Eventually we'll probably move the version checking to higher level code and report the actual version of context that got created, but to avoid breakage we'll leave it like this for now.
Yamagi
A customer of mine had the strange problem, that SDL_SetRelativeMouseMode() was failing for him on Windows 7. Luckily he was willing to provide some debug informations. We could track this problem down to RegisterRawInputDevices() failing due to security software running on his system (Norton Internet Security to be precise, but there are reports of similar problems with other products. For example [1]). Working around this issue with SDL_WarpMouseInWindow() is easy, and while I don't think that SDL2 can provide an internal workaround it would be really nice and helpfull if this could be documentated somewhere.
1: http://forums.codeguru.com/showthread.php?498374-How-to-run-a-very-long-SQL-statement
Testing:
* Set the SDL_HINT_MOUSE_RELATIVE_MODE_WARP hint true, run testsprite2, press Ctrl-R to enter relative mode, alt tab away from the window, then click on the title bar of the window. Didn't get the mouse button release before, and we do now.
CR: Yahn + Alfred
The reasoning behind this change is that source2 in -tools mode has a single OpenGL context that is used with multiple different windows. Some of those windows are created outside the engine (i.e. with Qt) and therefore we need to use SDL_CreateWindowFrom() to get an SDL_Window for those. The requirement for sharing an OpenGL context across multiple different windows is that each window has the same pixel format. To facilitate this, I now set SDL_HINT_VIDEO_WINDOW_SHARE_PIXEL_FORMAT for the main window before calling SDL_CreateWindowFrom(). When I do this, SDL_CreateWindowFrom() will:
1. Set the pixel format of the returned window to the same pixel format as this SDL_Window passed in with the hint
2. The flag SDL_WINDOW_OPENGL will be set on the new window so it can be used for OpenGL rendering.
I only currently implemented this for Win32/WGL so implementing it for other platforms (i.e. X11) remains a TODO.
CR: SamL
Some pseudocode that shows how this is used in Source2:
HWND hExternalHwnd; // HWND that was established outside of SDL
// Create main window (happens inside platwindow.cpp)
SDL_Window *mainWindow = SDL_CreateWindow( , SDL_WINDOW_OPENGL .. );
// Create GL context, happens inside rendersystemgl
SDL_GLContext onlyContext = SDL_GL_CreateContext( mainWindow );
// Now I need to create another window from hEternalHwnd for my swap chain that will have the same pixel format as mainWindow, so set the hint
SDL_SetHint( SDL_HINT_VIDEO_WINDOW_SHARE_PIXEL_FORMAT, CFmtStr( %p, mainWindow) );
// Create the secondary window. This returned window will have SDL_WINDOW_OPENGL set and share a pixel format with mainWindow from the hint
SDL_Window *secondaryWindow = SDL_CreateWindowFrom( hExternalHwnd );
// To render to the main window:
SDL_GL_MakeCurrent( mainWindow, onlyContext );
// Do some rendering to main window
// To render to the secondary window:
SDL_GLMakeCurrent( secondaryWindow, onlyContext );
// Do some rendering to secondary window
If your application wants to have access to the full resolution even when the system has DPI scaling enabled, call SetProcessDPIAware() before calling SDL_Init()
e.g.
typedef BOOL (WINAPI *SetProcessDPIAware_t)(void);
HMODULE hMod = LoadLibrary("user32.dll");
if ( hMod ) {
SetProcessDPIAware_t pSetProcessDPIAware = GetProcAddress( hMod, "SetProcessDPIAware" );
if ( pSetProcessDPIAware ) {
pSetProcessDPIAware();
}
FreeLibrary( hMod );
}
To enable this, set the environment variable SDL_MOUSE_RELATIVE_MODE_WARP to "1"
When mouse relative mode is disabled, put the cursor back where the application expects it to be, instead of where it was when relative mode was enabled.
