_imgscramble.nx source

1// _imgscramble.nx -- RED-TEAM INSTRUMENT for the image graders (operator 2026-08-04: "is this eval 2// doing the work or is it junk"): shuffle an image's PxP patches with a seeded deterministic permutation. 3// Scrambling DESTROYS all aesthetic/structural content (the face, the figure, the composition) while 4// approximately preserving LOCAL statistics -- so any judge that scores an image ~equal to its scramble 5// is measuring texture, not beauty, and cannot rank a styled character above a blob. license_tier: ORIGINAL 6// _imgscramble <in.png> <out.png> <patch_px> 7import "nx_syscalls.nx" 8import "nx_png_decoder.nx" 9import "nx_png.nx" 10const SCR_MAGIC_65536: i64 = 65536 11const SCR_LCG_A: i64 = 1103515245 12const SCR_LCG_C: i64 = 12345 13const SCR_LCG_M: i64 = 2147483647 14const SCR_SEED: i64 = 80404 15 16func sc_w(s: *u8) -> i64 { var n: i64=0; while s[n]!=(0 as u8){n=n+1} sys_write(1,s,n); return 0 } 17func sc_n(v: i64) -> i64 { 18 let b: *u8 = sys_mmap(32) 19 var x: i64 = v; var i: i64 = 31 20 if x == 0 { b[i]=48 as u8; i=i-1 } 21 while x > 0 { b[i]=(48+x%10) as u8; x=x/10; i=i-1 } 22 sys_write(1,(b as i64+i+1) as *u8,31-i) 23 return 0 24} 25func sc_atoi(s: *u8) -> i64 { var v: i64=0; var i: i64=0; while s[i]!=(0 as u8) { let c: i64 = s[i] as i64; if c>=48 { if c<=57 { v=v*10+(c-48) } } i=i+1 } return v } 26 27func main(argc: i64, argv: *i64) -> i64 { 28 let inp: *u8 = argv[1] as *u8 29 let outp: *u8 = argv[2] as *u8 30 let P: i64 = sc_atoi(argv[3] as *u8) 31 if P < 2 { sc_w("bad patch size\n" as *u8); return 2 } 32 let lenp: *i64 = sys_mmap(16) as *i64 33 let raw: *u8 = sys_read_file(inp, lenp) 34 if (raw as i64) == 0 { sc_w("read fail\n" as *u8); return 2 } 35 let res: *NxPngResult = nx_png_decode(raw, lenp[0]) 36 if (res as i64) == 0 { sc_w("decode null\n" as *u8); return 3 } 37 if res.error_code != 0 { sc_w("decode err " as *u8); sc_n(res.error_code); sc_w("\n" as *u8); return 3 } 38 let hdr: *NxPngHeader = res.header 39 let w: i64 = hdr.width 40 let h: i64 = hdr.height 41 let ch: i64 = res.n_channels 42 let px: *u8 = res.pixels 43 let fb: *i64 = sys_mmap(w*h*8) as *i64 44 var q: i64 = 0 45 while q < w*h { 46 var pr: i64 = 0 47 var pg: i64 = 0 48 var pb: i64 = 0 49 if ch >= 3 { pr = px[q*ch] as i64; pg = px[q*ch+1] as i64; pb = px[q*ch+2] as i64 } 50 if ch <= 2 { pr = px[q*ch] as i64; pg = pr; pb = pr } 51 fb[q] = pr + pg*256 + pb*SCR_MAGIC_65536 52 q = q + 1 53 } 54 let nx: i64 = w/P 55 let ny: i64 = h/P 56 let n: i64 = nx*ny 57 let perm: *i64 = sys_mmap(n*8) as *i64 58 var i: i64 = 0 59 while i < n { perm[i] = i; i = i + 1 } 60 var s: i64 = SCR_SEED 61 i = n - 1 62 while i > 0 { 63 s = (s*SCR_LCG_A + SCR_LCG_C) & SCR_LCG_M 64 let j: i64 = s % (i+1) 65 let t: i64 = perm[i]; perm[i] = perm[j]; perm[j] = t 66 i = i - 1 67 } 68 let ofb: *i64 = sys_mmap(w*h*8) as *i64 69 q = 0 70 while q < w*h { ofb[q] = fb[q]; q = q + 1 } // margins ride through unscrambled 71 i = 0 72 while i < n { 73 let src: i64 = perm[i] 74 let dx: i64 = (i%nx)*P 75 let dy: i64 = (i/nx)*P 76 let sx: i64 = (src%nx)*P 77 let sy: i64 = (src/nx)*P 78 var yy: i64 = 0 79 while yy < P { 80 var xx: i64 = 0 81 while xx < P { ofb[(dy+yy)*w + dx+xx] = fb[(sy+yy)*w + sx+xx]; xx = xx + 1 } 82 yy = yy + 1 83 } 84 i = i + 1 85 } 86 write_png(ofb, w, h, outp) 87 sc_w("SCRAMBLED " as *u8); sc_n(n); sc_w(" patches of " as *u8); sc_n(P); sc_w("px -> " as *u8); sc_w(outp); sc_w("\n" as *u8) 88 return 0 89}