--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/zamikongine/vulkan_helpers.nim	Mon Jan 09 11:04:19 2023 +0700
@@ -0,0 +1,245 @@
+import std/tables
+import std/strutils
+import std/strformat
+import std/logging
+import std/macros
+
+import ./vulkan
+import ./window
+
+
+const ENABLEVULKANVALIDATIONLAYERS* = not defined(release)
+
+
+template checkVkResult*(call: untyped) =
+  when defined(release):
+    discard call
+  else:
+    # yes, a bit cheap, but this is only for nice debug output
+    var callstr = astToStr(call).replace("\n", "")
+    while callstr.find("  ") >= 0:
+      callstr = callstr.replace("  ", " ")
+    debug "CALLING vulkan: ", callstr
+    let value = call
+    if value != VK_SUCCESS:
+      error "Vulkan error: ",  astToStr(call),  " returned ", $value
+      raise newException(Exception, "Vulkan error: " & astToStr(call) & " returned " & $value)
+
+func addrOrNil[T](obj: var openArray[T]): ptr T =
+  if obj.len > 0: addr(obj[0]) else: nil
+
+func VK_MAKE_API_VERSION*(variant: uint32, major: uint32, minor: uint32, patch: uint32): uint32 {.compileTime.} =
+  (variant shl 29) or (major shl 22) or (minor shl 12) or patch
+
+
+func filterForSurfaceFormat*(formats: seq[VkSurfaceFormatKHR]): seq[VkSurfaceFormatKHR] =
+  for format in formats:
+    if format.format == VK_FORMAT_B8G8R8A8_SRGB and format.colorSpace == VK_COLOR_SPACE_SRGB_NONLINEAR_KHR:
+      result.add(format)
+
+func getSuitableSurfaceFormat*(formats: seq[VkSurfaceFormatKHR]): VkSurfaceFormatKHR =
+  let usableSurfaceFormats = filterForSurfaceFormat(formats)
+  if len(usableSurfaceFormats) == 0:
+    raise newException(Exception, "No suitable surface formats found")
+  return usableSurfaceFormats[0]
+
+
+func cleanString*(str: openArray[char]): string =
+  for i in 0 ..< len(str):
+    if str[i] == char(0):
+      result = join(str[0 ..< i])
+      break
+
+proc getInstanceExtensions*(): seq[string] =
+  var extensionCount: uint32
+  checkVkResult vkEnumerateInstanceExtensionProperties(nil, addr(extensionCount), nil)
+  var extensions = newSeq[VkExtensionProperties](extensionCount)
+  checkVkResult vkEnumerateInstanceExtensionProperties(nil, addr(extensionCount), addrOrNil(extensions))
+
+  for extension in extensions:
+    result.add(cleanString(extension.extensionName))
+
+
+proc getDeviceExtensions*(device: VkPhysicalDevice): seq[string] =
+  var extensionCount: uint32
+  checkVkResult vkEnumerateDeviceExtensionProperties(device, nil, addr(extensionCount), nil)
+  var extensions = newSeq[VkExtensionProperties](extensionCount)
+  checkVkResult vkEnumerateDeviceExtensionProperties(device, nil, addr(extensionCount), addrOrNil(extensions))
+
+  for extension in extensions:
+    result.add(cleanString(extension.extensionName))
+
+
+proc getValidationLayers*(): seq[string] =
+  var n_layers: uint32
+  checkVkResult vkEnumerateInstanceLayerProperties(addr(n_layers), nil)
+  var layers = newSeq[VkLayerProperties](n_layers)
+  checkVkResult vkEnumerateInstanceLayerProperties(addr(n_layers), addrOrNil(layers))
+
+  for layer in layers:
+    result.add(cleanString(layer.layerName))
+
+
+proc getVulkanPhysicalDevices*(instance: VkInstance): seq[VkPhysicalDevice] =
+  var n_devices: uint32
+  checkVkResult vkEnumeratePhysicalDevices(instance, addr(n_devices), nil)
+  result = newSeq[VkPhysicalDevice](n_devices)
