mandelbrot Dart #3 program

/* The Computer Language Benchmarks Game
   https://salsa.debian.org/benchmarksgame-team/benchmarksgame/

   Andrey Filatkin's node #3 program made sequential by Isaac Gouy. 
*/

import 'dart:io';
import 'dart:typed_data';

  const iter = 50, limit = 4.0;

void main(List<String> args) {
  final h = (args.length > 0) ? int.parse(args[0]) : 200, w = h;
  final bytesPerRow = w >> 3;
  final initialR = new Float64List(w);
  final initialI = new Float64List(w);
  final inv = 2 / w;
  for (var xy = 0; xy < w; xy++) {
    final i = inv * xy;
    initialR[xy] = i - 1.5;
    initialI[xy] = i - 1.0;
  }

  Uint8List renderRow(int y) {
    final row = Uint8List(bytesPerRow);

    for (var xByte = 0; xByte < bytesPerRow; xByte++) {
      final ci = initialI[y];
      var res = 0;
      for (var i = 0; i < 8; i += 2) {
        final x = xByte << 3;
        final cr1 = initialR[x + i];
        final cr2 = initialR[x + i + 1];

        var zr1 = cr1;
        var zi1 = ci;

        var zr2 = cr2;
        var zi2 = ci;

        var b = 0;

        for (var j = 0; j < iter; j++) {
          final tr1 = zr1 * zr1;
          final ti1 = zi1 * zi1;
          zi1 = 2 * zr1 * zi1 + ci;
          zr1 = tr1 - ti1 + cr1;

          if (tr1 + ti1 > limit) {
            b |= 2;
            if (b == 3) {
              break;
            }
          }

          final tr2 = zr2 * zr2;
          final ti2 = zi2 * zi2;
          zi2 = 2 * zr2 * zi2 + ci;
          zr2 = tr2 - ti2 + cr2;

          if (tr2 + ti2 > limit) {
            b |= 1;
            if (b == 3) {
              break;
            }
          }
        }
        res = (res << 2) | b;
      }
      row[xByte] = ~res;
    }

    return row;
  }

  stdout.write('P4\n$w $h\n');

  for (int y = 0; y < h; ++y) {
    stdout.add(renderRow(y));
  }
}
    

NOTES:
64-bit Ubuntu quad core
Dart SDK version: 3.5.4 (stable)
Wed Oct 16 16:18:51 2024



 Wed, 23 Oct 2024 20:02:52 GMT

MAKE:
/opt/src/dart-sdk/bin/dart analyze 
Analyzing tmp...
No issues found!

/opt/src/dart-sdk/bin/dart compile exe mandelbrot.dartexe-3.dartexe -o mandelbrot.dartexe-3.dartexe_run
Generated: /home/dunham/all-benchmarksgame/benchmarksgame_i53330/mandelbrot/tmp/mandelbrot.dartexe-3.dartexe_run

6.15s to complete and log all make actions

COMMAND LINE:
 ./mandelbrot.dartexe-3.dartexe_run 16000

(BINARY) PROGRAM OUTPUT NOT SHOWN