Challenge #4 - Double Tap
The challenge :
- Create a control system that accepts a tap, a hold, and a double tap.
The only requirement is that these three things do something different for the same button.
—hartnell
Challenge #4 - Double Tap
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» Challenge #4 - Double Tap
Summary:
Strangely difficult.
Yay! I Finally made it!
I don't know what you mean with "control system" .. but I hope this is enough … And it's a hell of a crap … I look forward to see someone else doing this better than me …
But it works at least!
Where there is a will there is a way. I used a lot of time on this playing around with two variables to track when a key was pressed and when it was released. But the if-statements became so complex that i just couldn't manage. Finally i decided to put some design-thought into it and in no time i had a state machine drawn up. By then it was just a matter of writing off of the diagram and into code and it was up and running in no time. Here is a diagram for the state machine. The states that perform the actions are called: Hold, Tap and Double Tap.
For those who don't know about state-machines, you should really suggest it as a course. They are very useful :)
Here is the code in Brutus2D. Use space button to perform action.
Option explicit
graphics.initialize 640, 480
key.initialize
Dim font : font = graphics.createfont( "system", 10 )
' Adjustable timings
Const HOLD_THRESHOLD = 150
Const DOUBLE_TAP_THRESHOLD = 80
Const TAP_END_THRESHOLD = 10
' Used for the state-machine. It's nicer to have names for the states
Const IDLE = 0
Const WAIT_RELEASE = 1
Const HOLD = 2
Const WAIT_DBLTAP = 3
Const DOUBLE_TAP = 4
Const TAP = 5
Dim state, eventTimer
state = IDLE
Do
Dim curTime
curTime = system.gettime()
Dim lastAction, lastActionTime
' Implemented as a state diagram
If state = IDLE Then
If key.pressed( vk_space ) Then
state = WAIT_RELEASE
eventTimer = curTime
End If
ElseIf state = WAIT_RELEASE Then
If curTime - eventTimer > HOLD_THRESHOLD Then
state = HOLD
lastAction = "hold"
ElseIf Not key.pressed( vk_space ) Then
state = WAIT_DBLTAP
eventTimer = curTime
End If
ElseIf state = HOLD Then
lastActionTime = curTime
If Not key.pressed( vk_space ) Then
state = IDLE
End If
ElseIf state = WAIT_DBLTAP Then
If key.pressed( vk_space ) Then
state = DOUBLE_TAP
lastAction = "double tap"
lastActionTime = curTime
ElseIf curTime - eventTimer > DOUBLE_TAP_THRESHOLD Then
state = TAP
eventTimer = curTime
lastAction = "tap"
lastActionTime = curTime
End If
ElseIf state = DOUBLE_TAP Then
If Not key.pressed( vk_space ) Then
state = IDLE
End If
ElseIf state = TAP Then
If curTime - eventTimer > TAP_END_THRESHOLD Then
state = IDLE
End If
End If
If lastActionTime And curTime - lastActionTime > 1000 Then
lastAction = ""
lastActionTime = False
End If
graphics.clear
graphics.settext "Use space button. Action performed: " & lastAction, 10, 10, font, argb( 255, 255, 255, 255 )
graphics.settext "There are constants defined at the start of the file to change timing. Do play around with them", 10, 26, font, argb( 255, 200, 200, 200 )
graphics.display
system.processMessages
Loop until key.pressed( vk_escape ) Or key.pressed( vk_windowx )
key.terminate
graphics.terminateHmm… there is a delay before the command dis-appears again. I just added that delay so that one could see what command was executed. The command is registered as soon as the text is displayed. Maybe that is what you mean?
anyways, did you try and play around with the delays also?
Here's a Brutus2D demo. Use space and arrow keys to play. The double-tap has to be done quickly otherwise it just gets registered as a single-tap. Try also to hold the space key for a while.
Have fun.
p.s. let me know if it is "playable."
