feedback-loop.html (4192B)
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>WebGL Rendering Feedback Loop</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="example" width="1" height="1" style="width: 40px; height: 40px;"></canvas> 18 <div id="description"></div> 19 <div id="console"></div> 20 21 <script id="vs" type="text/something-not-javascript"> 22 attribute vec4 a_position; 23 attribute vec2 a_texCoord; 24 varying vec2 v_texCoord; 25 void main() { 26 gl_Position = a_position; 27 v_texCoord = a_texCoord; 28 } 29 </script> 30 <script id="fs" type="text/something-not-javascript"> 31 precision mediump float; 32 varying vec2 v_texCoord; 33 uniform sampler2D u_texture; 34 void main() { 35 // Shader swizzles color channels so we can tell if the draw succeeded. 36 gl_FragColor = texture2D(u_texture, v_texCoord).gbra; 37 } 38 </script> 39 <script> 40 "use strict"; 41 description("Checks that rendering feedback loops fail correctly."); 42 var wtu = WebGLTestUtils; 43 var gl = wtu.create3DContext("example"); 44 45 var texture = gl.createTexture(); 46 gl.bindTexture(gl.TEXTURE_2D, texture); 47 gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, 1, 1, 0, gl.RGBA, gl.UNSIGNED_BYTE, 48 new Uint8Array([255, 0, 0, 255])); 49 gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST); 50 gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST); 51 gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE); 52 gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE); 53 54 wtu.glErrorShouldBe(gl, gl.NO_ERROR, "after creating texture"); 55 56 var framebuffer = gl.createFramebuffer(); 57 gl.bindFramebuffer(gl.FRAMEBUFFER, framebuffer); 58 gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0); 59 60 assertMsg(gl.checkFramebufferStatus(gl.FRAMEBUFFER) == gl.FRAMEBUFFER_COMPLETE, 61 "framebuffer should be FRAMEBUFFER_COMPLETE."); 62 63 var program = wtu.setupProgram(gl, ["vs", "fs"], ["a_position", "a_texCoord"]); 64 gl.uniform1i(gl.getUniformLocation(program, "u_texture"), 0); 65 gl.disable(gl.BLEND); 66 gl.disable(gl.DEPTH_TEST); 67 wtu.glErrorShouldBe(gl, gl.NO_ERROR, "after initWebGL"); 68 69 // Drawing with a texture that is also bound to the current framebuffer should fail 70 var bufferObjects = wtu.setupUnitQuad(gl, 0, 1); 71 gl.bindTexture(gl.TEXTURE_2D, texture); 72 wtu.drawUnitQuad(gl); 73 wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "after draw with invalid feedback loop"); 74 75 // Ensure that the texture contents did not change after the previous render 76 gl.bindFramebuffer(gl.FRAMEBUFFER, null); 77 wtu.clearAndDrawUnitQuad(gl); 78 wtu.glErrorShouldBe(gl, gl.NO_ERROR, "after drawing"); 79 wtu.checkCanvas(gl, [0, 0, 255, 255], "Should be blue."); 80 81 // Drawing when texture is bound to an inactive uniform should succeed 82 var texture2 = gl.createTexture(); 83 gl.bindTexture(gl.TEXTURE_2D, texture2); 84 gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, 1, 1, 0, gl.RGBA, gl.UNSIGNED_BYTE, 85 new Uint8Array([0, 255, 0, 255])); 86 gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST); 87 gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST); 88 gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE); 89 gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE); 90 91 gl.bindFramebuffer(gl.FRAMEBUFFER, framebuffer); 92 gl.activeTexture(gl.TEXTURE1); 93 gl.bindTexture(gl.TEXTURE_2D, texture); 94 wtu.drawUnitQuad(gl); 95 wtu.glErrorShouldBe(gl, gl.NO_ERROR, "after draw where framebuffer texture is bound to inactive texture unit"); 96 wtu.checkCanvas(gl, [255, 0, 0, 255], "Should be red."); 97 98 var successfullyParsed = true; 99 </script> 100 101 <script src="../../js/js-test-post.js"></script> 102 103 </body> 104 </html>