QR = {}
-- i = row
-- j = column
-- Functions to use later
local function replaceChar(pos, str, r)
return str:sub(1, pos-1) .. r .. str:sub(pos+1)
end
local function boolBin(condition)
if condition == true then
return '1'
else
return '0'
end
end
local function binXOR(bin1,bin2)
local bin3 = bin1
print('BinXOR:')
print('bin1',bin1)
print('bin2',bin2)
for i = 1,#bin1,1 do
if bin1:sub(i,i) == '1' and bin2:sub(i,i) == '1' then
bin3 = replaceChar(i,bin3,'0')
else
bin3 = replaceChar(i,bin3,bin2:sub(i,i))
end
end
return bin3
end
local function bin(num,fillerZeroes,fillerIsMax)
local binTable = {}
local rest = 0
while num > 0 do
rest = math.fmod(num,2)
binTable[#binTable+1] = math.floor(rest)
num = (num-rest)/2
end
while #binTable < (fillerZeroes or 0) do
binTable[#binTable+1] = 0
end
if (fillerZeroes and fillerIsMax) and #binTable > fillerZeroes then
return bin(tonumber(string.rep('1',fillerZeroes),2),fillerZeroes)
end
local binString = string.reverse(table.concat(binTable))
return binString
end
QR.EncodingMode={
Numeric=1,
Alphanumeric=2,
Bit8Byte=4
}
QR.ErrorCorrectionLevel={
Low=1,
Medium=0,
Quadrant=3,
High=2
}
QR.Mask = {
[0] = {
MaskBinary = '000',
MaskPattern = '101',
Logic = function()
return (i+j)%2==0
end},
[1] = {
MaskBinary = '001',
Logic = function()
return i%2==0
end},
[2] = {
MaskBinary = '010',
Logic = function()
return j%3==0
end},
[3] = {
MaskBinary = '011',
Logic = function()
return (i+j)%3==0
end},
[4] = {
MaskBinary = '100',
Logic = function()
return (i/2+j/3)%2==0
end},
[5] = {
MaskBinary = '101',
Logic = function()
return (i*j)%2+(i*j)%3==0
end},
[6] = {
MaskBinary = '110',
Logic = function()
return ((i*j)%3+i*j)%2==0
end},
[7] = {
MaskBinary = '111',
Logic = function()
return ((i*j)%3+i+j)%2==0
end}
}
function QR.Mask:FromMaskBinary(MaskBinary)
return self[tonumber(MaskBinary,2)]
end
QR.Version={
v1={Value=1,Name='Version 1',Resolution=21},
v2={Value=2,Name='Version 2',Resolution=25},
v3={Value=3,Name='Version 3',Resolution=29},
v4={Value=4,Name='Version 4',Resolution=33},
v10={Value=10,Name='Version 10',Resolution=57},
v25={Value=25,Name='Version 25',Resolution=117},
v40={Value=40,Name='Version 40',Resolution=177}
}
QR._BinaryArrays={
PositionMarker={
NW = {
'11111110',
'10000010',
'10111010',
'10111010',
'10111010',
'10000010',
'11111110',
'00000000'
},
NE = {
'01111111',
'01000001',
'01011101',
'01011101',
'01011101',
'01000001',
'01111111',
'00000000'
},
SW = {
'00000000',
'11111110',
'10000010',
'10111010',
'10111010',
'10111010',
'10000010',
'11111110'
}
},
AlignmentMarker = {
'11111',
'10001',
'10101',
'10001',
'11111'
}
}
QR._BinarySpecifications={
FormatInformationString = {
[1] = {
[0]='111011111000100',
[1]='111001011110011',
[2]='111110110101010',
[3]='111100010011101',
[4]='110011000101111',
[5]='110001100011000',
[6]='110110001000001',
[7]='110100101110110'
},
[0] = {
[0]='101010000010010',
[1]='101000100100101',
[2]='101111001111100',
[3]='101101101001011',
[4]='100010111111001',
[5]='100000011001110',
[6]='100111110010111',
[7]='100101010100000'
},
[3] = {
[0]='011010101011111',
[1]='011000001101000',
[2]='011111100110001',
[3]='011101000000110',
