[RESOLVED] BitBlt issue smearing the character on a moving background...

[Conroy Vanderbluff]

I made visible the Character and CharacterMask for referencing


VB6
Windows 7

I am using BitBlt to move the map behind the character. I am also using BitBlt to draw the character. The character is animating (running). So, to keep the character centered, I am having to continually adjust the X and Y of the character, which is not the problem. The problem is the smearing I am getting. The code is in a Timer:

If (timerMapMover.Tag = "NORTH") And (MoveMapY < 0) Then
    MoveMapY = MoveMapY + 1
    myCharacter.Picture = LoadResPicture("NORTH" & MyAni, 0)
    MakeMask myCharacter, myCharacterMask, CLng(vbBlack), CLng(vbWhite), CLng(vbBlack)
    BltTheCharacter myBuffer, myCharacter, myCharacterMask, ConvertTwipsToPixelsX(Me.Width / 2) - MoveMapX, ConvertTwipsToPixelsY(Me.Height / 2) - MoveMapY
    BltFinal myStage, myBuffer, MoveMapX, MoveMapY
End If

myCharacter is my Hero
myCharacterMask is the masked version of my Hero
myBuffer is the buffer PictureBox
myStage is where everything is BitBlt'd once it is all combined in the buffer

Obviously I am moving North, therefore the map is moving down to give the appearance of the character moving North.
I am using images loaded in a .res file.
MakeMask calls a routine to create the mask.

What am I missing to clear up the smearing issue?

[jmsrickland]

Is this the same problem you had in your other thread? I thought you had that taken care of based on what you were told or is this a totally different problem.

[Conroy Vanderbluff]

Same project, different issue. Before, the map was smearing. I fixed that. Now my character is smearing.

[Arnoutdv]

I think this is because you don't repaint the background.
You are just blitting stuff on it, but not removing it.

Either restore the partial background when an item is moved, or in the main loop paint all items one by one, starting with the background.

[jmsrickland]

I believe Arnoutdv is correct. Anytime you move a drawing by BitBlt'ing it you need to first save the area you will BitBlt to then BitBlt to that position. Now save the next area you will BitBlt to and then again BitBlt to that position then restore the area you BitBlt from.

[passel]

edit: [I didn't see the first post, I thought this was a continuation of your ealier post... It certainly looks like you're using a tile based map, but maybe it was tiled offline, and you just moving a large map. In any case, perhaps the post can still be useful].

Or, if you were doing a tile based map, you would probably be redrawing all the background because you would be be bitblting all the tiles of your background as you move.
I did a short example for someone around 7 to 8 years ago. I did a search and found it, and will attach it. It doesn't do much. It was just thown to gether for someone who provided the car images to show moving the car around a tile based map. Since I didn't have a tile set, and wasn't going to take the time to build a map, I just "generate" four random tiles of different color and assign them randomly to the "map".
In this example, the car will move toward the center of the window, and then remain there as the map moves by, until an edge is reached, in which case the car will move out of the center area and out to the edge of the window. I found a zip file of it, a little over 7 years old and didn't retry it to make sure it works but I wouldn't have zipped it up if I didn't post it back then, so should work. You use the up key to go forward, and the down key to go backwards, and the left,right keys to turn.

[c080]

Just a note , to use picturebox.cls before drawing anything. Use once.
I also recommend using without a timer for drawing.

Public Const SRCAND = (&H8800C6) ' Use for your Mask , White Background
Public Const SRCPAINT = (&HEE0086) 'Use for your Picture , Black Background


