In short, I want to write a Gnome-Shell-style window switcher. So I need to fetch snapshots of all the windows. My current program looks like this:
char filename[101];
sprintf(filename, "%d.png", (int)win_list[i]);
GdkWindow *win_gdk = gdk_x11_window_foreign_new_for_display
(gdk_display_get_default(), win_list[i]);
gint _w, _h;
gdk_drawable_get_size(GDK_DRAWABLE(win_gdk), &_w, &_h);
XEvent _xevent;
_xevent.xexpose =
(XExposeEvent)
{
.type = Expose,
.send_event = True,
.display = xsu_vars.dpy,
.window = win_list[i],
.x = 0, .y = 0, .width = _w, .height = _h,
.count = 0
};
XSendEvent(xsu_vars.dpy, win_list[i], False, 0, &_xevent);
GdkPixbuf *_pb = gdk_pixbuf_get_from_drawable(
NULL, GDK_DRAWABLE(win_gdk), NULL, 0, 0, 0, 0, _w, _h);
if(_pb != NULL) {
cairo_surface_t *_surf_cairo = cairo_image_surface_create(
CAIRO_FORMAT_RGB24, _w, _h);
cairo_t *_cr = cairo_create(_surf_cairo);
gdk_cairo_set_source_pixbuf(_cr, _pb, 0, 0);
cairo_paint(_cr);
cairo_surface_write_to_png(_surf_cairo, filename);
printf("%s saved successfully!\n", filename);
} else {
printf("failed...\n");
}
The program works well well, but it will not generate correct images for those windows which are on a different desktop of minimized -- they would look like this:
Note that I send a expose event to all windows before generating pixbufs of them.
UPDATE:
It seems that xlib doesn't support that. So the only way may be creating cache manually.
This is possible with Composite extension - see "Preventing the backing pixmap from being freed when the window is hidden/destroyed" section in tutorial.
Yes, your update is correct. When a window is unmapped (or covered up), X just discards its contents; they don't exist anywhere in order to be snapshotted.
I believe libwnck contains code to do this and other parts of writing a switcher, btw. It's basically a library for writing things like window switchers.
Related
I wrote a font parser and renderer based on some functionality in the freetype library, but it currently only works for font files that I specify. I'd like to be able to retrieve fonts from the Windows Font Mapper and then parse and render them, but I can't figure out how to get the actual font data from a logical font.
I thought that the easy way to accomplish this would be to get the font file name from the logical font, but based on other stack overflow posts, there isn't any good solution to this because there isn't a 1 to 1 mapping of physical fonts to the logical font you specify.
This code shows how I'm currently retrieving a handle to a logical font:
HFONT windowsFont = CreateFontA(72, 0, 0, 0, 0,
0, 0, 0, ANSI_CHARSET,
OUT_DEFAULT_PRECIS, CLIP_DEFAULT_PRECIS,
DEFAULT_QUALITY, DEFAULT_PITCH, "Arial");
HDC deviceContext = GetDC(windowHandle);
SelectObject(deviceContext, windowsFont);
DWORD fontSize = GetFontData(deviceContext, 0, 0, NULL, 0);
void *fontData = malloc(fontSize);
fontSize = GetFontData(deviceContext, 0, 0, fontData, 0);
char *fontFileData;
size_t fontFileSize;
// This is a function that I wrote that does what you'd expect. It opens
// a file, reads all the bytes to a buffer and closes the file
readFileToBuff(&fontFileData, &fontFileSize, "c:/windows/fonts/arial.ttf");
assert(fontFileSize == fontSize); // This passes
assert(((char)fontFileData) == ((char)fontData)); // This fails
Based on this stack overflow post which is for Java, I'm thinking that what I want to do may not be possible. It seems that the only solution may be to look at all the system font files and try to figure out what they are.
How to get ttf font data from system fonts in java
This surprises me though, because it seems that it would be relatively common for a program to want to render fonts themselves, without relying on the Windows renderer. Does anyone know of a way to get the font data, or how other people have solved this problem?