' Demo of input control with tap, doulbe-tap and hold functionality
' 2. jun 2007
' u9 4T kallnet D0T fo
'
' Use space bar and arrow keys to play. The double-tap has to be done quickly
Option explicit
graphics.initialize 640, 480
key.initialize
Dim font : font = graphics.createfont( "system", 10 )
' Adjustable timings
Const HOLD_THRESHOLD = 150
Const DOUBLE_TAP_THRESHOLD = 60
Const TAP_END_THRESHOLD = 10
' Used for the state-machine. It's nicer to have names for the states
Const IDLE = 0
Const WAIT_RELEASE = 1
Const HOLD = 2
Const WAIT_DBLTAP = 3
Const DOUBLE_TAP = 4
Const TAP = 5
Dim state, eventTimer
state = IDLE
' --- Code for demonstrating the input control
Dim xBall, yBall, stateBall, eventTimerBall, jumpTimeBall
Const bIDLE = 0
Const bJUMPING = 1
Const bSHAKING = 2
stateBall = bIDLE
xBall = 320
yBall = 400
' --- end ------------------------------------
Do
Dim curTime
curTime = system.gettime()
Dim lastAction, lastActionTime
' Implemented as a state diagram
If state = IDLE Then
If key.pressed( vk_space ) Then
state = WAIT_RELEASE
eventTimer = curTime
End If
ElseIf state = WAIT_RELEASE Then
If curTime - eventTimer > HOLD_THRESHOLD Then
state = HOLD
lastAction = "hold"
ElseIf Not key.pressed( vk_space ) Then
state = WAIT_DBLTAP
eventTimer = curTime
End If
ElseIf state = HOLD Then
lastActionTime = curTime
If Not key.pressed( vk_space ) Then
state = IDLE
End If
ElseIf state = WAIT_DBLTAP Then
If key.pressed( vk_space ) Then
state = DOUBLE_TAP
lastAction = "double tap"
lastActionTime = curTime
ElseIf curTime - eventTimer > DOUBLE_TAP_THRESHOLD Then
state = TAP
eventTimer = curTime
lastAction = "tap"
lastActionTime = curTime
End If
ElseIf state = DOUBLE_TAP Then
If Not key.pressed( vk_space ) Then
state = IDLE
End If
ElseIf state = TAP Then
If curTime - eventTimer > TAP_END_THRESHOLD Then
state = IDLE
End If
End If
If lastActionTime And curTime - lastActionTime > 1000 Then
lastAction = ""
lastActionTime = False
End If
graphics.clear
' --- Code for demonstrating the input control
graphics.setline 40, 410, 600, 410, &hffffffff
If stateBall = bIDLE Then
yBall = 400
If state = hold Then
stateBall = bSHAKING
eventTimerBall = curTime
ElseIf state = TAP Then
stateBall = bJUMPING
jumpTimeBall = 1000
eventTimerBall = curTime + jumpTimeBall
ElseIf state = DOUBLE_TAP Then
stateBall = bJUMPING
jumpTimeBall = 3000
eventTimerBall = curTime + jumpTimeBall
End If
ElseIf stateBall = bJUMPING Then
yBall = yBall - sin(pi/2 + (curTime-(eventTimerBall-jumpTimeBall))/jumpTimeBall * pi) * 5
If yBall > 400 Then yBall = 400
If eventTimerBall < curTime Then
stateBall = bIDLE
End If
ElseIf stateBall = bSHAKING Then
xBall = xBall + cos( curTime/15 ) * min( (curTime - eventTimerBall)/1000, 3 )
If state = idle Then
stateBall = bIDLE
End If
End If
If key.pressed( vk_left ) Then
xBall = xBall - 2
ElseIf key.pressed( vk_right ) Then
xBall = xBall + 2
End If
graphics.setcircle xBall, yBall, 10, &hffffffff
graphics.settext "Ball state: " & stateBall, 10, 420, font, &hffffffff
' --- end ------------------------------------
graphics.settext "Use space button. Action performed: " & lastAction, 10, 10, font, argb( 255, 255, 255, 255 )
graphics.settext "There are constants defined at the start of the file to change timing. Do play around with them", 10, 26, font, argb( 255, 200, 200, 200 )
graphics.display
graphics.setfps 60
system.processMessages
Loop until key.pressed( vk_escape ) Or key.pressed( vk_windowx )
key.terminate
graphics.terminate/forum/t-10530/challenge-4-double-tap#post-
