diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..19e1bce
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+*.wasm
diff --git a/canvas/draw.go b/canvas/draw.go
index f16381c..a9a26a3 100644
--- a/canvas/draw.go
+++ b/canvas/draw.go
@@ -4,7 +4,7 @@ import (
"fmt"
"syscall/js"
- "git.kirsle.net/apps/doodle/lib/render"
+ "git.kirsle.net/go/render"
)
// Methods here implement the drawing functions of the render.Engine
diff --git a/canvas/engine.go b/canvas/engine.go
index ab458cf..3ae6dce 100644
--- a/canvas/engine.go
+++ b/canvas/engine.go
@@ -4,7 +4,7 @@ import (
"syscall/js"
"time"
- "git.kirsle.net/apps/doodle/lib/render/event"
+ "git.kirsle.net/go/render/event"
)
// Engine implements a rendering engine targeting an HTML canvas for
diff --git a/canvas/events.go b/canvas/events.go
index 7b20f91..bdb2862 100644
--- a/canvas/events.go
+++ b/canvas/events.go
@@ -3,7 +3,7 @@ package canvas
import (
"syscall/js"
- "git.kirsle.net/apps/doodle/lib/render/event"
+ "git.kirsle.net/go/render/event"
)
// EventClass to categorize JavaScript events.
diff --git a/canvas/text.go b/canvas/text.go
index a4ce4aa..43c2288 100644
--- a/canvas/text.go
+++ b/canvas/text.go
@@ -7,7 +7,7 @@ import (
"path/filepath"
"strings"
- "git.kirsle.net/apps/doodle/lib/render"
+ "git.kirsle.net/go/render"
)
// FontFilenameToName converts a FontFilename to its CSS font name.
diff --git a/canvas/texture.go b/canvas/texture.go
index be6da8a..2428e8d 100644
--- a/canvas/texture.go
+++ b/canvas/texture.go
@@ -8,7 +8,7 @@ import (
"image/png"
"syscall/js"
- "git.kirsle.net/apps/doodle/lib/render"
+ "git.kirsle.net/go/render"
)
// Texture can hold on to cached image textures.
diff --git a/examples/hello-wasm/DejaVuSans.ttf b/examples/hello-wasm/DejaVuSans.ttf
new file mode 100644
index 0000000..a5f96b7
Binary files /dev/null and b/examples/hello-wasm/DejaVuSans.ttf differ
diff --git a/examples/hello-wasm/Makefile b/examples/hello-wasm/Makefile
new file mode 100644
index 0000000..f6fe0b3
--- /dev/null
+++ b/examples/hello-wasm/Makefile
@@ -0,0 +1,11 @@
+.PHONY: build
+build:
+ GOOS=js GOARCH=wasm go build -v -o hello.wasm main_wasm.go
+
+.PHONY: serve
+serve: build
+ go run server.go
+
+.PHONY: clean
+clean:
+ rm -f hello.wasm
diff --git a/examples/hello-wasm/README.md b/examples/hello-wasm/README.md
new file mode 100644
index 0000000..5574532
--- /dev/null
+++ b/examples/hello-wasm/README.md
@@ -0,0 +1,81 @@
+# Hello WASM
+
+This is a port of the "hello-world" example for a WebAssembly target.
+
+Differences compared to the SDL2 version include:
+
+* Import render/canvas instead of render/sdl
+* Load the gopher.png via ajax HTTP request, as the syscall to open a file from
+ disk is not supported in a WASM environment.
+* A call to the `canvas.AddEventListeners()` function to set up DOM event
+ bindings, which enables key and mouse events to be handled in the
+ canvas.Engine.
+
+```diff
+--- ../hello-world/main.go 2019-12-22 15:17:42.186838967 -0800
++++ main_wasm.go 2019-12-22 16:21:58.449699021 -0800
+@@ -1,13 +1,17 @@
++// +build js,wasm
++
++// This is a version of the 'hello-world' example but build for WebAssembly.