+  checkVkResult vkEnumeratePhysicalDevices(instance, addr(n_devices), addrOrNil(result))
+
+
+proc getQueueFamilies*(device: VkPhysicalDevice): seq[VkQueueFamilyProperties] =
+  var n_queuefamilies: uint32
+  vkGetPhysicalDeviceQueueFamilyProperties(device, addr(n_queuefamilies), nil)
+  result = newSeq[VkQueueFamilyProperties](n_queuefamilies)
+  vkGetPhysicalDeviceQueueFamilyProperties(device, addr(n_queuefamilies), addrOrNil(result))
+
+
+proc getDeviceSurfaceFormats*(device: VkPhysicalDevice, surface: VkSurfaceKHR): seq[VkSurfaceFormatKHR] =
+  var n_formats: uint32
+  checkVkResult vkGetPhysicalDeviceSurfaceFormatsKHR(device, surface, addr(n_formats), nil);
+  result = newSeq[VkSurfaceFormatKHR](n_formats)
+  checkVkResult vkGetPhysicalDeviceSurfaceFormatsKHR(device, surface, addr(n_formats), addrOrNil(result))
+
+
+proc getDeviceSurfacePresentModes*(device: VkPhysicalDevice, surface: VkSurfaceKHR): seq[VkPresentModeKHR] =
+  var n_modes: uint32
+  checkVkResult vkGetPhysicalDeviceSurfacePresentModesKHR(device, surface, addr(n_modes), nil);
+  result = newSeq[VkPresentModeKHR](n_modes)
+  checkVkResult vkGetPhysicalDeviceSurfacePresentModesKHR(device, surface, addr(n_modes), addrOrNil(result))
+
+
+proc getSwapChainImages*(device: VkDevice, swapChain: VkSwapchainKHR): seq[VkImage] =
+  var n_images: uint32
+  checkVkResult vkGetSwapchainImagesKHR(device, swapChain, addr(n_images), nil);
+  result = newSeq[VkImage](n_images)
+  checkVkResult vkGetSwapchainImagesKHR(device, swapChain, addr(n_images), addrOrNil(result));
+
+
+func getPresentMode*(modes: seq[VkPresentModeKHR]): VkPresentModeKHR =
+  let preferredModes = [
+    VK_PRESENT_MODE_MAILBOX_KHR, # triple buffering
+    VK_PRESENT_MODE_FIFO_RELAXED_KHR, # double duffering
+    VK_PRESENT_MODE_FIFO_KHR, # double duffering
+    VK_PRESENT_MODE_IMMEDIATE_KHR, # single buffering
+  ]
+  for preferredMode in preferredModes:
+    for mode in modes:
+      if preferredMode == mode:
+        return mode
+  # should never be reached, but seems to be garuanteed by vulkan specs to always be available
+  return VK_PRESENT_MODE_FIFO_KHR
+
+
+proc createVulkanInstance*(vulkanVersion: uint32): VkInstance =
+
+  var requiredExtensions = @["VK_KHR_surface".cstring]
+  when defined(linux):
+    requiredExtensions.add("VK_KHR_xlib_surface".cstring)
+  when defined(windows):
+    requiredExtensions.add("VK_KHR_win32_surface".cstring)
+  when ENABLEVULKANVALIDATIONLAYERS:
+    requiredExtensions.add("VK_EXT_debug_utils".cstring)
+  
+  let availableExtensions = getInstanceExtensions()
+  for extension in requiredExtensions:
+    assert $extension in availableExtensions, $extension
+
+  let availableLayers = getValidationLayers()
+  var usableLayers = newSeq[cstring]()
+
+  when ENABLEVULKANVALIDATIONLAYERS:
+    const desiredLayers = ["VK_LAYER_KHRONOS_validation".cstring, "VK_LAYER_MESA_overlay".cstring]
+    for layer in desiredLayers:
+      if $layer in availableLayers:
+        usableLayers.add(layer)
+
+  echo "Available validation layers: ", availableLayers
+  echo "Using validation layers: ", usableLayers
+  echo "Available extensions: ", availableExtensions
+  echo "Using extensions: ", requiredExtensions
+
+  var appinfo = VkApplicationInfo(
+    sType: VK_STRUCTURE_TYPE_APPLICATION_INFO,
+    pApplicationName: "Hello Triangle",
+    pEngineName: "Custom engine",
+    apiVersion: vulkanVersion,
+  )
+  var createinfo = VkInstanceCreateInfo(
