false;
             if( !tutorial.OnWindowSizeChanged() ) {
-              loop = false;
+              result = false;
+              break;
             }
           }
-          if( !tutorial.Draw() ) {
-            loop = false;
+          if( tutorial.ReadyToDraw() ) {
+            if( !tutorial.Draw() ) {
+              result = false;
+              break;
+            }
+          } else {
+            std::this_thread::sleep_for( std::chrono::milliseconds( 100 ) );
           }
         }
       }
 
-      return true;
+      return result;
     }
 
 #elif defined(VK_USE_PLATFORM_XLIB_KHR)
@@ -299,6 +315,7 @@ namespace ApiWithoutSecrets {
       XEvent event;
       bool loop = true;
       bool resize = false;
+      bool result = true;
 
       while( loop ) {
         if( XPending( Parameters.DisplayPtr ) ) {
@@ -334,16 +351,22 @@ namespace ApiWithoutSecrets {
           if( resize ) {
             resize = false;
             if( !tutorial.OnWindowSizeChanged() ) {
-              loop = false;
+              result = false;
+              break;
             }
           }
-          if( !tutorial.Draw() ) {
-            loop = false;
+          if( tutorial.ReadyToDraw() ) {
+            if( !tutorial.Draw() ) {
+              result = false;
+              break;
+            }
+          } else {
+            std::this_thread::sleep_for( std::chrono::milliseconds( 100 ) );
           }
         }
       }
 
-      return true;
+      return result;
     }
 
 #endif

Project/Common/OperatingSystem.h

@@ -58,8 +58,19 @@ namespace ApiWithoutSecrets {
       virtual bool OnWindowSizeChanged() = 0;
       virtual bool Draw() = 0;
 
+      virtual bool ReadyToDraw() const final {
+        return CanRender;
+      }
+
+      TutorialBase() :
+        CanRender( false ) {
+      }
+
       virtual ~TutorialBase() {
       }
+
+    protected:
+      bool CanRender;
     };
 
     // ************************************************************ //

Project/Common/VulkanCommon.cpp

@@ -58,10 +58,14 @@ namespace ApiWithoutSecrets {
   bool VulkanCommon::OnWindowSizeChanged() {
     ChildClear();
 
-    if( !CreateSwapChain() ) {
-      return false;
+    if( CreateSwapChain() ) {
+      if( CanRender ) {
+        return ChildOnWindowSizeChanged();
+      }
+      return true;
     }
-    return ChildOnWindowSizeChanged();
+
+    return false;
   }
 
   VkPhysicalDevice VulkanCommon::GetPhysicalDevice() const {
@@ -434,6 +438,8 @@ namespace ApiWithoutSecrets {
   }
 
   bool VulkanCommon::CreateSwapChain() {
+    CanRender = false;
+
     if( Vulkan.Device != VK_NULL_HANDLE ) {
       vkDeviceWaitIdle( Vulkan.Device );
     }
@@ -492,6 +498,11 @@ namespace ApiWithoutSecrets {
     if( static_cast<int>(desired_present_mode) == -1 ) {
       return false;
     }
+    if( (desired_extent.width == 0) || (desired_extent.height == 0) ) {
+      // Current surface size is (0, 0) so we can't create a swap chain and render anything (CanRender == false)
+      // But we don't wont to kill the application as this situation may occur i.e. when window gets minimized
+      return true;
+    }
 
     VkSwapchainCreateInfoKHR swap_chain_create_info = {
       VK_STRUCTURE_TYPE_SWAPCHAIN_CREATE_INFO_KHR,  // VkStructureType                sType
@@ -576,6 +587,8 @@ namespace ApiWithoutSecrets {
       }
     }
 
+    CanRender = true;
+
     return true;
   }