++
+ package main
+
+ import (
+ "image/png"
+ "log"
+- "os"
++ "net/http"
+ "time"
+
+ "git.kirsle.net/go/render"
+- "git.kirsle.net/go/render/sdl"
++ "git.kirsle.net/go/render/canvas"
+ )
+
+ var (
+@@ -30,7 +34,11 @@
+ )
+
+ func main() {
+- mw := sdl.New("Hello World", 800, 600)
++ mw, _ := canvas.New("canvas")
+ setup(mw)
+
+ for {
+@@ -61,17 +69,22 @@
+ }
+ }
+
+-func setup(e render.Engine) {
++func setup(e *canvas.Engine) {
+ if err := e.Setup(); err != nil {
+ panic(err)
+ }
+
+- // Load gopher sprite.
+- fh, err := os.Open("gopher.png")
++ // Bind DOM event handlers.
++ e.AddEventListeners()
++
++ // Load gopher sprite via ajax request.
++ resp, err := http.Get("gopher.png")
+ if err != nil {
+ log.Fatalf("read gopher.png: %s", err)
+ }
++ defer resp.Body.Close()
+
+- img, _ := png.Decode(fh)
++ img, _ := png.Decode(resp.Body)
+
+ gopher, _ = e.StoreTexture("gopher.png", img)
+ texSize = gopher.Size()
+```
+
+## Credits
+
+Gopher image was created by Takuya Ueda (https://twitter.com/tenntenn)
+from https://github.com/golang-samples/gopher-vector
+
+This example comes with the DejaVu Sans font. License information
+at https://dejavu-fonts.github.io/License.html
diff --git a/examples/hello-wasm/gopher.png b/examples/hello-wasm/gopher.png
new file mode 100644
index 0000000..a4c4f68
Binary files /dev/null and b/examples/hello-wasm/gopher.png differ
diff --git a/examples/hello-wasm/index.html b/examples/hello-wasm/index.html
new file mode 100644
index 0000000..a1d353c
--- /dev/null
+++ b/examples/hello-wasm/index.html
@@ -0,0 +1,46 @@
+
+
+
+ go/render: hello wasm!
+
+
+
+
+
+
+
+
+
+
+
diff --git a/examples/hello-wasm/main_wasm.go b/examples/hello-wasm/main_wasm.go
new file mode 100644
index 0000000..9220f1e
--- /dev/null
+++ b/examples/hello-wasm/main_wasm.go
@@ -0,0 +1,177 @@
+// +build js,wasm
+
+// This is a version of the 'hello-world' example but build for WebAssembly.
+
+package main
+
+import (
+ "image/png"
+ "log"
+ "net/http"
+ "time"
+
+ "git.kirsle.net/go/render"
+ "git.kirsle.net/go/render/canvas"
+)
+
+var (
+ // Cap animation speed to 60 FPS
+ targetFPS = 1000 / 60
+
+ // Gopher sprite variables
+ gopher render.Texturer
+ texSize render.Rect
+ speed int32 = 4
+ position = render.NewPoint(0, 0)
+ velocity = render.NewPoint(speed, speed)
+
+ // Decorative border variables
+ borderColor = render.Red
+ borderSize int32 = 12
+
+ // Background color of the window.
+ bgColor = render.RGBA(255, 255, 128, 255)
+)
+
+func main() {
+ // Parameter to New() is the HTML Canvas ID.
+ mw, err := canvas.New("canvas")
+ if err != nil {
+ panic(err)
+ }
+ setup(mw)
+
+ for {
+ start := time.Now()
+
+ ev, err := mw.Poll()
+ if err != nil {
+ panic(err)
+ }
+
+ if ev.Escape {
+ mw.Teardown()
+ break
+ }
+
+ update(mw)
+ draw(mw)
+ mw.Present()
+
+ // Delay to maintain constant 60 FPS.
+ var delay uint32
+ elapsed := time.Now().Sub(start)
+ tmp := elapsed / time.Millisecond
+ if targetFPS-int(tmp) > 0 {
+ delay = uint32(targetFPS - int(tmp))
+ }
+ mw.Delay(delay)
+ }
+}
+
+func setup(e *canvas.Engine) {
+ if err := e.Setup(); err != nil {
+ panic(err)
+ }
+
+ // Bind DOM event handlers.
