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/ *
Von Millhausen ' s SF2000 Tools Shared JS Library
=== === === === === === === === === === === === === === === ==
There ' s a bit of overlap between what my SF2000 tools do ( e . g . , CRC32
recalculation is fairly common , etc . ) , and there ' s some general functions
that might be useful for future tools as well ( e . g . , ` bisrv.asd ` hash
checking ) , so rather than repeating code in each separate tool , any "shared"
functions will go here .
Just like the tools themselves , this file should be considered CC0 Public
Domain ( https : //creativecommons.org/publicdomain/zero/1.0/)
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Version 1.2 : Added support for blanking out the power curve monitoring bytes
in getFirmwareHash ( ) , and updated the hashes accordingly in knownHash ( )
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Version 1.1 : Added support for the August 3 rd BIOS in getFirmwareHash ( ) and
knownHash ( )
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Version 1.0 : Initial version
* /
// This function takes in a Uint8Array object, and patches bytes 0x18c to
// 0x18f with an updated CRC32 calculated on bytes 512 to the end of the
// array. Credit to `bnister` for this code!
function patchCRC32 ( data ) {
var c ;
var tabCRC32 = new Int32Array ( 256 ) ;
for ( var i = 0 ; i < 256 ; i ++ ) {
c = i << 24 ;
for ( var j = 0 ; j < 8 ; j ++ ) {
c = c & ( 1 << 31 ) ? c << 1 ^ 0x4c11db7 : c << 1 ;
}
tabCRC32 [ i ] = c ;
}
c = ~ 0 ;
for ( var i = 512 ; i < data . length ; i ++ ) {
c = c << 8 ^ tabCRC32 [ c >>> 24 ^ data [ i ] ] ;
}
data [ 0x18c ] = c & 255 ;
data [ 0x18d ] = c >>> 8 & 255 ;
data [ 0x18e ] = c >>> 16 & 255 ;
data [ 0x18f ] = c >>> 24 ;
}
// Returns an SHA-256 hash of a given firmware (ignoring common user changes),
// or returns false on failure...
function getFirmwareHash ( data ) {
// Data should be a Uint8Array, which as an object is passed by reference...
// we're going to be manipulating that data before generating our hash, but we
// don't want to modify the original object at all... so we'll create a copy,
// and work only on the copy...
var dataCopy = data . slice ( ) ;
// Only really worthwhile doing this for big bisrv.asd files...
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if ( dataCopy . length > 12600000 ) {
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// First, replace CRC32 bits with 00...
dataCopy [ 396 ] = 0x00 ;
dataCopy [ 397 ] = 0x00 ;
dataCopy [ 398 ] = 0x00 ;
dataCopy [ 399 ] = 0x00 ;
// Next identify the boot logo position, and blank it out too...
var badExceptionOffset = findSequence ( [ 0x62 , 0x61 , 0x64 , 0x5F , 0x65 , 0x78 , 0x63 , 0x65 , 0x70 , 0x74 , 0x69 , 0x6F , 0x6E , 0x00 , 0x00 , 0x00 ] , dataCopy ) ;
if ( badExceptionOffset > - 1 ) {
var bootLogoStart = badExceptionOffset + 16 ;
for ( var i = bootLogoStart ; i < ( bootLogoStart + 204800 ) ; i ++ ) {
dataCopy [ i ] = 0x00 ;
}
}
else {
return false ;
}
// Next identify the emulator button mappings (if they exist), and blank
// them out too...
