From 02496b75c9e1a6601ffbba25243a91a625f05c36 Mon Sep 17 00:00:00 2001
From: "R. Belmont" <rb6502@users.noreply.github.com>
Date: Mon, 28 Oct 2019 19:04:36 -0400
Subject: [PATCH] Support disabling vsync on Vulkan, take 2 (#1925)

* Support disabling Vsync on Vulkan [couriersud]

* Add missing lines to fix compiling.
---
 src/renderer_vk.cpp | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/src/renderer_vk.cpp b/src/renderer_vk.cpp
index 9985f6d8c..79a7687d5 100644
--- a/src/renderer_vk.cpp
+++ b/src/renderer_vk.cpp
@@ -2760,6 +2760,42 @@ VK_IMPORT_DEVICE
 					VK_CHECK(vkDeviceWaitIdle(m_device) );
 					releaseSwapchainFramebuffer();
 					releaseSwapchain();
+					
+					uint32_t numPresentModes(10);
+					VkPresentModeKHR presentModes[10];
+					vkGetPhysicalDeviceSurfacePresentModesKHR(m_physicalDevice, m_surface, &numPresentModes, presentModes);
+
+					uint32_t presentModeIdx = numPresentModes;
+					VkPresentModeKHR preferredPresentMode[] = {
+						VK_PRESENT_MODE_FIFO_KHR,
+						VK_PRESENT_MODE_FIFO_RELAXED_KHR,
+						VK_PRESENT_MODE_MAILBOX_KHR,
+						VK_PRESENT_MODE_IMMEDIATE_KHR,
+					};
+					bool has_vsync[] = { true, true, true, false };
+					bool vsync = (flags & BGFX_RESET_VSYNC ? true : false);
+
+					for (uint32_t ii = 0; ii < BX_COUNTOF(preferredPresentMode); ++ii)
+					{
+						for (uint32_t jj = 0; jj < numPresentModes; ++jj)
+						{
+							if ((presentModes[jj] == preferredPresentMode[ii]) && (vsync == has_vsync[ii]))
+							{
+								presentModeIdx = jj;
+								BX_TRACE("present mode: %d", (int)preferredPresentMode[ii]);
+								break;
+							}
+						}
+						if (presentModeIdx < numPresentModes)
+						{
+							break;
+						}
+					}
+					if (presentModeIdx == numPresentModes)
+					{
+						presentModeIdx = 0;
+					}
+					m_sci.presentMode = presentModes[presentModeIdx];
 
 					VkSurfaceCapabilitiesKHR surfaceCapabilities;
 					VK_CHECK(vkGetPhysicalDeviceSurfaceCapabilitiesKHR(m_physicalDevice, m_surface, &surfaceCapabilities) );