Public Const BLACKNESS = (&H42) 'All Black
Public Const DSINVERT = (&H550009) 'Invert.
Public Const MERGECOPY = (&HC000CA) 'Pattern and the source
Public Const MERGEPAINT = (&HBB0226) 'Inverted source
Public Const NOTSRCCOPY = (&H330008) 'Copies the inverted source bitmap to the destination.
Public Const NOTSRCERASE = (&H1100A6) 'Inverts the result of combining the destination.
Public Const PATCOPY = (&HF00021) 'Copies the pattern to the destination bitmap.
Public Const PATINVERT = (&H5A0049) 'Combines the destination bitmap with the pattern.
Public Const PATPAINT = (&HFB0A09) 'Combines the inverted source bitmap with the pattern.
Public Const SRCAND = (&H8800C6) 'Combines pixels of the destination and source bitmap.
Public Const SRCCOPY = (&HCC0020) 'Copies the source bitmap to destination bitmap.
Public Const SRCERASE = (&H4400328) 'Inverts the destination bitmap and combine.
Public Const SRCINVERT = (&H660046) 'Combines pixels of the destination and source bitmap
Public Const SRCPAINT = (&HEE0086) 'Combines pixels of the destination and source bitmap
Public Const WHITENESS = (&HFF0062) 'Turns all output white.

Just noting that if you havent done too much which i can see that maybe you havent.

I would try checking out my post here for reference. Would be good for any game.

http://www.vbforums.com/showthread.p...t=#post4557703

Good Luck

[jmsrickland]

C080,

Are you sure you're posting in the correct thread? What's with this picturebox.cls

[c080]

Im sorry , i wasnt specific. By not clearing what you are drawing to , it causes the smearing , whether form or picturebox.
I used this just as a general outline of any and wasnt precise.

[jmsrickland]

Well, anyway, that has already been mentioned previously

[c080]

Just a note when blitting , the first blit is always on the bottom , behind the next , so if you do a SRCCOPY blit of a picture , that just copys the picture then use SRCAND and SCCPAINT for your pictures with masks , you can test this.

Useful to know when game programming and wanting something in the background behind a character for sidescroll or to make something hidden.
If you

You could have a mainLoop which does all the drawing with coordinates and draws off screen then comes into focus. Ive noticed that with gdi , without drawing everything at once you come to a point where the game hangs or skips around. At some point or another.

So putting all your drawing into one loop makes this simple and the only code you would need is where they will be drawn.

Just a note.
I do to only help and i dont know everything , i state what i do from experience as i know i have much to learn , even ever so little.
Sometimes mentioning something in a different manor gets a better interpretation.

[Jacob Roman]

Just a note , to use picturebox.cls before drawing anything. Use once.
I also recommend using without a timer for drawing.

Public Const SRCAND = (&H8800C6) ' Use for your Mask , White Background
Public Const SRCPAINT = (&HEE0086) 'Use for your Picture , Black Background


Public Const BLACKNESS = (&H42) 'All Black
Public Const DSINVERT = (&H550009) 'Invert.
Public Const MERGECOPY = (&HC000CA) 'Pattern and the source
Public Const MERGEPAINT = (&HBB0226) 'Inverted source
Public Const NOTSRCCOPY = (&H330008) 'Copies the inverted source bitmap to the destination.
Public Const NOTSRCERASE = (&H1100A6) 'Inverts the result of combining the destination.
Public Const PATCOPY = (&HF00021) 'Copies the pattern to the destination bitmap.
Public Const PATINVERT = (&H5A0049) 'Combines the destination bitmap with the pattern.
Public Const PATPAINT = (&HFB0A09) 'Combines the inverted source bitmap with the pattern.
Public Const SRCAND = (&H8800C6) 'Combines pixels of the destination and source bitmap.
Public Const SRCCOPY = (&HCC0020) 'Copies the source bitmap to destination bitmap.
Public Const SRCERASE = (&H4400328) 'Inverts the destination bitmap and combine.
Public Const SRCINVERT = (&H660046) 'Combines pixels of the destination and source bitmap
Public Const SRCPAINT = (&HEE0086) 'Combines pixels of the destination and source bitmap
Public Const WHITENESS = (&HFF0062) 'Turns all output white.

Just noting that if you havent done too much which i can see that maybe you havent.