var preButtonMapOffset = findSequence ( [ 0x00 , 0x00 , 0x00 , 0x71 , 0xDB , 0x8E , 0x00 , 0x00 , 0x00 , 0x00 , 0x00 , 0x00 , 0x00 , 0x00 , 0x00 , 0x00 ] , dataCopy ) ;
if ( preButtonMapOffset > - 1 ) {
var postButtonMapOffset = findSequence ( [ 0x00 , 0x00 , 0x00 , 0x00 , 0x00 , 0x00 , 0x00 , 0x00 , 0x00 , 0x00 , 0x00 , 0x00 , 0x00 , 0x00 , 0x00 , 0x00 , 0x01 , 0x00 , 0x00 , 0x00 , 0x01 , 0x00 , 0x00 , 0x00 , 0x02 , 0x00 , 0x00 , 0x00 , 0x02 , 0x00 , 0x00 , 0x00 ] , dataCopy , preButtonMapOffset ) ;
if ( postButtonMapOffset > - 1 ) {
for ( var i = preButtonMapOffset + 16 ; i < postButtonMapOffset ; i ++ ) {
dataCopy [ i ] = 0x00 ;
}
}
else {
return false ;
}
}
else {
return false ;
}
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// Next we'll look for (and zero out) the five bytes that the power
// monitoring functions of the SF2000 use for switching the UI's battery
// level indicator. These unfortunately can't be searched for - they're just
// in specific known locations for specific firmware versions...
var prePowerCurve = findSequence ( [ 0x11 , 0x05 , 0x00 , 0x02 , 0x24 ] , dataCopy ) ;
if ( prePowerCurve > - 1 ) {
var powerCurveFirstByteLocation = prePowerCurve + 5 ;
switch ( powerCurveFirstByteLocation ) {
case 0x35A8F8 :
// Seems to match mid-March layout...
dataCopy [ 0x35A8F8 ] = 0x00 ;
dataCopy [ 0x35A900 ] = 0x00 ;
dataCopy [ 0x35A9B0 ] = 0x00 ;
dataCopy [ 0x35A9B8 ] = 0x00 ;
dataCopy [ 0x35A9D4 ] = 0x00 ;
break ;
case 0x35A954 :
// Seems to match April 20th layout...
dataCopy [ 0x35A954 ] = 0x00 ;
dataCopy [ 0x35A95C ] = 0x00 ;
dataCopy [ 0x35AA0C ] = 0x00 ;
dataCopy [ 0x35AA14 ] = 0x00 ;
dataCopy [ 0x35AA30 ] = 0x00 ;
break ;
case 0x35C78C :
// Seems to match May 15th layout...
dataCopy [ 0x35C78C ] = 0x00 ;
dataCopy [ 0x35C794 ] = 0x00 ;
dataCopy [ 0x35C844 ] = 0x00 ;
dataCopy [ 0x35C84C ] = 0x00 ;
dataCopy [ 0x35C868 ] = 0x00 ;
break ;
case 0x35C790 :
// Seems to match May 22nd layout...
dataCopy [ 0x35C790 ] = 0x00 ;
dataCopy [ 0x35C798 ] = 0x00 ;
dataCopy [ 0x35C848 ] = 0x00 ;
dataCopy [ 0x35C850 ] = 0x00 ;
dataCopy [ 0x35C86C ] = 0x00 ;
break ;
case 0x3564EC :
// Seems to match August 3rd layout...
dataCopy [ 0x3564EC ] = 0x00 ;
dataCopy [ 0x3564F4 ] = 0x00 ;
dataCopy [ 0x35658C ] = 0x00 ;
dataCopy [ 0x356594 ] = 0x00 ;
dataCopy [ 0x3565B0 ] = 0x00 ;
break ;
default :
return false ;
}
}
else {
return false ;
}
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// If we're here, we've zeroed-out all of the bits of the firmware that are
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// semi-user modifiable (CRC32 bits, boot logo, button mappings and power
// curve bytes); now we can generate a hash of what's left and compare it
// against some known values...
