Capturing screen

This topic contains 7 replies, has 3 voices, and was last updated by Mark Sibly 1 year, 11 months ago.

Viewing 8 posts - 1 through 8 (of 8 total)

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Posts

April 28, 2017 at 11:48 am #8068

Participant

Is there any way to capture the screen (Windows)?
I’m thinking the entire screen, not just of the application, I want the desktop and everything to be part of the picture.

April 28, 2017 at 10:00 pm #8070

cocon

Participant

This is as far I as go with it, now I need to figure out the datatype conversions. Whoever can continue it, will help a lot.

#Import "<windows.h>"
#Import "<libuser32.a>"

Extern
	Function MessageBoxA:Int(hWnd:Int, lpText:CString, lpCaption:CString, uType:Int)
	Function GetDesktopWindow:Int Ptr()
	Function GetForegroundWindow:Int Ptr()
	Function GetWindowRect:Bool(hWnd:Int Ptr, rect:Rect Ptr)
Public

Struct Rect ' StructLayout(LayoutKind.Sequential)
	Field Left:Int
	Field Top:Int
	Field Right:Int
	Field Bottom:Int
	Method To:String()
		Return "Rect (" + Left + ", " + Top + ", " + Right + ", " + Bottom + ")"
	End
End

Function CaptureWindow(handle:Int Ptr) ' should return Bitmap
	
	Local rect := New Rect
	GetWindowRect(handle, Varptr rect)
	'http://www.pinvoke.net/search.aspx?search=GetWindowRect&namespace=[All]
	'Print(rect)
	
'	var bounds = new Rectangle(rect.Left, rect.Top, rect.Right - rect.Left, rect.Bottom - rect.Top);
'	var result = new Bitmap(bounds.Width, bounds.Height);
'	using (var graphics = Graphics.FromImage(result))
'	{
'		graphics.CopyFromScreen(new Point(bounds.Left, bounds.Top), Point.Empty, bounds.Size);
'	}
'	return result;

End

Function CaptureDesktop()
	CaptureWindow(GetDesktopWindow())
End

Function CaptureActiveWindow()
	CaptureWindow(GetForegroundWindow())
End

Function Main:Void()
	' Tests
	'MessageBoxA(Null, "Test", "Test", 0)
	'Print(Cast<Int>(GetDesktopWindow())) 		' OK
	'Print(Cast<Int>(GetForegroundWindow())) 		' OK
	
	CaptureDesktop()
End

#Import "<windows.h>"

#Import "<libuser32.a>"

Extern

Function MessageBoxA:Int(hWnd:Int, lpText:CString, lpCaption:CString, uType:Int)

Function GetDesktopWindow:Int Ptr()

Function GetForegroundWindow:Int Ptr()

Function GetWindowRect:Bool(hWnd:Int Ptr, rect:Rect Ptr)

Public

Struct Rect ' StructLayout(LayoutKind.Sequential)

Field Left:Int

Field Top:Int

Field Right:Int

Field Bottom:Int

Method To:String()

Return "Rect (" + Left + ", " + Top + ", " + Right + ", " + Bottom + ")"

End

Function CaptureWindow(handle:Int Ptr) ' should return Bitmap

Local rect := New Rect

GetWindowRect(handle, Varptr rect)

'http://www.pinvoke.net/search.aspx?search=GetWindowRect&namespace=[All]

'Print(rect)

' var bounds = new Rectangle(rect.Left, rect.Top, rect.Right - rect.Left, rect.Bottom - rect.Top);

' var result = new Bitmap(bounds.Width, bounds.Height);

' using (var graphics = Graphics.FromImage(result))

' {

' graphics.CopyFromScreen(new Point(bounds.Left, bounds.Top), Point.Empty, bounds.Size);

' }

' return result;

End

Function CaptureDesktop()

CaptureWindow(GetDesktopWindow())

End

Function CaptureActiveWindow()

CaptureWindow(GetForegroundWindow())

End

Function Main:Void()

' Tests

'MessageBoxA(Null, "Test", "Test", 0)

'Print(Cast<Int>(GetDesktopWindow())) ' OK

'Print(Cast<Int>(GetForegroundWindow())) ' OK

CaptureDesktop()

End

April 30, 2017 at 4:28 pm #8082

Hezkore

Participant

Yeah I can’t figure it out either… :/
That’s for the help though!

