Add emscripten support

.gitmodules

@@ -5,3 +5,6 @@
 [submodule "generator/third_party/dawn"]
 	path = generator/third_party/dawn
 	url = https://dawn.googlesource.com/dawn
+[submodule "generator/third_party/emscripten"]
+	path = generator/third_party/emscripten
+	url = https://github.com/emscripten-core/emscripten

generator/cli.nim

@@ -1,20 +1,24 @@
 import common
 import gen_wgpu
 import gen_dawn
+import gen_emscripten
 
 import std/os
 import pkg/cligen
 
 type Bindings {.pure.} = enum
   `wgpu-native`
   dawn
+  emscripten
 
 func generatedFolder(b: Bindings): string=
   case b:
     of dawn:
       "dawn"
     of `wgpu-native`:
       "wgpu_native"
+    of emscripten:
+      "emscripten"
 
 proc cli(bindings: Bindings, release: bool = false, `out`: string)=
   const thirdPartyDir = currentSourcePath.parentDir/"third_party"
@@ -37,5 +41,11 @@ proc cli(bindings: Bindings, release: bool = false, `out`: string)=
         settings: settings,
         wgpuDir: thirdPartyDir/"wgpu-native"
       ).generate(`out`)
+
+    of emscripten:
+      EmscriptenGenerator(
+        settings: settings,
+        emscriptenDir: thirdPartyDir/"emscripten"
+      ).generate(`out`)
 
 dispatch cli

generator/gen_emscripten.nim

@@ -0,0 +1,28 @@
+import common, helpers
+
+import pkg/oolib
+import std/[options, os]
+
+class pub EmscriptenGenerator:
+  var
+    settings*: GeneratorSettings
+    emscriptenDir*: string
+
+    webgpuHeader: string
+
+  func preproc =
+    self.webgpuHeader = preprocWebgpuHeader(
+      self.webgpuHeader,
+      "", "importc"
+    )
+
+  proc generate: GeneratedFile =
+    self.webgpuHeader = readFile(
+      self.emscriptenDir/"system/include/webgpu/webgpu.h"
+    )
+    self.preproc()
+
+    ("webgpu.nim", c2nim(self.webgpuHeader).get)
+
+  iterator virtualFS*(): GeneratedFile=
+    yield self.generate()

nimgpu.nimble

@@ -28,4 +28,5 @@ macro generateTask(name: untyped{ident}, bindings: static string): untyped=
     taskRequires `nameStr`, "https://github.com/ASVIEST/c2nim#fix-clib"
 
 generateTask(generate_wgpu, "wgpu-native")
-generateTask(generate_dawn, "dawn")
+generateTask(generate_dawn, "dawn")
+generateTask(generate_emscripten, "emscripten")

src/nimgpu/emscripten.nim

@@ -0,0 +1,2 @@
+import emscripten/webgpu
+export webgpu