2 <body style="margin: 0">
3 <canvas width="100" height="100"></canvas>
7 var canvas = document.getElementsByTagName("canvas")[0];
8 gl = canvas.getContext("experimental-webgl");
9 gl.clearColor(0.0, 1.0, 0.0, 1.0);
10 gl.viewport(0, 0, canvas.width, canvas.height);
12 var vertexShader = gl.createShader(gl.VERTEX_SHADER);
13 gl.shaderSource(vertexShader, "attribute vec4 vPosition;\nvoid main() { gl_Position = vPosition; }");
14 gl.compileShader(vertexShader);
16 var fragmentShader = gl.createShader(gl.FRAGMENT_SHADER);
17 gl.shaderSource(fragmentShader, "void main() { gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0); }");
18 gl.compileShader(fragmentShader);
20 var shaderProgram = gl.createProgram();
21 gl.attachShader(shaderProgram, vertexShader);
22 gl.attachShader(shaderProgram, fragmentShader);
23 gl.bindAttribLocation(shaderProgram, 0, "vPosition");
24 gl.linkProgram(shaderProgram);
26 gl.useProgram(shaderProgram);
28 var buffer = gl.createBuffer();
29 gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
31 var vertices = [-1.0, -1.0,
37 gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertices), gl.STATIC_DRAW);
40 gl.vertexAttribPointer(0, 2, gl.FLOAT, false, 0, 0);
41 gl.enableVertexAttribArray(0);
42 gl.clear(gl.COLOR_BUFFER_BIT);
43 gl.drawArrays(gl.TRIANGLES, 0, 3);