ELLIPSEARC2 has baffling semantics for "startangle" input
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#94 ELLIPSEARC2 has baffling semantics for "startangle" input
ELLIPSEARC2 has baffling semantics for the "startangle"
input. It does not seem to follow the pattern set by
ELLIPSE and I can't figure out what it's supposed to do.
It seems okay if you give 90, 180, or 270, but if you
give other values, the turtle jumps away from where the
line is drawn. This looks very strange, given that
ELLIPSEARC2 is supposed to just move the turtle. Even
worse, I cannot document the behavior because I cannot
figure out how to explain what it's doing.
I don't know what the fix is for the bug. I have filed
it for tracking purposes.
How Reproducible:
Every Time
Steps to Reproduce:
ellipsearc2 90 50 100 45
What Happens:
An arc is drawn and the turtle is displaced from the arc.
Expected Result:
An arc is drawn and the turtle is on the arc.
Related
Another problem with the startangle was reported to me in private email. In this case, the user was porting a program from UCBLogo to FMSLogo and the ARC was drawn in a different place.
For example, "ARC 90 50" in FMSLogo draws the arc on the turtle's back left. In UCBLogo, it draws the arc on the turtle's front right. Even though the UCBLogo behavior is more sensible, I cannot fix it without breaking existing programs. To work around the problem, you can create an ARC that negates the radius parameter if on FMSLogo.
have found that ellipsearc2 XX 200 200 X produces the desired results. as in where the horizontal and vertical dimensions are the same. Sorry I can't be of more help. Only getting into Logo now because of Primary Curriculum changes in England
I have added documentation for ELLIPSEARC2 in [r4410] and [r4411], including some examples on how to use start.angle. This will be included in FMSLogo 7.2.0.
Related
Commit: [r4410]
Commit: [r4411]