proposals/phone-ar-depth-gpu.html - external/github.com/immersive-web/webxr-samples - Git at Google

 <!doctype html>
 <!--
 Copyright 2020 The Immersive Web Community Group

 Permission is hereby granted, free of charge, to any person obtaining a copy of
 this software and associated documentation files (the "Software"), to deal in
 the Software without restriction, including without limitation the rights to
 use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 the Software, and to permit persons to whom the Software is furnished to do so,
 subject to the following conditions:

 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 -->
 <html>
   <head>
     <meta charset='utf-8'>
     <meta name='viewport' content='width=device-width, initial-scale=1, user-scalable=no'>
     <meta name='mobile-web-app-capable' content='yes'>
     <meta name='apple-mobile-web-app-capable' content='yes'>
     <link rel='icon' type='image/png' sizes='32x32' href='/favicon-32x32.png'>
     <link rel='icon' type='image/png' sizes='96x96' href='/favicon-96x96.png'>
     <link rel='stylesheet' href='../css/common.css'>

     <meta http-equiv="origin-trial" content="AmlTjhi6a1TYxVFo0Fwd+PAUO65z4LCMqEgRcQ8bM+fAU3p065iOmG4QnItkAzD5X0F0Y0VccvAp3WOAIgnGpg8AAABbeyJvcmlnaW4iOiJodHRwczovL2ltbWVyc2l2ZS13ZWIuZ2l0aHViLmlvOjQ0MyIsImZlYXR1cmUiOiJXZWJYUkRlcHRoIiwiZXhwaXJ5IjoxNjA5MzczOTMzfQ==">

     <title>AR Depth API - GPU access</title>
   </head>
   <body>
     <header>
       <details open>
         <summary>AR Depth API - GPU access</summary>
         <p>
           This sample demonstrates the use of a depth API in an immersive-ar session.
           The data will be uploaded to the GPU & accessed from a shader.
           <a class="back" href="./index.html">Back</a>
         </p>
       </details>
     </header>
     <script id="vertexShader" type="x-shader/x-vertex">
       precision mediump float;

       attribute vec2 aVertexPosition;
       attribute vec2 aTexCoord;

       varying vec2 vTexCoord;

       void main(void) {
         gl_Position = vec4(aVertexPosition, 0.0, 1.0);
         vTexCoord = aTexCoord;
       }
     </script>
     <script id="fragmentShader" type="x-shader/x-fragment" src="../shaders/depth-api-gpu.frag"></script>
     <script id="turboFragment" type="x-shader/x-fragment" src="../shaders/turbo.glsl"></script>

     <script type="module">
       import {mat4, vec3, mat3, vec2} from '../js/render/math/gl-matrix.js';
       import {WebXRButton} from '../js/util/webxr-button.js';

       // XR globals.
       let xrButton = null;
       let xrRefSpace = null;

       // WebGL scene globals.
       let gl = null;
       let shaderProgram = null;
       let programInfo = null;
       let vertexBuffer = null;
       let depthTexture = null;

       // shader code
       let vertexShaderSource = null;
       let fragmentShaderSource = null;

       function initXR() {
         xrButton = new WebXRButton({
           onRequestSession: onRequestSession,
           onEndSession: onEndSession,
           textEnterXRTitle: "START AR",
           textXRNotFoundTitle: "AR NOT FOUND",
           textExitXRTitle: "EXIT AR",
         });
         document.querySelector('header').appendChild(xrButton.domElement);

         if (navigator.xr) {
           navigator.xr.isSessionSupported('immersive-ar')
                       .then((supported) => {
             xrButton.enabled = supported;
           });
         }
       }

       function onRequestSession() {
         // Requests an immersive session with environment integration.

         let options = {
           requiredFeatures: ['depth-sensing'],
         };

         navigator.xr.requestSession('immersive-ar', options).then((session) => {
             session.mode = 'immersive-ar';
             xrButton.setSession(session);

             fetchShaders().then(() => {
               onSessionStarted(session);
             });
         });
       }

       function onSessionStarted(session) {
         session.addEventListener('end', onSessionEnded);

         let canvas = document.createElement('canvas');
         gl = canvas.getContext('webgl', {
             xrCompatible: true
         });

         initializeGL();

