[Ohrrpgce] SVN: teeemcee/12887 gfx_fb: clamp the mouse position to the window. "mouse pixel x/y" now gu

[subversion at HamsterRepublic.com]

teeemcee
2022-04-06 21:37:16 -0700 (Wed, 06 Apr 2022)
316
gfx_fb: clamp the mouse position to the window. "mouse pixel x/y" now guaranteed it

All other backends already did.
I don't actually *want* the mouse position to be clamped to the window, but
currently the backends don't support it, and we will need some way to tell
mousepixelx/y to return non-clamped coordinates.
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U   wip/allmodex.bas
U   wip/docs/plotdict.xml
U   wip/docs/plotdictionary.html
U   wip/gfx_fb.bas