Save a screenshot?

[Jacob123]

im trying to make a hotkey to save a screenshot of a fullscreen directx game.
this game is not mine and therfore dont have access to its source code.

but i do know api and i can get a processhandle from this application. i have also hooked the keyboard in this game so the hotkey is not a problem.

the only thing i need to know how to do is save a screenshot? anyone know? thanks

[Hack]

Option Explicit
 
Private Declare Sub keybd_event Lib "user32" (ByVal bVk As Byte, ByVal bScan As Byte, _
ByVal dwFlags As Long, ByVal dwExtraInfo As Long)
 
Private Const VK_SNAPSHOT = &H2C
 
Private Function SaveScreen(ByVal pstrFileName As String) As Boolean
'To get the Active Window
Call keybd_event(vbKeySnapshot, 0, 0, 0)
 
SavePicture Clipboard.GetData(vbCFBitmap), pstrFileName
 
SaveScreen = True
Exit Function
End Function
 
Private Sub Command1_Click()
Call SaveScreen("C:\code\vb6\shot1.bmp")
End Sub

[Joacim Andersson]

Since your program doesn't have the focus when you want to save the screen. You might want to look into using the RegisterHotKey function to register a hotkey to be used to save the screen. You could then use the code posted by Hack above in the callback function to save the image.

[Jacob123]

What makes you so sure I dont have focus? Like i said, i have already hooked the keyboard for use of it ingame, so i can just press a button and it saves a screen.

so yes i do have focus. i will try the code now, thanks

[Joacim Andersson]

I'm sorry I didn't read your origional post careful enough.

[Jacob123]

Does anyone know if i could possibly blueprint all these images im saving with some simple text at the bottom or something?

I have the filenames saved based on the time right now.

BTW can i save them as jpg instead of bmp because bmp is large files

[Joacim Andersson]

You could put the image inside a memory dc and use DrawText and then store it or simply put it in a hidden PictureBox and use the Print statement and then save the image (the PicBox need to have the AutoRedraw property set). To save as a JPG you need some third party control. I think I have a simple BMP2JPG dll somewhere, I'll see if I can dig it out for you.

[Keithuk]

Bmp2Jpeg.dll

http://www.vbforums.com/showthread.php?t=335938

[Jacob Roman]

Here's the DirectX approach to saving snapshots. You can save it as bmp as well as jpg or any other format. DirectX does it for you.

Public Sub DirectX_Snapshot(ByVal File_Path As String)
 
    Dim Surface As Direct3DSurface8
    Dim SrcPalette As PALETTEENTRY
    Dim SrcRect As RECT
    Dim Direct3D_Display_Mode As D3DDISPLAYMODE
 
    'get display dimensions
    Direct3D_Device.GetDisplayMode Direct3D_Display_Mode
 
    'create a surface to put front buffer on,
    'GetFrontBuffer always returns D3DFMT_A8R8G8B8
    Set Surface = Direct3D_Device.CreateImageSurface(Direct3D_Display_Mode.Width, Direct3D_Display_Mode.Height, D3DFMT_A8R8G8B8)
 
    'get data from front buffer
    Direct3D_Device.GetFrontBuffer Surface
 
    'we are saving entire area of this surface
    
    With SrcRect
    
        .Left = 0
        .Right = Direct3D_Display_Mode.Width
        .Top = 0
        .bottom = Direct3D_Display_Mode.Height
        
    End With
 
    'save this surface to a BMP file
    'Direct3DX.SaveSurfaceToFile File_Path, D3DXIFF_BMP, Surface, SrcPalette, SrcRect
 
    'save this surface to a JPG file
    Direct3DX.SaveSurfaceToFile File_Path, D3DXIFF_JPG, Surface, SrcPalette, SrcRect
 
'Here are some more formats
 
'D3DXIFF_TGA
'D3DXIFF_PNG
'D3DXIFF_DIB
'D3DXIFF_DDS
'D3DXIFF_PPM
'D3DXIFF_FORCE_DWORD <---- Don't know what that does.
 