I would try checking out my post here for reference. Would be good for any game.

http://www.vbforums.com/showthread.p...t=#post4557703

Good Luck

I actually don't recommend you use a Timer. Timers are horrible. Instead you use whats called a game loop locked at 60 frames per second:

Option Explicit
 
Private Declare Function QueryPerformanceCounter Lib "kernel32" (lpPerformanceCount As Currency) As Long
Private Declare Function QueryPerformanceFrequency Lib "kernel32" (lpFrequency As Currency) As Long
 
Private Ticks_Per_Second As Currency
Private Start_Time As Currency
Private Milliseconds As Long
Private Last_Time As Long
 
Private Get_Frames_Per_Second As Long
Private Frame_Count As Long
 
Private Running As Boolean
 
Public Function Hi_Res_Timer_Initialize() As Boolean
    If QueryPerformanceFrequency(Ticks_Per_Second) = 0 Then
        Hi_Res_Timer_Initialize = False
    Else
        QueryPerformanceCounter Start_Time
        Hi_Res_Timer_Initialize = True
    End If
End Function
 
Public Function Get_Elapsed_Time() As Single
    Dim Last_Time As Currency
    Dim Current_Time As Currency
    
    QueryPerformanceCounter Current_Time
    Get_Elapsed_Time = (Current_Time - Last_Time) / Ticks_Per_Second
    QueryPerformanceCounter Last_Time
End Function
 
Private Sub Lock_Framerate(Target_FPS As Long)
    Static Last_Time As Currency
    Dim Current_Time As Currency
    Dim FPS As Single
    
    Do
        QueryPerformanceCounter Current_Time
        FPS = Ticks_Per_Second / (Current_Time - Last_Time)
    Loop While (FPS > Target_FPS)
    
    QueryPerformanceCounter Last_Time
End Sub
 
Private Function Get_FPS() As String
    Frame_Count = Frame_Count + 1
        
    If Get_Elapsed_Time - Milliseconds >= 1 Then
        Get_Frames_Per_Second = Frame_Count
        Frame_Count = 0
        Milliseconds = Get_Elapsed_Time
    End If
    
    Get_FPS = "FPS: " & Get_Frames_Per_Second
End Function
 
Private Sub Shutdown()
    Running = False
    Unload Me
End Sub
 
Private Sub Main()
    With Me
        .Show
        .ScaleMode = 3
        .AutoRedraw = True
        .BackColor = RGB(0, 0, 0)
    End With
 
    Running = True
    Hi_Res_Timer_Initialize
    Milliseconds = Get_Elapsed_Time
    Game_Loop
 
End Sub
 
Private Sub Game_Loop()
    Do While Running = True
 
        'Game code goes here
 
        Me.Caption = Get_FPS
        Lock_Framerate 60
        DoEvents
    Loop
End Sub
 
Private Sub Form_Load()
    Main
End Sub
 
Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer)
    If KeyCode = vbKeyEscape Then
        Shutdown
    End If
End Sub
 
Private Sub Form_Unload(Cancel As Integer)
    Shutdown
End Sub

But if you were to build a whole game off that idea, you would have game states. This is just an example:

Option Explicit
 
Private Enum GAME_STATUS
    INTRO = 1
    TITLE_SCREEN = 2
    LOAD_SCREEN = 3
    GAME_WORLD = 4
    ENDING = 5
End Enum
 
Private Declare Function QueryPerformanceCounter Lib "kernel32" (lpPerformanceCount As Currency) As Long
Private Declare Function QueryPerformanceFrequency Lib "kernel32" (lpFrequency As Currency) As Long
 
Private Ticks_Per_Second As Currency
Private Start_Time As Currency
Private Milliseconds As Long
Private Last_Time As Long
 
Private Get_Frames_Per_Second As Long
Private Frame_Count As Long
 
Private Running As Boolean
 
Public Function Hi_Res_Timer_Initialize() As Boolean
    If QueryPerformanceFrequency(Ticks_Per_Second) = 0 Then
        Hi_Res_Timer_Initialize = False
    Else
        QueryPerformanceCounter Start_Time
        Hi_Res_Timer_Initialize = True
    End If
End Function
 
