--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/vulkan_api/vulkan_api_generator.nim	Mon Feb 20 10:33:53 2023 +0700
@@ -0,0 +1,346 @@
+import std/os
+import std/sugar
+import std/algorithm
+import std/strformat
+import std/strutils
+import std/sequtils
+import std/streams
+import std/tables
+import httpClient
+import std/xmlparser
+import std/xmltree
+
+type
+  FileContent = seq[string]
+
+const
+  TYPEMAP = {
+    "void": "void",
+    "char": "char",
+    "float": "float32",
+    "double": "float64",
+    "int8_t": "int8",
+    "uint8_t": "uint8",
+    "int16_t": "int16",
+    "uint16_t": "uint16",
+    "int32_t": "int32",
+    "uint32_t": "uint32",
+    "uint64_t": "uint64",
+    "int64_t": "int64",
+    "size_t": "csize_t",
+    "int": "cint",
+    "void*": "pointer",
+    "char*": "cstring",
+    "ptr char": "cstring",
+    "ptr void": "pointer",
+    "VK_DEFINE_HANDLE": "VkHandle",
+    "VK_DEFINE_NON_DISPATCHABLE_HANDLE": "VkNonDispatchableHandle",
+  }.toTable
+  PLATFORM_HEADER_MAP = {
+    "X11/Xlib.h": "xlib",
+    "X11/extensions/Xrandr.h": "xlib_xrandr",
+    "wayland-client.h": "wayland",
+    "windows.h": "win32",
+    "xcb/xcb.h": "xcb",
+    "directfb.h": "directfb",
+    "zircon/types.h": "fuchsia",
+    "ggp_c/vulkan_types.h": "ggp",
+    "screen/screen.h": "screen",
+    "nvscisync.h": "nvidia",
+    "nvscibuf.h": "nvidia",
+    "vk_video/vulkan_video_codec_h264std.h": "vk_video",
+    "vk_video/vulkan_video_codec_h264std_decode.h": "vk_video",
+    "vk_video/vulkan_video_codec_h264std_encode.h": "vk_video",
+    "vk_video/vulkan_video_codec_h265std.h": "vk_video",
+    "vk_video/vulkan_video_codec_h265std_decode.h": "vk_video",
+    "vk_video/vulkan_video_codec_h265std_encode.h": "vk_video",
+  }.toTable
+  MAP_KEYWORD = {
+    "object": "theobject",
+    "type": "thetype",
+  }.toTable
+
+# helpers
+func mapType(typename: string): auto =
+  TYPEMAP.getOrDefault(typename.strip(), typename.strip()).strip(chars={'_'})
+func mapName(thename: string): auto =
+  MAP_KEYWORD.getOrDefault(thename.strip(), thename.strip()).strip(chars={'_'})
+func smartParseInt(value: string): int =
+  if value.startsWith("0x"):
+    parseHexInt(value)
+  else:
+    parseInt(value)
+func hasAttr(node: XmlNode, attr: string): bool = node.attr(attr) != ""
+func tableSorted(table: Table[int, string]): seq[(int, string)] =
+  result = toSeq(table.pairs)
+  result.sort((a, b) => cmp(a[0], b[0]))
+
+# serializers
+func serializeEnum(node: XmlNode, root: XmlNode): seq[string] =
+  let name = node.attr("name")
+  if name == "":
+    return result
+
+  # find additional enum defintion in feature definitions
+  var values: Table[int, string]
+  for feature in root.findAll("feature"):
+    for require in feature.findAll("require"):
+      for theenum in require.findAll("enum"):
+        if theenum.attr("extends") == name:
+          if theenum.hasAttr("offset"):
+            let enumBase = 1000000000 + (smartParseInt(theenum.attr("extnumber")) - 1) * 1000
+            var value = smartParseInt(theenum.attr("offset")) + enumBase
+            if theenum.attr("dir") == "-":
+              value = -value
+            values[value] = theenum.attr("name")
+          elif theenum.hasAttr("value"):
+            var value = smartParseInt(theenum.attr("value"))
+            if theenum.attr("dir") == "-":
+              value = -value
+            values[value] = theenum.attr("name")
+          elif theenum.hasAttr("bitpos"):
+            var value = smartParseInt(theenum.attr("bitpos"))
+            if theenum.attr("dir") == "-":
+              value = -value
+            values[value] = theenum.attr("name")
+          elif theenum.hasAttr("alias"):
+            discard
+          else:
+            raise newException(Exception, &"Unknown extension value: {feature}\nvalue:{theenum}")
+  # find additional enum defintion in extension definitions
+  for extension in root.findAll("extension"):
+    let extensionNumber = parseInt(extension.attr("number"))
+    let enumBase = 1000000000 + (extensionNumber - 1) * 1000
+    for require in extension.findAll("require"):
+      for theenum in require.findAll("enum"):
+        if theenum.attr("extends") == name:
+          if theenum.hasAttr("offset"):
+            if theenum.hasAttr("extnumber"):
+              let otherBase = 1000000000 + (smartParseInt(theenum.attr("extnumber")) - 1) * 1000
+              var value = smartParseInt(theenum.attr("offset")) + otherBase
+              if theenum.attr("dir") == "-":
+                value = -value
+              values[value] = theenum.attr("name")
+            else:
+              var value = smartParseInt(theenum.attr("offset")) + enumBase
