From 9ae5a4675a151b858536dc76b6a2f6efc158242a Mon Sep 17 00:00:00 2001
From: Mars <mars@pupbrained.xyz>
Date: Tue, 1 Oct 2024 16:10:20 -0400
Subject: [PATCH] up to right before choosing the right settings for the swap
 chain

---
 src/main.cpp | 58 +++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 46 insertions(+), 12 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index 576420e..f61c1d9 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -18,6 +18,13 @@ constexpr i32 HEIGHT = 600;
 
 constexpr std::array<const char*, 1> validationLayers = { "VK_LAYER_KHRONOS_validation" };
 
+#ifdef __APPLE__
+constexpr std::array<const char*, 2> deviceExtensions = { vk::KHRSwapchainExtensionName,
+                                                          vk::KHRPortabilitySubsetExtensionName };
+#else
+constexpr std::array<const char*, 1> deviceExtensions = { vk::KHRSwapchainExtensionName };
+#endif
+
 #ifdef NDEBUG
 constexpr bool enableValidationLayers = false;
 #else
@@ -56,6 +63,12 @@ class VulkanApp {
     fn isComplete() -> bool { return graphics_family.has_value() && present_family.has_value(); }
   };
 
+  struct SwapChainSupportDetails {
+    vk::SurfaceCapabilitiesKHR        capabilities;
+    std::vector<vk::SurfaceFormatKHR> formats;
+    std::vector<vk::PresentModeKHR>   present_modes;
+  };
+
   fn initWindow() -> void {
     mGLFWInstance = vkfw::initUnique();
 
@@ -92,9 +105,9 @@ class VulkanApp {
     // Retrieve extensions using custom function
     std::vector<const char*> extensions = getRequiredExtensions();
 
+#ifdef __APPLE__
     // Enable the portability extension and set flags
     extensions.emplace_back(vk::KHRPortabilityEnumerationExtensionName);
-#ifdef __APPLE__
     // Technically deprecated but vulkan complains if I don't include it for macOS
     // So instead of using the vk::KHRPortabilitySubsetExtensionName, I just use
     // the direct string.
@@ -187,19 +200,11 @@ class VulkanApp {
 
     vk::PhysicalDeviceFeatures deviceFeatures;
 
-#ifdef __APPLE__
     vk::DeviceCreateInfo createInfo { .queueCreateInfoCount    = static_cast<u32>(queueCreateInfos.size()),
                                       .pQueueCreateInfos       = queueCreateInfos.data(),
-                                      .enabledExtensionCount   = 1,
-                                      .ppEnabledExtensionNames = &vk::KHRPortabilitySubsetExtensionName,
+                                      .enabledExtensionCount   = static_cast<u32>(deviceExtensions.size()),
+                                      .ppEnabledExtensionNames = deviceExtensions.data(),
                                       .pEnabledFeatures        = &deviceFeatures };
-#else
-    vk::DeviceCreateInfo createInfo { .queueCreateInfoCount    = static_cast<u32>(queueCreateInfos.size()),
-                                      .pQueueCreateInfos       = queueCreateInfos.data(),
-                                      .enabledExtensionCount   = 0,
-                                      .ppEnabledExtensionNames = nullptr,
-                                      .pEnabledFeatures        = &deviceFeatures };
-#endif
 
     mDevice = mPhysicalDevice.createDeviceUnique(createInfo);
 
@@ -210,7 +215,26 @@ class VulkanApp {
   fn isDeviceSuitable(vk::PhysicalDevice device) -> bool {
     QueueFamilyIndices indices = findQueueFamilies(device);
 
-    return indices.isComplete();
+    bool extensionsSupported = checkDeviceExtensionSupport(device);
+
+    bool swapChainAdequate = false;
+
+    if (extensionsSupported) {
+      SwapChainSupportDetails swapChainSupport = querySwapChainSupport(device);
+      swapChainAdequate = !swapChainSupport.formats.empty() && !swapChainSupport.present_modes.empty();
+    }
+
+    return indices.isComplete() && extensionsSupported && swapChainAdequate;
+  }
+
+  static fn checkDeviceExtensionSupport(vk::PhysicalDevice device) -> bool {
+    std::vector<vk::ExtensionProperties> availableExtensions = device.enumerateDeviceExtensionProperties();
+
+    std::set<string> requiredExtensions(deviceExtensions.begin(), deviceExtensions.end());
+
+    for (const auto& extension : availableExtensions) requiredExtensions.erase(extension.extensionName);
+
+    return requiredExtensions.empty();
   }
 
   fn findQueueFamilies(vk::PhysicalDevice device) -> QueueFamilyIndices {
@@ -234,6 +258,16 @@ class VulkanApp {
     return indices;
   }
 
+  fn querySwapChainSupport(vk::PhysicalDevice device) -> SwapChainSupportDetails {
+    SwapChainSupportDetails details;
+
+    details.capabilities  = device.getSurfaceCapabilitiesKHR(mSurface.get());
+    details.formats       = device.getSurfaceFormatsKHR(mSurface.get());
+    details.present_modes = device.getSurfacePresentModesKHR(mSurface.get());
+
+    return details;
+  }
+
   static fn getRequiredExtensions() -> std::vector<const char*> {
     std::span<const char*> extensionsSpan = vkfw::getRequiredInstanceExtensions();