VulkanDevice: Allow 0x0 window size

Fixes minimizing in render-to-separate-window mode.

Author: stenzek

src/core/gpu.cpp

@@ -666,7 +666,7 @@ float GPU::ComputeDisplayAspectRatio() const
     if (g_settings.display_aspect_ratio == DisplayAspectRatio::MatchWindow)
     {
       const WindowInfo& wi = GPUThread::GetRenderWindowInfo();
-      if (!wi.IsSurfaceless())
+      if (!wi.IsSurfaceless() && wi.surface_width > 0 && wi.surface_height > 0)
         ar = static_cast<float>(wi.surface_width) / static_cast<float>(wi.surface_height);
     }
     else if (g_settings.display_aspect_ratio == DisplayAspectRatio::Custom)

src/core/gpu_thread.cpp

@@ -1270,8 +1270,9 @@ void GPUThread::DisplayWindowResizedOnThread()
   if (!swap_chain)
     return;
 
-  const float f_width = static_cast<float>(swap_chain->GetWidth());
-  const float f_height = static_cast<float>(swap_chain->GetHeight());
+  // our imgui stuff can't cope with 0x0/hidden windows
+  const float f_width = static_cast<float>(std::max(swap_chain->GetWidth(), 1u));
+  const float f_height = static_cast<float>(std::max(swap_chain->GetHeight(), 1u));
   ImGuiManager::WindowResized(f_width, f_height);
   InputManager::SetDisplayWindowSize(f_width, f_height);
 

src/util/vulkan_swap_chain.cpp

@@ -540,8 +540,7 @@ bool VulkanSwapChain::CreateSwapChain(VulkanDevice& dev, Error* error)
   if (old_swap_chain != VK_NULL_HANDLE)
     vkDestroySwapchainKHR(vkdev, old_swap_chain, nullptr);
 
-  if (window_size.width == 0 || window_size.width > std::numeric_limits<u16>::max() || window_size.height == 0 ||
-      window_size.height > std::numeric_limits<u16>::max())
+  if (window_size.width > std::numeric_limits<u16>::max() || window_size.height > std::numeric_limits<u16>::max())
   {
     Error::SetStringFmt(error, "Invalid swap chain dimensions: {}x{}", window_size.width, window_size.height);
     return false;