- A Fractal Generator

Key Features

• Output in multiple formats (png file, output of base-64 encoded PNG, etc.)
• Many different configuration options from generation formula, color and shadow setting and more.
• Comprehensive error messages & help menus.
• Configuration for background & foreground color.

Color Settings

Kyros uses csscolorparser, a rust parser library for css colors. This means that any color parameter can be set the same way it would be in css. Ex:

kyros.exe --background transparent --foreground "rgba(255, 0, 0, 1)" --rgba -y

GPU

Kyros implements most of its arguments to work both on the CPU and GPU. The GPU acceleration is done with the Vulkan rust API called Vulkano as well as using the shaderc-rs library for run time SPIR-V compilation. Because of the overhead of this implementation, generally images under 1000px x 1000px will be faster on CPU however this will vary by system. To use the GPU implementation, the vulkan library must be installed first.

Limitations and Implementation details

• Because the minimum byte width of the GPU array is 4, the GPU always uses RGBA color even if this isn't specified in the CLI arguments.
• The size of the image depends on the amount of memory available in GPU. Because of this, run-time errors can occur at higher resolutions (around 25kpx x 25kpx for a NVIDIA GeForce GTX 1060 6GB GPU.)

Performance

• At higher resolutions, the bottleneck for performance becomes saving images instead of generation. Using the GTX 1060 a 20kpx x 20kpx image can be generated in under 2s however saving that image can take up to 5 seconds (depending of course on hardware.)
• Without GPU acceleration and with identical settings (except GPU flag) the same 20xpx x 20xpx image mentioned above (which took 6.61 seconds) takes 280.30s for generation meaning there is a 42x increase with the GPU flag.
• This performance improvement is even more dramatic when higher max iterations are set and there are more pixels with higher iterations.

Examples (with outputs)

• kyros.exe -y
  • Generates basic mandelbrot image with reasonable defaults.
• kyros.exe -p 1024 -y
  • Generates basic mandelbrot image with higher resolution.
• kyros.exe -i 1024 -y
  • Generates basic mandelbrot image with more iterations per pixel.
• kyros.exe -f HELP -y
  • Shows help menu to display different options for the -f command.
• kyros.exe -f R -y
  • Changes the formula to generate the image with.
• kyros.exe --save-method HELP -y
  • Displays options for the --save-method flag.
• kyros.exe --save-method B64 -y
  • Outputs a base64 encoded version of the image to stdout.
• kyros.exe --logs INFO -y
  • Shows progress and other generation information.
• kyros.exe --gpu -p 20000 --background transparent -y
  • Generates a 20000px x 20000px image using the GPU.

And there are many more different combinations of these flags to get unique outputs.

Current Maximums

Part of this project was to see how large of an image I could generate. The current largest image size (which is a power of 2) I could hit is a 131072x131072 png image on both the SD & R generation method. Both of which are ~500MB in filesize. By using rust for this project I could cut down the amount of memory requried (by its python counterpart by saving to a PNG) by around half because of the way its libraries are designed (except for certain save methods.) as well as other performance improvements. In addition I don't have to worry about dependencies, python versions to fit with dependencies and the cost of a virtual environment.