From Test-Scratch-Wiki
| 与 () 的间距 | |
與 [角色 v] 的間距 | |
| 类别 | 侦测类积木 |
| 形狀 | 椭圆形积木 |
The Distance to () 积木 is a 侦测类积木 and a 椭圆形积木. The block reports the 距离 (a measurement of pixels) between it and a specified 角色的 造型中心点, or the 滑鼠游标.
用法示例
As this block can give distances between objects, it is very useful in 专案 that require a great deal of careful sensing and movement.
Some common uses for the Distance to () block:
- Estimating when collisions will occur
如果 <(與 [snowball v] 的間距) < (40)> 那麼 說出 [Watch out!] 等待直到 <碰到 [snowball v] ?> 說出 [] // stop saying the message end
- Helping determine how long it should take a sprite to move somewhere, judging from the distance
變數 [movements v] 設為 ([ceiling v] 數值 ((與 [meteor v] 的間距) / (10))) // "movements" being the amount of 10 pixel motions to reach the meteor
- Determining how far a rocket should fire
變數 [real distance v] 設為 (字串組合 ((與 [asteroid v] 的間距) * (10000)) 和 [ kilometers]) // for relating pixel distance to real life
应用
- Main article: List of Block Workarounds
This block can be replicated with the following code:
([sqrt v] 數值 ((((x座標) - ([x座標 v] \( [Wanted Sprite v] \))) * ((x座標) - ([x座標 v] \( [Wanted Sprite v] \)))) + (((y 座標) - ([y 座標 v] \( [Wanted Sprite v] \))) * ((y 座標) - ([y 座標 v] \( [Wanted Sprite v] \))))))
Related Suggestion
Some Scratchers want a block that gives the distance to any location, not just a 角色.[1] It would be like this:
(distance to x: () y: ())//category=sensing
It is technically unnecessary because it can be replicated with a similar [[Eng:#Workaround|workaround]]:
([sqrt v] 數值 ((((x座標) - (wanted x)) * ((x座標) - (wanted x))) + (((y 座標) - (wanted y)) * ((y 座標) - (wanted y)))))
参见
