use glitch-canvas as dependency since it is a separate library now

Georg Fischer 2014-04-11 21:34:16 +02:00
parent 2e0baf1c1d
commit a140553c7e
3 changed files with 185 additions and 196 deletions

@ -0,0 +1,184 @@
//! glitch-canvas by snorpey, MIT License
(function(window, factory) {
if (typeof define === "function" && define.amd) {
define(factory);
} else if (typeof exports === "object") {
module.exports = factory();
} else {
window.glitch = factory();
}
})(this, function() {
var canvas_1 = document.createElement("canvas");
var canvas_2 = document.createElement("canvas");
var ctx_1 = canvas_1.getContext("2d");
var ctx_2 = canvas_2.getContext("2d");
var base64_chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
var base64_map = base64_chars.split("");
var reversed_base64_map = {};
var params;
var base64;
var byte_array;
var jpg_header_length;
var img;
var new_image_data;
var i;
var len;
base64_map.forEach(function(val, key) {
reversed_base64_map[val] = key;
});
function glitchImageData(image_data, parameters, callback) {
if (isValidImageData(image_data) && checkType(parameters, "parameters", "object") && checkType(callback, "callback", "function")) {
params = getNormalizedParameters(parameters);
resizeCanvas(canvas_1, image_data);
resizeCanvas(canvas_2, image_data);
base64 = getBase64FromImageData(image_data, params.quality);
byte_array = base64ToByteArray(base64);
jpg_header_length = getJpegHeaderSize(byte_array);
for (i = 0, len = params.iterations; i < len; i++) {
glitchJpegBytes(byte_array, jpg_header_length, params.seed, params.amount, i, params.iterations);
}
img = new Image();
img.onload = function() {
ctx_1.drawImage(img, 0, 0);
new_image_data = ctx_1.getImageData(0, 0, image_data.width, image_data.height);
callback(new_image_data);
};
img.src = byteArrayToBase64(byte_array);
}
}
function resizeCanvas(canvas, size) {
if (canvas.width !== size.width) {
canvas.width = size.width;
}
if (canvas.height !== size.height) {
canvas.height = size.height;
}
}
function glitchJpegBytes(byte_array, jpg_header_length, seed, amount, i, len) {
var max_index = byte_array.length - jpg_header_length - 4;
var px_min = parseInt(max_index / len * i, 10);
var px_max = parseInt(max_index / len * (i + 1), 10);
var delta = px_max - px_min;
var px_i = parseInt(px_min + delta * seed, 10);
if (px_i > max_index) {
px_i = max_index;
}
var index = Math.floor(jpg_header_length + px_i);
byte_array[index] = Math.floor(amount * 256);
}
function getBase64FromImageData(image_data, quality) {
var q = typeof quality === "number" && quality < 1 && quality > 0 ? quality : .1;
ctx_2.putImageData(image_data, 0, 0);
return canvas_2.toDataURL("image/jpeg", q);
}
function getJpegHeaderSize(data) {
var result = 417;
for (i = 0, len = data.length; i < len; i++) {
if (data[i] === 255 && data[i + 1] === 218) {
result = i + 2;
break;
}
}
return result;
}
function base64ToByteArray(str) {
var result = [];
var digit_num;
var cur;
var prev;
for (i = 23, len = str.length; i < len; i++) {
cur = reversed_base64_map[str.charAt(i)];
digit_num = (i - 23) % 4;
switch (digit_num) {
case 1:
result.push(prev << 2 | cur >> 4);
break;
case 2:
result.push((prev & 15) << 4 | cur >> 2);
break;
case 3:
result.push((prev & 3) << 6 | cur);
break;
}
prev = cur;
}
return result;
}
function byteArrayToBase64(arr) {
var result = [ "data:image/jpeg;base64," ];
var byte_num;
var cur;
var prev;
for (i = 0, len = arr.length; i < len; i++) {
cur = arr[i];
byte_num = i % 3;
switch (byte_num) {
case 0:
result.push(base64_map[cur >> 2]);
break;
case 1:
result.push(base64_map[(prev & 3) << 4 | cur >> 4]);
break;
case 2:
result.push(base64_map[(prev & 15) << 2 | cur >> 6]);
result.push(base64_map[cur & 63]);
break;
}
prev = cur;
}
if (byte_num === 0) {
result.push(base64_map[(prev & 3) << 4]);
result.push("==");
} else if (byte_num === 1) {
result.push(base64_map[(prev & 15) << 2]);
result.push("=");
}
return result.join("");
}
function getImageDataCopy(image_data) {
var copy = ctx_2.createImageData(image_data.width, image_data.height);
copy.data.set(image_data.data);
return copy;
}
function getNormalizedParameters(parameters) {
return {
seed: (parameters.seed || 0) / 100,
quality: (parameters.quality || 0) / 100,
amount: (parameters.amount || 0) / 100,
iterations: parameters.iterations || 0
};
}
function isValidImageData(image_data) {
if (checkType(image_data, "image_data", "object") && checkType(image_data.width, "image_data.width", "number") && checkType(image_data.height, "image_data.height", "number") && checkType(image_data.data, "image_data.data", "object") && checkType(image_data.data.length, "image_data.data.length", "number") && checkNumber(image_data.data.length, "image_data.data.length", isPositive, "> 0")) {
return true;
} else {
return false;
}
}
function checkType(it, name, expected_type) {
if (typeof it === expected_type) {
return true;
} else {
error(it, "typeof " + name, '"' + expected_type + '"', '"' + typeof it + '"');
return false;
}
}
function checkNumber(it, name, condition, condition_name) {
if (condition(it) === true) {
return true;
} else {
error(it, name, condition_name, "not");
}
}
function isPositive(nr) {
return nr > 0;
}
function error(it, name, expected, result) {
throw new Error("glitch(): Expected " + name + " to be " + expected + ", but it was " + result + ".");
}
return glitchImageData;
});