+    sType: VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO,
+    pApplicationInfo: addr(appinfo),
+    enabledLayerCount: usableLayers.len.uint32,
+    ppEnabledLayerNames: cast[ptr UncheckedArray[cstring]](addrOrNil(usableLayers)),
+    enabledExtensionCount: requiredExtensions.len.uint32,
+    ppEnabledExtensionNames: cast[ptr UncheckedArray[cstring]](addr(requiredExtensions[0]))
+  )
+  checkVkResult vkCreateInstance(addr(createinfo), nil, addr(result))
+
+  loadVK_KHR_surface()
+  when defined(linux):
+    loadVK_KHR_xlib_surface()
+  when defined(windows):
+    loadVK_KHR_win32_surface()
+  loadVK_KHR_swapchain()
+  when ENABLEVULKANVALIDATIONLAYERS:
+    loadVK_EXT_debug_utils(result)
+
+
+proc getVulcanDevice*(
+  physicalDevice: var VkPhysicalDevice,
+  features: var VkPhysicalDeviceFeatures,
+  graphicsQueueFamily: uint32,
+  presentationQueueFamily: uint32,
+): (VkDevice, VkQueue, VkQueue) =
+  # setup queue and device
+  # TODO: need check this, possibly wrong logic, see Vulkan tutorial
+  var priority = 1.0'f32
+  var queueCreateInfo = [
+    VkDeviceQueueCreateInfo(
+      sType: VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO,
+      queueFamilyIndex: graphicsQueueFamily,
+      queueCount: 1,
+      pQueuePriorities: addr(priority),
+    ),
+  ]
+
+  var requiredExtensions = ["VK_KHR_swapchain".cstring]
+  var deviceCreateInfo = VkDeviceCreateInfo(
+    sType: VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO,
+    queueCreateInfoCount: uint32(queueCreateInfo.len),
+    pQueueCreateInfos: addrOrNil(queueCreateInfo),
+    pEnabledFeatures: addr(features),
+    enabledExtensionCount: requiredExtensions.len.uint32,
+    ppEnabledExtensionNames: cast[ptr UncheckedArray[cstring]](addr(requiredExtensions))
+  )
+  checkVkResult vkCreateDevice(physicalDevice, addr(deviceCreateInfo), nil, addr(result[0]))
+  vkGetDeviceQueue(result[0], graphicsQueueFamily, 0'u32, addr(result[1]));
+  vkGetDeviceQueue(result[0], presentationQueueFamily, 0'u32, addr(result[2]));
+
+proc debugCallback*(
+  messageSeverity: VkDebugUtilsMessageSeverityFlagBitsEXT,
+  messageTypes: VkDebugUtilsMessageTypeFlagsEXT,
+  pCallbackData: VkDebugUtilsMessengerCallbackDataEXT,
+  userData: pointer
+): VkBool32 {.cdecl.} =
+  echo &"{messageSeverity}: {VkDebugUtilsMessageTypeFlagBitsEXT(messageTypes)}: {pCallbackData.pMessage}"
+  return VK_FALSE
+
+proc getSurfaceCapabilities*(device: VkPhysicalDevice, surface: VkSurfaceKHR): VkSurfaceCapabilitiesKHR =
+    checkVkResult device.vkGetPhysicalDeviceSurfaceCapabilitiesKHR(surface, addr(result))
+
+when defined(linux):
+  proc createVulkanSurface*(instance: VkInstance, window: NativeWindow): VkSurfaceKHR =
+    var surfaceCreateInfo = VkXlibSurfaceCreateInfoKHR(
+      sType: VK_STRUCTURE_TYPE_XLIB_SURFACE_CREATE_INFO_KHR,
+      dpy: window.display,
+      window: window.window,
+    )
+    checkVkResult vkCreateXlibSurfaceKHR(instance, addr(surfaceCreateInfo), nil, addr(result))
+when defined(windows):
+  proc createVulkanSurface*(instance: VkInstance, window: NativeWindow): VkSurfaceKHR =
+    var surfaceCreateInfo = VkWin32SurfaceCreateInfoKHR(
+      sType: VK_STRUCTURE_TYPE_WIN32_SURFACE_CREATE_INFO_KHR,
+      hinstance: window.hinstance,
+      hwnd: window.hwnd,
+    )
+    checkVkResult vkCreateWin32SurfaceKHR(instance, addr(surfaceCreateInfo), nil, addr(result))