         session.updateRenderState({ baseLayer: new XRWebGLLayer(session, gl) });
         session.requestReferenceSpace('local').then((refSpace) => {
           xrRefSpace = refSpace;
           session.requestAnimationFrame(onXRFrame);
         });
       }

       function onEndSession(session) {
         session.end();
       }

       function onSessionEnded(event) {
         xrButton.setSession(null);
       }

       // Helper, fetches shader source code based on the passed in ID of the <script> element.
       // Will inspect src attribute value and issue fetch API call to obtain the script body.
       async function fetchShader(id) {
         const element = document.getElementById(id);
         const url = element.src;

         const response = await fetch(url);
         const text = await response.text();

         return text;
       }

       async function fetchShaders() {
         vertexShaderSource = document.getElementById('vertexShader').textContent;
         fragmentShaderSource = await fetchShader("fragmentShader") + "\n"
                              + await fetchShader("turboFragment");

       }

       function initializeGL() {
         shaderProgram = initShaderProgram(vertexShaderSource, fragmentShaderSource);

         programInfo = {
             program: shaderProgram,
             attribLocations: {
               vertexPosition: gl.getAttribLocation(shaderProgram, 'aVertexPosition'),
               texCoord: gl.getAttribLocation(shaderProgram, 'aTexCoord'),
             },
             uniformLocations: {
               depthTexture: gl.getUniformLocation(shaderProgram, 'uDepthTexture'),
               uvTransform: gl.getUniformLocation(shaderProgram, 'uUvTransform'),
             },
         };

         vertexBuffer = gl.createBuffer();

         // clip space coordinates + texture space coordinates
         const vertices_data = [
           -1, -1,    0, 0,  // bottom left
            1, -1,    1, 0,  // bottom right
           -1,  1,    0, 1,  // top left
            1,  1,    1, 1,  // top right
         ];

         gl.bindBuffer(gl.ARRAY_BUFFER, vertexBuffer);
         gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertices_data), gl.STATIC_DRAW);
         gl.bindBuffer(gl.ARRAY_BUFFER, null);

         depthTexture = gl.createTexture();
         gl.bindTexture(gl.TEXTURE_2D, depthTexture);

         // depth texture will likely not be power-of-2-sized, set parameters
         // that would still make it work, see
         // https://www.khronos.org/webgl/wiki/WebGL_and_OpenGL_Differences#Non-Power_of_Two_Texture_Support
         gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
         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.bindTexture(gl.TEXTURE_2D, null);
       }

       function initShaderProgram(vsSource, fsSource) {
         const vertexShader = loadShader(gl.VERTEX_SHADER, vsSource);
         const fragmentShader = loadShader(gl.FRAGMENT_SHADER, fsSource);

         // Create the shader program
         const shaderProgram = gl.createProgram();
         gl.attachShader(shaderProgram, vertexShader);
         gl.attachShader(shaderProgram, fragmentShader);
         gl.linkProgram(shaderProgram);

         // If creating the shader program failed, alert
         if (!gl.getProgramParameter(shaderProgram, gl.LINK_STATUS)) {
           alert("Unable to initialize the shader program: " +
               gl.getProgramInfoLog(shaderProgram)
           );
           return null;
         }

         return shaderProgram;
       }

       function loadShader(type, source) {
         const shader = gl.createShader(type);

         gl.shaderSource(shader, source);
         gl.compileShader(shader);

         if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
           alert(
             "An error occurred compiling the shaders: " +
               gl.getShaderInfoLog(shader)
           );
           gl.deleteShader(shader);
           return null;
         }

         return shader;
       }

       // Called every time a XRSession requests that a new frame be drawn.
       function onXRFrame(t, frame) {
         const session = frame.session;
         session.requestAnimationFrame(onXRFrame);

         const baseLayer = session.renderState.baseLayer;

         const pose = frame.getViewerPose(xrRefSpace);

         if(pose) {
           gl.bindFramebuffer(gl.FRAMEBUFFER, session.renderState.baseLayer.framebuffer);