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return crypto . subtle . digest ( "SHA-256" , dataCopy . buffer )
. then ( function ( digest ) {
var array = Array . from ( new Uint8Array ( digest ) ) ;
var hash = array . map ( byte => ( "00" + byte . toString ( 16 ) ) . slice ( - 2 ) ) . join ( "" ) ;
return hash ;
} )
. catch ( function ( error ) {
return false ;
} ) ;
}
else {
return false ;
}
}
// This function searches for array needle in array haystack starting at offset
// and returns the zero-based index of the first match found, or -1 if not
// found...
function findSequence ( needle , haystack , offset ) {
// If offset is not provided, default to 0...
offset = offset || 0 ;
// Loop through the haystack array starting from the offset...
for ( var i = offset ; i < haystack . length - needle . length + 1 ; i ++ ) {
// Assume a match until proven otherwise...
var match = true ;
// Loop through the needle array and compare each byte...
for ( var j = 0 ; j < needle . length ; j ++ ) {
if ( haystack [ i + j ] !== needle [ j ] ) {
// Mismatch found, break the inner loop and continue the outer loop...
match = false ;
break ;
}
}
// If match is still true after the inner loop, we have found a match;
// return the index of the start of the match...
if ( match ) {
return i ;
}
}
// If we reach this point, no match was found...
return - 1 ;
}
// Generic download function, for sending data to the user's browser as a
// download...
function downloadToBrowser ( data , type , name ) {
// Send the data to the user's browser as a file download...
var link = document . createElement ( "a" ) ;
link . href = window . URL . createObjectURL ( new Blob ( [ data ] , { type : type } ) ) ;
link . download = name ;
link . style . display = "none" ;
document . body . appendChild ( link ) ;
link . click ( ) ;
window . URL . revokeObjectURL ( link . href ) ;
document . body . removeChild ( link ) ;
}
// This simple function takes in a string representing an SHA1 hash, and
// compares it against the known hashes my tools use for the various stock
// firmware versions; returns a string with my internal "MM.DD" firmware naming
// convention, or false if the provided hash doesn't match...
function knownHash ( hash ) {
switch ( hash ) {
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case "17b931ed95cc5506b06941cc1ea152fda9eef94d8109168f6e180fce8043ef66" :
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return "03.15" ;
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case "c4ae6c69e6ca1a39bae1f8e342e41779bd45ee396e29855b795e1bacddd5916a" :
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return "04.20" ;
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case "48f86e1ff56223349186029270c6c022ce0de1ff47d6704c73e55c31ad68aec4" :
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return "05.15" ;
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case "1cd37343576a6584565884fcbbe2ffaf18b50466144b356aa0b885cd9cf10484" :
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return "05.22" ;
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case "334c8f0a8584db07078d7dfc940e540e6538dde948cb6fdbf50754e4e113d6bc" :
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return "08.03" ;
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default :
return false ;
}
}
// Takes in an ImageData object, and returns a Uint8Array object containing the
// data in little-endian RGB565 format...
function imageDataToRgb565 ( input ) {
// Loop through the image data, and convert it to little-endian RGB565. First,
// we'll store the raw RGB565-converted integers in an array, one entry per
// pixel...
var intArray = [ ] ;
var pixelCount = 0 ;
for ( var i = 0 ; i < input . data . length ; i += 4 ) {
// Read in the raw source RGB colours from the image data stream...
var red = input . data [ i ] ;
var green = input . data [ i + 1 ] ;
var blue = input . data [ i + 2 ] ;
// Use some shifting and masking to get a big-endian version of the RGB565
// colour and store it in our array before moving on...
intArray [ pixelCount ] = ( ( red & 248 ) << 8 ) + ( ( green & 252 ) << 3 ) + ( blue >> 3 ) ;
pixelCount ++ ;
}
// Create a data buffer and a data view; we'll use the view to convert our int
// array data to little-endian format (the "true" below) to be stored in the
// buffer...
var buffer = new ArrayBuffer ( intArray . length * 2 ) ;
var dataView = new DataView ( buffer ) ;
for ( var i = 0 ; i < intArray . length ; i ++ ) {
dataView . setInt16 ( i * 2 , intArray [ i ] , true ) ;
}
// Use the buffer to fill a Uint8Array, which we'll return...
return new Uint8Array ( buffer ) ;
}
// Takes in an ImageData object, and returns a Uint8Array object containing the
// data in BGRA format...
