readpixels-4gb-wasm-memory.html (1916B)
1 <!-- 2 Copyright (c) 2023 The Khronos Group Inc. 3 Use of this source code is governed by an MIT-style license that can be 4 found in the LICENSE.txt file. 5 --> 6 <!DOCTYPE html> 7 <html> 8 <head> 9 <meta charset="utf-8"> 10 <title>gl.readPixels() test to Wasm Memory 4GB in size.</title> 11 <link rel="stylesheet" href="../../resources/js-test-style.css"/> 12 <script src="../../js/js-test-pre.js"></script> 13 <script src="../../js/webgl-test-utils.js"> </script> 14 </head> 15 <body> 16 <canvas id="canvas" width="2" height="2" style="width: 40px; height: 40px;"></canvas> 17 <div id="description"></div> 18 <div id="console"></div> 19 <script> 20 "use strict"; 21 description(document.title); 22 debug("Tests that gl.readPixels() can be called on WebAssembly Memory of 4GB in size."); 23 debug(""); 24 let wtu = WebGLTestUtils; 25 let gl = wtu.create3DContext("canvas", undefined, 2); 26 27 const PAGE = 65536; 28 const SIZE = 4*1024*1024*1024 - PAGE; // when uint32_t size is max, we can only reach one page short of full 4GB 29 let view = new Uint8Array(new WebAssembly.Memory({ initial: SIZE/PAGE }).buffer); 30 31 // Clear the canvas to a specific color 32 const expectedColor = [42, 84, 128, 255]; 33 gl.clearColor(expectedColor[0]/255.0, expectedColor[1]/255.0, expectedColor[2]/255.0, expectedColor[3]/255.0); 34 gl.clear(gl.COLOR_BUFFER_BIT); 35 36 // Test that gl.readPixels() can be called with a high offset to Memory 37 const offset = SIZE - 4; 38 view.set([0,0,0,0], offset); // For good measure, clear data at offset before reading 39 gl.readPixels(0, 0, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, view, offset); 40 wtu.glErrorShouldBe(gl, gl.NO_ERROR); 41 let obtainedColor = view.subarray(offset, offset+4); 42 shouldBe('obtainedColor[0]', 'expectedColor[0]'); 43 shouldBe('obtainedColor[1]', 'expectedColor[1]'); 44 shouldBe('obtainedColor[2]', 'expectedColor[2]'); 45 shouldBe('obtainedColor[3]', 'expectedColor[3]'); 46 var successfullyParsed = true; 47 </script> 48 <script src="../../js/js-test-post.js"></script> 49 </body> 50 </html>