I don't understand why it's getting the exact same amount of bytes as
the file, but the data isn't the same.
From the official sample, I found the correct way to use GetFontData.
This is the modified code, and the returned data is the same as fontFileData.
HRESULT hr = S_OK;
LPVOID ptr = NULL;
HGLOBAL hGlobal = NULL;
...
HFONT windowsFont = CreateFontA(72, 0, 0, 0, 0,
0, 0, 0, ANSI_CHARSET,
OUT_DEFAULT_PRECIS, CLIP_DEFAULT_PRECIS,
DEFAULT_QUALITY, DEFAULT_PITCH, "Arial");
HDC deviceContext = GetDC(hWnd);
SelectObject(deviceContext, windowsFont);
DWORD fontSize = GetFontData(deviceContext, 0, 0, NULL, 0);
hGlobal = GlobalAlloc(GMEM_MOVEABLE, fontSize);
ptr = GlobalLock(hGlobal);
if (!ptr)
{
hr = HRESULT_FROM_WIN32(GetLastError());
fwprintf(stderr, L"ERROR: Could not lock global memory object: %08X\n", hr);
}
else
{
if (GetFontData(deviceContext, 0, 0, ptr, fontSize) == GDI_ERROR)
{
fwprintf(stderr, L"ERROR: Could not get font data\n");
hr = E_UNEXPECTED;
}
GlobalUnlock(hGlobal);
}
char *fontFileData;
size_t fontFileSize;
// This is a function that I wrote that does what you'd expect. It opens
// a file, reads all the bytes to a buffer and closes the file
readFileToBuff(&fontFileData, &fontFileSize, "c:/windows/fonts/arial.ttf");
assert(fontFileSize == fontSize); // This passes
assert(((char)fontFileData) == ((char)fontData)); // This fails
I have a CMake project with an executable and a static library (linked to the exe). The library is responsible for implementing the creation of the window (using WinAPI for Windows OS), and the executable contains the main entry point (in this case a simple int main(...) function).
I've been googling for a day but cannot find a way to create a window with Aero support (can maximize by dropping to the top, the title bar is a little bit transparent, etc). I've read the Enabling Visual Styles MSDN article but I'm not sure how I should handle this with CMake. Especially that the window implementation is hidden to the client (since it's implemented in the library).
The windowing code is really basic right now for simplicity. Some of the code will be refactored, the point is not that right now. Here is the (almost) full code for creating the window.
bool WindowsWindow::create(const WindowCreateInfo& info)
{
// register custom window class
{
WNDCLASSEX wnd = { 0 };
wnd.cbSize = sizeof(wnd);
wnd.lpszClassName = CLASS_NAME;
wnd.hInstance = GetModuleHandle(nullptr);
wnd.lpfnWndProc = wndProc;
wnd.style = CS_OWNDC;
wnd.hbrBackground = reinterpret_cast<HBRUSH>(COLOR_WINDOW);
wnd.hCursor = LoadCursor(NULL, IDC_ARROW);
if (RegisterClassEx(&wnd) == 0) {
return false;
}
hInstance = wnd.hInstance;
}
HMONITOR monitor = MonitorFromWindow(nullptr, MONITOR_DEFAULTTOPRIMARY);
MONITORINFO monitorInfo;
monitorInfo.cbSize = sizeof(MONITORINFO);
GetMonitorInfo(monitor, &monitorInfo);
LONG style = 0;
LONG exStyle = WS_EX_APPWINDOW;
int x = CW_USEDEFAULT;
int y = CW_USEDEFAULT;
int width = info.width;
int height = info.height;
if (info.isWindowed) {
style = WS_OVERLAPPED | WS_BORDER | WS_CAPTION;
if (info.hasSysMenu) {
style |= WS_SYSMENU;
}
if (info.allowMinimize) {
style |= WS_MINIMIZEBOX;
}
if (info.allowMaximize) {
style |= WS_MAXIMIZEBOX;
}
// ... positioning, adjusting size, etc.
