program-test-1.html (2569B)
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 <!DOCTYPE html> 7 <html> 8 <head> 9 <meta charset="utf-8"> 10 <!-- This is a visual test that programs must have both a vertex and 11 fragment shader attached; the fixed function pipeline on the 12 desktop must remain disabled. --> 13 <script type="application/javascript"> 14 function log() { 15 var s = ""; 16 for (var i = 0; i < arguments.length; ++i) { 17 s += arguments[i] + " "; 18 } 19 document.getElementById("log").innerHTML += s + "<br>"; 20 } 21 22 function go() { 23 var gl = document.getElementById("c").getContext("experimental-webgl"); 24 25 gl.clearColor(0.0, 0.0, 0.0, 0.0); 26 gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT); 27 28 var vs = gl.createShader(gl.VERTEX_SHADER); 29 gl.shaderSource(vs, "attribute vec4 aVertex; attribute vec4 aColor; varying vec4 vColor; void main() { vColor = aColor; gl_Position = aVertex; }"); 30 gl.compileShader(vs); 31 32 var fs = gl.createShader(gl.FRAGMENT_SHADER); 33 gl.shaderSource(fs, "precision mediump float; varying vec4 vColor; void main() { gl_FragColor = vColor; }"); 34 gl.compileShader(fs); 35 36 var prog = gl.createProgram(); 37 gl.attachShader(prog, vs); 38 // don't attach a fragment shader -- may use fixed pipeline on desktop if the implementation doesn't check! 39 //gl.attachShader(prog, fs); 40 41 gl.bindAttribLocation(prog, 0, "aVertex"); 42 gl.bindAttribLocation(prog, 1, "aColor"); 43 44 gl.linkProgram(prog); 45 46 var vbuf = gl.createBuffer(); 47 gl.bindBuffer(gl.ARRAY_BUFFER, vbuf); 48 gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([ 49 -1.0, -1.0, 0.0, 1.0, 50 -1.0, 1.0, 0.0, 1.0, 51 1.0, -1.0, 0.0, 1.0, 52 1.0, 1.0, 0.0, 1.0]), gl.STATIC_DRAW); 53 gl.vertexAttribPointer(0, 4, gl.FLOAT, false, 0, 0); 54 55 var cbuf = gl.createBuffer(); 56 gl.bindBuffer(gl.ARRAY_BUFFER, cbuf); 57 gl.bufferData(gl.ARRAY_BUFFER, new Uint8Array([255, 0, 0, 58 0, 255, 0, 59 0, 0, 255, 60 255, 255, 0]), gl.STATIC_DRAW); 61 gl.vertexAttribPointer(1, 3, gl.UNSIGNED_BYTE, false, 0, 0); 62 63 gl.enableVertexAttribArray(0); 64 gl.enableVertexAttribArray(1); 65 66 gl.useProgram(prog); 67 68 gl.drawArrays(gl.TRIANGLE_STRIP, 0, 4); 69 70 log("glError", "0x" + gl.getError().toString(16)); 71 } 72 </script> 73 </head> 74 75 <body onload="go()"> 76 <p>Should be green in the rectangle below:</p> 77 <canvas style="background: green;" id="c"></canvas> 78 <div id="log"></div> 79 </body> 80 </html>