Added by David Baldwin about 4 years ago. Updated about 4 years ago.
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Description
Bob Rotate is corrupting certain sums and displaying incorrectly, namely addition and subtraction. In the attached example, you can try 4 different Bob Rotate commands that should rotate the Bob through 90 degrees. You will see that the addition and subtraction ones don't.
Files
| BobRotateBug.aozip (175 KB) BobRotateBug.aozip | David Baldwin, 09/03/2020 06:32 PM |
I've found what the problem is. In degree mode, in the command Bob Rotate 1,a+b , a is treated as a radian and b as degrees. This can be proved by trying the line Bob Rotate 1,6.283+360. The result is the bob doesn't rotate.
Verified this is a problem.
Using a variable works fine, putting a constant in an expression is a problem.
Fixed! Missing brackets in instruction definitions.
I also corrected the same problem for sprites and screens. :)
The sums are calculated correctly now with 9 Oct updates!
...but, why does it appear that a positive (clockwise) rotation angle rotates in the negative (counter-clockwise) direction? (Francois, see private comments I left you on Discord.)
Example:
Palette 0,$FFFFFF,$777777
Cls 0 : Curs Off
Degree
Message$="This is a test"
L=16*Len(Message$)
Locate 0,0:Print Message$
Get Bob 1,0,0 To L,32
Get Bob 2,0,0 To L,32
Hot Spot 1,$11
I$="1"
angle=0
cls 0
Locate 8,3 : Print "It seems like these should be reversed."
do
Locate 13,4 : Print Using "Angle -#####";angle
Locate 30,4 : Print Using "Angle -#####";-angle
Bob 1,300,300,1 : Bob 2,560,300,1
Bob Rotate 1,angle : Bob Rotate 2,-angle
Wait 0.01
angle=angle+2
Loop```