May 1, 2017 at 12:22 am #8084

Mark Sibly

Keymaster

There’s this, but it appears to be c++14 only. I have asked the author if he can backport it to c++11 for us (I’m not moving to c++14 just yet…) but I don’t like our chances.

In the meantime, here’s some Windows only source…

#Import "<std>"

Using std..

#Import "<windows.h>"
#Import "<libuser32.a>"

Extern

Alias DWORD:UInt

Alias HGDIOBJ:Void Ptr

Struct HDC__
End
Alias HDC:HDC__ Ptr

Struct HWND__
End
Alias HWND:HWND__ Ptr

Struct HBITMAP__
End
Alias HBITMAP:HBITMAP__ Ptr

Struct BITMAPINFOHEADER
	Field biSize:DWORD
	Field biWidth:Int
	Field biHeight:Int
	Field biPlanes:Short
	Field biBitCount:Short
	Field biCompression:DWORD
End

Struct BITMAPINFO
	Field bmiHeader:BITMAPINFOHEADER
End

Const SM_CYVIRTUALSCREEN:Int
Const SM_CXVIRTUALSCREEN:Int

Const SRCCOPY:DWORD
Const NOTSRCCOPY:DWORD
Const CAPTUREBLT:DWORD

Const DIB_PAL_COLORS:UInt
Const DIB_RGB_COLORS:UInt

Const BI_RGB:DWORD
	
Function GetDesktopWindow:HWND()
Function GetDC:HDC(hwnd:HWND)
Function CreateCompatibleDC:HDC(hdc:HDC)
Function GetSystemMetrics:int(index:Int)
Function CreateCompatibleBitmap:HBITMAP(hdc:HDC,width:Int,height:Int)
Function SelectObject:HGDIOBJ(hdc:HDC,hgdiobj:HGDIOBJ)
Function DeleteObject:Int( hgdiobj:HGDIOBJ )
Function BitBlt:Int(hdcDest:HDC,nXDest:Int,nYDest:Int,nWidth:Int,nHeight:Int,hdcSrc:HDC,nXSrc:Int,nYSrc:Int,dwRop:DWORD)
Function ReleaseDC:Int(hwnd:HWND,hdc:HDC)
Function DeleteDC:Int(hdc:HDC)
Function GetDIBits:Int( hdc:HDC,hbmp:HBITMAP,firstLine:UInt,numlines:UInt,bitmapData:Void Ptr,bitmapInfo:BITMAPINFO Ptr,usage:UInt )
	
Public

Function CaptureWindow:Pixmap()
	
	Local hwnd:=GetDesktopWindow()
	Local w:=GetSystemMetrics( SM_CXVIRTUALSCREEN )
	Local h:=GetSystemMetrics( SM_CYVIRTUALSCREEN )
	
	Local hwnddc:=GetDC( hwnd )
	Local hcapturedc:=CreateCompatibleDC( hwnddc )
	Local hcapturebmp:=CreateCompatibleBitmap( hwnddc,w,h )
	
	SelectObject( hcapturedc,hcapturebmp )
		
	BitBlt( hcapturedc,0,0,w,h,hwnddc,0,0,SRCCOPY|CAPTUREBLT )
	
	Local bmpInfo:BITMAPINFO
	
	libc.memset( Varptr bmpInfo,0,libc.sizeof( bmpInfo ) )
	
    bmpInfo.bmiHeader.biSize = libc.sizeof( bmpInfo.bmiHeader )
    bmpInfo.bmiHeader.biWidth = w
    bmpInfo.bmiHeader.biHeight = -h
    bmpInfo.bmiHeader.biPlanes = 1
    bmpInfo.bmiHeader.biBitCount = 24
    bmpInfo.bmiHeader.biCompression = BI_RGB
    
    Local pixmap:=New Pixmap( w,h,PixelFormat.RGB8 )
    pixmap.Clear( Color.Red )
    
    GetDIBits( hcapturedc,hcapturebmp,0,h,pixmap.Data,Varptr bmpInfo,DIB_RGB_COLORS )
    
	DeleteDC( hcapturedc )
	DeleteObject( hcapturebmp )
	
    Return pixmap
End

Function Main()
	
	Local pm:=CaptureWindow()
	
	Print "Captured! w="+pm.Width+", h="+pm.Height
	
	pm.Save( DesktopDir()+"test.png" )
	
End

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#Import "<std>"

Using std..