+ e.AddEventListeners()
+
+ // Load gopher sprite via ajax request.
+ resp, err := http.Get("gopher.png")
+ if err != nil {
+ log.Fatalf("GET gopher.png: %s", err)
+ }
+ defer resp.Body.Close()
+
+ img, _ := png.Decode(resp.Body)
+
+ gopher, _ = e.StoreTexture("gopher.png", img)
+ texSize = gopher.Size()
+}
+
+func update(e render.Engine) {
+ position.X += velocity.X
+ position.Y += velocity.Y
+
+ // Bounce off the walls.
+ w, h := e.WindowSize()
+
+ if velocity.X > 0 && position.X+texSize.W >= int32(w)-borderSize {
+ velocity.X *= -1
+ } else if velocity.X < 0 && position.X <= borderSize {
+ velocity.X *= -1
+ }
+
+ if velocity.Y > 0 && position.Y+texSize.H >= int32(h)-borderSize {
+ velocity.Y *= -1
+ } else if velocity.Y < 0 && position.Y <= borderSize {
+ velocity.Y *= -1
+ }
+}
+
+func draw(e render.Engine) {
+ w, h := e.WindowSize()
+
+ drawBorder(e, w, h)
+
+ // Draw some text centered along the top of the canvas.
+ text := render.Text{
+ Text: "Hello, world!",
+ Size: 24,
+ Color: render.SkyBlue,
+ Shadow: render.Blue,
+ FontFilename: "DejaVuSans.ttf",
+ }
+ rect, _ := e.ComputeTextRect(text)
+ e.DrawText(text, render.NewPoint(
+ (int32(w)/2)-(rect.W/2),
+ 25,
+ ))
+
+ e.Copy(gopher, texSize, render.Rect{
+ X: position.X,
+ Y: position.Y,
+ W: texSize.W,
+ H: texSize.H,
+ })
+}
+
+func drawBorder(e render.Engine, w, h int) {
+ // Draw the decorative border. We're going for a "ridged" border
+ // style here. First draw the light and dark edges of the top/left
+ // sides of the border.
+ e.DrawBox(borderColor.Lighten(40), render.Rect{
+ X: 0,
+ Y: 0,
+ W: int32(w),
+ H: int32(h),
+ })
+ e.DrawBox(borderColor.Darken(40), render.Rect{
+ X: borderSize / 2,
+ Y: borderSize / 2,
+ W: int32(w) - (borderSize / 2),
+ H: int32(h) - (borderSize / 2),
+ })
+
+ // Now inset a bit and draw the light/dark edges of the bottom/right.
+ e.DrawBox(borderColor.Darken(40), render.Rect{
+ X: borderSize,
+ Y: borderSize,
+ W: int32(w),
+ H: int32(h),
+ })
+ e.DrawBox(borderColor.Lighten(40), render.Rect{
+ X: borderSize,
+ Y: borderSize,
+ W: int32(w) - borderSize - (borderSize / 2),
+ H: int32(h) - borderSize - (borderSize / 2),
+ })
+
+ e.DrawBox(bgColor, render.Rect{
+ X: borderSize,
+ Y: borderSize,
+ W: int32(w) - (borderSize * 2),
+ H: int32(h) - (borderSize * 2),
+ })
+}
diff --git a/examples/hello-wasm/server.go b/examples/hello-wasm/server.go
new file mode 100644
index 0000000..919b57a
--- /dev/null
+++ b/examples/hello-wasm/server.go
@@ -0,0 +1,127 @@
+// +build disabled
+
+package main
+
+import (
+ "fmt"
+ "io/ioutil"
+ "log"
+ "net/http"
+ "os/exec"
+ "path/filepath"
+
+ "github.com/fsnotify/fsnotify"
+)
+
+func main() {
+ const wasm = "/doodle.wasm"
+
+ // Watch the dev directory for changes.
+ go watchChanges()
+
+ http.Handle("/", http.FileServer(http.Dir(".")))