@ -1,195 +0,0 @@
/*global define*/
define(
[ 'util/canvas' ],
function( canvas_helper )
{
var canvas = document.createElement( 'canvas' );
var ctx = canvas.getContext( '2d' );
var tmp_canvas = document.createElement( 'canvas' );
var tmp_ctx = tmp_canvas.getContext( '2d' );
var canvas_size = { width: 10, height: 10 };
var base64_chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
var base64_map = base64_chars.split( '' );
var reverse_base64_map = { };
var iterations;
var quality;
var seed;
var amount;
var base64;
var byte_array;
var jpg_header_length;
var img;
var new_image_data;
var i;
var len;
base64_map.forEach( function( val, key ) { reverse_base64_map[val] = key; } );
function getGlitchedImageSrc( image_data, input, callback )
{
seed = input.seed / 100;
quality = input.quality / 100;
amount = input.amount / 100;
iterations = input.iterations;
canvas_helper.resize( canvas, image_data );
canvas_helper.resize( tmp_canvas, image_data );
base64 = getBase64FromImageData( image_data, quality );
byte_array = base64ToByteArray( base64 );
jpg_header_length = getJpegHeaderSize( byte_array );
for ( i = 0; i < iterations; i++ )
{
glitchJpegBytes( byte_array, jpg_header_length, seed, amount, i, iterations );
}
img = new Image();
img.onload = function() {
ctx.drawImage( img, 0, 0 );
new_image_data = ctx.getImageData( 0, 0, image_data.width, image_data.height );
callback( new_image_data );
};
img.src = byteArrayToBase64( byte_array );
}
function glitchJpegBytes( byte_array, jpg_header_length, seed, amount, i, len )
{
var max_index = byte_array.length - jpg_header_length - 4;
var px_min = parseInt( max_index / len * i, 10 );
var px_max = parseInt( max_index / len * ( i + 1 ), 10 );
var delta = px_max - px_min;
var px_i = parseInt( px_min + delta * seed, 10 );
if ( px_i > max_index )
{
px_i = max_index;
}
var index = Math.floor( jpg_header_length + px_i );
byte_array[index] = Math.floor( amount * 256 );
}
function getBase64FromImageData( image_data, quality )
{
var q = typeof quality === 'number' && quality < 1 && quality > 0 ? quality : 0.1;
tmp_ctx.putImageData( image_data, 0, 0 );
return tmp_canvas.toDataURL( 'image/jpeg', q );
}
function getJpegHeaderSize( data )
{
var result = 417;
for ( var i = 0, l = data.length; i < l; i++ )
{
if (
data[i] === 0xFF &&
data[i + 1] === 0xDA
)
{
result = i + 2;
break;
}
}
return result;
}
// https://github.com/mutaphysis/smackmyglitchupjs/blob/master/glitch.html
// base64 is 2^6, byte is 2^8, every 4 base64 values create three bytes
function base64ToByteArray( str )
{
var result = [ ];
var digit_num;
var cur;
var prev;
for ( var i = 23, l = str.length; i < l; i++ )
{
cur = reverse_base64_map[ str.charAt( i ) ];
digit_num = ( i - 23 ) % 4;
switch ( digit_num )
{
// case 0: first digit - do nothing, not enough info to work with
case 1: // second digit
result.push( prev << 2 | cur >> 4 );
break;
case 2: // third digit
result.push( ( prev & 0x0f ) << 4 | cur >> 2 );
break;
case 3: // fourth digit
result.push( ( prev & 3 ) << 6 | cur );
break;
}
prev = cur;
}
return result;
}
function byteArrayToBase64( arr )
{
var result = [ 'data:image/jpeg;base64,' ];
var byte_num;
var cur;
var prev;
var i;
for ( var i = 0, l = arr.length; i < l; i++ )
{
cur = arr[i];
byte_num = i % 3;
switch ( byte_num )
{
case 0: // first byte
result.push( base64_map[ cur >> 2 ] );
break;
case 1: // second byte
result.push( base64_map[( prev & 3 ) << 4 | ( cur >> 4 )] );
break;
case 2: // third byte
result.push( base64_map[( prev & 0x0f ) << 2 | ( cur >> 6 )] );
result.push( base64_map[cur & 0x3f] );
break;
}
prev = cur;
}
if ( byte_num === 0 )
{
result.push( base64_map[( prev & 3 ) << 4] );
result.push( '==' );
}
else if ( byte_num === 1 )
{
result.push( base64_map[( prev & 0x0f ) << 2] );
result.push( '=' );
}
return result.join( '' );
}
function getImageDataCopy( image_data )
{
var copy = tmp_ctx.createImageData( image_data.width, image_data.height );
copy.data.set( image_data.data );
return copy;
}
return getGlitchedImageSrc;
}
);

@ -1,6 +1,6 @@
/*global define, requestAnimationFrame*/ /*global define, requestAnimationFrame*/
define( define(
[ 'src/glitch', 'util/canvas', 'lib/raf' ], [ 'lib/glitch-canvas', 'util/canvas', 'lib/raf' ],
function( glitch, canvas_helper ) function( glitch, canvas_helper )
{ {
var tmp_canvas = document.createElement( 'canvas' ); var tmp_canvas = document.createElement( 'canvas' );