#Import "<windows.h>"

#Import "<libuser32.a>"

Extern

Alias DWORD:UInt

Alias HGDIOBJ:Void Ptr

Struct HDC__

End

Alias HDC:HDC__ Ptr

Struct HWND__

End

Alias HWND:HWND__ Ptr

Struct HBITMAP__

End

Alias HBITMAP:HBITMAP__ Ptr

Struct BITMAPINFOHEADER

Field biSize:DWORD

Field biWidth:Int

Field biHeight:Int

Field biPlanes:Short

Field biBitCount:Short

Field biCompression:DWORD

End

Struct BITMAPINFO

Field bmiHeader:BITMAPINFOHEADER

End

Const SM_CYVIRTUALSCREEN:Int

Const SM_CXVIRTUALSCREEN:Int

Const SRCCOPY:DWORD

Const NOTSRCCOPY:DWORD

Const CAPTUREBLT:DWORD

Const DIB_PAL_COLORS:UInt

Const DIB_RGB_COLORS:UInt

Const BI_RGB:DWORD

Function GetDesktopWindow:HWND()

Function GetDC:HDC(hwnd:HWND)

Function CreateCompatibleDC:HDC(hdc:HDC)

Function GetSystemMetrics:int(index:Int)

Function CreateCompatibleBitmap:HBITMAP(hdc:HDC,width:Int,height:Int)

Function SelectObject:HGDIOBJ(hdc:HDC,hgdiobj:HGDIOBJ)

Function DeleteObject:Int( hgdiobj:HGDIOBJ )

Function BitBlt:Int(hdcDest:HDC,nXDest:Int,nYDest:Int,nWidth:Int,nHeight:Int,hdcSrc:HDC,nXSrc:Int,nYSrc:Int,dwRop:DWORD)

Function ReleaseDC:Int(hwnd:HWND,hdc:HDC)

Function DeleteDC:Int(hdc:HDC)

Function GetDIBits:Int( hdc:HDC,hbmp:HBITMAP,firstLine:UInt,numlines:UInt,bitmapData:Void Ptr,bitmapInfo:BITMAPINFO Ptr,usage:UInt )

Public

Function CaptureWindow:Pixmap()

Local hwnd:=GetDesktopWindow()

Local w:=GetSystemMetrics( SM_CXVIRTUALSCREEN )

Local h:=GetSystemMetrics( SM_CYVIRTUALSCREEN )

Local hwnddc:=GetDC( hwnd )

Local hcapturedc:=CreateCompatibleDC( hwnddc )

Local hcapturebmp:=CreateCompatibleBitmap( hwnddc,w,h )

SelectObject( hcapturedc,hcapturebmp )

BitBlt( hcapturedc,0,0,w,h,hwnddc,0,0,SRCCOPY|CAPTUREBLT )

Local bmpInfo:BITMAPINFO

libc.memset( Varptr bmpInfo,0,libc.sizeof( bmpInfo ) )

bmpInfo.bmiHeader.biSize = libc.sizeof( bmpInfo.bmiHeader )

bmpInfo.bmiHeader.biWidth = w

bmpInfo.bmiHeader.biHeight = -h

bmpInfo.bmiHeader.biPlanes = 1

bmpInfo.bmiHeader.biBitCount = 24

bmpInfo.bmiHeader.biCompression = BI_RGB

Local pixmap:=New Pixmap( w,h,PixelFormat.RGB8 )

pixmap.Clear( Color.Red )

GetDIBits( hcapturedc,hcapturebmp,0,h,pixmap.Data,Varptr bmpInfo,DIB_RGB_COLORS )

DeleteDC( hcapturedc )

DeleteObject( hcapturebmp )

Return pixmap

End

Function Main()

Local pm:=CaptureWindow()

Print "Captured! w="+pm.Width+", h="+pm.Height

pm.Save( DesktopDir()+"test.png" )

End

Windows only…

May 1, 2017 at 6:16 pm #8090

Hezkore

Participant

Ah, so that’s why you added some more pixelformats.
I always get weird colours with it though, almost inverted colours.

May 1, 2017 at 10:06 pm #8091

Mark Sibly

Keymaster

Actually, PixelFormat.RGB8 is just an alias I added for RGB24 – should probably have used RGB24 in the above code to prevent confusion. I recently added a number of GL depth/float pixel formats recently (which aren’t well supported in the Pixmap class yet) and decided I quite like the GL ‘notation’ (which is very similar to mx2 anyway) so have been playing around with switching to it (but leaving the old ones in there). Haven’t decided what to do here in general though.

