Add option to draw images with WebGL

2025-12-15 20:08:30 +00:00 · 2017-10-06 10:29:21 +02:00
parent f36a47b9a2
commit a9c82d2d6e
4 changed files with 124 additions and 17 deletions
--- a/README.md
+++ b/README.md
@@ -18,10 +18,10 @@ or

 Binaries are compiled with static OpenCV library:

- - [Android 32bit](https://github.com/gen2brain/cam2ip/releases/download/1.1/cam2ip-1.1-android.tar.gz)
- - [Linux 64bit](https://github.com/gen2brain/cam2ip/releases/download/1.1/cam2ip-1.1-64bit.tar.gz)
- - [RPi 32bit](https://github.com/gen2brain/cam2ip/releases/download/1.1/cam2ip-1.1-RPi.tar.gz)
- - [Windows 32bit](https://github.com/gen2brain/cam2ip/releases/download/1.1/cam2ip-1.1.zip)
+ - [Android 32bit](https://github.com/gen2brain/cam2ip/releases/download/1.2/cam2ip-1.2-android.tar.gz)
+ - [Linux 64bit](https://github.com/gen2brain/cam2ip/releases/download/1.2/cam2ip-1.2-64bit.tar.gz)
+ - [RPi 32bit](https://github.com/gen2brain/cam2ip/releases/download/1.2/cam2ip-1.2-RPi.tar.gz)
+ - [Windows 32bit](https://github.com/gen2brain/cam2ip/releases/download/1.2/cam2ip-1.2.zip)


 ### Installation
@@ -35,17 +35,19 @@ This will install app in `$GOPATH/bin/cam2ip`.
 ```
 Usage of ./cam2ip:
  -bind-addr string
-    	Bind address (default ":56000")
+        Bind address (default ":56000")
  -delay int
-    	Delay between frames, in milliseconds (default 10)
+        Delay between frames, in milliseconds (default 10)
  -frame-height float
-    	Frame height (default 480)
+        Frame height (default 480)
  -frame-width float
-    	Frame width (default 640)
+        Frame width (default 640)
  -htpasswd-file string
-    	Path to htpasswd file, if empty auth is disabled
+        Path to htpasswd file, if empty auth is disabled
  -index int
-    	Camera index
+        Camera index
+  -webgl
+        Use WebGL to draw images
 ```

 ### Handlers
--- a/cam2ip.go
+++ b/cam2ip.go
@@ -21,6 +21,7 @@ func main() {
 	flag.IntVar(&srv.Delay, "delay", 10, "Delay between frames, in milliseconds")
 	flag.Float64Var(&srv.FrameWidth, "frame-width", 640, "Frame width")
 	flag.Float64Var(&srv.FrameHeight, "frame-height", 480, "Frame height")
+	flag.BoolVar(&srv.WebGL, "webgl", false, "Use WebGL to draw images")
 	flag.StringVar(&srv.Bind, "bind-addr", ":56000", "Bind address")
 	flag.StringVar(&srv.Htpasswd, "htpasswd-file", "", "Path to htpasswd file, if empty auth is disabled")
 	flag.Parse()
--- a/handlers/html.go
+++ b/handlers/html.go
@@ -13,7 +13,7 @@ type HTML struct {
 }

 // NewHTML returns new HTML handler.
-func NewHTML(bind string, width, height float64) *HTML {
+func NewHTML(bind string, width, height float64, gl bool) *HTML {
 	h := &HTML{}

 	b := strings.Split(bind, ":")
@@ -21,11 +21,16 @@ func NewHTML(bind string, width, height float64) *HTML {
 		bind = "127.0.0.1" + bind
 	}

-	html = strings.Replace(html, "{BIND}", bind, -1)
-	html = strings.Replace(html, "{WIDTH}", fmt.Sprintf("%.0f", width), -1)
-	html = strings.Replace(html, "{HEIGHT}", fmt.Sprintf("%.0f", height), -1)
+	tpl := html
+	if gl {
+		tpl = htmlWebGL
+	}

-	h.Template = []byte(html)
+	tpl = strings.Replace(tpl, "{BIND}", bind, -1)
+	tpl = strings.Replace(tpl, "{WIDTH}", fmt.Sprintf("%.0f", width), -1)
+	tpl = strings.Replace(tpl, "{HEIGHT}", fmt.Sprintf("%.0f", height), -1)
+
+	h.Template = []byte(tpl)
 	return h
 }