+ http.HandleFunc(wasm, func(w http.ResponseWriter, r *http.Request) {
+ w.Header().Set("Content-Type", "application/wasm")
+ http.ServeFile(w, r, "."+wasm)
+ })
+
+ fmt.Println("Listening at http://localhost:8080/")
+ log.Fatal(http.ListenAndServe(":8080", nil))
+}
+
+// onChange handler to rebuild the wasm file automatically.
+func onChange() {
+ out, err := exec.Command("make").Output()
+ if err != nil {
+ log.Printf("error: %s", err)
+ }
+ log.Printf("%s", out)
+ log.Printf("Doodle WASM file rebuilt")
+}
+
+// Watch the Doodle source tree for changes to Go files and rebuild
+// the wasm binary automatically.
+func watchChanges() {
+ watcher, err := fsnotify.NewWatcher()
+ if err != nil {
+ log.Printf("error: %s", err)
+ return
+ }
+ defer watcher.Close()
+
+ done := make(chan bool)
+ go func() {
+ log.Println("Starting watch files loop")
+ for {
+ select {
+ case event, ok := <-watcher.Events:
+ if !ok {
+ return
+ }
+
+ log.Printf("event: %s", event)
+ if event.Op&fsnotify.Write == fsnotify.Write {
+ log.Printf("modified file: %s", event.Name)
+ onChange()
+ }
+ case err, ok := <-watcher.Errors:
+ if !ok {
+ return
+ }
+
+ log.Printf("error: %s", err)
+ }
+ }
+ }()
+
+ log.Println("Adding source directory to watcher")
+ dirs := crawlDirectory("../")
+
+ // Watch all these folders.
+ for _, dir := range dirs {
+ err = watcher.Add(dir)
+ if err != nil {
+ log.Printf("error: %s", err)
+ }
+ }
+ <-done
+}
+
+// Crawl the filesystem and return paths with Go files.
+func crawlDirectory(root string) []string {
+ var (
+ ext = ".go"
+ result []string
+ has bool
+ )
+
+ files, err := ioutil.ReadDir(root)
+ if err != nil {
+ log.Fatalln(err)
+ }
+
+ for _, file := range files {
+ if file.Name() == ".git" {
+ continue
+ }
+
+ // Recursively scan subdirectories.
+ if file.IsDir() {
+ result = append(result,
+ crawlDirectory(filepath.Join(root, file.Name()))...,
+ )
+ continue
+ }
+
+ // This root has a file we want?
+ if filepath.Ext(file.Name()) == ext {
+ has = true
+ }
+ }
+
+ if has {
+ result = append(result, root)
+ }
+
+ return result
+}
diff --git a/examples/hello-wasm/wasm_exec.js b/examples/hello-wasm/wasm_exec.js
new file mode 100644
index 0000000..a54bb9a
--- /dev/null
+++ b/examples/hello-wasm/wasm_exec.js
@@ -0,0 +1,533 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+(() => {
+ // Map multiple JavaScript environments to a single common API,
+ // preferring web standards over Node.js API.