Public Function Get_Elapsed_Time() As Single
    Dim Last_Time As Currency
    Dim Current_Time As Currency
    
    QueryPerformanceCounter Current_Time
    Get_Elapsed_Time = (Current_Time - Last_Time) / Ticks_Per_Second
    QueryPerformanceCounter Last_Time
End Function
 
Private Sub Lock_Framerate(Target_FPS As Long)
    Static Last_Time As Currency
    Dim Current_Time As Currency
    Dim FPS As Single
    
    Do
        QueryPerformanceCounter Current_Time
        FPS = Ticks_Per_Second / (Current_Time - Last_Time)
    Loop While (FPS > Target_FPS)
    
    QueryPerformanceCounter Last_Time
End Sub
 
Private Function Get_FPS() As String
    Frame_Count = Frame_Count + 1
        
    If Get_Elapsed_Time - Milliseconds >= 1 Then
        Get_Frames_Per_Second = Frame_Count
        Frame_Count = 0
        Milliseconds = Get_Elapsed_Time
    End If
    
    Get_FPS = "FPS: " & Get_Frames_Per_Second
End Function
 
Private Sub Shutdown()
    Running = False
    Unload Me
End Sub
 
Private Sub Main()
    With Me
        .Show
        .ScaleMode = 3
        .AutoRedraw = True
        .BackColor = RGB(0, 0, 0)
    End With
 
    Running = True
    Hi_Res_Timer_Initialize
    Milliseconds = Get_Elapsed_Time
    Game_Loop
 
End Sub
 
Private Sub Game_Loop()
    Do While Running = True
 
        'Game code goes here
 
        Select Case Status
            Case INTRO
                'Intro_Loop
            Case TITLE_SCREEN
                'Title_Screen_Loop
            Case LOAD_SCREEN
                'Load_Screen_Loop
            Case GAME_WORLD
                'Game_World_Loop
            Case ENDING
                'Ending_Loop
        End Select
 
 
        Me.Caption = Get_FPS
        Lock_Framerate 60
        DoEvents
    Loop
End Sub
 
Private Sub Form_Load()
    Main
End Sub
 
Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer)
    If KeyCode = vbKeyEscape Then
        Shutdown
    End If
End Sub
 
Private Sub Form_Unload(Cancel As Integer)
    Shutdown
End Sub

Another thing is that you shouldn't use BitBlt for making games with as it is a royal pain to work with. Your better off either using TransparentBlt which doesnt require a mask for transparency, or step into the realm of DirectX in VB. With DirectX, you can make beautiful enriched games both in 2D and 3D such as these:





I have lots and lots of DirectX examples in my signature

[jmsrickland]

This simple example shows you how to move an image across a canvas using BitBlt API. This example uses a Picturebox control where you move the image using the command buttons or the up, down, left, and right keyboard keys.

The basic steps to move an image are:

1) Save the rectangle area from the Picturebox the size of the rectangle of the original image.

2) BitBlt the original image from it's source to that area on the Picturebox. It is better to use TransparentBlt instead of BitBlt because it does not require that you use masking to make image transparent.

3) Restore the area that was saved

4) Set next position

5) Save the area that represents the next position you want to move the image to

6) BitBlt image to next position

Repeat at Step 3

The attached project use this method.

[jmsrickland]

Here's another example. This one uses BitBlt to move the balls so it requires masking. The balls are moved using the mouse pointer and can be moved anywhere on the screen

[c080]

I also recommend using without a timer for drawing. 'Quoting myself
'See Above.
My attached Link , shows a thread ' Loop from that post. = Boolean , that is continuous. Until false.
No Timer.

Cheers

[Conroy Vanderbluff]

Here is the :::cough:::finished:::cough::: product.

http://www.vbforums.com/showthread.p...91#post4600591

Marking this thread as Resolved.