gr[dimensions] is how many characters are in each cell, starting from 0. So gr[dimensions] of 2 is actually 3 characters.

gr[width] is how many cells in length

gr[height] is how many cells in height

All the math is directly taken from https://mzucker.github.io/html/perlin-n ... h-faq.html. I've tried to comment what each part does.

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```
@ECHO OFF
SETLOCAL ENABLEDELAYEDEXPANSION
FOR /F %%A in ('ECHO prompt $E^| cmd') DO SET "ESC=%%A"
(CHCP 65001)>NUL
::gr = gradient, d = dummy, px = pixel
::parameters
SET /A "gr[dimensions]=2","gr[width]=4","gr[height]=4"
::Other variables needed. gr[itery] and gr[iterx] is how many times to actually iterate
SET /A "gr[width]*=gr[dimensions]","gr[height]*=gr[dimensions]","gr[itery]=gr[height]-gr[dimensions]","gr[iterx]=gr[width]-gr[dimensions]"
SET lerp="a=d[dot1]", "b=d[dot2]", "c=wei[x]", "px[x#]=(10-c)*a+(c*b)"
CALL :MACROS
ECHO Generating...
::Make gradient vectors
FOR /L %%Y in (0, %gr[dimensions]%, %gr[height]%) DO (
FOR /L %%X in (0, %gr[dimensions]%, %gr[width]%) DO (
SET /A "d[x]=!RANDOM!*(2+2+1)/32768-1","d[y]=!RANDOM!*(2+2+1)/32768-2"
SET "gr[%%X][%%Y]=!d[x]!;!d[y]!"
)
)
::starting point of texture to 5 down, 10 right
<NUL SET /P "=%ESC%[2J%ESC%[5;10H"
::loop through and create. the first 2 for loops are to get the randoms vectors, and the inner 2 for loops are for each character
::also, for the final px[final], I do (px[final]*4)+150 for the colour value, since it is pretty small
FOR /L %%Y in (0, %gr[dimensions]%, %gr[itery]%) DO (
FOR /L %%X in (0, %gr[dimensions]%, %gr[iterx]%) DO (
SET /A "gr[x]=%%X+gr[dimensions]","gr[y]=%%Y+gr[dimensions]"
FOR /L %%y in (0, 1, %gr[dimensions]%) DO (
FOR /L %%x in (0, 1, %gr[dimensions]%) DO (
%perlin% %%x %%y %%X %%Y !gr[x]! !gr[y]!
SET /A "px[final]=(px[final]*4)+150"
<NUL SET /P "=%ESC%[38;2;100;!px[final]!;!px[final]!m█"
)
<NUL SET /P "=%ESC%[%gr[dimensions]%D%ESC%[D%ESC%[B"
)
<NUL SET /P "=%ESC%[%gr[dimensions]%C%ESC%[C%ESC%[%gr[dimensions]%A%ESC%[A"
)
SET /A "d[num]=(gr[dimensions]+1)*((gr[iterx]/gr[dimensions])+1)"
<NUL SET /P "=%ESC%[!d[num]!D%ESC%[%gr[dimensions]%B%ESC%[B"
)
PAUSE
EXIT /B
::This function returns 2 dot products : x y and the values of gx1 gy1, and x y and the values of gx2 gy2
:DOTPRODUCT <x> <y> <gx1> <gy1> <gx2> <gy2>
FOR /F "tokens=1-4 delims=;" %%A in ("!gr[%3][%4]!;!gr[%5][%6]!") DO (
SET /A "d[dot1]=((%1-%3)*%%A)+((%2-%4)*%%B)","d[dot2]=((%1-%5)*%%C)+((%2-%6)*%%D)"
)
GOTO :EOF
:MACROS
SET ^"LF=^
^" Above empty line is required - do not remove
SET ^"\n=^^^%LF%%LF%^%LF%%LF%^^"
::<x> <y> <bx> <by> <nx> <ny>
::this is follows the same steps as the link provided, except the "weight" is just a normal exponential curve
::returns px[final] as the number
SET perlin=FOR %%# in (1, 1, 2) DO IF %%#==2 ( FOR /F "tokens=1-6" %%A in ("^!args^!") DO (%\n%
SET /A "wei[x]=%%A*%%A","wei[y]=%%B*%%B"%\n%
CALL :DOTPRODUCT %%A %%B %%C %%D %%E %%D%\n%
SET /A %lerp:#=1% %\n%
CALL :DOTPRODUCT %%A %%B %%C %%F %%E %%F%\n%
SET /A %lerp:#=2% %\n%
SET /A "a=px[x1]","b=px[x2]", "c=wei[y]", "px[final]=((10-c)*a+(c*b))/100"%\n%
)) else SET args=
```

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`SET /A "gr[dimensions]=3","gr[width]=4","gr[height]=4"`

And it looks okay, but sometimes there are some glaring "bright spots" that don't make sense, especially with larger cell numbers. For example, with

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`SET /A "gr[dimensions]=12","gr[width]=2","gr[height]=2"`

Which is obviously wrong. I'm not exactly sure what I'm doing wrong, except that I know the results are wrong. If anyone has any clues or tips, it'd be really appreciated! Thanks