function imageDataToBgra ( input ) {
// This is pretty simple - we just loop through the input data (which is in
// RGBA format), and swap the Red and Blue channels to output BGRA instead...
output = new Uint8Array ( input . data . length ) ;
for ( var i = 0 ; i < input . data . length ; i += 4 ) {
output [ i ] = input . data [ i + 2 ] ;
output [ i + 1 ] = input . data [ i + 1 ] ;
output [ i + 2 ] = input . data [ i ] ;
output [ i + 3 ] = input . data [ i + 3 ] ;
}
return output ;
}
// Takes in a Uint8Array object containing little-endian RGB565 image data, a
// width and a height, and outputs an ImageData object...
function rgb565ToImageData ( input , width , height ) {
// Create an output ImageData object of the specified dimensions; it'll
// default to transparent black, but we'll fill it with our input data...
output = new ImageData ( width , height ) ;
outputIndex = 0 ;
for ( var i = 0 ; i < input . length ; i += 2 ) {
// Check to make sure we haven't run out of space in our output buffer...
if ( outputIndex < output . data . length ) {
// Read in two bytes, representing one RGB565 pixel in little-endian
// format...
var byte1 = input [ i ] ;
var byte2 = input [ i + 1 ] ;
// Extract the red, green and blue components from them. The first five
// bits of byte2 are red, the first three bits of byte1 and the last
// three bits of byte 2 are green, and the last five bits of byte1 are
// blue...
var red = ( byte2 & 0b11111000 ) >> 3 ;
var green = ( ( byte1 & 0b11100000 ) >> 5 ) | ( ( byte2 & 0b00000111 ) << 3 ) ;
var blue = byte1 & 0b00011111 ;
// These values are in 5-bit/6-bit ranges; we need to scale them to 8-bit
// ranges for the colours to look right...
red = Math . round ( red * 255 / 31 ) ;
green = Math . round ( green * 255 / 63 ) ;
blue = Math . round ( blue * 255 / 31 ) ;
// Finally, store the RGB values in our ImageData's data array, being
// sure to set the A component to 255...
output . data [ outputIndex ] = red ;
output . data [ outputIndex + 1 ] = green ;
output . data [ outputIndex + 2 ] = blue ;
output . data [ outputIndex + 3 ] = 255 ;
outputIndex += 4 ;
}
else {
// Oops, we've run out of room in our output data buffer; no point in
// trying to process any more input data!
break ;
}
}
// If we've run out of input data, but haven't reached the end of our
// ImageData object's buffer, fill the rest of that buffer with white...
while ( outputIndex / 4 < width * height ) {
output . data [ outputIndex ] = 255 ;
output . data [ outputIndex + 1 ] = 255 ;
output . data [ outputIndex + 2 ] = 255 ;
output . data [ outputIndex + 3 ] = 255 ;
outputIndex += 4 ;
}
// Finally, return our ImageData object...
return output ;
}
// Takes in a Uint8Array object containing raw BGRA image data, a width and a
// height, and outputs an ImageData object...
function bgraToImageData ( input , width , height ) {
// Create an output ImageData object of the specified dimensions; it'll
// default to transparent black, but we'll fill it with our input data...
output = new ImageData ( width , height ) ;
outputIndex = 0 ;
for ( var i = 0 ; i < input . length ; i += 4 ) {
// Check to make sure we haven't run out of space in our output buffer...
if ( outputIndex < output . data . length ) {
// The input data is *nearly* RGBA as it is - it's just that the R and B
// colour channels are swapped... so, just swap them back!
output . data [ i ] = input [ i + 2 ] ;
output . data [ i + 1 ] = input [ i + 1 ] ;
output . data [ i + 2 ] = input [ i ] ;
output . data [ i + 3 ] = input [ i + 3 ] ;
outputIndex += 4 ;
}
else {
// Oops, we've run out of room in our output data buffer; no point in
// trying to process any more input data!
break ;
}
}
// If we've run out of input data, but haven't reached the end of our
// ImageData object's buffer, fill the rest of that buffer with white...