End Sub

And in your game loop, you put this in:

'Declare this variable in the General Declarations
 
       Dim Snapshot_Number As Long
 
       'Then put this in your loop
 
        If DirectInput_Key_State(DIK_F12) Then
            
            If Dir$(App.Path & "\Snapshots\", vbDirectory) = "" Then
                
                MkDir App.Path & "\Snapshots\"
                
            End If
            
            If Dir$(App.Path & "\Snapshots\SNAP" & Format(Snapshot_Number, "####") & ".jpg") = "" Then
            
                DirectX_Snapshot App.Path & "\Snapshots\SNAP" & Format(Snapshot_Number, "####") & ".jpg"
            
            End If
            
            While Dir$(App.Path & "\Snapshots\SNAP" & Format(Snapshot_Number, "####") & ".jpg") <> ""
                
                DoEvents
                
                Snapshot_Number = Snapshot_Number + 1
                
            Wend
            
        End If

[RobCrombie]

Hi Jacob Roman,

If any of us want to build a stand alone pgm using your code, is there any other things we need to declare (or know), to build into the pgm.

Your sample aimed at jacob123, assumes that he has Directx 'stuff' already in his pgm (which he has).

Thanks for sharing,

[Jacob Roman]

Well if you wanted to use my code, you must have some knowledge of DirectX. Otherwise I'm not sure how it'll work with a stand alone app to be honest with ya.

And I just found out that I need to know the correct color format to get that code working. Already posted this problem in www.gamedev.net. It'll be solved shortly, I hope.

The format D3DFMT_A8R8G8B8 works very well with bmp files. Jpg it's something else.

[Jacob123]

Does this 'DirectX approach' have any advantages? The code that Hack posted has been working fine.

Is it possible to blueprint my screenshots with an actual IMAGE? Maybe even an img with some low-level png transparency?

[Jacob Roman]

I was just pointing out another method, which DirectX has. They both should do the same thing. The only advantage is the fact that it supports multiple formats that gets converted for you by DirectX.

My question in gamedev got no replys

[MartinLiss]

Try this app.

[RobCrombie]

Nice one Martin.

Two things -

If user captures the wrong Active Window, or just wants to re-capture that window (content changed), or capture another active Window, the 'focus' is still on that option. That prevents a re-click.
I have added an option 4 to the control array. Placed it at the bottom/center of Frame1. Set it's style to Graphical, and made it's Caption 'Clear'
The large button 'Clear Picture Box' can be removed, as this smaller Clear button does the same thing, and also frees up the options. Thus any of them can be re-clicked after the new Clear is used.

Can anyone add the ability to Save the image as jpg ?
(That would make me a very happy 'mother' this Mother's Day)

[dglienna]

Post the new project, and I'll see about adding the dll. I think I have a project using it somewhere else.

[RobCrombie]

Ta,
See attached

[dglienna]

Not bad. Make sure you put the dll in the system32 folder.

[RobCrombie]

Martin, dglienna,

This pgm is now just to good.

If you both agree, I think we should delete this entire thread, before too many people get a chance to download it ?

[dglienna]

Why? Someone else may want to add something else in the future.
I had an old version, before your update. Now it's better than before and it also does jpeg. That's what the forum is all about.

[RobCrombie]

I have been accused of having a dry sense of humour <======

[RobCrombie]

I have added many enhancements to the Saving area.
You can still use the Dialog.
However it remembers where you put it (in txtFolder), and what you called it (in txtFile).
You can then quickly Save subsequent captures, into the same folder.
I have also added a button to allow you to just save into the app.path

When the Form closes it Saves the Folder and File names used, and restores them (in those textboxes), when the pgm next runs.