+              if theenum.attr("dir") == "-":
+                value = -value
+              values[value] = theenum.attr("name")
+          elif theenum.hasAttr("value"):
+            var value = smartParseInt(theenum.attr("value"))
+            if theenum.attr("dir") == "-":
+              value = -value
+            values[value] = theenum.attr("name")
+          elif theenum.hasAttr("bitpos"):
+            var value = smartParseInt(theenum.attr("bitpos"))
+            if theenum.attr("dir") == "-":
+              value = -value
+            values[value] = theenum.attr("name")
+          elif theenum.hasAttr("alias"):
+            discard
+          else:
+            raise newException(Exception, &"Unknown extension value: {extension}\nvalue:{theenum}")
+
+  # generate enums
+  if node.attr("type") == "enum":
+    for value in node.findAll("enum"):
+      if value.hasAttr("alias"):
+        continue
+      if value.attr("value").startsWith("0x"):
+        values[parseHexInt(value.attr("value"))] = value.attr("name")
+      else:
+        values[smartParseInt(value.attr("value"))] = value.attr("name")
+    if values.len > 0:
+      result.add "  " & name & "* {.size: sizeof(cint).} = enum"
+      for (value, name) in tableSorted(values):
+        let enumEntry = &"    {name} = {value}"
+        result.add enumEntry
+
+  # generate bitsets (normal enums in the C API, but bitfield-enums in Nim)
+  elif node.attr("type") == "bitmask":
+    for value in node.findAll("enum"):
+      if value.hasAttr("alias") or not value.hasAttr("bitpos"):
+        continue
+      values[smartParseInt(value.attr("bitpos"))] = value.attr("name")
+    if values.len > 0:
+      if node.hasAttr("bitwidth"):
+        result.add "  " & name & "* {.size: " & $(smartParseInt(node.attr("bitwidth")) div 8) & ".} = enum"
+      else:
+        result.add "  " & name & "* {.size: sizeof(cint).} = enum"
+      for (bitpos, enumvalue) in tableSorted(values):
+        var value = "00000000000000000000000000000000"# makes the bit mask nicely visible
+        if node.hasAttr("bitwidth"): # assumes this is always 64
+          value = value & value
+        value[^(bitpos + 1)] = '1'
+        let enumEntry = &"    {enumvalue} = 0b{value}"
+        if not (enumEntry in result): # the specs define duplicate entries for backwards compat
+          result.add enumEntry
+    let cApiName = name.replace("FlagBits", "Flags")
+    if node.hasAttr("bitwidth"): # assumes this is always 64
+      if values.len > 0:
+        result.add &"""converter BitsetToNumber*(flags: openArray[{name}]): {cApiName} =
+  for flag in flags:
+    result = {cApiName}(uint64(result) or uint(flag))"""
+        result.add "type"
+    else:
+      if values.len > 0:
+        result.add &"""converter BitsetToNumber*(flags: openArray[{name}]): {cApiName} =
+  for flag in flags:
+    result = {cApiName}(uint(result) or uint(flag))"""
+        result.add "type"
+
+func serializeStruct(node: XmlNode, root: XmlNode): seq[string] =
+  let name = node.attr("name")
+  var union = ""
+  if node.attr("category") == "union":
+    union = "{.union.}"
+  result.add &"  {name}* {union} = object"
+  for member in node.findAll("member"):
+    if not member.hasAttr("api") or member.attr("api") == "vulkan":
+      let fieldname = member.child("name")[0].text.strip(chars={'_'})
+      var fieldtype = member.child("type")[0].text.strip(chars={'_'})
+      if member[member.len - 2].kind == xnText and member[member.len - 2].text.strip() == "*":
+        fieldtype = &"ptr {mapType(fieldtype)}"
+      fieldtype = mapType(fieldtype)
+      result.add &"    {mapName(fieldname)}*: {fieldtype}"
+
+func serializeFunctiontypes(api: XmlNode): seq[string] =
+  for node in api.findAll("type"):
+    if node.attr("category") == "funcpointer":
+      let name = node[1][0]
+      let returntype = mapType(node[0].text[8 .. ^1].split('(', 1)[0])
+      var params: seq[string]
+      for i in countup(3, node.len - 1, 2):
+        var paramname = node[i + 1].text.split(',', 1)[0].split(')', 1)[0]
+        var paramtype = node[i][0].text
+        if paramname[0] == '*':
+          paramname = paramname.rsplit(" ", 1)[1]
+          paramtype = "ptr " & paramtype
+        paramname = mapName(paramname)
+        params.add &"{paramname}: {mapType(paramtype)}"
+      let paramsstr = params.join(", ")
+      result.add(&"  {name} = proc({paramsstr}): {returntype} {{.cdecl.}}")
+
+func serializeType(node: XmlNode): Table[string, seq[string]] =
+  if node.attrsLen == 0:
+    return
+  if node.attr("requires") == "vk_platform" or node.attr("category") == "include":
+    return
+  result["basetypes"] = @[]
+  result["enums"] = @[]
+