           // Clear the framebuffer
           gl.clearColor(0, 0, 0, 0);
           gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);

           for(const view of pose.views) {
             const viewport = baseLayer.getViewport(view);
             gl.viewport(viewport.x, viewport.y,
                         viewport.width, viewport.height);

             const depthData = frame.getDepthInformation(view);
             if(depthData){
               renderDepthInformationGPU(depthData, view, viewport);
             }
           }
         }
       }

       function renderDepthInformationGPU(depthData, view, viewport) {
         const depth_width = depthData.width;
         const depth_height = depthData.height;

         gl.useProgram(programInfo.program);

         gl.bindBuffer(gl.ARRAY_BUFFER, vertexBuffer);

         gl.vertexAttribPointer(
           programInfo.attribLocations.vertexPosition,
           2,      // 2 components
           gl.FLOAT,
           false,  // don't normalize
           16,     // stride = 4 floats * 4 bytes
           0       // start at offset 0 of the buffer
         );
         gl.enableVertexAttribArray(
           programInfo.attribLocations.vertexPosition
         );

         gl.vertexAttribPointer(
           programInfo.attribLocations.texCoord,
           2,      // 2 components
           gl.FLOAT,
           false,  // don't normalize
           16,     // stride = 4 floats * 4 bytes
           8       // start at offset of 2 floats * 4 bytes of the buffer
         );
         gl.enableVertexAttribArray(
           programInfo.attribLocations.texCoord
         );

         const dataBuffer = depthData.data;

         gl.bindTexture(gl.TEXTURE_2D, depthTexture);

         // Supply the data buffer after converting it to Uint8Array - the
         // dataBuffer.buffer is an Uint16Array, but the gl.texImage2D expects Uint8Array
         // when using gl.UNSIGNED_BYTE type.
         gl.texImage2D(gl.TEXTURE_2D, 0, gl.LUMINANCE_ALPHA, depthData.width,
                       depthData.height, 0, gl.LUMINANCE_ALPHA, gl.UNSIGNED_BYTE,
                       new Uint8Array(dataBuffer.buffer, dataBuffer.byteOffset, dataBuffer.byteLength));

         gl.activeTexture(gl.TEXTURE0);
         gl.uniform1i(programInfo.uniformLocations.depthTexture, 0);

         gl.uniformMatrix4fv(programInfo.uniformLocations.uvTransform, false,
                             depthData.normTextureFromNormView.matrix);

         gl.drawArrays(gl.TRIANGLE_STRIP, 0, 4);
       }

       // Start the XR application.
       initXR();
     </script>
   </body>
 </html>
	<!doctype html>
	<!--
	Copyright 2020 The Immersive Web Community Group

	Permission is hereby granted, free of charge, to any person obtaining a copy of
	this software and associated documentation files (the "Software"), to deal in
	the Software without restriction, including without limitation the rights to
	use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
	the Software, and to permit persons to whom the Software is furnished to do so,
	subject to the following conditions:

	The above copyright notice and this permission notice shall be included in all
	copies or substantial portions of the Software.

	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
	FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
	COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
	IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
	-->
	<html>
	<head>
	<meta charset='utf-8'>
	<meta name='viewport' content='width=device-width, initial-scale=1, user-scalable=no'>
	<meta name='mobile-web-app-capable' content='yes'>
	<meta name='apple-mobile-web-app-capable' content='yes'>
	<link rel='icon' type='image/png' sizes='32x32' href='/favicon-32x32.png'>
	<link rel='icon' type='image/png' sizes='96x96' href='/favicon-96x96.png'>
	<link rel='stylesheet' href='../css/common.css'>

	<meta http-equiv="origin-trial" content="AmlTjhi6a1TYxVFo0Fwd+PAUO65z4LCMqEgRcQ8bM+fAU3p065iOmG4QnItkAzD5X0F0Y0VccvAp3WOAIgnGpg8AAABbeyJvcmlnaW4iOiJodHRwczovL2ltbWVyc2l2ZS13ZWIuZ2l0aHViLmlvOjQ0MyIsImZlYXR1cmUiOiJXZWJYUkRlcHRoIiwiZXhwaXJ5IjoxNjA5MzczOTMzfQ==">

	<title>AR Depth API - GPU access</title>
	</head>
	<body>
	<header>
	<details open>
	<summary>AR Depth API - GPU access</summary>
	<p>
	This sample demonstrates the use of a depth API in an immersive-ar session.
	The data will be uploaded to the GPU & accessed from a shader.
	<a class="back" href="./index.html">Back</a>
	</p>
	</details>
	</header>
	<script id="vertexShader" type="x-shader/x-vertex">
	precision mediump float;

	attribute vec2 aVertexPosition;
	attribute vec2 aTexCoord;

	varying vec2 vTexCoord;

	void main(void) {
	gl_Position = vec4(aVertexPosition, 0.0, 1.0);
	vTexCoord = aTexCoord;
	}
	</script>
	<script id="fragmentShader" type="x-shader/x-fragment" src="../shaders/depth-api-gpu.frag"></script>
	<script id="turboFragment" type="x-shader/x-fragment" src="../shaders/turbo.glsl"></script>

