libtogl-dev 2.0-1 (riscv64 binary) in ubuntu focal

 Togl is a Tk widget for OpenGL rendering. Togl was originally
 based on OGLTK, written by Benjamin Bederson at the University
 of New Mexico. Togl's main features
 are:
 .
  * unifies Microsoft Windows, X11 (Linux/IRIX/...), and Mac OS X
    Aqua support
  * support for requesting stencil, accumulation, alpha buffers, etc.
  * multiple OpenGL drawing windows
  * simple stereo rendering support
  * simple, portable font support
  * color-index mode support including color allocation functions
  * overlay plane support
  * OpenGL extension testing from Tcl
  * Tcl Extension Architecture (TEA) 3 compliant
 .
 This package contains development files for using optimized shared libraries.