ext-polygon-offset-clamp.html (5306B)
1 <!-- 2 Copyright (c) 2023 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 EXT_polygon_offset_clamp 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 <canvas width="32" height="32" id="c"></canvas> 18 <div id="description"></div> 19 <div id="console"></div> 20 <script> 21 "use strict"; 22 description("This test verifies the functionality of the EXT_polygon_offset_clamp extension, if it is available."); 23 24 debug(""); 25 26 var wtu = WebGLTestUtils; 27 var gl = wtu.create3DContext(); 28 var ext; 29 const w = gl.drawingBufferWidth; 30 const h = gl.drawingBufferHeight; 31 32 function runTestNoExtension() { 33 debug(""); 34 debug("Check the parameter without the extension"); 35 shouldBeNull("gl.getParameter(0x8E1B /* POLYGON_OFFSET_CLAMP_EXT */)"); 36 wtu.glErrorShouldBe(gl, gl.INVALID_ENUM, "parameter unknown without enabling the extension"); 37 wtu.glErrorShouldBe(gl, gl.NO_ERROR, "should be no errors"); 38 } 39 40 function checkEnums() { 41 debug(""); 42 debug("Check enums"); 43 shouldBe("ext.POLYGON_OFFSET_CLAMP_EXT", "0x8E1B"); 44 } 45 46 function checkQueries() { 47 debug(""); 48 debug("Check default state"); 49 shouldBe('gl.getParameter(gl.POLYGON_OFFSET_FACTOR)', '0.0'); 50 shouldBe('gl.getParameter(gl.POLYGON_OFFSET_UNITS)', '0.0'); 51 shouldBe('gl.getParameter(ext.POLYGON_OFFSET_CLAMP_EXT)', '0.0'); 52 wtu.glErrorShouldBe(gl, gl.NO_ERROR, "should be no errors"); 53 debug(""); 54 debug("Check state update using the new function"); 55 ext.polygonOffsetClampEXT(1.0, 2.0, 3.0); 56 shouldBe('gl.getParameter(gl.POLYGON_OFFSET_FACTOR)', '1.0'); 57 shouldBe('gl.getParameter(gl.POLYGON_OFFSET_UNITS)', '2.0'); 58 shouldBe('gl.getParameter(ext.POLYGON_OFFSET_CLAMP_EXT)', '3.0'); 59 wtu.glErrorShouldBe(gl, gl.NO_ERROR, "should be no errors"); 60 debug(""); 61 debug("Check that the unextended function resets the clamp value to zero"); 62 gl.polygonOffset(4.0, 5.0); 63 shouldBe('gl.getParameter(gl.POLYGON_OFFSET_FACTOR)', '4.0'); 64 shouldBe('gl.getParameter(gl.POLYGON_OFFSET_UNITS)', '5.0'); 65 shouldBe('gl.getParameter(ext.POLYGON_OFFSET_CLAMP_EXT)', '0.0'); 66 wtu.glErrorShouldBe(gl, gl.NO_ERROR, "should be no errors"); 67 } 68 69 function checkClamping() { 70 debug(""); 71 debug("Check polygon offset clamp operation"); 72 73 // The shader creates a depth slope from left (0) to right (1). 74 // 75 // This test issues two draw calls: 76 // 77 // Draw 2 (green): factor width, offset 0, clamp 0.5, depth test: Greater 78 // ^ | __________________ 79 // | | __/ __/ 80 // | V __/ __/ <--- Draw 1 (red): factor width, offset 0, clamp 0.25 81 // | __/ __/ 82 // | __/ __/ 83 // |/ __/ 84 // | __/ 85 // | __/ 86 // |/ 87 // | 88 // | 89 // +-------------------------------> 90 // 91 // Result: <---------green--------><--red--> 92 93 94 const program = wtu.setupProgram(gl, [wtu.simpleVertexShader, 95 wtu.simpleColorFragmentShader]); 96 gl.useProgram(program); 97 const colorLoc = gl.getUniformLocation(program, "u_color"); 98 99 const buf = gl.createBuffer(); 100 gl.bindBuffer(gl.ARRAY_BUFFER, buf); 101 gl.bufferData( 102 gl.ARRAY_BUFFER, 103 new Float32Array([-1, -1, -1, 1, -1, 1, -1, 1, -1, 1, 1, 1]), 104 gl.STATIC_DRAW); 105 gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0); 106 gl.enableVertexAttribArray(0); 107 108 wtu.glErrorShouldBe(gl, gl.NO_ERROR, "should be no errors"); 109 110 gl.enable(gl.POLYGON_OFFSET_FILL); 111 gl.clearColor(0, 0, 0, 1); 112 gl.clearDepth(0); 113 gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT); 114 115 gl.enable(gl.DEPTH_TEST); 116 117 gl.depthFunc(gl.ALWAYS); 118 gl.uniform4f(colorLoc, 1, 0, 0, 1); 119 ext.polygonOffsetClampEXT(w, 0, 0.25); 120 gl.drawArrays(gl.TRIANGLE_STRIP, 0, 4); 121 122 gl.depthFunc(gl.GREATER); 123 gl.uniform4f(colorLoc, 0, 1, 0, 1); 124 ext.polygonOffsetClampEXT(w, 0, 0.5); 125 gl.drawArrays(gl.TRIANGLE_STRIP, 0, 4); 126 127 wtu.checkCanvasRect( 128 gl, 129 0, 0, 3 * w / 4 - 1, h, 130 [0, 255, 0, 255], "should be green"); 131 132 wtu.checkCanvasRect( 133 gl, 134 3 * w / 4 + 1, 0, w / 4 - 1, h, 135 [255, 0, 0, 255], "should be red"); 136 137 wtu.glErrorShouldBe(gl, gl.NO_ERROR, "should be no errors"); 138 } 139 140 function runTestExtension() { 141 checkEnums(); 142 checkQueries(); 143 checkClamping(); 144 } 145 146 function runTest() { 147 if (!gl) { 148 testFailed("WebGL context does not exist"); 149 return; 150 } 151 testPassed("WebGL context exists"); 152 153 runTestNoExtension(); 154 155 ext = gl.getExtension("EXT_polygon_offset_clamp"); 156 157 wtu.runExtensionSupportedTest(gl, "EXT_polygon_offset_clamp", ext !== null); 158 159 if (ext !== null) { 160 runTestExtension(); 161 } else { 162 testPassed("No EXT_polygon_offset_clamp support -- this is legal"); 163 } 164 } 165 166 runTest(); 167 168 var successfullyParsed = true; 169 </script> 170 <script src="../../js/js-test-post.js"></script> 171 </body> 172 </html>