I believe that a capture pgm has to be quick and easy to use, when you really need it. At those times, you don't want to be stuffing around browsing and naming all your images.
Thus there is also a 'lazy' feature that allows you to just tell it to save the flippin image, and not bother you with minor details, like having to tell it where to put it, or what to call it.
If no folder has been specified, it uses app.path
If no file has been specifed, it uses yyyymmdd.jpg

AH! you might say 'What happens if I am lazy twice ?'
That is, when you use the same file name (or no file name, and it uses the yyyymmdd again)
There is an auto increment feature that adds an incrementing number, whenever it detects a clash.
Thus if you were super lazy (like me), it would create in app.path -
20050428.jpg
20050428_001.jpg
20050428_002.jpg

If you have specified a File name in txtFile, then it does the same, but uses that File name.

It could have more commenting, than it has. So I figure you'll make some small deductions from your PayPal transfers (to punish me).

I am attaching the DLL separately, as some of you may have downloaded that already.

There may be some bugs (it is 4:00 AM in OZ). (More PayPal deductions ?)

[RobCrombie]

'But wait there's more'

I have added 'Minimize to SysTray'

Icon is always in the SysTray (when pgm is running).
It never appears in the TaskBar.

Click the Icon to show, and click to hide.

[RobCrombie]

Pretty soon, it'll be ready for the CodeBank!
just make sure to give credit where credit is due

'Oh yee of little faith'
In this link
Minimize To SysTray
I said

in 'my' (cough!) project

So that should arrest your fears (humour again)

[RobCrombie]

The click to hide and click to show, was ok, except you had to hide some Apps to see our Form.
I have enhanced the attached, to hopefully fix that inconvenience

Let me know if it is still hard to find(see), when un-hiding 'our' Form.
When you are singing about 'us' around the camp fire, the 'our'' refers to Martin, David and Rob.

PS Don't forget to download David's DLL, which I attached separately above Bmp2Jpeg.zip

[dglienna]

You really should include the jpeg.dll in the zip file, as most people will not have it, which will cause an error. It looks good.

[RobCrombie]

Hi David,
I have edited the above post, to include your two suggestionsi

[Hack]

Perhaps the finished product for the screen capturing should be popped into the CodeBank where it could be more easily found.

[MartinLiss]

Perhaps the finished product for the screen capturing should be popped into the CodeBank where it could be more easily found.

I think the UtilityBank would be better.

[RobCrombie]

Hi,
I have a couple of improvements I'm working on.
Also I think the middle two options are not much use, or am I missing something ?

An nice additional option, would be the ability to use mouse to define an area of the screen to capture.
Anyone got a sample that I could slot into this project ?

[Joacim Andersson]

An nice additional option, would be the ability to use mouse to define an area of the screen to capture.
Anyone got a sample that I could slot into this project ?

I did something like that a few years back. What I basically did was to take a snapshot of the entire screen and put it on a non-border topmost fullscreen Form which the user could select an area from.

[systech44]

Hi Hack,

I am facing problem with the below line. I get vb error 380: invalid property value.
SavePicture Clipboard.GetData(vbCFBitmap), pstrFileName


I like to take the screenshot of only my working form. Is it possible ? Please help.

[Keithuk]

Thats because you need to put a DoEvents in there.

Option Explicit
 
Private Declare Sub keybd_event Lib "user32" (ByVal bVk As Byte, _
ByVal bScan As Byte, ByVal dwFlags As Long, ByVal dwExtraInfo As Long)
 
Private Sub SaveScreen(ByVal pstrFileName As String)
 
'To get the Active Form
Call keybd_event(vbKeySnapshot, 0, 0, 0)
 
'To get the Full Screen
'Call keybd_event(vbKeySnapshot, 1, 0, 0)
 
Clipboard.Clear
DoEvents
SavePicture Clipboard.GetData(vbCFBitmap), pstrFileName
 
End Sub
 
Private Sub Command1_Click()
 
Call SaveScreen("C:\shot1.bmp")
 
End Sub