But I’m surprised the code doesn’t work for you. What OS are you using? What desktop mode? Can you post a pic?

May 2, 2017 at 6:14 pm #8097

Hezkore

Participant

Windows 10 @ 1080p 32bit.
I’m not sure, but I think Red and Blue’s been switched.

May 2, 2017 at 10:10 pm #8098

Mark Sibly

Keymaster

> I’m not sure, but I think Red and Blue’s been switched.

Haha!

It’s actually doing the same thing here, only my desktop is so psychedelic I didn’t notice!

Fixed code:

#Import "<std>"

Using std..

#Import "<windows.h>"
#Import "<libuser32.a>"

Extern

Alias DWORD:UInt

Alias HGDIOBJ:Void Ptr

Struct HDC__
End
Alias HDC:HDC__ Ptr

Struct HWND__
End
Alias HWND:HWND__ Ptr

Struct HBITMAP__
End
Alias HBITMAP:HBITMAP__ Ptr

Struct BITMAPINFOHEADER
	Field biSize:DWORD
	Field biWidth:Int
	Field biHeight:Int
	Field biPlanes:Short
	Field biBitCount:Short
	Field biCompression:DWORD
End

Struct BITMAPINFO
	Field bmiHeader:BITMAPINFOHEADER
End

Const SM_CYVIRTUALSCREEN:Int
Const SM_CXVIRTUALSCREEN:Int

Const SRCCOPY:DWORD
Const NOTSRCCOPY:DWORD
Const CAPTUREBLT:DWORD

Const DIB_PAL_COLORS:UInt
Const DIB_RGB_COLORS:UInt

Const BI_RGB:DWORD
	
Function GetDesktopWindow:HWND()
Function GetDC:HDC(hwnd:HWND)
Function CreateCompatibleDC:HDC(hdc:HDC)
Function GetSystemMetrics:int(index:Int)
Function CreateCompatibleBitmap:HBITMAP(hdc:HDC,width:Int,height:Int)
Function SelectObject:HGDIOBJ(hdc:HDC,hgdiobj:HGDIOBJ)
Function DeleteObject:Int( hgdiobj:HGDIOBJ )
Function BitBlt:Int(hdcDest:HDC,nXDest:Int,nYDest:Int,nWidth:Int,nHeight:Int,hdcSrc:HDC,nXSrc:Int,nYSrc:Int,dwRop:DWORD)
Function ReleaseDC:Int(hwnd:HWND,hdc:HDC)
Function DeleteDC:Int(hdc:HDC)
Function GetDIBits:Int( hdc:HDC,hbmp:HBITMAP,firstLine:UInt,numlines:UInt,bitmapData:Void Ptr,bitmapInfo:BITMAPINFO Ptr,usage:UInt )
	
Public

Function CaptureWindow:Pixmap()
	
	Local hwnd:=GetDesktopWindow()
	Local w:=GetSystemMetrics( SM_CXVIRTUALSCREEN )
	Local h:=GetSystemMetrics( SM_CYVIRTUALSCREEN )
	
	Local hwnddc:=GetDC( hwnd )
	Local hcapturedc:=CreateCompatibleDC( hwnddc )
	Local hcapturebmp:=CreateCompatibleBitmap( hwnddc,w,h )
	
	SelectObject( hcapturedc,hcapturebmp )
		
	BitBlt( hcapturedc,0,0,w,h,hwnddc,0,0,SRCCOPY|CAPTUREBLT )
	
	Local bmpInfo:BITMAPINFO
	
	libc.memset( Varptr bmpInfo,0,libc.sizeof( bmpInfo ) )
	
    bmpInfo.bmiHeader.biSize = libc.sizeof( bmpInfo.bmiHeader )
    bmpInfo.bmiHeader.biWidth = w
    bmpInfo.bmiHeader.biHeight = -h
    bmpInfo.bmiHeader.biPlanes = 1
    bmpInfo.bmiHeader.biBitCount = 24
    bmpInfo.bmiHeader.biCompression = BI_RGB
    
    Local pixmap:=New Pixmap( w,h,PixelFormat.RGB8 )
    
    GetDIBits( hcapturedc,hcapturebmp,0,h,pixmap.Data,Varptr bmpInfo,DIB_RGB_COLORS )
    
    For Local y:=0 Until h
	    Local p:=pixmap.PixelPtr( 0,y )
	    For Local x:=0 Until w
		    Local t:=p[0]
		    p[0]=p[2]
		    p[2]=t
		    p+=3
		Next
	Next
    
	DeleteDC( hcapturedc )
	DeleteObject( hcapturebmp )
	
    Return pixmap
End

Function Main()
	
	Local pm:=CaptureWindow()
	
	Print "Captured! w="+pm.Width+", h="+pm.Height
	
	pm.Save( DesktopDir()+"test.png" )
	
End

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#Import "<std>"

Using std..

