| <!-- |
| 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>WebGL Transform Feedback Conformance Tests</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> |
| <div id="description"></div> |
| <canvas id="canvas" style="width: 50px; height: 50px;"> </canvas> |
| <div id="console"></div> |
| <script id="vshader" type="x-shader/x-vertex">#version 300 es |
| in vec4 in_data; |
| uniform int flag; |
| out vec4 out_data; |
| void main(void) { |
| if (flag > 0) { |
| out_data = in_data + vec4(2.0, 3.0, 4.0, 5.0); |
| } |
| } |
| </script> |
| <script id="fshader" type="x-shader/x-fragment">#version 300 es |
| precision mediump float; |
| out vec4 out_color; |
| void main(void) { |
| out_color = vec4(1.0, 1.0, 1.0, 1.0); |
| } |
| </script> |
| <script> |
| "use strict"; |
| 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."); |
| |
| debug(""); |
| |
| var wtu = WebGLTestUtils; |
| var canvas = document.getElementById("canvas"); |
| var gl = wtu.create3DContext(canvas, null, 2); |
| |
| if (!gl) { |
| testFailed("WebGL context does not exist"); |
| } else { |
| testPassed("WebGL context exists"); |
| |
| debug(""); |
| debug("Testing transform feedback works fine"); |
| runTest(1); |
| |
| debug(""); |
| debug("Testing unwritten output variables default to zero"); |
| runTest(0); |
| } |
| |
| function runTest(flag) { |
| var in_data = [ |
| 1.0, 2.0, 3.0, 4.0, |
| 2.0, 4.0, 8.0, 16.0, |
| 0.75, 0.5, 0.25, 0.0 |
| ]; |
| |
| var in_buffer = gl.createBuffer(); |
| gl.bindBuffer(gl.ARRAY_BUFFER, in_buffer); |
| gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(in_data), gl.STATIC_DRAW); |
| |
| var out_buffer = gl.createBuffer(); |
| gl.bindBuffer(gl.TRANSFORM_FEEDBACK_BUFFER, out_buffer); |
| gl.bufferData(gl.TRANSFORM_FEEDBACK_BUFFER, Float32Array.BYTES_PER_ELEMENT * in_data.length, gl.STATIC_DRAW); |
| |
| // Create the transform feedback program |
| var program = wtu.setupTransformFeedbackProgram(gl, ["vshader", "fshader"], |
| ["out_data"], gl.SEPARATE_ATTRIBS, |
| ["in_data"]); |
| var loc = gl.getUniformLocation(program, "flag"); |
| if (!program || !loc) { |
| testFailed("Fail to set up the program"); |
| return; |
| } |
| gl.uniform1i(loc, flag); |
| wtu.glErrorShouldBe(gl, gl.NO_ERROR, "Set up program should succeed"); |
| |
| // Draw the the transform feedback buffers |
| var tf = gl.createTransformFeedback(); |
| |
| gl.enableVertexAttribArray(0); |
| gl.bindBuffer(gl.ARRAY_BUFFER, in_buffer); |
| gl.vertexAttribPointer(0, 4, gl.FLOAT, false, 16, 0); |
| |
| gl.bindTransformFeedback(gl.TRANSFORM_FEEDBACK, tf); |
| gl.bindBufferBase(gl.TRANSFORM_FEEDBACK_BUFFER, 0, out_buffer); |
| |
| gl.enable(gl.RASTERIZER_DISCARD); |
| gl.beginTransformFeedback(gl.POINTS); |
| |
| gl.drawArrays(gl.POINTS, 0, 3); |
| |
| gl.endTransformFeedback(); |
| gl.disable(gl.RASTERIZER_DISCARD); |
| |
| gl.bindBufferBase(gl.TRANSFORM_FEEDBACK_BUFFER, 0, null); |
| |
| // Verify the output buffer contents |
| var expected_data; |
| if (flag > 0) { |
| expected_data = [ |
| 3.0, 5.0, 7.0, 9.0, |
| 4.0, 7.0, 12.0, 21.0, |
| 2.75, 3.5, 4.25, 5.0 |
| ]; |
| } else { |
| expected_data = [ |
| 0.0, 0.0, 0.0, 0.0, |
| 0.0, 0.0, 0.0, 0.0, |
| 0.0, 0.0, 0.0, 0.0 |
| ]; |
| } |
| gl.bindBuffer(gl.TRANSFORM_FEEDBACK_BUFFER, out_buffer); |
| wtu.checkFloatBuffer(gl, gl.TRANSFORM_FEEDBACK_BUFFER, expected_data); |
| } |
| |
| debug(""); |
| var successfullyParsed = true; |
| </script> |
| <script src="../../js/js-test-post.js"></script> |
| |
| </body> |
| </html> |
