pow-of-small-constant-in-user-defined-function.html (2154B)
1 <!-- 2 Copyright (c) 2019 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 7 <!DOCTYPE html> 8 <html> 9 <head> 10 <meta charset="utf-8"> 11 <title>Bug - calculating powers of constants smaller than 1.0e-5 in user-defined functions should work</title> 12 <link rel="stylesheet" href="../../../resources/js-test-style.css"/> 13 <script src="../../../js/js-test-pre.js"></script> 14 <script src="../../../js/webgl-test-utils.js"></script> 15 </head> 16 <body> 17 <canvas id="canvas" width="256" height="256"> </canvas> 18 <div id="description"></div> 19 <div id="console"></div> 20 <script id="vshader" type="x-shader/x-vertex"> 21 attribute vec3 aPosition; 22 23 void main() { 24 gl_Position = vec4(aPosition, 1); 25 } 26 </script> 27 <script id="fshader" type="x-shader/x-fragment"> 28 precision highp float; 29 30 float fun(float arg) { 31 // These values are still easily within the highp range. 32 // The minimum range in terms of 10's exponent is around -19 to 19, and IEEE-754 single precision range is higher than that. 33 return 1.0e12 * pow(arg, 2.0); 34 } 35 36 void main() { 37 // Note that the bug did not reproduce if an uniform was passed to the function instead of a constant, 38 // or if the expression was moved outside the user-defined function. 39 const float a = 1.0e-6; 40 float b = fun(a); 41 if (abs(b - 1.0) < 0.01) { 42 gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0); // green 43 } else { 44 gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0); // red 45 } 46 } 47 </script> 48 <script type="application/javascript"> 49 "use strict"; 50 description(); 51 debug(""); 52 var wtu = WebGLTestUtils; 53 function test() { 54 var gl = wtu.create3DContext("canvas"); 55 if (!gl) { 56 testFailed("context does not exist"); 57 return; 58 } 59 if (gl.getShaderPrecisionFormat(gl.FRAGMENT_SHADER, gl.HIGH_FLOAT).precision == 0) { 60 testPassed("highp precision not supported"); 61 } else { 62 wtu.setupUnitQuad(gl); 63 var program = wtu.setupProgram(gl, ["vshader", "fshader"], ["aPosition"], undefined, true); 64 wtu.drawUnitQuad(gl); 65 wtu.checkCanvasRect(gl, 0, 0, 256, 256, [0, 255, 0, 255]); 66 } 67 }; 68 69 test(); 70 finishTest(); 71 </script> 72 </body> 73 </html>