while ( outputIndex / 4 < width * height ) {
output . data [ outputIndex ] = 255 ;
output . data [ outputIndex + 1 ] = 255 ;
output . data [ outputIndex + 2 ] = 255 ;
output . data [ outputIndex + 3 ] = 255 ;
outputIndex += 4 ;
}
// Finally, return our ImageData object...
return output ;
}
// This function takes in a Javascript Image object, and outputs it as an
// ImageData object instead...
function imageToImageData ( image ) {
// Create a virtual canvas, and load it up with our image file...
var canvas = document . createElement ( "canvas" ) ;
var context = canvas . getContext ( "2d" ) ;
canvas . width = image . width ;
canvas . height = image . height ;
// Draw our image to the canvas, which will allow us to get data about the
// image...
context . drawImage ( image , 0 , 0 , image . width , image . height ) ;
var imageData = context . getImageData ( 0 , 0 , image . width , image . height ) ;
// Return the ImageData object...
return imageData ;
}
// This function takes in an ImageData object, and returns a new ImageData
// object containing a scaled version of the original image. The new image's
// width, height and scaling method are also specified...
function scaleImage ( input , newWidth , newHeight , method ) {
// Utility function which takes in an ImageData object, and returns
// a (partially) upscaled version using bilinear filtering...
function _bilinear ( imageData , newWidth , newHeight ) {
var canvas = document . createElement ( "canvas" ) ;
var context = canvas . getContext ( "2d" ) ;
canvas . width = imageData . width ;
canvas . height = imageData . height ;
context . putImageData ( imageData , 0 , 0 ) ;
var outCanvas = document . createElement ( "canvas" ) ;
var outContext = outCanvas . getContext ( "2d" ) ;
outContext . imageSmoothingEnabled = true ;
outContext . imageSmoothingQuality = "high" ;
outCanvas . width = newWidth ;
outCanvas . height = newHeight ;
outContext . drawImage ( canvas , 0 , 0 , canvas . width , canvas . height , 0 , 0 , newWidth , newHeight ) ;
return outContext . getImageData ( 0 , 0 , newWidth , newHeight ) ;
}
// Utility function which takes in an ImageData object, and returns
// a (partially) downscaled version using gaussian resampling...
// [Side note: I asked Bing AI for this function; ain't technology grand!]
function _gaussian ( imageData , newWidth , newHeight ) {
// Get the original width and height of the image data
let oldWidth = imageData . width ;
let oldHeight = imageData . height ;
// Get the pixel data array of the image data
let oldData = imageData . data ;
// Create a new pixel data array for the scaled image data
let newData = new Uint8ClampedArray ( newWidth * newHeight * 4 ) ;
// Calculate the scaling factor along each axis
let scaleX = newWidth / oldWidth ;
let scaleY = newHeight / oldHeight ;
// Calculate the radius of the Gaussian kernel based on the scaling factor
let radiusX = Math . ceil ( 1 / scaleX ) ;
let radiusY = Math . ceil ( 1 / scaleY ) ;
// Calculate the size of the Gaussian kernel along each axis
let sizeX = radiusX * 2 + 1 ;
let sizeY = radiusY * 2 + 1 ;
// Create a Gaussian kernel array
let kernel = new Float32Array ( sizeX * sizeY ) ;
// Calculate the standard deviation of the Gaussian distribution based on
// the radius
let sigmaX = radiusX / 3 ;
let sigmaY = radiusY / 3 ;
// Calculate the inverse of the variance of the Gaussian distribution along
// each axis
let invVarX = 1 / ( 2 * sigmaX * sigmaX ) ;
let invVarY = 1 / ( 2 * sigmaY * sigmaY ) ;