} else {
style = WS_POPUP;
x = monitorInfo.rcMonitor.left;
y = monitorInfo.rcMonitor.top;
width = monitorInfo.rcMonitor.right - x;
height = monitorInfo.rcMonitor.bottom - y;
}
handle = CreateWindowEx(
exStyle,
CLASS_NAME,
info.title,
style,
x,
y,
width,
height,
HWND_DESKTOP,
nullptr,
hInstance,
nullptr
);
if (!handle) {
return false;
}
running = true;
ShowWindow(handle, SW_SHOW);
return true;
}
The loop is the standard Peek-Translate-Dispatch trio and the WndProc only handles the WM_CLOSE message, otherwise returns with DefWindowProc.
How could I enable the Aero support in this kind of setup?
If the proper manifest file would be the solution, how should I handle it correctly? I mean the client (the executable) should not care that the underlying library is using WinAPI or not
A CMake example would be really helpful
Current solution
I was able to find an example (actually from a Vulkan SDK) that pointed out that I need the WS_THICKFRAME style (a resize border) in order to my window become modern looking (Aero-like).
I want to bounce a midi file offline, and as the PlaySequence example does exactly this, I am trying to understand it.
I keep reading everywhere that you need a callback function to do anything in CoreAudio, yet I cannot see any in this project.
I paste the loop containing the AudioUnitRender, thanks for your help!
CAStreamBasicDescription clientFormat = CAStreamBasicDescription();
size = sizeof(clientFormat);
FailIf ((result = AudioUnitGetProperty (outputUnit,
kAudioUnitProperty_StreamFormat,
kAudioUnitScope_Output, 0,
&clientFormat, &size)), fail, "AudioUnitGetProperty: kAudioUnitProperty_StreamFormat");
size = sizeof(clientFormat);
FailIf ((result = ExtAudioFileSetProperty(outfile, kExtAudioFileProperty_ClientDataFormat, size, &clientFormat)), fail, "ExtAudioFileSetProperty: kExtAudioFileProperty_ClientDataFormat");
{
MusicTimeStamp currentTime;
AUOutputBL outputBuffer (clientFormat, numFrames);
AudioTimeStamp tStamp;
memset (&tStamp, 0, sizeof(AudioTimeStamp));
tStamp.mFlags = kAudioTimeStampSampleTimeValid;
int i = 0;
int numTimesFor10Secs = (int)(10. / (numFrames / srate));
do {
outputBuffer.Prepare();
AudioUnitRenderActionFlags actionFlags = 0;
FailIf ((result = AudioUnitRender (outputUnit, &actionFlags, &tStamp, 0, numFrames, outputBuffer.ABL())), fail, "AudioUnitRender");
tStamp.mSampleTime += numFrames;
FailIf ((result = ExtAudioFileWrite(outfile, numFrames, outputBuffer.ABL())), fail, "ExtAudioFileWrite");
FailIf ((result = MusicPlayerGetTime (player, ¤tTime)), fail, "MusicPlayerGetTime");
if (shouldPrint && (++i % numTimesFor10Secs == 0))
printf ("current time: %6.2f beats\n", currentTime);
} while (currentTime < sequenceLength);
}
I had a look at the project and you're right, it does not have a rendercallback. Render callbacks have their place withing coreaudio audiounit effect processing. The call to setup a render callback looks like this:
inline OSStatus SetInputCallback (CAAudioUnit &inUnit, AURenderCallbackStruct &inInputCallback)
{
return inUnit.SetProperty (kAudioUnitProperty_SetRenderCallback,
kAudioUnitScope_Input,
0,
&inInputCallback,
sizeof(inInputCallback));
}
However this code is just one big main() which setups up the sequence, augraph, music player and then the filewriter WriteOutputFile in case there's an outputfile to bounce to.
I recommend you set some breakpoints at key methods, and walk through the code, watching what it does and looking at variables.
