cinco/glitch-images
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remove obsolete files

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This commit is contained in:
Georg Fischer 2013-09-11 21:45:13 +02:00
parent 3c403604bd
commit 9d64a16c64
3 changed files with 0 additions and 278 deletions
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38
scripts/aux/canvas.js
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@ -1,38 +0,0 @@
/*global define*/
define(
function()
{
var update = false;
function resize( canvas, size )
{
if ( canvas.width !== size.width )
{
canvas.width = size.width;
update = true;
}
if ( canvas.height !== size.height )
{
canvas.height = size.height;
update = true;
}
if ( update )
{
canvas.width = size.width;
canvas.height = size.height;
}
update = false;
}
function clear( canvas, ctx )
{
ctx.clearRect( ctx, 0, 0, canvas.width, canvas.height );
}
return { resize: resize, clear: clear };
}
);

48
scripts/aux/feature-test.js
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@ -1,48 +0,0 @@
/*global define*/
define(
function()
{
var tests = {
'canvas': { required: true, test: function(){ return !! document.createElement('canvas').getContext; } },
'query-selector-all': { required: false, test: function(){ return !! document.querySelectorAll; } },
'drag-drop': { required: false, test: function(){ return 'draggable' in document.createElement('span'); } },
'file-api': { required: false, test: function(){ return typeof FileReader !== 'undefined'; } }
};
function test( success, error )
{
var required_supported = true;
var results = { };
var required_features_missing = [ ];
for ( var key in tests )
{
var result = tests[key].test();
if ( ! result )
{
if ( tests[key].required )
{
required_supported = false;
required_features_missing.push( key );
}
}
results[key] = result;
}
if ( required_supported )
{
success( results );
}
else
{
error( required_features_missing, results );
}
}
return test;
}
);

192
scripts/aux/glitch.js
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@ -1,192 +0,0 @@
/*global define*/
define(
[ 'aux/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;
}
);