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webgl-utils.js
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webgl-utils.js
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function getWebglContext(canvas) {
var names = ["webgl", "experimental-webgl", "moz-webgl", "webkit-3d"];
var context = null;
for (var i = 0; i < names.length; i++) {
try {
context = canvas.getContext(names[i]);
} catch(e) {}
if (context) {
break;
}
}
return context;
}
function degToRad(degrees) {
return degrees * Math.PI / 180;
}
function getShader(gl, id) {
var shaderScript = document.getElementById(id);
if (!shaderScript) {
return null;
}
var str = "";
var k = shaderScript.firstChild;
while (k) {
if (k.nodeType == 3) {
str += k.textContent;
}
k = k.nextSibling;
}
var shader;
if (shaderScript.type == "x-shader/x-fragment") {
shader = gl.createShader(gl.FRAGMENT_SHADER);
} else if (shaderScript.type == "x-shader/x-vertex") {
shader = gl.createShader(gl.VERTEX_SHADER);
} else {
return null;
}
gl.shaderSource(shader, str);
gl.compileShader(shader);
if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
alert(gl.getShaderInfoLog(shader));
return null;
}
return shader;
}
if (!window.requestAnimationFrame) {
window.requestAnimationFrame = (function() {
return window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
window.oRequestAnimationFrame ||
window.msRequestAnimationFrame ||
function (callback, element ) {
window.setTimeout( callback, 1000 / 60 );
};
})();
}