+ //
+ // Environments considered:
+ // - Browsers
+ // - Node.js
+ // - Electron
+ // - Parcel
+
+ if (typeof global !== "undefined") {
+ // global already exists
+ } else if (typeof window !== "undefined") {
+ window.global = window;
+ } else if (typeof self !== "undefined") {
+ self.global = self;
+ } else {
+ throw new Error("cannot export Go (neither global, window nor self is defined)");
+ }
+
+ if (!global.require && typeof require !== "undefined") {
+ global.require = require;
+ }
+
+ if (!global.fs && global.require) {
+ global.fs = require("fs");
+ }
+
+ if (!global.fs) {
+ let outputBuf = "";
+ global.fs = {
+ constants: { O_WRONLY: -1, O_RDWR: -1, O_CREAT: -1, O_TRUNC: -1, O_APPEND: -1, O_EXCL: -1 }, // unused
+ writeSync(fd, buf) {
+ outputBuf += decoder.decode(buf);
+ const nl = outputBuf.lastIndexOf("\n");
+ if (nl != -1) {
+ console.log(outputBuf.substr(0, nl));
+ outputBuf = outputBuf.substr(nl + 1);
+ }
+ return buf.length;
+ },
+ write(fd, buf, offset, length, position, callback) {
+ if (offset !== 0 || length !== buf.length || position !== null) {
+ throw new Error("not implemented");
+ }
+ const n = this.writeSync(fd, buf);
+ callback(null, n);
+ },
+ open(path, flags, mode, callback) {
+ const err = new Error("not implemented");
+ err.code = "ENOSYS";
+ callback(err);
+ },
+ read(fd, buffer, offset, length, position, callback) {
+ const err = new Error("not implemented");
+ err.code = "ENOSYS";
+ callback(err);
+ },
+ fsync(fd, callback) {
+ callback(null);
+ },
+ };
+ }
+
+ if (!global.crypto) {
+ const nodeCrypto = require("crypto");
+ global.crypto = {
+ getRandomValues(b) {
+ nodeCrypto.randomFillSync(b);
+ },
+ };
+ }
+
+ if (!global.performance) {
+ global.performance = {
+ now() {
+ const [sec, nsec] = process.hrtime();
+ return sec * 1000 + nsec / 1000000;
+ },
+ };
+ }
+
+ if (!global.TextEncoder) {
+ global.TextEncoder = require("util").TextEncoder;
+ }
+
+ if (!global.TextDecoder) {
+ global.TextDecoder = require("util").TextDecoder;
+ }
+
+ // End of polyfills for common API.
+
+ const encoder = new TextEncoder("utf-8");
+ const decoder = new TextDecoder("utf-8");
+
+ global.Go = class {
+ constructor() {
+ this.argv = ["js"];
+ this.env = {};
+ this.exit = (code) => {
+ if (code !== 0) {
+ console.warn("exit code:", code);
+ }
+ };
+ this._exitPromise = new Promise((resolve) => {
+ this._resolveExitPromise = resolve;
+ });
+ this._pendingEvent = null;
+ this._scheduledTimeouts = new Map();
+ this._nextCallbackTimeoutID = 1;
+
+ const mem = () => {
+ // The buffer may change when requesting more memory.
+ return new DataView(this._inst.exports.mem.buffer);
+ }
+
+ const setInt64 = (addr, v) => {
+ mem().setUint32(addr + 0, v, true);
+ mem().setUint32(addr + 4, Math.floor(v / 4294967296), true);
+ }
+
+ const getInt64 = (addr) => {
+ const low = mem().getUint32(addr + 0, true);
+ const high = mem().getInt32(addr + 4, true);
+ return low + high * 4294967296;
+ }
+
+ const loadValue = (addr) => {
+ const f = mem().getFloat64(addr, true);
+ if (f === 0) {
+ return undefined;
+ }
+ if (!isNaN(f)) {
+ return f;
+ }
+
+ const id = mem().getUint32(addr, true);
+ return this._values[id];
+ }
+
+ const storeValue = (addr, v) => {
+ const nanHead = 0x7FF80000;
+
+ if (typeof v === "number") {
+ if (isNaN(v)) {
+ mem().setUint32(addr + 4, nanHead, true);
+ mem().setUint32(addr, 0, true);