	<script type="module">
	import {mat4, vec3, mat3, vec2} from '../js/render/math/gl-matrix.js';
	import {WebXRButton} from '../js/util/webxr-button.js';

	// XR globals.
	let xrButton = null;
	let xrRefSpace = null;

	// WebGL scene globals.
	let gl = null;
	let shaderProgram = null;
	let programInfo = null;
	let vertexBuffer = null;
	let depthTexture = null;

	// shader code
	let vertexShaderSource = null;
	let fragmentShaderSource = null;

	function initXR() {
	xrButton = new WebXRButton({
	onRequestSession: onRequestSession,
	onEndSession: onEndSession,
	textEnterXRTitle: "START AR",
	textXRNotFoundTitle: "AR NOT FOUND",
	textExitXRTitle: "EXIT AR",
	});
	document.querySelector('header').appendChild(xrButton.domElement);

	if (navigator.xr) {
	navigator.xr.isSessionSupported('immersive-ar')
	.then((supported) => {
	xrButton.enabled = supported;
	});
	}
	}

	function onRequestSession() {
	// Requests an immersive session with environment integration.

	let options = {
	requiredFeatures: ['depth-sensing'],
	};

	navigator.xr.requestSession('immersive-ar', options).then((session) => {
	session.mode = 'immersive-ar';
	xrButton.setSession(session);

	fetchShaders().then(() => {
	onSessionStarted(session);
	});
	});
	}

	function onSessionStarted(session) {
	session.addEventListener('end', onSessionEnded);

	let canvas = document.createElement('canvas');
	gl = canvas.getContext('webgl', {
	xrCompatible: true
	});

	initializeGL();

	session.updateRenderState({ baseLayer: new XRWebGLLayer(session, gl) });
	session.requestReferenceSpace('local').then((refSpace) => {
	xrRefSpace = refSpace;
	session.requestAnimationFrame(onXRFrame);
	});
	}

	function onEndSession(session) {
	session.end();
	}

	function onSessionEnded(event) {
	xrButton.setSession(null);
	}

	// Helper, fetches shader source code based on the passed in ID of the <script> element.
	// Will inspect src attribute value and issue fetch API call to obtain the script body.
	async function fetchShader(id) {
	const element = document.getElementById(id);
	const url = element.src;

	const response = await fetch(url);
	const text = await response.text();

	return text;
	}

	async function fetchShaders() {
	vertexShaderSource = document.getElementById('vertexShader').textContent;
	fragmentShaderSource = await fetchShader("fragmentShader") + "\n"
	+ await fetchShader("turboFragment");

	}

	function initializeGL() {
	shaderProgram = initShaderProgram(vertexShaderSource, fragmentShaderSource);

	programInfo = {
	program: shaderProgram,
	attribLocations: {
	vertexPosition: gl.getAttribLocation(shaderProgram, 'aVertexPosition'),
	texCoord: gl.getAttribLocation(shaderProgram, 'aTexCoord'),
	},
	uniformLocations: {
	depthTexture: gl.getUniformLocation(shaderProgram, 'uDepthTexture'),
	uvTransform: gl.getUniformLocation(shaderProgram, 'uUvTransform'),
	},
	};

	vertexBuffer = gl.createBuffer();

	// clip space coordinates + texture space coordinates
	const vertices_data = [
	-1, -1, 0, 0, // bottom left
	1, -1, 1, 0, // bottom right
	-1, 1, 0, 1, // top left
	1, 1, 1, 1, // top right
	];

	gl.bindBuffer(gl.ARRAY_BUFFER, vertexBuffer);
	gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertices_data), gl.STATIC_DRAW);
	gl.bindBuffer(gl.ARRAY_BUFFER, null);

	depthTexture = gl.createTexture();
	gl.bindTexture(gl.TEXTURE_2D, depthTexture);

