From e487eb9da0805519261687339da2e77686ed9efc Mon Sep 17 00:00:00 2001
From: Mahmood - Zer0xFF <5013823+Zer0xFF@users.noreply.github.com>
Date: Wed, 11 Dec 2024 13:30:35 +0000
Subject: [PATCH] Backends: Vulkan: Fixed setting
 VkSwapchainCreateInfoKHR::preTransform for platforms not supporting
 VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR. (#8222)

---
 backends/imgui_impl_vulkan.cpp | 11 ++++++-----
 docs/CHANGELOG.txt             |  3 +++
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/backends/imgui_impl_vulkan.cpp b/backends/imgui_impl_vulkan.cpp
index b41970304..1de6e2353 100644
--- a/backends/imgui_impl_vulkan.cpp
+++ b/backends/imgui_impl_vulkan.cpp
@@ -26,6 +26,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2024-12-11: Vulkan: Fixed setting VkSwapchainCreateInfoKHR::preTransform for platforms not supporting VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR. (#8222)
 //  2024-11-27: Vulkan: Make user-provided descriptor pool optional. As a convenience, when setting init_info->DescriptorPoolSize the backend will create one itself. (#8172, #4867)
 //  2024-10-07: Vulkan: Changed default texture sampler to Clamp instead of Repeat/Wrap.
 //  2024-10-07: Vulkan: Expose selected render state in ImGui_ImplVulkan_RenderState, which you can access in 'void* platform_io.Renderer_RenderState' during draw callbacks.
@@ -1426,6 +1427,10 @@ void ImGui_ImplVulkanH_CreateWindowSwapChain(VkPhysicalDevice physical_device, V
 
     // Create Swapchain
     {
+        VkSurfaceCapabilitiesKHR cap;
+        err = vkGetPhysicalDeviceSurfaceCapabilitiesKHR(physical_device, wd->Surface, &cap);
+        check_vk_result(err);
+
         VkSwapchainCreateInfoKHR info = {};
         info.sType = VK_STRUCTURE_TYPE_SWAPCHAIN_CREATE_INFO_KHR;
         info.surface = wd->Surface;
@@ -1435,19 +1440,15 @@ void ImGui_ImplVulkanH_CreateWindowSwapChain(VkPhysicalDevice physical_device, V
         info.imageArrayLayers = 1;
         info.imageUsage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT;
         info.imageSharingMode = VK_SHARING_MODE_EXCLUSIVE;           // Assume that graphics family == present family
-        info.preTransform = VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR;
+        info.preTransform = (cap.supportedTransforms & VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR) ? VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR : cap.currentTransform;
         info.compositeAlpha = VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR;
         info.presentMode = wd->PresentMode;
         info.clipped = VK_TRUE;
         info.oldSwapchain = old_swapchain;
-        VkSurfaceCapabilitiesKHR cap;
-        err = vkGetPhysicalDeviceSurfaceCapabilitiesKHR(physical_device, wd->Surface, &cap);
-        check_vk_result(err);
         if (info.minImageCount < cap.minImageCount)
             info.minImageCount = cap.minImageCount;
         else if (cap.maxImageCount != 0 && info.minImageCount > cap.maxImageCount)
             info.minImageCount = cap.maxImageCount;
-
         if (cap.currentExtent.width == 0xffffffff)
         {
             info.imageExtent.width = wd->Width = w;
diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt
index 68f5d8d4c..d95012d9f 100644
--- a/docs/CHANGELOG.txt
+++ b/docs/CHANGELOG.txt
@@ -43,6 +43,9 @@ Breaking changes:
 
 Other changes:
 
+- Backends: Vulkan: Fixed setting VkSwapchainCreateInfoKHR::preTransform for
+  platforms not supporting VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR. (#8222) [@Zer0xFF]
+
 
 -----------------------------------------------------------------------
  VERSION 1.91.6 (Released 2024-12-11)