Added implementation for a wasm backend

README.md

@@ -1,41 +1,89 @@
-prototype
-=========
+# prototype
 
-Simply prototype 2D games using an easy, minimal interface that lets you draw simple primitives and images on the screen, easily handle mouse and keyboard events and play sounds.
+Simply prototype 2D games using an easy, minimal interface that lets you draw simple primitives and images on the screen, easily handle mouse and keyboard events, and play sounds.
 
 ![Games](https://github.com/gonutz/prototype/blob/master/samples/screenshots/games.png)
 
-Installation
-------------
+## Installation
 
 Install the [Go programming language](https://golang.org/dl/). After clicking the download link you will be referred to the installation instructions for your specific operating system.
 
-Install [Git](https://git-scm.com/downloads) and make it available in the PATH so the go tool can use it.
+Install [Git](https://git-scm.com/downloads) and make it available in the PATH so the Go tool can use it.
 
-For Linux and OS X you need a C compiler installed. On Windows this is not necessary.
+For Linux and macOS, you need a C compiler installed. On Windows this is not necessary.
 
-On Linux there are two backends available, GLFW and SDL2. For GLFW you need these libraries installed (tested on Linux Mint, other distros might be slightly different):
+### Supported Targets
 
-`libx11-dev libxrandr-dev libgl1-mesa-dev libxcursor-dev libxinerama-dev libxi-dev`
+The prototype framework supports multiple targets:
 
-GLFW is used by default. To use SDL2 you need to add `-tags sdl2` to your Go builds, e.g. `go run -tags sdl2 main.go`. Also you need the SDL2 libraries installed:
+#### Windows (default)
 
-`libsdl2-dev libsdl2-mixer-dev libsdl2-image-dev`
+- Uses Direct3D 9
+- No additional dependencies needed
 
+#### Linux/macOS (GLFW backend)
 
-Install the library and samples by running the following on your command line:
+- Uses OpenGL via GLFW
+- Install required packages (example for Ubuntu/Debian):
+  ```sh
+  sudo apt install libx11-dev libxrandr-dev libgl1-mesa-dev libxcursor-dev libxinerama-dev libxi-dev
+  ```
 
-	go get github.com/gonutz/prototype/...
+#### Linux (SDL2 backend)
 
-Documentation
--------------
+- Install SDL2 libraries:
+  ```sh
+  sudo apt install libsdl2-dev libsdl2-mixer-dev libsdl2-image-dev
+  ```
+- Use build tag:
+  ```sh
+  go run -tags sdl2 main.go
+  ```
 
-For a description of all library functions, see [the godoc page](http://godoc.org/github.com/gonutz/prototype/draw) for this project. Note that most of the functionality is in the Window interface and hence the descriptions are listed as code comments in the source for that type.
+#### WebAssembly (experimental)
 
-Example
--------
+- Implemented via HTML5 Canvas and Web Audio using `syscall/js`
+- Requires Go 1.21+
+- Compile using:
+  ```sh
+  GOOS=js GOARCH=wasm go build -o main.wasm
+  ```
+- Use a simple HTML wrapper with a canvas and `wasm_exec.js` (from Go installation):
+  ```html
+  <canvas id="gameCanvas" width="800" height="600" style="touch-action:none;"></canvas>
+  <script src="wasm_exec.js"></script>
+  <script>
+    const go = new Go();
+    WebAssembly.instantiateStreaming(fetch("main.wasm"), go.importObject).then((result) => {
+      go.run(result.instance);
+    });
+  </script>
+  ```
 
-```Go
+> [!NOTE]
+> The required `wasm_exec.js` file is included in the Go installation. You can find it in the `$(go env GOROOT)/misc/wasm` or `$(go env GOROOT)/lib/wasm` directory. Copy it to your project directory.
+
+To serve locally:
+
+```sh
+python3 -m http.server
+```
+
+## Installation (Library & Samples)
+
+Install the library and samples by running:
+
+```sh
+go get github.com/gonutz/prototype/...
+```
+
+## Documentation
+
+For a description of all library functions, see [the GoDoc page](http://godoc.org/github.com/gonutz/prototype/draw). Most functionality is in the `Window` interface, and documented via code comments.
+
+## Example
+
+```go
 package main
 
 import (
@@ -49,11 +97,9 @@ func main() {
 }
 
 func update(window draw.Window) {
-	// find the screen center
 	w, h := window.Size()
 	centerX, centerY := w/2, h/2
 
-	// draw a button in the center of the screen
 	mouseX, mouseY := window.MousePosition()
 	mouseInCircle := math.Hypot(float64(mouseX-centerX), float64(mouseY-centerY)) < 20
 	color := draw.DarkRed
@@ -66,16 +112,13 @@ func update(window draw.Window) {
 		window.DrawScaledText("Close!", centerX-40, centerY+25, 1.6, draw.Green)
 	}
 
-	// check all mouse clicks that happened during this frame
 	for _, click := range window.Clicks() {
 		dx, dy := click.X-centerX, click.Y-centerY
-		squareDist := dx*dx + dy*dy
-		if squareDist <= 20*20 {
-			// close the window and end the application
+		if dx*dx+dy*dy <= 20*20 {
 			window.Close()
 		}
 	}
 }
 ```
-	
-This example displays a window with a round button in the middle to close it. It demonstrates some basic drawing and event handling code.
+
+This example displays a window with a round button in the middle to close it. It demonstrates basic drawing and event handling.

draw/window_glfw.go

@@ -1,5 +1,6 @@
-//go:build glfw || (!windows && !sdl2)
+//go:build (glfw || (!windows && !sdl2)) && !js
 // +build glfw !windows,!sdl2
+// +build !js
 
 package draw
 

draw/window_sdl2.go

@@ -1,5 +1,5 @@
-//go:build sdl2 && !glfw
-// +build sdl2,!glfw
+//go:build sdl2 && !glfw && !js
+// +build sdl2,!glfw,!js
 
 package draw