line scroller

[rdepalma]

well, okay, this is exactly what I want to do...
lets take a tredmill for example.
I want to make, say a training program, where I tell the runner how fast he has to run. let say this speed is going to vary. So, I have a speed versus time line. with the left edge being zero and the right being 100 feet per second, the line will start at the top and scroll down. This is theoretical speed. Now, we take the cursor which is actual speed of the tredmill (I can handle all the hardware to get the speed from the transducer into a variable). This will scroll left to right (left zero right 100). The name of the game is for the runner to keep his cursor over the line as it varies. If he is off the line, say by 2 fps, the cursor turns red. I can deal with all the hardware and all the other logic behind it, its just this graphical subroutine that has me stumped.

[opus]

If I get you right, you want to do:
First show the desired speed.
Do that by printing a point or a small line segment at the actual time line (left/rigth for speed differences up/down for time) in PictureBox.
Second you want that line to show also the old values of the speed (i.e. the history).
To do that just "bitBlt" the whole PictureBox nearly onto itself (move it for one Timestep). By that you will see the last time/speed Line/Point moved ontop or under itself. Now you can erase the last printed value and print a new one (each time at the same timeline!). Use "GetTickCount" for the time-schedule.
Now you will have a "waterfall" display of the desired speed.
The next is your "Cursor". Take your value of the tredmill and use the it to place a line object ontop of the picturebox. The Time position should never change.
If you need more help, call back. I used that technic the make a waterfall-display in another application, it works!!
Bye the way, the better running-training is doing it for real! You get fresh air and sometimes even a good look onto other runners (hopefully from the other sex).
My Marathon PB 3:08!!

[beachbum]

hi
here is some code to give u some ideas. I have gone for an eternal looping set of pictures rather than one big picture. you could use one big picture and just set the top property however you will max out at 96000 if that is a problem.

This code uses 2 picture boxes that are alternatively the current drawing pic and the one above or below that is simply scrolling.

It doesnt use any API routines and so u may want to go that way for less flicker (i write financial software not graphics ).
hope it helps
Regards
Stuart

Form contains
1 command button Command1 on form
1 Timer.. timer1 with Interval = 200
1 picture called pic_container on form
2 pictures pic_inner(0) and (1) inside pic_container
I have set most properties thru code so it should run straight from here. If i have missed any properties that i set at design time just ask and i will check for you.

Option Explicit
 
Private Const GridScale As Long = 1000 'Grid Height and Width . U may want to have one for each
Private Const ScrollPosn As Long = 700 'Point at where the tape starts scrolling
Private Const ScrollJump As Long = 20 'X and Y jump. Again u may want to separate
 
Dim lCounter As Integer 'Loop counter
 
Dim XPosn As Single 'X Posn of line
Dim YPosn As Single 'Y Posn of line
Dim XMarker As Single 'Your minimum line
Dim CurPicture As Integer 'Which picture is being drawn on
Dim lScroll As Boolean 'Are we ready to scroll
 
Private Sub SetupTreadMill()
    XPosn = GridScale / 2 'Default X Posn
    YPosn = 0
    XMarker = GridScale / 2
    CurPicture = 0
    Randomize 'Used to make 'runner' .. u would use actuals
    
    With pic_container 'Set up container picture
        .BorderStyle = 0
        .Height = 4 * GridScale
        .Width = 4 * GridScale
        .ScaleHeight = GridScale
        .ScaleWidth = GridScale
    End With
        
    'These 2 pictures are IN pic_container
    For lCounter = 0 To 1
        With pic_inner(lCounter)
            .Cls
            .AutoRedraw = True
            .BackColor = vbWhite
            .BorderStyle = 0
            .DrawWidth = 1
            .Move 0, lCounter * GridScale, GridScale, GridScale
            .ScaleHeight = GridScale 'Set scaling
            .ScaleWidth = GridScale
        End With
    
        With Line1(lCounter) 'Your minimum line
            .X1 = XMarker: .X2 = XMarker: .Y1 = 0: .Y2 = GridScale
        End With
    Next
    
    With HScroll1 'Scroll bar for your minimum line
        .Move pic_container.Left - 300, pic_container.Top + pic_container.Height, pic_container.Width + 600
        .Min = 0
        .Max = GridScale
        .Value = XMarker
        .SmallChange = GridScale / 50
        .LargeChange = GridScale / 20
    End With
End Sub
 
Private Sub Command1_Click()
    SetupTreadMill 'Set up the form
    DrawGridLines 0 'Draw grid lines for first pic
    DrawGridLines 1
    SetStartPosn 0 'Set starting position for first pic
    Timer1.Enabled = True 'Start it rolling
End Sub
 
