mandel-lua

Mandelbrot renderer in pure Lua

Usage

Single images

Usage: lua main.lua [options]
Options:
  -w, --width <width>       Width of the image                 [Default: 900]
  -h, --height <height>     Height of the image                [Default: 600]

  -r, --real <real>         Real part of the center point      [Default: -0.5]
  -i, --imag <imag>         Imaginary part of the center point [Default: 0]
  -z, --zoom <zoom>         Zoom level                         [Default: 0]
  -n, --iterations <iter>   Maximum number of iterations       [Default: 255]

  --color1 <hex>            First gradient color (RGB hex)     [Default: 000000]
  --color2 <hex>            Second gradient color (RGB hex)    [Default: 808080]
  --color3 <hex>            Third gradient color (RGB hex)     [Default: FFFFFF]

  -o, --output <file>       Output file path                   [Default: ./mandel-<width>x<height>.bmp]
  -x, --interactive         Interactive mode
  -b, --black               Black inside the set
  -v, --verbose             Verbose output
  -p, --progress            Show progress
  -?, --help                Show this help

Examples

# renders a 900x600 image by default
lua main.lua

# renders a 3000x2000 image
lua main.lua -w 3000 -h 2000

# renders a 9000x6000 image
lua main.lua -w 9000 -h 6000

# renders a 900x600 image with 512 iterations
lua main.lua -i 512

# renders a 900x600 image with black inside the set
lua main.lua -b
# renders with a fire gradient (red → yellow → blue)
lua main.lua --color1 FF0000 --color2 FFFF00 --color3 0000FF

Sample output file

See higher res images here

Image	Resolution	Render Time	Size
mandel-900x600.bmp	900x600	0.24s	1.55 MB
mandel-3000x2000.bmp	3000x2000	2.83s	17.2 MB
mandel-9000x6000.bmp	9000x6000	47.99s	154 MB

Sequences

Requires ffmpeg to be installed and in the PATH in order to create gifs.

For instructions on using LuaJIT as the runtime for child processes launched from sequence.lua, see docs/luajit.md. This will speed up the generation of sequences significantly.

Usage: lua sequence.lua [options]
Options:
  -w, --width <width>       Width of the image                 [Default: 900]
  -h, --height <height>     Height of the image                [Default: 600]

  -r, --real <real>         Real part of the center point      [Default: -0.5]
  -i, --imag <imag>         Imaginary part of the center point [Default: 0]
  -z, --zoom <zoom>         Zoom level                         [Default: 0]
  -n, --iterations <iter>   Maximum number of iterations       [Default: 255]

  -R, --real2 <real>        Target -r for sequence             [Default: -0.5]
  -I, --imag2 <imag>        Target -i for sequence             [Default: 0]
  -Z, --zoom2 <zoom>        Target -z for sequence             [Default: 0]
  -N, --iterations2 <iter>  Target -n for sequence             [Default: 255]
  -s, --sequence <frames>   Number of frames in the sequence   [Default: 10]
  -b, --black               Black inside the set

  --color1 <hex>            Initial first gradient color       [Default: 000000]
  --color2 <hex>            Initial second gradient color      [Default: 808080]
  --color3 <hex>            Initial third gradient color       [Default: FFFFFF]
  --targetcolor1 <hex>      Target first gradient color        [Default: same as --color1]
  --targetcolor2 <hex>      Target second gradient color       [Default: same as --color2]
  --targetcolor3 <hex>      Target third gradient color        [Default: same as --color3]

  -g, --gif                 Use ffmpeg to create a gif

Example (white)

luajit sequence.lua -n 1000 -v -R -1.7635735993133 -I 0 -Z 4 -N 2000 -s 80 --gif

Output

Example (black)

luajit sequence.lua -n 1000 -v -R -1.7635735993133 -I 0 -Z 4 -N 2000 -s 80 --gif -b

Output

Example (color sequence)

luajit sequence.lua --color1 FF0000 --targetcolor1 00FFFF \
                   --color2 0000FF --targetcolor2 FF00FF \
                   --color3 FFFFFF --targetcolor3 FFFF00 \
                   -s 80 --gif

Output

Color Gradients & Interpolation

• 3-Point Color Gradients: Use --color1, --color2, --color3 to set custom RGB colors for the Mandelbrot gradient.
• Sequence Color Interpolation: Use --targetcolor1, --targetcolor2, --targetcolor3 to define the target gradient for smooth transitions in sequences.
• Flexible Input: Accepts hex colors with or without # prefix.
• Defaults: Black → Gray → White (000000 → 808080 → FFFFFF) if not specified.
• Error Handling: Invalid hex values will show a clear error message.
• Backwards Compatible: Defaults to grayscale if no color options are provided.