[4]='010010010110100',
[5]='010000110000011',
[6]='010111011011010',
[7]='010101111101101'
},
[2] = {
[0]='001011010001001',
[1]='001001110111110',
[2]='001110011100111',
[3]='001100111010000',
[4]='000011101100010',
[5]='000001001010101',
[6]='000110100001100',
[7]='000100000111011'
},
}
}
function QR.maskBit(mask,bitValue,j,i)
if QR.Mask.Logic[mask]() == true then
if bitValue == 0 then
bitValue = 1
else
bitValue = 0
end
end
return bitValue
end
function QR.OneZeroBlock(str)
str,_ = str:gsub('1','█')
str,_ = str:gsub('0',' ')
return str
end
function QR.new(str,version,mask,encodingMode,errorCorrectionLevel)
str = str or ''
version = version or QR.Version.v2
mask = mask or QR.Mask[0]
encodingMode = encodingMode or QR.EncodingMode.Alphanumeric
errorCorrectionLevel = errorCorrectionLevel or QR.ErrorCorrectionLevel.Low
local QRStruct = {
Text=str,
Version=version,
Mask=mask,
EncodingMode=encodingMode,
ErrorCorrectionLevel=errorCorrectionLevel
}
function QRStruct:PrintInfo()
print(
string.format('QR Version: %s\nContent: %s\nMask: %s\nEncoding: %s\nECL: %s',
self.Version.Name..' ('..tostring(self.Version.Resolution)..'x'..tostring(self.Version.Resolution)..')',
'"'..self.Text..'"',
self.Mask.MaskBinary,
bin(self.EncodingMode,4)..' ('..tostring(self.EncodingMode)..')',
self.ErrorCorrectionLevel
))
end
function QRStruct:GetBinaryArray()
local binaryArray = {}
local function writeToArrayPos(array,posX,posY,allowOverwrite)
if posY then posY = posY - 1 end
if posX then posX = posX - 1 end
if #array+posY > self.Version.Resolution then
posY = self.Version.Resolution-#array
end
if #array[1]+posX > self.Version.Resolution then
posX = self.Version.Resolution-#array[1]
end
for rowInx = 1+posY,#array+posY,1 do
for charInx = 1,#array[rowInx-posY],1 do
if binaryArray[rowInx]:sub(charInx+posX,charInx+posX) ~= 'x' and not allowOverwrite then
else
binaryArray[rowInx] = replaceChar(
charInx+posX,
binaryArray[rowInx],
array[rowInx-posY]:sub(charInx,charInx)
)
end
end
end
end
for binRow = 1,self.Version.Resolution,1 do
-- 'x' represents an empty space, can be written over
binaryArray[binRow] = string.rep('x',self.Version.Resolution)
end
-- Post-masking:
local Format5Bits = bin(self.ErrorCorrectionLevel,2)..self.Mask.MaskBinary
print(Format5Bits)
-- Calculation of the Error Correction bits
local GeneratorPolynomial = '10100110111' -- > Constant value
-- Pad with zeroes to the right, and then remove leading zeroes
local ErrorCorrectionBits = (Format5Bits..string.rep('0',15-#Format5Bits)):sub(string.find(Format5Bits,'1'),15)
while #ErrorCorrectionBits >= 11 do
local GeneratorPolyPadded = GeneratorPolynomial..string.rep('0',#ErrorCorrectionBits-#GeneratorPolynomial)
-- > Generator polynomial padded so its length is equal to the ErrorCorrectionBits string
local XOR_ECB = binXOR(ErrorCorrectionBits,GeneratorPolyPadded)
-- > XOR_ECB = XOR Error Correction Bits
print('XOR Result:',XOR_ECB)
-- Removing leading zeroes from XOR_ECB and assign it to ErrorCorrectionBits for next loop
ErrorCorrectionBits = XOR_ECB:sub(string.find(XOR_ECB,'1'),15)
print(ErrorCorrectionBits,'('..tostring(#ErrorCorrectionBits)..')')
