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#1 2012-10-18 13:35:16
Keeping sprite A in position over sprite B as sprite B rotates
How do I code keeping a sprite (A) in position over the left end of rectangular shaped sprite (B) as (B) rotates left or right. Say sprite B is a star ship and sprite A is a turret overlaid sprite B. I want sprite A to be able to 'orbit' sprite B and visually remain in position as sprite B rotates. Sprite B does not move, it only rotates.
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#2 2012-10-18 13:41:07
- subzerostig
- Scratcher
- Registered: 2010-09-08
- Posts: 100+
Re: Keeping sprite A in position over sprite B as sprite B rotates
Try setting the center rotation to make it work. Then simply set it to keep to the same rotation as A
There are 10 types of people people in this world, those that understand binary and those that do not: My latest Project: Present catcher V2 06/12/2012
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#4 2012-10-18 13:58:19
Re: Keeping sprite A in position over sprite B as sprite B rotates
In the costume/paint editor, there is a crosshair/plus sign that you can click and then select somewhere on the costume to change the center/rotation point of the sprite. 
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#6 2012-10-18 23:02:41
Re: Keeping sprite A in position over sprite B as sprite B rotates
OK I found my answer
when [right-arrow v] key pressed go to front set [b_cos v] to <[cos v] of angle> set [b_sin v] to <[sin v] of angle> set [b_dy v] to <(b_sin) * (b_hyp)> set [b_dx v] to <(b_cos) * (b_hyp)> go to x: (b_dx) y: (b_dy) stop scriptWhere:
angle is the measurement in degrees that sprite B is facing.
b_cos is the cosine of angle
b_sin is the sine of angle
b_hyp is the pixel distance from the center point of Sprite B to the center point of Sprite A
A press of the right arrow rotates Sprite B 1 degree to the right
A press of the left arrow rotates Sprite B 1 degree to the left
I hope this helps others.
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#7 2012-10-18 23:22:39
- thebriculator
- Scratcher
- Registered: 2011-07-11
- Posts: 500+
Re: Keeping sprite A in position over sprite B as sprite B rotates
or more simply,
go to x: (([sin v] of ([direction v] of [arm v])) * (length)) y: (([cos v] of ([direction v] of [arm v])) * (length))be sure your rotating thing is at (0,0)
if not, you will need to adjust accordingly
Last edited by thebriculator (2012-10-18 23:28:37)
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