+ return;
+ }
+ if (v === 0) {
+ mem().setUint32(addr + 4, nanHead, true);
+ mem().setUint32(addr, 1, true);
+ return;
+ }
+ mem().setFloat64(addr, v, true);
+ return;
+ }
+
+ switch (v) {
+ case undefined:
+ mem().setFloat64(addr, 0, true);
+ return;
+ case null:
+ mem().setUint32(addr + 4, nanHead, true);
+ mem().setUint32(addr, 2, true);
+ return;
+ case true:
+ mem().setUint32(addr + 4, nanHead, true);
+ mem().setUint32(addr, 3, true);
+ return;
+ case false:
+ mem().setUint32(addr + 4, nanHead, true);
+ mem().setUint32(addr, 4, true);
+ return;
+ }
+
+ let ref = this._refs.get(v);
+ if (ref === undefined) {
+ ref = this._values.length;
+ this._values.push(v);
+ this._refs.set(v, ref);
+ }
+ let typeFlag = 0;
+ switch (typeof v) {
+ case "string":
+ typeFlag = 1;
+ break;
+ case "symbol":
+ typeFlag = 2;
+ break;
+ case "function":
+ typeFlag = 3;
+ break;
+ }
+ mem().setUint32(addr + 4, nanHead | typeFlag, true);
+ mem().setUint32(addr, ref, true);
+ }
+
+ const loadSlice = (addr) => {
+ const array = getInt64(addr + 0);
+ const len = getInt64(addr + 8);
+ return new Uint8Array(this._inst.exports.mem.buffer, array, len);
+ }
+
+ const loadSliceOfValues = (addr) => {
+ const array = getInt64(addr + 0);
+ const len = getInt64(addr + 8);
+ const a = new Array(len);
+ for (let i = 0; i < len; i++) {
+ a[i] = loadValue(array + i * 8);
+ }
+ return a;
+ }
+
+ const loadString = (addr) => {
+ const saddr = getInt64(addr + 0);
+ const len = getInt64(addr + 8);
+ return decoder.decode(new DataView(this._inst.exports.mem.buffer, saddr, len));
+ }
+
+ const timeOrigin = Date.now() - performance.now();
+ this.importObject = {
+ go: {
+ // Go's SP does not change as long as no Go code is running. Some operations (e.g. calls, getters and setters)
+ // may synchronously trigger a Go event handler. This makes Go code get executed in the middle of the imported
+ // function. A goroutine can switch to a new stack if the current stack is too small (see morestack function).
+ // This changes the SP, thus we have to update the SP used by the imported function.
+
+ // func wasmExit(code int32)
+ "runtime.wasmExit": (sp) => {
+ const code = mem().getInt32(sp + 8, true);
+ this.exited = true;
+ delete this._inst;
+ delete this._values;
+ delete this._refs;
+ this.exit(code);
+ },
+
+ // func wasmWrite(fd uintptr, p unsafe.Pointer, n int32)
+ "runtime.wasmWrite": (sp) => {
+ const fd = getInt64(sp + 8);
+ const p = getInt64(sp + 16);
+ const n = mem().getInt32(sp + 24, true);
+ fs.writeSync(fd, new Uint8Array(this._inst.exports.mem.buffer, p, n));
+ },
+
+ // func nanotime() int64
+ "runtime.nanotime": (sp) => {
+ setInt64(sp + 8, (timeOrigin + performance.now()) * 1000000);
+ },
+
+ // func walltime() (sec int64, nsec int32)
+ "runtime.walltime": (sp) => {
+ const msec = (new Date).getTime();
+ setInt64(sp + 8, msec / 1000);
+ mem().setInt32(sp + 16, (msec % 1000) * 1000000, true);
+ },
+
+ // func scheduleTimeoutEvent(delay int64) int32
+ "runtime.scheduleTimeoutEvent": (sp) => {
+ const id = this._nextCallbackTimeoutID;
+ this._nextCallbackTimeoutID++;
+ this._scheduledTimeouts.set(id, setTimeout(
+ () => {
+ this._resume();
+ while (this._scheduledTimeouts.has(id)) {
+ // for some reason Go failed to register the timeout event, log and try again
+ // (temporary workaround for https://github.com/golang/go/issues/28975)
