import type { IntBuffer } from "@thi.ng/pixel" ; import { GRAY16 } from "@thi.ng/pixel/format/gray16" ; const formatComments = ( comments = [ "generated by @thi.ng/pixel-io-netpbm" ] ) => comments . map ( ( x ) => `# ${ x }` ) . join ( "\n" ) ; /**
 * Initializes byte array & PBM header for given  IntBuffer and format
 * details.
 *
 *  param magic param limits param size param buf internal const initHeader = ( magic , limits , size , buf , comments ? ) => { const { width , height } = buf ; let header = magic + "\n" ; const comm = formatComments ( comments ) ; if ( comm . length ) header += comm + "\n" ; header += `${ width } ${ height }\n` ; if ( limits > 0 ) header += limits + "\n" ; const dest = new Uint8Array ( size + header . length ) ; dest . set ( [ ... header ] . map ( ( x ) => x . charCodeAt ( 0 ) ) ) ; return { dest , start : header . length , abgr : buf . format . toABGR } ; } ; /**
 * Converts a  IntBuffer into a 1bit PBM byte array (binary format).
 *
 *  remarks param buf param comments export const asPBM = ( buf , comments ? ) => { const { data , width , height } = buf ; const { dest , start , abgr } = initHeader ( "P4" , 0 , Math . ceil ( width / 8 ) * height , buf , comments ) ; const w1 = width - 1 ; for ( let y = 0 , i = start , j = 0 ; y < height ; y ++ ) { for ( let x = 0 , b = 0 ; x <= w1 ; x ++ , j ++ ) { const xx = ~ x & 7 ; if ( luminance ( abgr ( data [ j ] ) ) < 128 ) { b |= 1 << xx ; } if ( xx === 0 || x === w1 ) { dest [ i ++ ] = b ; b = 0 ; } } } return dest ; } ; /**
 * Converts a  IntBuffer into a 8bit grayscale PGM byte array (binary
 * format).
 *
 *  remarks param buf param comments export const asPGM = ( buf , comments ? ) => { const { data , width , height } = buf ; const { dest , start , abgr } = initHeader ( "P5" , 0xff , width * height , buf , comments ) ; for ( let i = start , j = 0 ; j < data . length ; i ++ , j ++ ) { dest [ i ] = luminance ( abgr ( data [ j ] ) ) ; } return dest ; } ; /**
 * Converts a  IntBuffer into a 16bit grayscale PGM byte array (binary
 * format).
 *
 *  remarks param buf param comments export const asPGM16 = ( buf , comments ? ) => { if ( buf . format !== GRAY16 ) buf = buf . as ( GRAY16 ) ; const { data , width , height } = buf ; const { dest , start } = initHeader ( "P5" , 0xffff , width * height * 2 , buf , comments ) ; for ( let i = start , j = 0 ; j < data . length ; i += 2 , j ++ ) { dest [ i ] = data [ j ] >> 8 ; dest [ i + 1 ] = data [ j ] & 0xff ; } return dest ; } ; /**
 * Converts a  IntBuffer into a 24bit PPM byte array (binary format).
 *
 *  remarks param buf param comments export const asPPM = ( buf , comments ? ) => { const { data , width , height } = buf ; const { dest , start , abgr } = initHeader ( "P6" , 255 , width * 3 * height , buf , comments ) ; for ( let i = start , j = 0 ; j < data . length ; i += 3 , j ++ ) { const col = abgr ( data [ j ] ) ; dest [ i ] = col & 0xff ; dest [ i + 1 ] = ( col >> 8 ) & 0xff ; dest [ i + 2 ] = ( col >> 16 ) & 0xff ; } return dest ; } ; const luminance = ( c ) => ( ( ( c >>> 16 ) & 0xff ) * 29 + ( ( c >>> 8 ) & 0xff ) * 150 + ( c & 0xff ) * 76 ) / 255 ;