@@ -51,7 +56,7 @@ var html = `<html>
        var image = new Image();

        ws.onopen = function() {
-            var context = document.getElementById("canvas").getContext("2d");
+            var context = document.getElementById("canvas").getContext("2d", {alpha: false});
            image.onload = function() {
                context.drawImage(image, 0, 0);
            }
@@ -72,3 +77,101 @@ var html = `<html>
        </table>
    </body>
 </html>`
+
+var htmlWebGL = `<html>
+    <head>
+        <meta charset="utf-8"/>
+        <title>cam2ip</title>
+        <script>
+		var texture, vloc, tloc, vertexBuff, textureBuff;
+
+		ws = new WebSocket("ws://{BIND}/socket");
+		var image = new Image();
+
+		ws.onopen = function() {
+			var gl = document.getElementById('canvas').getContext('webgl');
+
+			var vertexShaderSrc =
+				"attribute vec2 aVertex;" +
+				"attribute vec2 aUV;" +
+				"varying vec2 vTex;" +
+				"void main(void) {" +
+				"  gl_Position = vec4(aVertex, 0.0, 1.0);" +
+				"  vTex = aUV;" +
+				"}";
+
+			var fragmentShaderSrc =
+				"precision mediump float;" +
+				"varying vec2 vTex;" +
+				"uniform sampler2D sampler0;" +
+				"void main(void){" +
+				"  gl_FragColor = texture2D(sampler0, vTex);"+
+				"}";
+
+			var vertShaderObj = gl.createShader(gl.VERTEX_SHADER);
+			var fragShaderObj = gl.createShader(gl.FRAGMENT_SHADER);
+			gl.shaderSource(vertShaderObj, vertexShaderSrc);
+			gl.shaderSource(fragShaderObj, fragmentShaderSrc);
+			gl.compileShader(vertShaderObj);
+			gl.compileShader(fragShaderObj);
+
+			var program = gl.createProgram();
+			gl.attachShader(program, vertShaderObj);
+			gl.attachShader(program, fragShaderObj);
+
+			gl.linkProgram(program);
+			gl.useProgram(program);
+
+			gl.viewport(0, 0, {WIDTH}, {HEIGHT});
+
+			vertexBuff = gl.createBuffer();
+			gl.bindBuffer(gl.ARRAY_BUFFER, vertexBuff);
+			gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([-1, 1, -1, -1, 1, -1, 1, 1]), gl.STATIC_DRAW);
+
+			textureBuff = gl.createBuffer();
+			gl.bindBuffer(gl.ARRAY_BUFFER, textureBuff);
+			gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([0, 1, 0, 0, 1, 0, 1, 1]), gl.STATIC_DRAW);
+
+			vloc = gl.getAttribLocation(program, "aVertex");
+			tloc = gl.getAttribLocation(program, "aUV");
+
+			texture = gl.createTexture();
+
+			image.onload = function() {
+				gl.bindTexture(gl.TEXTURE_2D, texture);
+
+				gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
+				gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
+				gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
+				gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
+
+				gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, true);
+				gl.texImage2D(gl.TEXTURE_2D, 0,  gl.RGBA,  gl.RGBA, gl.UNSIGNED_BYTE, image);
+
+				gl.bindBuffer(gl.ARRAY_BUFFER, vertexBuff);
+				gl.enableVertexAttribArray(vloc);
+				gl.vertexAttribPointer(vloc, 2, gl.FLOAT, false, 0, 0);
+
+				gl.bindBuffer(gl.ARRAY_BUFFER, textureBuff);
+				gl.enableVertexAttribArray(tloc);
+				gl.vertexAttribPointer(tloc, 2, gl.FLOAT, false, 0, 0);
+
+				gl.drawArrays(gl.TRIANGLE_FAN, 0, 4);
+			}
+		}
+
+		ws.onmessage = function(e) {
+			image.setAttribute("src", "data:image/jpeg;base64," + e.data);
+		}
+        </script>
+    </head>
+    <body style="background-color: #000000">
+        <table style="width:100%; height:100%">
+            <tr style="height:100%">
+                <td style="height:100%; text-align:center">
+                    <canvas id="canvas" width="{WIDTH}" height="{HEIGHT}"></canvas>
+                </td>
+           </tr>
+        </table>
+    </body>
+</html>`
--- a/server/server.go
+++ b/server/server.go
@@ -24,6 +24,7 @@ type Server struct {
 	Delay       int
 	FrameWidth  float64
 	FrameHeight float64
+	WebGL       bool

 	Camera *camera.Camera
 }
@@ -42,7 +43,7 @@ func (s *Server) ListenAndServe() error {
 		basic = auth.NewBasicAuthenticator(realm, auth.HtpasswdFileProvider(s.Htpasswd))
 	}

-	http.Handle("/html", newAuthHandler(handlers.NewHTML(s.Bind, s.FrameWidth, s.FrameHeight), basic))
+	http.Handle("/html", newAuthHandler(handlers.NewHTML(s.Bind, s.FrameWidth, s.FrameHeight, s.WebGL), basic))
 	http.Handle("/jpeg", newAuthHandler(handlers.NewJPEG(s.Camera), basic))
 	http.Handle("/mjpeg", newAuthHandler(handlers.NewMJPEG(s.Camera, s.Delay), basic))