+  # include-defined types (in platform headers)
+  if node.hasAttr("requires") and node.hasAttr("name") and node.attr("category") != "define":
+    let platform = "platform/" & PLATFORM_HEADER_MAP[node.attr("requires")]
+    if not result.hasKey(platform):
+      result[platform] = @[]
+    result[platform].add "type " & node.attr(
+        "name") & " {.header: \"" & node.attr("requires") & "\".} = object"
+  # generic base types
+  elif node.attr("category") == "basetype":
+    let typechild = node.child("type")
+    let namechild = node.child("name")
+    if typechild != nil and namechild != nil:
+      var typename = typechild[0].text
+      if node[2].kind == xnText and node[2].text.strip() == "*":
+        typename = &"ptr {typename}"
+      result["basetypes"].add &"  {namechild[0].text}* = {mapType(typename)}"
+    elif namechild != nil:
+      result["basetypes"].add &"  {namechild[0].text}* = object"
+  # function pointers need to be handled with structs
+  elif node.attr("category") == "funcpointer":
+    discard
+  # preprocessor defines, ignored
+  elif node.attr("category") == "define":
+    discard
+  # bitmask aliases
+  elif node.attr("category") == "bitmask":
+    if node.hasAttr("alias"):
+      let name = node.attr("name")
+      let alias = node.attr("alias")
+      result["enums"].add &"  {name}* = {alias}"
+  # distinct resource ID types aka handles
+  elif node.attr("category") == "handle":
+    if not node.hasAttr("alias"):
+      let name = node.child("name")[0].text
+      var thetype = mapType(node.child("type")[0].text)
+      result["basetypes"].add &"  {name}* = distinct {thetype}"
+  # enum aliases
+  elif node.attr("category") == "enum":
+    if node.hasAttr("alias"):
+      let name = node.attr("name")
+      let alias = node.attr("alias")
+      result["enums"].add &"  {name}* = {alias}"
+  else:
+    discard
+
+
+proc update(a: var Table[string, seq[string]], b: Table[string, seq[string]]) =
+  for k, v in b.pairs:
+    if not a.hasKey(k):
+      a[k] = @[]
+    a[k].add v
+
+
+proc main() =
+  if not os.fileExists("vk.xml"):
+    let client = newHttpClient()
+    let glUrl = "https://raw.githubusercontent.com/KhronosGroup/Vulkan-Docs/main/xml/vk.xml"
+    client.downloadFile(glUrl, "vk.xml")
+
+  let api = loadXml("vk.xml")
+
+  const outdir = "src/vulkan_api/output"
+  removeDir outdir
+  createDir outdir
+  createDir outdir / "platform"
+
+  # index all names that are only available on certain platforms
+  var platformTypes: Table[string, string]
+  for extension in api.findAll("extension"):
+    if extension.hasAttr("platform"):
+      for thetype in extension.findAll("type"):
+        platformTypes[thetype.attr("name")] = extension.attr("platform")
+      for command in extension.findAll("command"):
+        platformTypes[command.attr("name")] = extension.attr("platform")
+    elif extension.attr("name").startsWith("VK_KHR_video"):
+      for thetype in extension.findAll("type"):
+        platformTypes[thetype.attr("name")] = "vk_video"
+      for command in extension.findAll("command"):
+        platformTypes[command.attr("name")] = "vk_video"
+
+  var outputFiles = {
+    "basetypes": @["type", "  VkHandle* = distinct pointer", "  VkNonDispatchableHandle* = distinct pointer"],
+    "structs": @["import ./enums", "import ./basetypes", "type"],
+    "enums": @["import ./basetypes", "type"],
+  }.toTable
+
+  # enums
+  for thetype in api.findAll("type"):
+    if thetype.attr("category") == "bitmask" and not thetype.hasAttr("alias") and (not thetype.hasAttr("api") or thetype.attr("api") == "vulkan"):
+      let name = thetype.child("name")[0].text
+      outputFiles["enums"].add &"  {name}* = distinct VkFlags"
+  for theenum in api.findAll("enums"):
+    outputFiles["enums"].add serializeEnum(theenum, api)
+
+  # structs and function types need to be in same "type" block to avoid forward-declarations
+  outputFiles["structs"].add serializeFunctiontypes(api)
+  for thetype in api.findAll("type"):
+    if thetype.attr("category") == "struct" or thetype.attr("category") == "union":
+      var outfile = "structs"
+      if thetype.attr("name") in platformTypes:
+        outfile = "platform/" & platformTypes[thetype.attr("name")]
+      if not (outfile in outputFiles):
+        outputFiles[outfile] = @[]
+      outputFiles[outfile].add "type"
+      outputFiles[outfile].add serializeStruct(thetype, api)
+
+  # types
+  for typesgroup in api.findAll("types"):
+    for thetype in typesgroup.findAll("type"):
+      outputFiles.update serializeType(thetype)
+  for filename, filecontent in outputFiles.pairs:
+    writeFile outdir / &"{filename}.nim", filecontent.join("\n")
+
+when isMainModule:
+  main()