#Import "<windows.h>"

#Import "<libuser32.a>"

Extern

Alias DWORD:UInt

Alias HGDIOBJ:Void Ptr

Struct HDC__

End

Alias HDC:HDC__ Ptr

Struct HWND__

End

Alias HWND:HWND__ Ptr

Struct HBITMAP__

End

Alias HBITMAP:HBITMAP__ Ptr

Struct BITMAPINFOHEADER

Field biSize:DWORD

Field biWidth:Int

Field biHeight:Int

Field biPlanes:Short

Field biBitCount:Short

Field biCompression:DWORD

End

Struct BITMAPINFO

Field bmiHeader:BITMAPINFOHEADER

End

Const SM_CYVIRTUALSCREEN:Int

Const SM_CXVIRTUALSCREEN:Int

Const SRCCOPY:DWORD

Const NOTSRCCOPY:DWORD

Const CAPTUREBLT:DWORD

Const DIB_PAL_COLORS:UInt

Const DIB_RGB_COLORS:UInt

Const BI_RGB:DWORD

Function GetDesktopWindow:HWND()

Function GetDC:HDC(hwnd:HWND)

Function CreateCompatibleDC:HDC(hdc:HDC)

Function GetSystemMetrics:int(index:Int)

Function CreateCompatibleBitmap:HBITMAP(hdc:HDC,width:Int,height:Int)

Function SelectObject:HGDIOBJ(hdc:HDC,hgdiobj:HGDIOBJ)

Function DeleteObject:Int( hgdiobj:HGDIOBJ )

Function BitBlt:Int(hdcDest:HDC,nXDest:Int,nYDest:Int,nWidth:Int,nHeight:Int,hdcSrc:HDC,nXSrc:Int,nYSrc:Int,dwRop:DWORD)

Function ReleaseDC:Int(hwnd:HWND,hdc:HDC)

Function DeleteDC:Int(hdc:HDC)

Function GetDIBits:Int( hdc:HDC,hbmp:HBITMAP,firstLine:UInt,numlines:UInt,bitmapData:Void Ptr,bitmapInfo:BITMAPINFO Ptr,usage:UInt )

Public

Function CaptureWindow:Pixmap()

Local hwnd:=GetDesktopWindow()

Local w:=GetSystemMetrics( SM_CXVIRTUALSCREEN )

Local h:=GetSystemMetrics( SM_CYVIRTUALSCREEN )

Local hwnddc:=GetDC( hwnd )

Local hcapturedc:=CreateCompatibleDC( hwnddc )

Local hcapturebmp:=CreateCompatibleBitmap( hwnddc,w,h )

SelectObject( hcapturedc,hcapturebmp )

BitBlt( hcapturedc,0,0,w,h,hwnddc,0,0,SRCCOPY|CAPTUREBLT )

Local bmpInfo:BITMAPINFO

libc.memset( Varptr bmpInfo,0,libc.sizeof( bmpInfo ) )

bmpInfo.bmiHeader.biSize = libc.sizeof( bmpInfo.bmiHeader )

bmpInfo.bmiHeader.biWidth = w

bmpInfo.bmiHeader.biHeight = -h

bmpInfo.bmiHeader.biPlanes = 1

bmpInfo.bmiHeader.biBitCount = 24

bmpInfo.bmiHeader.biCompression = BI_RGB

Local pixmap:=New Pixmap( w,h,PixelFormat.RGB8 )

GetDIBits( hcapturedc,hcapturebmp,0,h,pixmap.Data,Varptr bmpInfo,DIB_RGB_COLORS )

For Local y:=0 Until h

Local p:=pixmap.PixelPtr( 0,y )

For Local x:=0 Until w

Local t:=p[0]

p[0]=p[2]

p[2]=t

p+=3

DeleteDC( hcapturedc )

DeleteObject( hcapturebmp )

Return pixmap

End

Function Main()

Local pm:=CaptureWindow()

Print "Captured! w="+pm.Width+", h="+pm.Height

pm.Save( DesktopDir()+"test.png" )

End

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Capturing screen

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