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<!DOCTYPE html>
<head>
<meta charset="utf-8"/>
<title>Ямайка</title>
<script src="webgl-fmi.js"></script>
<script id="vshader" type="x-shader/x-vertex">
attribute vec2 aXY;
attribute vec3 aRGB;
varying vec3 vRGB;
void main ()
{
gl_Position = vec4(aXY,0,1);
gl_PointSize = 4.0;
vRGB = aRGB;
}
</script>
<script id="fshader" type="x-shader/x-fragment">
precision mediump float;
varying vec3 vRGB;
void main( )
{
gl_FragColor = vec4(vRGB,1);
}
</script>
<script>
function start( )
{
gl = getContext("picasso");
glprog = getProgram("vshader","fshader");
aXY = gl.getAttribLocation(glprog,"aXY");
aRGB = gl.getAttribLocation(glprog,"aRGB");
gl.clearColor(1,0.84,0,1);
gl.clear(gl.COLOR_BUFFER_BIT);
var data = [];
var black = [0, 0, 0];
// Left triangle
data.push(-1, 0.8);
data = data.concat(black);
data.push(-1, -0.8);
data = data.concat(black);
data.push(-0.2, 0);
data = data.concat(black);
// Right triangle
data.push(1, 0.8);
data = data.concat(black);
data.push(1, -0.8);
data = data.concat(black);
data.push(0.2, 0);
data = data.concat(black);
var green = [0, 0.5, 0];
// Top triangle
data.push(-0.8, 1);
data = data.concat(green);
data.push(0.8, 1);
data = data.concat(green);
data.push(0, 0.2);
data = data.concat(green);
// Bottom triangle
data.push(-0.8, -1);
data = data.concat(green);
data.push(0.8, -1);
data = data.concat(green);
data.push(0, -0.2);
data = data.concat(green);
var buf = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER,buf);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(data), gl.STATIC_DRAW);
gl.enableVertexAttribArray(aXY);
gl.vertexAttribPointer(aXY,2,gl.FLOAT,false, 5 * FLOATS, 0);
gl.enableVertexAttribArray(aRGB);
gl.vertexAttribPointer(aRGB, 3, gl.FLOAT, false, 5 * FLOATS, 2 * FLOATS);
gl.drawArrays(gl.TRIANGLES, 0, 4 * 3);
}
</script>
</head>
<body onload="start()">
<h2>Ямайка</h2>
<noscript>
Искаме JavaScript, но няма!
</noscript>
<canvas id="picasso" width="600" height="300" style="border: solid;">
Искаме canvas, но няма!
</canvas>
</body>
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