| <!-- |
| 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"> |
| <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> |
| |
| <script> |
| "use strict"; |
| |
| var wtu = WebGLTestUtils; |
| |
| // This declaration needs to be global for "shouldBe" to see it |
| var gl; |
| |
| function init() |
| { |
| description('Verify that a WebGL context with alpha:false still works correctly after handling textures with an alpha channel.'); |
| |
| runTest(); |
| } |
| |
| function getWebGL(contextAttribs) |
| { |
| return wtu.create3DContext("c", contextAttribs); |
| } |
| |
| function runTest() |
| { |
| var buf = new Uint8Array(1 * 1 * 4); |
| shouldBeNonNull("gl = getWebGL({ alpha: false, antialias: false })"); |
| |
| // Clear to black. Alpha channel of clearColor() is ignored. |
| gl.clearColor(0.0, 0.0, 0.0, 0.7); |
| gl.clear(gl.COLOR_BUFFER_BIT); |
| wtu.checkCanvasRect(gl, 0, 0, 1, 1, [0, 0, 0, 255], |
| "Alpha channel of clearColor should be ignored"); |
| |
| wtu.waitForComposite(function() { |
| // Make a new framebuffer and attach a texture with an alpha channel. |
| var fbo = gl.createFramebuffer(); |
| gl.bindFramebuffer(gl.FRAMEBUFFER, fbo); |
| var texture = gl.createTexture(); |
| gl.bindTexture(gl.TEXTURE_2D, texture); |
| gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, 1, 1, 0, gl.RGBA, gl.UNSIGNED_BYTE, null); |
| gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0); |
| |
| // Clear texture. Note that alpha channel is not 1.0. |
| gl.clearColor(1.0, 0.0, 0.0, 0.5); |
| gl.clear(gl.COLOR_BUFFER_BIT); |
| wtu.checkCanvasRect(gl, 0, 0, 1, 1, [255, 0, 0, 128], |
| "Alpha channel of clearColor should be obeyed for FBO with alpha channel", |
| 1); |
| |
| // Bind back buffer and check that its alpha channel is still 1.0. |
| gl.bindFramebuffer(gl.FRAMEBUFFER, null); |
| wtu.checkCanvasRect(gl, 0, 0, 1, 1, [0, 0, 0, 255], |
| "Alpha channel of back buffer should still be 255"); |
| finishTest(); |
| }); |
| } |
| |
| </script> |
| </head> |
| <body onload="init()"> |
| <div id="description"></div> |
| <div id="console"></div> |
| <canvas width="20" height="20" style="border: 1px solid blue;" id="c"></canvas> |
| </body> |
| </html> |
