Mandelbrot fractal set explorer based on OpenGL

3fd87047 Update · by Martin Lambers


This is an experimental program to explore Mandelbrot fractal set images.

The fractals are computed on the GPU using one of the following precisions:

  • single precision
  • extended precision based on 2x single precision
  • double precision
  • extended precision based on 2x double precision

The main feature are the 2x single or double precision modes, but unfortunately these do not work with many OpenGL implementations.

  • Known to work:
    • Mesa 11.0 i965 on Sandybridge Mobile
    • Mesa 11.0 llvmpipe (LIBGL_ALWAYS_SOFTWARE=1)
    • Mesa 18.1.3 llvmpipe (LIBGL_ALWAYS_SOFTWARE=1)
    • Mesa 18.1.3 softpipe (LIBGL_ALWAYS_SOFTWARE=1 GALLIUM_DRIVER=softpipe)
  • Known not to work:
    • Mesa 11.0 i965 on Bay Trail (strange artifacts)
    • Mesa 18.1.3 i965 on Kaby Lake U (strange artifacts, same as above)
    • NVIDIA proprietary drivers, any version (no additional precision; apparently the driver ignores the precise keyword from GL_ARB_gpu_shader5)

Coloring is based on user-defined color maps (e.g. created with gencolormap) and can be animated.

GUI screen shot