EDIT: Note, that in setting up your rendercallback on iOS on your RemoteIO (which doubles as input & output units), getting the correct stream format on the correct scope & bus element numbers in your setproperty calls can be tricky. Refer to this from the Apple docs.
Can we change/increase the size of console output to view large size of data in console application at once?
There seem to be different ways to Rome:
This should be the recommended way I would think, cause the name says it all: GetConsoleWindow as is demonstrated here.
A quick hack might be the windows API function SendInput. If you simulate Alt+Enter, you could probably fullscreen the active window.
Here are some propositions using API calls from user32.dll
Check out the SetConsoleScreenBufferInfoEx API. It takes a CONSOLE_SCREEN_BUFFER_INFOEX as input and that has a dwSize member which contains the size of the console screen buffer, in character columns and rows.
MSDN for SetConsoleScreenBufferInfoEx Function: http://msdn.microsoft.com/en-us/library/ms686039(v=VS.85).aspx
I once used a small hack that is first setting the console's output buffer and then trying to find the console window and resize it. It worked well on XP, I never tested it on newer Windows versions.
HANDLE h = GetStdHandle(STD_OUTPUT_HANDLE);
SMALL_RECT sr;
sr.Top = 0;
sr.Left = 0;
sr.Bottom = 10;
sr.Right = 79;
SetConsoleWindowInfo(h, TRUE, &sr);
TCHAR title[512];
GetConsoleTitle(title, 512);
HWND hWnd = FindWindow(NULL, title);
if(hWnd != NULL) {
HWND hWndInsertAfter = NULL;
UINT nFlags = SWP_NOSIZE | SWP_NOZORDER;
#if 0 // Don't move?
nFlags |= SWP_NOMOVE;
#endif
SetWindowPos(hWnd, hWndInsertAfter , 40, 350, 0, 0, nFlags);
SetForegroundWindow(hWnd);
}
If you are using the command prompt window, right click it's label on the task bar and click the Properties option.
I'm using D3DXSaveSurfaceToFile to save windowed Direct3D 9 surfaces to PNG, BMP and JPG files. There are no errors returned from the D3DXSaveSurfaceToFile call and all files open fine in Windows Photo Viewer and Paint. But they will not open in a higher end image editing program such as Paint Shop Pro or Photoshop. The error messages from these programs basically say that the file is corrupted. If I open the files in Paint and then save them in the same file format with a different file name, then they'll open fine in the other programs.
This leads me to believe that D3DXSaveSurfaceToFile is writing out non-standard versions of these file formats. Is there some way I can get this function to write out files that can be opened in programs like Photoshop without the intermediate step of resaving the files in Paint? Or is there another function I should be using that does a better job of saving a Direct3D surfaces to an image?
Take a look at the file in a image meta viewer. What does it tell you?
Unfortunately D3DXSaveSurfaceToFile() isn't the most stable (it's also exceptionally slow). Personally I do something like the below code. It works even on Anti-aliased displays by doing an offscreen render to take the screenshot then getting it into a buffer. It also supports only the most common of the pixel formats. Sorry for any errors in it, pulled it out of an app I used to work on.
You can then, in your code and probably in another thread, then convert said 'bitmap' to anything you like using a variety of different code.