	// depth texture will likely not be power-of-2-sized, set parameters
	// that would still make it work, see
	// https://www.khronos.org/webgl/wiki/WebGL_and_OpenGL_Differences#Non-Power_of_Two_Texture_Support
	gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
	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.bindTexture(gl.TEXTURE_2D, null);
	}

	function initShaderProgram(vsSource, fsSource) {
	const vertexShader = loadShader(gl.VERTEX_SHADER, vsSource);
	const fragmentShader = loadShader(gl.FRAGMENT_SHADER, fsSource);

	// Create the shader program
	const shaderProgram = gl.createProgram();
	gl.attachShader(shaderProgram, vertexShader);
	gl.attachShader(shaderProgram, fragmentShader);
	gl.linkProgram(shaderProgram);

	// If creating the shader program failed, alert
	if (!gl.getProgramParameter(shaderProgram, gl.LINK_STATUS)) {
	alert("Unable to initialize the shader program: " +
	gl.getProgramInfoLog(shaderProgram)
	);
	return null;
	}

	return shaderProgram;
	}

	function loadShader(type, source) {
	const shader = gl.createShader(type);

	gl.shaderSource(shader, source);
	gl.compileShader(shader);

	if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
	alert(
	"An error occurred compiling the shaders: " +
	gl.getShaderInfoLog(shader)
	);
	gl.deleteShader(shader);
	return null;
	}

	return shader;
	}

	// Called every time a XRSession requests that a new frame be drawn.
	function onXRFrame(t, frame) {
	const session = frame.session;
	session.requestAnimationFrame(onXRFrame);

	const baseLayer = session.renderState.baseLayer;

	const pose = frame.getViewerPose(xrRefSpace);

	if(pose) {
	gl.bindFramebuffer(gl.FRAMEBUFFER, session.renderState.baseLayer.framebuffer);

	// Clear the framebuffer
	gl.clearColor(0, 0, 0, 0);
	gl.clear(gl.COLOR_BUFFER_BIT \| gl.DEPTH_BUFFER_BIT);

	for(const view of pose.views) {
	const viewport = baseLayer.getViewport(view);
	gl.viewport(viewport.x, viewport.y,
	viewport.width, viewport.height);

	const depthData = frame.getDepthInformation(view);
	if(depthData){
	renderDepthInformationGPU(depthData, view, viewport);
	}
	}
	}
	}

	function renderDepthInformationGPU(depthData, view, viewport) {
	const depth_width = depthData.width;
	const depth_height = depthData.height;

	gl.useProgram(programInfo.program);

	gl.bindBuffer(gl.ARRAY_BUFFER, vertexBuffer);

	gl.vertexAttribPointer(
	programInfo.attribLocations.vertexPosition,
	2, // 2 components
	gl.FLOAT,
	false, // don't normalize
	16, // stride = 4 floats * 4 bytes
	0 // start at offset 0 of the buffer
	);
	gl.enableVertexAttribArray(
	programInfo.attribLocations.vertexPosition
	);

	gl.vertexAttribPointer(
	programInfo.attribLocations.texCoord,
	2, // 2 components
	gl.FLOAT,
	false, // don't normalize
	16, // stride = 4 floats * 4 bytes
	8 // start at offset of 2 floats * 4 bytes of the buffer
	);
	gl.enableVertexAttribArray(
	programInfo.attribLocations.texCoord
	);

	const dataBuffer = depthData.data;

	gl.bindTexture(gl.TEXTURE_2D, depthTexture);

	// Supply the data buffer after converting it to Uint8Array - the
	// dataBuffer.buffer is an Uint16Array, but the gl.texImage2D expects Uint8Array
	// when using gl.UNSIGNED_BYTE type.
	gl.texImage2D(gl.TEXTURE_2D, 0, gl.LUMINANCE_ALPHA, depthData.width,
	depthData.height, 0, gl.LUMINANCE_ALPHA, gl.UNSIGNED_BYTE,
	new Uint8Array(dataBuffer.buffer, dataBuffer.byteOffset, dataBuffer.byteLength));

	gl.activeTexture(gl.TEXTURE0);
	gl.uniform1i(programInfo.uniformLocations.depthTexture, 0);

	gl.uniformMatrix4fv(programInfo.uniformLocations.uvTransform, false,
	depthData.normTextureFromNormView.matrix);

	gl.drawArrays(gl.TRIANGLE_STRIP, 0, 4);
	}

	// Start the XR application.
	initXR();
	</script>
	</body>
	</html>