Private Sub DrawGridLines(ByVal WhichPic As Integer)
    'Downward lines
    With pic_inner(WhichPic)
        .Cls
        For lCounter = 1 To 3
            pic_inner(WhichPic).Line (lCounter * GridScale / 4, 0)-(lCounter * GridScale / 4, GridScale), vbBlue
        Next
    End With
End Sub
 
Private Sub SetStartPosn(ByVal WhichPic As Integer)
    'Starting positions
    With pic_inner(WhichPic)
        .CurrentX = XPosn
        .CurrentY = YPosn
        .ZOrder
    End With
End Sub
 
Private Sub Timer1_Timer()
    GetRandomValues
    DrawLine
    ScrollDown
End Sub
 
Private Sub GetRandomValues()
    'Add or subtract from the current x position
    XPosn = Int(Rnd * ScrollJump * 2) - ScrollJump + XPosn
    If XPosn < 0 Then XPosn = 0
    If XPosn > GridScale Then XPosn = GridScale
    YPosn = YPosn + ScrollJump 'Move down a bit
End Sub
 
Private Sub DrawLine()
    Dim lColour As Long
    
    'Set colour based on above or below minimum
    lColour = vbBlack
    If XPosn < XMarker Then lColour = vbRed
    With pic_inner(CurPicture)
        'Draw line
        pic_inner(CurPicture).Line -(XPosn, YPosn), lColour
        .CurrentX = XPosn 'Update X Y posn
        .CurrentY = YPosn
    End With
End Sub
 
Private Sub ScrollDown()
    If YPosn > ScrollPosn Then lScroll = True 'Once only to set scrolling
    If lScroll Then
        With pic_inner(CurPicture)
            .Top = ScrollPosn - YPosn 'Move picture up
            If .Top <= 0 Then 'Is it negative?
                'then other pic should be below it
                pic_inner(1 - CurPicture).Top = .Top + .Height
            Else 'otherwise it is above it
                pic_inner(1 - CurPicture).Top = .Top - .Height
            End If
            'Is the non current pic fully off the page?
            If pic_inner(1 - CurPicture).Top <= -.Height + ScrollJump * 2 Then
                pic_inner(1 - CurPicture).Cls 'Clear it
                DrawGridLines 1 - CurPicture 'REdraw lines
            End If
        End With
        
        If YPosn >= GridScale Then 'Have we reached end of current pic
            CurPicture = 1 - CurPicture 'Swap to other pic
            YPosn = 0 'Reset Y to top
            With pic_inner(CurPicture)
                .CurrentX = XPosn 'Get X position
                .CurrentY = YPosn
            End With
        End If
    End If
End Sub
 
Private Sub HScroll1_Change()
    'Move the minimum line
    XMarker = HScroll1.Value
    For lCounter = 0 To 1
        With Line1(lCounter)
            .X1 = XMarker: .X2 = XMarker: .Y1 = 0: .Y2 = GridScale
        End With
    Next
End Sub

[beachbum]

oops
and 1 Horizontal scroll bar Hscroll1

[beachbum]

dang frig again

emmm would u believe there are 2 more!!
Line1(0) is inside pic_inner(0)
and Line1(1) inside pic_inner(1)

Hope this is it!!

[opus]

beachburn did give some code but as he said

It doesnt use any API routines and so u may want to go that way for less flicker

I believe you will get lots of flickering.
Sorry at present I can't send you my code example, which uses API. You have to wait til this evening (GMT+1).
One question for beachburn, whow do you show the changing "desired" speed. If I understand your code correctly the gridlines never change the position. I'd prefer to show a change in desired speed by changing this "target " line. But that way you will have a "snaking" Line (sorry, but I'm not a native english speaker).

[rdepalma]

well actually, a "snaking" line is what I was looking for. Lets say the entire screen top to bottom represents 20 seconds. I would like time zero (now) to be 5 seconds from the bottom. This would give me a little history of what I was supposed to do and a 15 second window of what is coming up.

graphics is not my thing at all. I am a hardware guy that can do some logic programming (plc's). So, you will have to be the judge as to what will look good. Remember, this has to be smooth, otherwise the runner will get "sea sick" from the flicker.