void HandleScreenshot(IDirect3DDevice9* device)
{
DWORD tcHandleScreenshot = GetTickCount();
LPDIRECT3DSURFACE9 pd3dsBack = NULL;
LPDIRECT3DSURFACE9 pd3dsTemp = NULL;
// Grab the back buffer into a surface
if ( SUCCEEDED ( device->GetBackBuffer(0, 0, D3DBACKBUFFER_TYPE_MONO, &pd3dsBack) ))
{
D3DSURFACE_DESC desc;
pd3dsBack->GetDesc(&desc);
LPDIRECT3DSURFACE9 pd3dsCopy = NULL;
if (desc.MultiSampleType != D3DMULTISAMPLE_NONE)
{
if (SUCCEEDED(device->CreateRenderTarget(desc.Width, desc.Height, desc.Format, D3DMULTISAMPLE_NONE, 0, FALSE, &pd3dsCopy, NULL)))
{
if (SUCCEEDED(device->StretchRect(pd3dsBack, NULL, pd3dsCopy, NULL, D3DTEXF_NONE)))
{
pd3dsBack->Release();
pd3dsBack = pd3dsCopy;
}
else
{
pd3dsCopy->Release();
}
}
}
if (SUCCEEDED(device->CreateOffscreenPlainSurface(desc.Width, desc.Height, desc.Format, D3DPOOL_SYSTEMMEM, &pd3dsTemp, NULL)))
{
DWORD tmpTimeGRTD = GetTickCount();
if (SUCCEEDED(device->GetRenderTargetData(pd3dsBack, pd3dsTemp)))
{
D3DLOCKED_RECT lockedSrcRect;
if (SUCCEEDED(pd3dsTemp->LockRect(&lockedSrcRect, NULL, D3DLOCK_READONLY | D3DLOCK_NOSYSLOCK | D3DLOCK_NO_DIRTY_UPDATE)))
{
int nSize = desc.Width * desc.Height * 3;
BYTE* pixels = new BYTE[nSize +1];
int iSrcPitch = lockedSrcRect.Pitch;
BYTE* pSrcRow = (BYTE*)lockedSrcRect.pBits;
LPBYTE lpDest = pixels;
LPDWORD lpSrc;
switch (desc.Format)
{
case D3DFMT_A8R8G8B8:
case D3DFMT_X8R8G8B8:
for (int y = desc.Height - 1; y >= 0; y--)
{
lpSrc = reinterpret_cast<LPDWORD>(lockedSrcRect.pBits) + y * desc.Width;
for (unsigned int x = 0; x < desc.Width; x++)
{
*reinterpret_cast<LPDWORD>(lpDest) = *lpSrc;
lpSrc++; // increment source pointer by 1 DWORD
lpDest += 3; // increment destination pointer by 3 bytes
}
}
break;
default:
ZeroMemory(pixels, nSize);
}
pd3dsTemp->UnlockRect();
BITMAPINFOHEADER header;
header.biWidth = desc.Width;
header.biHeight = desc.Height;
header.biSizeImage = nSize;
header.biSize = sizeof(BITMAPINFOHEADER);
header.biPlanes = 1;
header.biBitCount = 3 * 8; // RGB
header.biCompression = 0;
header.biXPelsPerMeter = 0;
header.biYPelsPerMeter = 0;
header.biClrUsed = 0;
header.biClrImportant = 0;
BITMAPFILEHEADER bfh = {0};
bfh.bfType = 0x4d42;
bfh.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);
bfh.bfSize = bfh.bfOffBits + nSize;
unsigned int rough_size = sizeof(BITMAPINFOHEADER) + sizeof(BITMAPFILEHEADER) + nSize;
unsigned char* p = new unsigned char[rough_size]
memcpy(p, &bfh, sizeof(BITMAPFILEHEADER));
p += sizeof(BITMAPFILEHEADER);
memcpy(p, &header, sizeof(BITMAPINFOHEADER));
p += sizeof(BITMAPINFOHEADER);
memcpy(p, pixels, nSize);
delete [] pixels;
/**********************************************/
// p now has a full BMP file, write it out here
}
}
pd3dsTemp->Release();
}
pd3dsBack->Release();
}
}
Turns out that it was a combination of a bug in my code and Paint being more forgiving than Photoshop when it comes to reading files. The bug in my code caused the files to be saved with the wrong extension (i.e. Image.bmp was actually saved using D3DXIFF_JPG). When opening a file that contained a JPG image, but had a BMP extension, Photoshop just failed the file. I guess Paint worked since it ignored the file extension and just decoded the file contents.
Looking at a file in an image meta viewer helped me to see the problem.