Make a a webGL HTML document that provides Setereo side by side video that is captured from the desctop or any window with a distorted image in barrel distortion fir a proper 3D effect
Creating a WebGL HTML document that displays stereo side-by-side video with barrel distortion requires several steps. We'll use a simple approach to set up a web page with video elements and apply barrel distortion using fragment shaders.
### Note:
You will need a video capture mechanism to grab your desktop or window, which can be done with WebRTC or other methods, but for the sake of this example, we will simulate this with a video tag pointing to a source video.
### Example Code
Here's an example of a minimal HTML document that should accomplish your goal:
```html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Stereo Side-by-Side Video with Barrel Distortion</title>
<style>
body {
margin: 0;
display: flex;
justify-content: center;
align-items: center;
height: 100vh;
background-color: black;
}
canvas {
display: block;
}
</style>
</head>
<body>
<!-- Use a couple of video elements for stereo output -->
<video id="left" src="path_to_your_video.mp4" autoplay loop muted></video>
<video id="right" src="path_to_your_video.mp4" autoplay loop muted></video>
<canvas id="canvas"></canvas>
<script>
const canvas = document.getElementById('canvas');
const gl = canvas.getContext('webgl');
const leftVideo = document.getElementById('left');
const rightVideo = document.getElementById('right');
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
// Shader code
const vertexShaderSrc = `
attribute vec4 a_position;
varying vec2 v_texCoord;
void main() {
gl_Position = a_position;
v_texCoord = a_position.xy * 0.5 + 0.5;
}
`;
const fragmentShaderSrc = `
precision mediump float;
varying vec2 v_texCoord;
uniform sampler2D u_texture;
uniform float u_distortion;
vec2 barrelDistortion(vec2 uv, float k) {
vec2 center = vec2(0.5, 0.5);
vec2 delta = uv - center;
float r2 = dot(delta, delta);
return uv + delta * k * r2; // Barrel distortion equation
}
void main() {
vec2 distortedCoord = barrelDistortion(v_texCoord, u_distortion);
gl_FragColor = texture2D(u_texture, distortedCoord);
}
`;
function compileShader(gl, source, type) {
const shader = gl.createShader(type);
gl.shaderSource(shader, source);
gl.compileShader(shader);
if (gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
return shader;
} else {
console.error(gl.getShaderInfoLog(shader));
gl.deleteShader(shader);
}
}
const vertexShader = compileShader(gl, vertexShaderSrc, gl.VERTEX_SHADER);
const fragmentShader = compileShader(gl, fragmentShaderSrc, gl.FRAGMENT_SHADER);
const program = gl.createProgram();
gl.attachShader(program, vertexShader);
gl.attachShader(program, fragmentShader);
gl.linkProgram(program);
gl.useProgram(program);
// Buffer setup
const positions = new Float32Array([
-1, -1, 1, -1, -1, 1,
1, -1, 1, 1, -1, 1
]);
const positionBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, positionBuffer);
gl.bufferData(gl.ARRAY_BUFFER, positions, gl.STATIC_DRAW);
const positionLocation = gl.getAttribLocation(program, "a_position");
gl.enableVertexAttribArray(positionLocation);
gl.vertexAttribPointer(positionLocation, 2, gl.FLOAT, false, 0, 0);
const u_texture = gl.getUniformLocation(program, "u_texture");
const u_distortion = gl.getUniformLocation(program, "u_distortion");
gl.uniform1f(u_distortion, 0.5);
function render() {
gl.clear(gl.COLOR_BUFFER_BIT);
// Configure left video texture
const leftTexture = createVideoTexture(gl, leftVideo);
gl.uniform1i(u_texture, 0);
gl.drawArrays(gl.TRIANGLES, 0, 6);
// Configure right video texture
const rightTexture = createVideoTexture(gl, rightVideo);
gl.uniform1i(u_texture, 1);
gl.drawArrays(gl.TRIANGLES, 0, 6);
requestAnimationFrame(render);
}
function createVideoTexture(gl, video) {
const texture = gl.createTexture();
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.LINEAR);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, video);
return texture;
}
// Start rendering
render();
</script>
</body>
</html>
```
### Explanation:
1. **HTML Structure**: It includes two video elements for the left and right channels, and a `canvas` element where the image will be rendered.
2. **Shaders**: The vertex shader transforms the coordinates, and the fragment shader implements the barrel distortion effect.
3. **Texture Handling**: A simple rendering loop is set up to continuously draw the current frames of the video onto the canvas, applying the distortion effect.
4. **Rendering Loop**: The `render` function draws the left and right videos side by side with barrel distortion. You may further enhance the code to adjust the aspect ratio or position of the videos.
### Important Notes:
- **Video Source**: Replace `path_to_your_video.mp4` with the actual path of your video file.
- **Desktop Capture**: For desktop capture, you would normally use `navigator.mediaDevices.getDisplayMedia()`, but I've omitted that for simplicity. Implementing desktop capture directly is more complex and beyond this example. You should also handle permissions to capture the screen.
- **Browser Compatibility**: Ensure you test this in browsers that support WebGL and the video formats you are using.
Feel free to modify this base example as needed!