Sub-pixel accuracy is a myth. Only thing you have do is to set BLTAPT to 4(dy-dx).
category: residue [glöplog]
garbage thread, should be marked as residue
Mental issues are no laughing matter.
Aren't all these threads a byproduct of toxic elite ghetto scene attitude though?
Took a look at the routine...
My conclusion there is an error in the routine was based on the assumption that
lines were drawn like it is usually done for filled vector gfx, but you draw the
lines from right to left with or-minterm.
And indeed, loading of BLTAPTL with 4(dy-dx) seems to fix filling issues for your
routine at points where the end(!) of two lines meet; when 4dy-2dx is used in
BLTAPTL, lines (whose delta y > delta x) appear to be one pixel too long at
those sites in some occasions. Interesting! However, your quirk does not fix the
filling artifacts that occur at the "tips" at the top and bottom of the rotated
object that you are hiding by not filling the entire height of the object, i.e., you
leave out the outermost (screen)lines of the object, and subsequently -
obviously to get rid of the non-filled remnants - you copy the filled area to a new
region.
Another observation: The rotating square is flickering when run on a A500.
My conclusion there is an error in the routine was based on the assumption that
lines were drawn like it is usually done for filled vector gfx, but you draw the
lines from right to left with or-minterm.
And indeed, loading of BLTAPTL with 4(dy-dx) seems to fix filling issues for your
routine at points where the end(!) of two lines meet; when 4dy-2dx is used in
BLTAPTL, lines (whose delta y > delta x) appear to be one pixel too long at
those sites in some occasions. Interesting! However, your quirk does not fix the
filling artifacts that occur at the "tips" at the top and bottom of the rotated
object that you are hiding by not filling the entire height of the object, i.e., you
leave out the outermost (screen)lines of the object, and subsequently -
obviously to get rid of the non-filled remnants - you copy the filled area to a new
region.
Another observation: The rotating square is flickering when run on a A500.
