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Mini Shell
Mini Shell
/* global define, require */
(function (root, factory) {
'use strict';
if (typeof define === 'function' && define.amd) {
// AMD. Register as an anonymous module.
define(['seriously'], factory);
} else if (typeof exports === 'object') {
// Node/CommonJS
factory(require('seriously'));
} else {
if (!root.Seriously) {
root.Seriously = { plugin: function (name, opt) { this[name] = opt; } };
}
factory(root.Seriously);
}
}(window, function (Seriously) {
'use strict';
// Adapted from http://rastergrid.com/blog/2011/01/frei-chen-edge-detector/
var sqrt = Math.sqrt,
i, j,
flatMatrices = [],
matrices,
freiChenMatrixConstants,
sobelMatrixConstants;
//initialize shader matrix arrays
function multiplyArray(factor, a) {
var i;
for (i = 0; i < a.length; i++) {
a[i] *= factor;
}
return a;
}
matrices = [
multiplyArray(1.0 / (2.0 * sqrt(2.0)), [ 1.0, sqrt(2.0), 1.0, 0.0, 0.0, 0.0, -1.0, -sqrt(2.0), -1.0 ]),
multiplyArray(1.0 / (2.0 * sqrt(2.0)), [1.0, 0.0, -1.0, sqrt(2.0), 0.0, -sqrt(2.0), 1.0, 0.0, -1.0]),
multiplyArray(1.0 / (2.0 * sqrt(2.0)), [0.0, -1.0, sqrt(2.0), 1.0, 0.0, -1.0, -sqrt(2.0), 1.0, 0.0]),
multiplyArray(1.0 / (2.0 * sqrt(2.0)), [sqrt(2.0), -1.0, 0.0, -1.0, 0.0, 1.0, 0.0, 1.0, -sqrt(2.0)]),
multiplyArray(1.0 / 2.0, [0.0, 1.0, 0.0, -1.0, 0.0, -1.0, 0.0, 1.0, 0.0]),
multiplyArray(1.0 / 2.0, [-1.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.0, -1.0]),
multiplyArray(1.0 / 6.0, [1.0, -2.0, 1.0, -2.0, 4.0, -2.0, 1.0, -2.0, 1.0]),
multiplyArray(1.0 / 6.0, [-2.0, 1.0, -2.0, 1.0, 4.0, 1.0, -2.0, 1.0, -2.0]),
multiplyArray(1.0 / 3.0, [1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0])
];
for (i = 0; i < matrices.length; i++) {
for (j = 0; j < matrices[i].length; j++) {
flatMatrices.push(matrices[i][j]);
}
}
freiChenMatrixConstants = new Float32Array(flatMatrices);
sobelMatrixConstants = new Float32Array([
1.0, 2.0, 1.0, 0.0, 0.0, 0.0, -1.0, -2.0, -1.0,
1.0, 0.0, -1.0, 2.0, 0.0, -2.0, 1.0, 0.0, -1.0
]);
Seriously.plugin('edge', {
initialize: function (initialize) {
initialize();
this.uniforms.pixelWidth = 1 / this.width;
this.uniforms.pixelHeight = 1 / this.height;
if (this.inputs.mode === 'sobel') {
this.uniforms.G = sobelMatrixConstants;
} else {
this.uniforms.G = freiChenMatrixConstants;
}
},
shader: function (inputs, shaderSource) {
var defines;
if (inputs.mode === 'sobel') {
defines = '#define N_MATRICES 2\n' +
'#define SOBEL\n';
} else {
//frei-chen
defines = '#define N_MATRICES 9\n';
}
shaderSource.fragment = [
defines,
'precision mediump float;',
'varying vec2 vTexCoord;',
'uniform sampler2D source;',
'uniform float pixelWidth;',
'uniform float pixelHeight;',
'uniform mat3 G[9];',
'void main(void) {',
' mat3 I;',
' float dp3, cnv[9];',
' vec3 tc;',
// fetch the 3x3 neighbourhood and use the RGB vector's length as intensity value
' float fi = 0.0, fj = 0.0;',
' for (int i = 0; i < 3; i++) {',
' fj = 0.0;',
' for (int j = 0; j < 3; j++) {',
' I[i][j] = length( ' +
'texture2D(source, ' +
'vTexCoord + vec2((fi - 1.0) * pixelWidth, (fj - 1.0) * pixelHeight)' +
').rgb );',
' fj += 1.0;',
' };',
' fi += 1.0;',
' };',
// calculate the convolution values for all the masks
' for (int i = 0; i < N_MATRICES; i++) {',
' dp3 = dot(G[i][0], I[0]) + dot(G[i][1], I[1]) + dot(G[i][2], I[2]);',
' cnv[i] = dp3 * dp3;',
' };',
//Sobel
'#ifdef SOBEL',
' tc = vec3(0.5 * sqrt(cnv[0]*cnv[0]+cnv[1]*cnv[1]));',
'#else',
//Frei-Chen
// Line detector
' float M = (cnv[4] + cnv[5]) + (cnv[6] + cnv[7]);',
' float S = (cnv[0] + cnv[1]) + (cnv[2] + cnv[3]) + (cnv[4] + cnv[5]) + (cnv[6] + cnv[7]) + cnv[8];',
' tc = vec3(sqrt(M/S));',
'#endif',
' gl_FragColor = vec4(tc, 1.0);',
'}'
].join('\n');
return shaderSource;
},
resize: function () {
this.uniforms.pixelWidth = 1 / this.width;
this.uniforms.pixelHeight = 1 / this.height;
},
inputs: {
source: {
type: 'image',
uniform: 'source'
},
mode: {
type: 'enum',
shaderDirty: true,
defaultValue: 'sobel',
options: [
['sobel', 'Sobel'],
['frei-chen', 'Frei-Chen']
],
update: function () {
if (this.inputs.mode === 'sobel') {
this.uniforms.G = sobelMatrixConstants;
} else {
this.uniforms.G = freiChenMatrixConstants;
}
}
}
},
description: 'Edge Detect',
title: 'Edge Detect'
});
}));
Zerion Mini Shell 1.0