[mythtv-commits] [MythTV/mythtv] 422c4c: MythRenderOpenGL: Greatly simplify drawing rounded...

[Mark Kendall]

  Branch: refs/heads/master
  Home:   https://github.com/MythTV/mythtv
  Commit: 422c4ce109b0ee390023e92eabc3960a2fb2f968
      https://github.com/MythTV/mythtv/commit/422c4ce109b0ee390023e92eabc3960a2fb2f968
  Author: Mark Kendall <mark.kendall at gmail.com>
  Date:   2020-12-10 (Thu, 10 Dec 2020)

  Changed paths:
    M mythtv/libs/libmythui/opengl/mythrenderopengl.cpp
    M mythtv/libs/libmythui/opengl/mythrenderopengl.h
    M mythtv/libs/libmythui/opengl/mythrenderopenglshaders.h

  Log Message:
  -----------
  MythRenderOpenGL: Greatly simplify drawing rounded rects

- convert the shaders to use signed distance functions (https://
www.iquilezles.org/www/articles/distfunctions2d/distfunctions2d.htm)
- shader speed is probably on a par with the old implementation but the
actual rendering is simplified to 2 draw calls and 2 shaders, which
should improve performance
- subtle rendering artifacts are fixed (that resulted from compositing
the rectangle from different parts) and the overall result is a little
smoother than the old version