| <!-- |
| Copyright (c) 2019 The Khronos Group Inc. |
| Use of this source code is governed by an MIT-style license that can be |
| found in the LICENSE.txt file. |
| --> |
| |
| <!DOCTYPE html> |
| <html> |
| <head> |
| <meta charset="utf-8"> |
| <title>gl-fragcoord Test</title> |
| <link rel="stylesheet" href="../../../resources/js-test-style.css"/> |
| <script src="../../../js/js-test-pre.js"></script> |
| <script src="../../../js/webgl-test-utils.js"> </script> |
| </head> |
| <body> |
| <canvas id="example" width="32" height="32"> |
| </canvas> |
| <div id="description"></div> |
| <div id="console"></div> |
| <script id="vshader" type="x-shader/x-vertex"> |
| attribute vec4 vPosition; |
| void main() |
| { |
| gl_Position = vPosition; |
| } |
| </script> |
| |
| <script id="fshader" type="x-shader/x-fragment"> |
| precision mediump float; |
| void main() |
| { |
| gl_FragColor = vec4( |
| gl_FrontFacing ? 1.0 : 0.0, |
| gl_FrontFacing ? 0.0 : 1.0, |
| 0, |
| 1); |
| } |
| </script> |
| |
| <script> |
| "use strict"; |
| function init() |
| { |
| description("tests gl_FrontFacing"); |
| |
| var wtu = WebGLTestUtils; |
| var gl = wtu.create3DContext("example"); |
| var program = wtu.setupProgram(gl, ["vshader", "fshader"], ["vPosition"]); |
| |
| var gridRes = 4; |
| wtu.setupIndexedQuad(gl, gridRes, 0, true); |
| |
| gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT); |
| gl.drawElements(gl.TRIANGLES, gridRes * gridRes * 6, gl.UNSIGNED_SHORT, 0); |
| wtu.glErrorShouldBe(gl, gl.NO_ERROR, "no errors from draw"); |
| |
| var step = 32 / gridRes; |
| var halfStep = step / 2; |
| var quarterStep = halfStep / 2; |
| for (var xx = 0; xx < 32; xx += step) { |
| for (var yy = 0; yy < 32; yy += step) { |
| for (var ii = 0; ii < 2; ++ii) { |
| var color = [ |
| ii == 0 ? 255 : 0, |
| ii == 0 ? 0 : 255, |
| 0 |
| ]; |
| var msg = "should be " + color; |
| wtu.checkCanvasRect( |
| gl, |
| xx + quarterStep + halfStep * ii, |
| yy + quarterStep + halfStep * ii, |
| 1, 1, color, msg, 4); |
| } |
| } |
| } |
| } |
| |
| init(); |
| var successfullyParsed = true; |
| </script> |
| <script src="../../../js/js-test-post.js"></script> |
| |
| </body> |
| </html> |