Thanx
BoB

[opus]

You need on your form a PicureBox and 2 Line-Objects (VerticalLine, HorizontalLine) (They make a cross)
The PictureBox will showw the desired speed at present at the lower horizontal limit, the older values will be move to the top.(I didn't use your times, so you have to work them out yourself).
The cross(VerticalLine, HorizontalLine) should show the actual treadmill speed. You can show that cross always at the lower limit (that way you will not see which speed should be used in the future) or you can show somewhere to the top (that way you can see future and history speeds)
In here the speed ranges from 0 to 100 (PictureBox.Scalewidth)
Start/stop is done by clicking onto the PictureBox

Option Explizit
'API for TimeControlling
Private Declare Function GetTickCount Lib "kernel32.dll" () As Long
'API for the Graphic Part
Private Declare Function BitBlt Lib "gdi32" (ByVal hDestDC As Long, ByVal xDest As Long, ByVal_   yDest As Long, ByVal nWidth As Long, ByVal nHeight As Long, ByVal hSrcDC As Long, ByVal_  xSrc  As Long, ByVal ySrc As Long, ByVal dwRop As Long) As Long
Dim Start as Boolean
Dim ActualTime as Long
Dim LastTime as Long
Dim Tread_Mill_Speed as Single
Dim DesiredSpeed as Single

Private Sub Form_Load()
Dim Ret As Integer
MainForm.PictureBox. AutoRedraw      =   -1  'True
MainForm.PictureBox.ScaleHeight     =   125
MainForm.PictureBox. ScaleMode       =   3  'Pixel
MainForm.PictureBox. ScaleWidth      =  100
Call Show_Tread_Mill_Speed (MainForm.PictureBox. ScaleWidth /2 )
End Sub

Private Sub PictureBox_MouseDown (Button As Integer, Shift As Integer, x As Single, y As Single)
If  Start=True then
    Start=False
Else
    Start=True
End Sub

Private Sub Time_Control()
    Do
        If Start = True Then
            ActualTime = GetTickCount()
           'In here you can control whow fast the display is running to the top 
           If LastTime +1000 <= ActualZeit Then
                Call PictureBox_Mover
                'In here you must give Tread_Mill_speed the correct value
                 If Tread_Mill_Speed< DesiredSpeed then
		VerticalLine.ForeColor=vbRed
		HorizontalLine.ForeColor=vbRed
                 Else
                         If Tread_Mill_Speed< DesiredSpeed then
		VerticalLine.ForeColor=vbBlue
		HorizontalLine.ForeColor=vbBlue
                         Else
		VerticalLine.ForeColor=vbGreen
		HorizontalLine.ForeColor=vbGreen
                        End If
               End If
                 Call Show_Tread_Mill_Speed (Trad_Mill_Speed)
                 LastSimTime = ActualZeit
            End If
            DoEvents
        Else
            Exit Do
     End If
    Loop
End Sub

Private Sub Show_Tread_Mill_Speed (Trad_Mill_Speed as single)
MainForm.VerticalLine.X1=Trad_Mill_Speed 
MainForm.VerticalLine.X2=Trad_Mill_Speed 
MainForm.VerticalLine.Y1=MainForm.PictureBox.ScaleHeight
MainForm.VerticalLine.Y2=MainForm.PictureBox.ScaleHeight-6
MainForm.HorizontalLine.X1=Trad_Mill_Speed -3
MainForm.HorizontalLine.X2=Trad_Mill_Speed +3
MainForm.HorizontalLine.Y1=MainForm.PictureBox.ScaleHeight
MainForm.HorizontalLine.Y2=MainForm.PictureBox.ScaleHeight-3
End Sub

Private Sub PictureBox_Mover
'Set a Point at the actual desired Speed onto the picturebox
PictureBox.PSet (DesiredSpeed, PictureBox.Height - 6), vbBlack
'Move the upper (i.e.)older part further up
Ret = BitBlt(PictureBox.hdc, 0, 0,PictureBox.ScaleWidth, PictureBox.ScaleHeight, PictureBox.hdc, 0,_ 1, SRCCOPY)
End Sub

I hope that works. I had to do it without VB, since I'm at home. Sorry for any errors.

[beachbum]

Originally posted by opus
I believe you will get lots of flickering.

Actually, u don't get much flickering at all because the grid lines and speed line are all vertical. Make any horizontal lines and bammo flicker.

Originally posted by opus
One question for beachburn, whow do you show the changing "desired" speed. If I understand your code correctly the gridlines never change the position. I'd prefer to show a change in desired speed by changing this "target " line. But that way you will have a "snaking" Line (sorry, but I'm not a native english speaker).

The Line1(0) and Line1(1) are used for the 'target minimum' value. This line is moved with the scroller bar. Anyways, rdepalma, try it out in a blank project and let me know if this is the concept that you are after. ps opus, question for you. why so many object references? Surely that will slow things down considerably. Can't u just use With... End With and also remove any references to the form as the routines are private.
Regards
Stuart

[opus]

That point goes to you, Beach