// Calculate the normalization factor for the Gaussian kernel
let norm = Math . sqrt ( 2 * Math . PI * sigmaX * sigmaY ) ;
// Loop through each element in the Gaussian kernel array
for ( let ky = - radiusY ; ky <= radiusY ; ky ++ ) {
for ( let kx = - radiusX ; kx <= radiusX ; kx ++ ) {
// Calculate the index of the element in the Gaussian kernel array
let k = ( ky + radiusY ) * sizeX + ( kx + radiusX ) ;
// Calculate the value of the element using the Gaussian formula
kernel [ k ] = Math . exp ( - ( kx * kx ) * invVarX - ( ky * ky ) * invVarY ) / norm ;
}
}
// Loop through each pixel in the new image data
for ( let y = 0 ; y < newHeight ; y ++ ) {
for ( let x = 0 ; x < newWidth ; x ++ ) {
// Calculate the corresponding coordinates in the old image data
let oldX = x / scaleX ;
let oldY = y / scaleY ;
// Initialize the RGBA values of the pixel to zero
let r7 = 0 ;
let g7 = 0 ;
let b7 = 0 ;
let a7 = 0 ;
// Initialize the sum of the kernel values to zero
let sum = 0 ;
// Loop through each element in the Gaussian kernel array
for ( let ky = - radiusY ; ky <= radiusY ; ky ++ ) {
for ( let kx = - radiusX ; kx <= radiusX ; kx ++ ) {
// Calculate the index of the element in the Gaussian kernel array
let k = ( ky + radiusY ) * sizeX + ( kx + radiusX ) ;
// Get the value of the element in the Gaussian kernel array
let w = kernel [ k ] ;
// Calculate the coordinates of the pixel in the old image data that
// corresponds to this element
let x1 = Math . round ( oldX + kx ) ;
let y1 = Math . round ( oldY + ky ) ;
// Clamp the coordinates to the valid range
x1 = Math . max ( 0 , Math . min ( x1 , oldWidth - 1 ) ) ;
y1 = Math . max ( 0 , Math . min ( y1 , oldHeight - 1 ) ) ;
// Get the index of the pixel in the old pixel data array
let i1 = ( y1 * oldWidth + x1 ) * 4 ;
// Get the RGBA values of the pixel in the old pixel data array
let r1 = oldData [ i1 ] ;
let g1 = oldData [ i1 + 1 ] ;
let b1 = oldData [ i1 + 2 ] ;
let a1 = oldData [ i1 + 3 ] ;
// Multiply the RGBA values by the kernel value and add them to the
// pixel values
r7 += r1 * w ;
g7 += g1 * w ;
b7 += b1 * w ;
a7 += a1 * w ;
// Add the kernel value to the sum
sum += w ;
}
}
// Divide the RGBA values by the sum to get an average value
r7 /= sum ;
g7 /= sum ;
b7 /= sum ;
a7 /= sum ;
// Round the RGBA values to integers
r7 = Math . round ( r7 ) ;
g7 = Math . round ( g7 ) ;
b7 = Math . round ( b7 ) ;
a7 = Math . round ( a7 ) ;
// Get the index of the pixel in the new pixel data array
let j = ( y * newWidth + x ) * 4 ;
// Set the RGBA values of the pixel in the new pixel data array
newData [ j ] = r7 ;
newData [ j + 1 ] = g7 ;
newData [ j + 2 ] = b7 ;
newData [ j + 3 ] = a7 ;
}
}
// Create and return a new ImageData object with the new pixel data array
// and dimensions
return new ImageData ( newData , newWidth , newHeight ) ;
}
// Get the original width and height...
var width = input . width ;
var height = input . height ;
// Before we consider doing *any* scaling, let's check to make sure the new
// dimensions are different from the old ones; if they're not, there's no
// point in doing any scaling!
if ( width == newWidth && height == newHeight ) {
return input ;
}
// If we're here, then we're really scaling; the process to follow is
// *heavily* dependent upon the provided method, so let's switch based on
// that...
switch ( method ) {
// If the method is "Nearest Neighbour"...
case "Nearest Neighbour" :
// Create a new canvas element to draw the scaled image (we'll use the
// canvas to get our output ImageData object)...