+ console.warn("scheduleTimeoutEvent: missed timeout event");
+ this._resume();
+ }
+ },
+ getInt64(sp + 8) + 1, // setTimeout has been seen to fire up to 1 millisecond early
+ ));
+ mem().setInt32(sp + 16, id, true);
+ },
+
+ // func clearTimeoutEvent(id int32)
+ "runtime.clearTimeoutEvent": (sp) => {
+ const id = mem().getInt32(sp + 8, true);
+ clearTimeout(this._scheduledTimeouts.get(id));
+ this._scheduledTimeouts.delete(id);
+ },
+
+ // func getRandomData(r []byte)
+ "runtime.getRandomData": (sp) => {
+ crypto.getRandomValues(loadSlice(sp + 8));
+ },
+
+ // func stringVal(value string) ref
+ "syscall/js.stringVal": (sp) => {
+ storeValue(sp + 24, loadString(sp + 8));
+ },
+
+ // func valueGet(v ref, p string) ref
+ "syscall/js.valueGet": (sp) => {
+ const result = Reflect.get(loadValue(sp + 8), loadString(sp + 16));
+ sp = this._inst.exports.getsp(); // see comment above
+ storeValue(sp + 32, result);
+ },
+
+ // func valueSet(v ref, p string, x ref)
+ "syscall/js.valueSet": (sp) => {
+ Reflect.set(loadValue(sp + 8), loadString(sp + 16), loadValue(sp + 32));
+ },
+
+ // func valueIndex(v ref, i int) ref
+ "syscall/js.valueIndex": (sp) => {
+ storeValue(sp + 24, Reflect.get(loadValue(sp + 8), getInt64(sp + 16)));
+ },
+
+ // valueSetIndex(v ref, i int, x ref)
+ "syscall/js.valueSetIndex": (sp) => {
+ Reflect.set(loadValue(sp + 8), getInt64(sp + 16), loadValue(sp + 24));
+ },
+
+ // func valueCall(v ref, m string, args []ref) (ref, bool)
+ "syscall/js.valueCall": (sp) => {
+ try {
+ const v = loadValue(sp + 8);
+ const m = Reflect.get(v, loadString(sp + 16));
+ const args = loadSliceOfValues(sp + 32);
+ const result = Reflect.apply(m, v, args);
+ sp = this._inst.exports.getsp(); // see comment above
+ storeValue(sp + 56, result);
+ mem().setUint8(sp + 64, 1);
+ } catch (err) {
+ storeValue(sp + 56, err);
+ mem().setUint8(sp + 64, 0);
+ }
+ },
+
+ // func valueInvoke(v ref, args []ref) (ref, bool)
+ "syscall/js.valueInvoke": (sp) => {
+ try {
+ const v = loadValue(sp + 8);
+ const args = loadSliceOfValues(sp + 16);
+ const result = Reflect.apply(v, undefined, args);
+ sp = this._inst.exports.getsp(); // see comment above
+ storeValue(sp + 40, result);
+ mem().setUint8(sp + 48, 1);
+ } catch (err) {
+ storeValue(sp + 40, err);
+ mem().setUint8(sp + 48, 0);
+ }
+ },
+
+ // func valueNew(v ref, args []ref) (ref, bool)
+ "syscall/js.valueNew": (sp) => {
+ try {
+ const v = loadValue(sp + 8);
+ const args = loadSliceOfValues(sp + 16);
+ const result = Reflect.construct(v, args);
+ sp = this._inst.exports.getsp(); // see comment above
+ storeValue(sp + 40, result);
+ mem().setUint8(sp + 48, 1);
+ } catch (err) {
+ storeValue(sp + 40, err);
+ mem().setUint8(sp + 48, 0);
+ }
+ },
+
+ // func valueLength(v ref) int
+ "syscall/js.valueLength": (sp) => {
+ setInt64(sp + 16, parseInt(loadValue(sp + 8).length));
+ },
+
+ // valuePrepareString(v ref) (ref, int)
+ "syscall/js.valuePrepareString": (sp) => {
+ const str = encoder.encode(String(loadValue(sp + 8)));
+ storeValue(sp + 16, str);
+ setInt64(sp + 24, str.length);
+ },
+
+ // valueLoadString(v ref, b []byte)
+ "syscall/js.valueLoadString": (sp) => {
+ const str = loadValue(sp + 8);
+ loadSlice(sp + 16).set(str);
+ },
+
+ // func valueInstanceOf(v ref, t ref) bool
+ "syscall/js.valueInstanceOf": (sp) => {
+ mem().setUint8(sp + 24, loadValue(sp + 8) instanceof loadValue(sp + 16));
