From 33e40a8f164f3589b74746d006339132814d9222 Mon Sep 17 00:00:00 2001
From: BearOso <bearoso@gmail.com>
Date: Thu, 13 Jun 2024 11:37:00 -0500
Subject: [PATCH] Vulkan: Refactor present modes. Add relaxed.

---
 vulkan/vulkan_swapchain.cpp | 51 ++++++++++++++++++++-----------------
 vulkan/vulkan_swapchain.hpp |  2 ++
 2 files changed, 29 insertions(+), 24 deletions(-)

diff --git a/vulkan/vulkan_swapchain.cpp b/vulkan/vulkan_swapchain.cpp
index 5ec08fc3..424811f4 100644
--- a/vulkan/vulkan_swapchain.cpp
+++ b/vulkan/vulkan_swapchain.cpp
@@ -92,6 +92,28 @@ vk::Image Swapchain::get_image()
     return image_data[current_swapchain_image].image;
 }
 
+template<typename T>
+static bool vector_find(std::vector<T> haystack, T&& needle)
+{
+    for (auto &elem : haystack)
+        if (elem == needle)
+            return true;
+    return false;
+}
+
+vk::PresentModeKHR Swapchain::get_present_mode() {
+    auto present_mode = vk::PresentModeKHR::eFifo;
+    if (supports_relaxed)
+        present_mode = vk::PresentModeKHR::eFifoRelaxed;
+    if (!vsync) {
+        if (supports_mailbox)
+            present_mode = vk::PresentModeKHR::eMailbox;
+        if (supports_immediate)
+            present_mode = vk::PresentModeKHR::eImmediate;
+    }
+    return present_mode;
+}
+
 bool Swapchain::check_and_resize(int width, int height)
 {
     vk::SurfaceCapabilitiesKHR surface_capabilities;
@@ -167,21 +189,9 @@ bool Swapchain::create(unsigned int desired_num_swapchain_images, int new_width,
         extents.height = surface_capabilities.minImageExtent.height;
 
     auto present_modes = physical_device.getSurfacePresentModesKHR(surface).value;
-    supports_mailbox =
-        std::find(present_modes.begin(), present_modes.end(),
-                  vk::PresentModeKHR::eMailbox) != present_modes.end();
-    supports_immediate =
-        std::find(present_modes.begin(), present_modes.end(),
-                  vk::PresentModeKHR::eImmediate) != present_modes.end();
-
-    auto present_mode = vk::PresentModeKHR::eFifo;
-    if (!vsync)
-    {
-        if (supports_mailbox)
-            present_mode = vk::PresentModeKHR::eMailbox;
-        if (supports_immediate)
-            present_mode = vk::PresentModeKHR::eImmediate;
-    }
+    supports_mailbox = vector_find(present_modes, vk::PresentModeKHR::eMailbox);
+    supports_immediate = vector_find(present_modes, vk::PresentModeKHR::eImmediate);
+    supports_relaxed = vector_find(present_modes, vk::PresentModeKHR::eFifoRelaxed);
 
     auto swapchain_maintenance_info = vk::SwapchainPresentModesCreateInfoEXT{}
         .setPresentModes(present_modes);
@@ -195,7 +205,7 @@ bool Swapchain::create(unsigned int desired_num_swapchain_images, int new_width,
         .setImageUsage(vk::ImageUsageFlagBits::eColorAttachment | vk::ImageUsageFlagBits::eTransferSrc)
         .setCompositeAlpha(vk::CompositeAlphaFlagBitsKHR::eOpaque)
         .setClipped(true)
-        .setPresentMode(present_mode)
+        .setPresentMode(get_present_mode())
         .setSurface(surface)
         .setPreTransform(vk::SurfaceTransformFlagBitsKHR::eIdentity)
         .setImageArrayLayers(1)
@@ -342,14 +352,7 @@ bool Swapchain::swap()
         .setImageIndices(current_swapchain_image);
 
     vk::SwapchainPresentModeInfoEXT present_mode_info;
-    vk::PresentModeKHR present_mode = vk::PresentModeKHR::eFifo;
-    if (!vsync)
-    {
-        if (supports_mailbox)
-            present_mode = vk::PresentModeKHR::eMailbox;
-        if (supports_immediate)
-            present_mode = vk::PresentModeKHR::eImmediate;
-    }
+    auto present_mode = get_present_mode();
     present_mode_info.setPresentModes(present_mode);
     present_info.setPNext(&present_mode_info);
 
diff --git a/vulkan/vulkan_swapchain.hpp b/vulkan/vulkan_swapchain.hpp
index 8159ee73..974b4f9f 100644
--- a/vulkan/vulkan_swapchain.hpp
+++ b/vulkan/vulkan_swapchain.hpp
@@ -31,6 +31,7 @@ class Swapchain
     bool set_vsync(bool on);
     void on_render_pass_end(std::function<void()> function);
     int get_num_frames() { return num_swapchain_images; }
+    vk::PresentModeKHR get_present_mode();
 
     vk::Image get_image();
     vk::Framebuffer get_framebuffer();
@@ -69,6 +70,7 @@ class Swapchain
     bool vsync = true;
     bool supports_immediate = false;
     bool supports_mailbox = false;
+    bool supports_relaxed = false;
     std::vector<Frame> frames;
     std::vector<ImageData> image_data;