unwritten-output-defaults-to-zero.html (3801B)
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 Transform Feedback Conformance Tests</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 <div id="description"></div> 18 <canvas id="canvas" style="width: 50px; height: 50px;"> </canvas> 19 <div id="console"></div> 20 <script id="vshader" type="x-shader/x-vertex">#version 300 es 21 in vec4 in_data; 22 uniform int flag; 23 out vec4 out_data; 24 void main(void) { 25 if (flag > 0) { 26 out_data = in_data + vec4(2.0, 3.0, 4.0, 5.0); 27 } 28 } 29 </script> 30 <script id="fshader" type="x-shader/x-fragment">#version 300 es 31 precision mediump float; 32 out vec4 out_color; 33 void main(void) { 34 out_color = vec4(1.0, 1.0, 1.0, 1.0); 35 } 36 </script> 37 <script> 38 "use strict"; 39 description("This test verifies if an output variable is specified to be streamed to a transform feedback buffer but not actually written, the value defaults to 0."); 40 41 debug(""); 42 43 var wtu = WebGLTestUtils; 44 var canvas = document.getElementById("canvas"); 45 var gl = wtu.create3DContext(canvas, null, 2); 46 47 if (!gl) { 48 testFailed("WebGL context does not exist"); 49 } else { 50 testPassed("WebGL context exists"); 51 52 debug(""); 53 debug("Testing transform feedback works fine"); 54 runTest(1); 55 56 debug(""); 57 debug("Testing unwritten output variables default to zero"); 58 runTest(0); 59 } 60 61 function runTest(flag) { 62 var in_data = [ 63 1.0, 2.0, 3.0, 4.0, 64 2.0, 4.0, 8.0, 16.0, 65 0.75, 0.5, 0.25, 0.0 66 ]; 67 68 var in_buffer = gl.createBuffer(); 69 gl.bindBuffer(gl.ARRAY_BUFFER, in_buffer); 70 gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(in_data), gl.STATIC_DRAW); 71 72 var out_buffer = gl.createBuffer(); 73 gl.bindBuffer(gl.TRANSFORM_FEEDBACK_BUFFER, out_buffer); 74 gl.bufferData(gl.TRANSFORM_FEEDBACK_BUFFER, Float32Array.BYTES_PER_ELEMENT * in_data.length, gl.STATIC_DRAW); 75 76 // Create the transform feedback program 77 var program = wtu.setupTransformFeedbackProgram(gl, ["vshader", "fshader"], 78 ["out_data"], gl.SEPARATE_ATTRIBS, 79 ["in_data"]); 80 var loc = gl.getUniformLocation(program, "flag"); 81 if (!program || !loc) { 82 testFailed("Fail to set up the program"); 83 return; 84 } 85 gl.uniform1i(loc, flag); 86 wtu.glErrorShouldBe(gl, gl.NO_ERROR, "Set up program should succeed"); 87 88 // Draw the the transform feedback buffers 89 var tf = gl.createTransformFeedback(); 90 91 gl.enableVertexAttribArray(0); 92 gl.bindBuffer(gl.ARRAY_BUFFER, in_buffer); 93 gl.vertexAttribPointer(0, 4, gl.FLOAT, false, 16, 0); 94 95 gl.bindTransformFeedback(gl.TRANSFORM_FEEDBACK, tf); 96 gl.bindBufferBase(gl.TRANSFORM_FEEDBACK_BUFFER, 0, out_buffer); 97 98 gl.enable(gl.RASTERIZER_DISCARD); 99 gl.beginTransformFeedback(gl.POINTS); 100 101 gl.drawArrays(gl.POINTS, 0, 3); 102 103 gl.endTransformFeedback(); 104 gl.disable(gl.RASTERIZER_DISCARD); 105 106 gl.bindBufferBase(gl.TRANSFORM_FEEDBACK_BUFFER, 0, null); 107 108 // Verify the output buffer contents 109 var expected_data; 110 if (flag > 0) { 111 expected_data = [ 112 3.0, 5.0, 7.0, 9.0, 113 4.0, 7.0, 12.0, 21.0, 114 2.75, 3.5, 4.25, 5.0 115 ]; 116 } else { 117 expected_data = [ 118 0.0, 0.0, 0.0, 0.0, 119 0.0, 0.0, 0.0, 0.0, 120 0.0, 0.0, 0.0, 0.0 121 ]; 122 } 123 gl.bindBuffer(gl.TRANSFORM_FEEDBACK_BUFFER, out_buffer); 124 wtu.checkFloatBuffer(gl, gl.TRANSFORM_FEEDBACK_BUFFER, expected_data); 125 } 126 127 debug(""); 128 var successfullyParsed = true; 129 </script> 130 <script src="../../js/js-test-post.js"></script> 131 132 </body> 133 </html>