var canvas = document . createElement ( "canvas" ) ;
var context = canvas . getContext ( "2d" ) ;
// Set the canvas size to the new dimensions...
canvas . width = newWidth ;
canvas . height = newHeight ;
// Create a new image data object to store the scaled pixel data...
var scaledData = context . createImageData ( newWidth , newHeight ) ;
// Loop through each pixel of the new image...
for ( var y = 0 ; y < newHeight ; y ++ ) {
for ( var x = 0 ; x < newWidth ; x ++ ) {
// Calculate the index of the new pixel in the scaled data array...
var index = ( y * newWidth + x ) * 4 ;
// Calculate the x and y coordinates of the corresponding pixel in
// the original image...
var x2 = Math . floor ( x * width / newWidth ) ;
var y2 = Math . floor ( y * height / newHeight ) ;
// Calculate the index of the original pixel in the data array...
var index2 = ( y2 * width + x2 ) * 4 ;
// Copy the color values from the original pixel to the new pixel...
scaledData . data [ index ] = input . data [ index2 ] ; // Red
scaledData . data [ index + 1 ] = input . data [ index2 + 1 ] ; // Green
scaledData . data [ index + 2 ] = input . data [ index2 + 2 ] ; // Blue
scaledData . data [ index + 3 ] = input . data [ index2 + 3 ] ; // Alpha
}
}
// Finally, return the scaled ImageData object...
return scaledData ;
// If the method is "Bilinear"...
case "Bilinear" :
// OK, "Bilinear" is a bit of a lie... bilinear filtering is fine when
// you're *upscaling* an image, but if you're *downscaling* an image
// by more than half the original's width/height, then true bilinear
// filtering creates just as much of an aliased mess as nearest
// neighbour filtering. Most image editing apps therefore cheat and
// use a resampling algorithm when downscaling, and bilinear filtering
// when upscaling... so that's what we're going to do here too! We'll
// use gaussian resampling for any image axis that's being downscaled,
// and bilinear for any axis that's being upscaled; this should give
// the user a result that's much closer to what they'd expect to see...
// Let's see which kind of scaling scenario we're in...
if ( newWidth > width && newHeight > height ) {
// All dimensions being upscaled, so we'll use bilinear filtering for
// everything...
return _bilinear ( input , newWidth , newHeight ) ;
}
else if ( newWidth < width && newHeight < height ) {
// All dimensions being downscaled, so we'll use gaussian resampling
// for everything...
return _gaussian ( input , newWidth , newHeight ) ;
}
else {
// It's a mix!
if ( newWidth < width ) {
// Gaussian for width, bilinear for height...
let partial = _gaussian ( input , newWidth , height ) ;
return _bilinear ( partial , newWidth , newHeight ) ;
}
else if ( newHeight < height ) {
// Gaussian for height, bilinear for width...
let partial = _gaussian ( input , width , newHeight ) ;
return _bilinear ( partial , newWidth , newHeight ) ;
}
}
break ;
}
}
// This utility function is used for adding info, warning and error messages to
// the appropriate spots in my tools. It uses custom-modified versions of the
// SVG Famfamfam Silk icon set via https://github.com/frhun/silk-icon-scalable
function setMessage ( type , divID , text ) {
var icon ;
switch ( type ) {
case "info" :
icon = '<img class="icon" alt="An icon of a blue circle with a white lowercase letter I, indicating an informative message" aria-hidden="true" src="data:image/svg+xml;base64,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">' ;
break ;
case "warning" :
icon = '<img class="icon" alt="An icon of a yellow triangle with a dark orange exclamation point, indicating a warning or notice" aria-hidden="true" src="data:image/svg+xml;base64,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">' ;
break ;
case "error" :
icon = '<img class="icon" alt="An icon of a red circle with a white exclamation point, indicating an error has occurred" aria-hidden="true" src="data:image/svg+xml;base64,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">' ;
break ;
}
document . getElementById ( divID ) . innerHTML = "<p class=\"" + type + "\">" + icon + " " + text + "</p>" ;
return ;
}