rgl 1.2.1

Major changes

• Support for non-PNG textures has been added. Currently
  supported: JPEG files and any other object
  for which grDevices::as.raster() works, e.g. matrices.
  (Fixes issue #196.)

Minor changes

• Support for "alt" text has been added to rglwidget().
  Full support in R Markdown or knitr requires a knitr update
  to version 1.42.12 or newer.
• Some of the tests have been relaxed slightly so they
  shouldn't trigger errors on the M1Mac test platform.
• Internally, the C code has dropped the use of the internally
  defined String type, settling on std::string instead.
• subdivision3d(), clipMesh3d() and related functions now
  (optionally) record the original faces associated with each new one
  in a mesh$tags addition to the output.

Bug fixes

• The Makevars.win file was being produced incorrectly on
  older Windows versions.
• rgl.window2user() did not work correctly when multiple panes
  were showing. This caused arrow3d() to fail in some panes
  (issue #354).
• selectpoints3d() had a typo which was revealed by
  warnings in recent R versions.
• getShaders() was broken in 1.1.3.
• arc3d() can now handle "arcs" that are straight lines along
  a radius (issue #357).
• Spheres did not show textures correctly (issue #360).
• hover3d() failed to display default labels in R (issue #362).
• shade3d() didn't handle meshes with a mix of triangles and
  quads properly when meshColor == "faces".
• subdivision3d() and related functions now handle colors
  properly.
• addNormals() sometimes gave NaN values due to rounding
  error (issue #372).
• arc3d() sometimes missed plotting the last segment of the arc (issue #369).
• R_NO_REMAP has been defined and header includes have been
  rearranged to prevent conflict between R internals and C 17
  library. (Thanks to Prof. B. D. Ripley and G. Csardi for
  suggested fixes.)