Scratch
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#1 2007-09-07 12:53:19
keydown/keyup, mouseup
One thing that could make games possibly a lot more fun would be sensing keydown/keyup as opposed to just keypress. With keypress the repeat delay and repeat rate of the keyboard (system preferences dependent) affects how things move and makes things a bit jerky. If you could sense keydown/keyup, on keydown you could set a variable "speed" to 5 and have it update smoothly, and on keyup you could reset "speed" to 0. This way people could have the same smooth experience regardless of what their keyboard settings are.
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#2 2007-09-07 16:42:01
Re: keydown/keyup, mouseup
Everything you need to do what you're after exists. I don't think that Scratch "pays attention" to delays or repeats, just "pressed or not". Try this demo that shows how to make a variable (Throttle for the Airplane) respond smoothly:
http://scratch.mit.edu/projects/EdnaC/34922
If this is doing what you want, download for a look. Feel free to remix into a full-fledged game. This demo is a stripped-down verson of Stealthfighter.
Last edited by EdnaC (2007-09-09 08:46:21)
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#3 2007-09-08 10:45:34
- kevin_karplus
- Scratcher
- Registered: 2007-04-27
- Posts: 1000+
Re: keydown/keyup, mouseup
On my Mac, the
[blocks]
<when[ space ]key pressed>
[/blocks]
block certainly is sensitive to the repeat delay and rate of the key.
but
[blocks]
<forever if><key[ a ]pressed?>
[/blocks]
is not sensitive to repeats.
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#4 2007-09-09 08:37:00
Re: keydown/keyup, mouseup
You're right. It looks like the "When (key) Pressed" hat responds to both the delay and the repeat. The <key pressed?> operator seems to not respond to the delay. I don't know how to tell if the repeat is happening or the Scratch code is just executing over and over when the key is held.
In either case, I haven't run into this being an issue.
Vaz,
Have you found a solution to the issue you were having? If not; Can you post a link to an example?
-Mr Ed
Last edited by EdnaC (2007-09-09 08:41:02)
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#5 2007-09-09 10:22:45
Re: keydown/keyup, mouseup
Ok. I wasn't aware that the"key pressed?" worked that way (I assumed it worked the same as kevin's first example, which is what I was using). The "when ? key pressed" block definitely depends on the delay/repeat rate of the keyboard, you can tell in games where the sprite you're controlling will jerk forward when you hit the key, wait a second and then start moving (somewhat) more smoothly.
I think "key pressed?" will do everything I was looking for. Thanks. 
Oh. I put "mouseup" in the title but didn't mention anything about it. Sometimes it could be neat to trigger things on mouseup events. I haven't tried this at all so there could very well be a way to do this, even something similar to the keypress situation, I just noticed the "mouse down" block and thought about mouseup.
Last edited by vaz (2007-09-09 10:27:11)
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#6 2007-09-11 13:02:49
- kevin_karplus
- Scratcher
- Registered: 2007-04-27
- Posts: 1000+
Re: keydown/keyup, mouseup
mouse down and mouse up are not events, but states, so not(mouse down?) should work for you. The "when sprite clicked" *is* an event, like "when key pressed" and actually doesn't happen until the mouse is released.
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#7 2012-01-26 14:40:56
Re: keydown/keyup, mouseup
More generally, if I want to make a 2-player (on same keyboard) game with real-time action (not a turn-based game), what is the best way to ensure that a player cannot "cheat" by simply holding down a key forever?
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