+ },
+
+ // func copyBytesToGo(dst []byte, src ref) (int, bool)
+ "syscall/js.copyBytesToGo": (sp) => {
+ const dst = loadSlice(sp + 8);
+ const src = loadValue(sp + 32);
+ if (!(src instanceof Uint8Array)) {
+ mem().setUint8(sp + 48, 0);
+ return;
+ }
+ const toCopy = src.subarray(0, dst.length);
+ dst.set(toCopy);
+ setInt64(sp + 40, toCopy.length);
+ mem().setUint8(sp + 48, 1);
+ },
+
+ // func copyBytesToJS(dst ref, src []byte) (int, bool)
+ "syscall/js.copyBytesToJS": (sp) => {
+ const dst = loadValue(sp + 8);
+ const src = loadSlice(sp + 16);
+ if (!(dst instanceof Uint8Array)) {
+ mem().setUint8(sp + 48, 0);
+ return;
+ }
+ const toCopy = src.subarray(0, dst.length);
+ dst.set(toCopy);
+ setInt64(sp + 40, toCopy.length);
+ mem().setUint8(sp + 48, 1);
+ },
+
+ "debug": (value) => {
+ console.log(value);
+ },
+ }
+ };
+ }
+
+ async run(instance) {
+ this._inst = instance;
+ this._values = [ // TODO: garbage collection
+ NaN,
+ 0,
+ null,
+ true,
+ false,
+ global,
+ this,
+ ];
+ this._refs = new Map();
+ this.exited = false;
+
+ const mem = new DataView(this._inst.exports.mem.buffer)
+
+ // Pass command line arguments and environment variables to WebAssembly by writing them to the linear memory.
+ let offset = 4096;
+
+ const strPtr = (str) => {
+ const ptr = offset;
+ const bytes = encoder.encode(str + "\0");
+ new Uint8Array(mem.buffer, offset, bytes.length).set(bytes);
+ offset += bytes.length;
+ if (offset % 8 !== 0) {
+ offset += 8 - (offset % 8);
+ }
+ return ptr;
+ };
+
+ const argc = this.argv.length;
+
+ const argvPtrs = [];
+ this.argv.forEach((arg) => {
+ argvPtrs.push(strPtr(arg));
+ });
+
+ const keys = Object.keys(this.env).sort();
+ argvPtrs.push(keys.length);
+ keys.forEach((key) => {
+ argvPtrs.push(strPtr(`${key}=${this.env[key]}`));
+ });
+
+ const argv = offset;
+ argvPtrs.forEach((ptr) => {
+ mem.setUint32(offset, ptr, true);
+ mem.setUint32(offset + 4, 0, true);
+ offset += 8;
+ });
+
+ this._inst.exports.run(argc, argv);
+ if (this.exited) {
+ this._resolveExitPromise();
+ }
+ await this._exitPromise;
+ }
+
+ _resume() {
+ if (this.exited) {
+ throw new Error("Go program has already exited");
+ }
+ this._inst.exports.resume();
+ if (this.exited) {
+ this._resolveExitPromise();
+ }
+ }
+
+ _makeFuncWrapper(id) {
+ const go = this;
+ return function () {
+ const event = { id: id, this: this, args: arguments };
+ go._pendingEvent = event;
+ go._resume();
+ return event.result;
+ };
+ }
+ }
+
+ if (
+ global.require &&
+ global.require.main === module &&
+ global.process &&
+ global.process.versions &&
+ !global.process.versions.electron
+ ) {
+ if (process.argv.length < 3) {
+ console.error("usage: go_js_wasm_exec [wasm binary] [arguments]");
+ process.exit(1);
+ }
+
+ const go = new Go();
+ go.argv = process.argv.slice(2);
+ go.env = Object.assign({ TMPDIR: require("os").tmpdir() }, process.env);
+ go.exit = process.exit;
+ WebAssembly.instantiate(fs.readFileSync(process.argv[2]), go.importObject).then((result) => {
+ process.on("exit", (code) => { // Node.js exits if no event handler is pending
+ if (code === 0 && !go.exited) {
+ // deadlock, make Go print error and stack traces
+ go._pendingEvent = { id: 0 };
+ go._resume();
+ }
+ });
+ return go.run(result.instance);
+ }).catch((err) => {
+ console.error(err);
+ process.exit(1);
+ });
+ }
+})();