end
if #ErrorCorrectionBits < 10 then
ErrorCorrectionBits = string.rep('0',10-#ErrorCorrectionBits)..ErrorCorrectionBits
end
local Format15String = Format5Bits..ErrorCorrectionBits
local MaskXORString = QR._BinarySpecifications.FormatInformationString[self.ErrorCorrectionLevel][tonumber(self.Mask.MaskBinary,2)]
print('Final ErrCorrection:',ErrorCorrectionBits)
print('15-Bit Format String:',Format15String)
print('Mask XOR String:',MaskXORString)
local MaskedFormat15String = binXOR(Format15String,MaskXORString)
print('Masked 15-Bit Format String:',MaskedFormat15String)
-- Placement: NW Marker
local R = self.Version.Resolution
for inx,val in ipairs({
-- # X Y
{1,1,9},{2,2,9},{3,3,9},{4,4,9},
{5,5,9},{6,6,9},{7,8,9},{8,9,9},
{9,9,8},{10,9,6},{11,9,5},{12,9,4},
{13,9,3},{14,9,2},{15,9,1},
{1,9,R-1},{2,9,R-2},{3,9,R-3},{4,9,R-4},
{5,9,R-5},{6,9,R-6},{7,9,R-7},{8,R-7,9},
{9,R-6,9},{10,R-5,9},{11,R-4,9},{12,R-3,9},
{13,R-2,9},{14,R-1,9},{15,R,9}
}) do
writeToArrayPos(
{MaskedFormat15String:sub(val[1],val[1])},
val[2],
val[3]
)
end
-- Timing Markers (NW -> SW)
for i = 8,self.Version.Resolution-8,1 do
writeToArrayPos(
{boolBin((i-1)%2==0)},
7,
i,
true
)
end
-- Timing Markers (NW -> NE)
for i = 8,self.Version.Resolution-8,1 do
writeToArrayPos(
{boolBin((i-1)%2==0)},
i,
7,
true
)
end
-- NW Position Marker's 5 Formatting Bits
writeToArrayPos(
{Format5Bits},
1,
9,
true
)
-- SW Position Marker's 5 Formatting Bits (Vertical Copy)
writeToArrayPos(
{
Format5Bits:sub(5,5),
Format5Bits:sub(4,4),
Format5Bits:sub(3,3),
Format5Bits:sub(2,2),
Format5Bits:sub(1,1)
},
9,
self.Version.Resolution,
true
)
-- Constants: do not change
-- Dark Module
writeToArrayPos({'1'},9,self.Version.Resolution-7,true)
writeToArrayPos(QR._BinaryArrays.PositionMarker.NW,1,1,true)
writeToArrayPos(QR._BinaryArrays.PositionMarker.SW,1,self.Version.Resolution,true)
writeToArrayPos(QR._BinaryArrays.PositionMarker.NE,self.Version.Resolution,1,true)
if self.Version.Value >= 3 then
-- Alignment marker
writeToArrayPos(QR._BinaryArrays.AlignmentMarker,self.Version.Resolution-8,self.Version.Resolution-8,true)
end
-- Cleanup the x
for cleanupInx,cleanupVal in ipairs(binaryArray) do
local cleanedString,_ = cleanupVal:gsub('x','0')
--binaryArray[cleanupInx] = cleanedString
end
return binaryArray
end
return QRStruct
end
local newQRCode = QR.new('test',QR.Version.v1)
newQRCode.ErrorCorrectionLevel = QR.ErrorCorrectionLevel.Low
newQRCode.Mask = QR.Mask[4]
newQRCode:PrintInfo()
local qrcodeBinaryArray = newQRCode:GetBinaryArray()
for i,v in ipairs(qrcodeBinaryArray) do
print(i,QR.OneZeroBlock(v))
end
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-- global variables
a = 10
-- local variables
local x = 30
| Value Type | Description |
|---|---|
| number | Represents numbers |
| string | Represents text |
| nil | Differentiates values whether it has data or not |
| boolean | Value can be either true or false |
| function | Represents a sub-routine |
| userdata | Represents arbitary C data |
| thread | Represents independent threads of execution. |
| table | Can hold any value except nil |
While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.
while(condition)
do
--code
end
Repeat-Until is also used to iterate a set of statements based on a condition. It is very similar to Do-While, it is mostly used when you need to execute the statements atleast once.
repeat
--code
until( condition )
For loop is used to iterate a set of statements based on a condition.
for init,max/min value, increment
do
--code
end
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optional_function_scope function function_name( argument1, argument2, argument3........, argumentn)
--code
return params with comma seperated
end