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
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.
Based on the original port to Wayland by: Joel Teichroeb, Benjamin Franzke, Scott Moreau, et al.
Additional changes in this commit, done by me:
* Wayland uses the common EGL framework
* EGL can now create a desktop OpenGL context
* testgl2 loads GL functions dynamically, no need to link to libGL anymore
* Assorted fixes to the Wayland backend
Tested on the Weston Compositor (v1.0.5) that ships with Ubuntu 13.10,
running Weston under X. Tests ran: testrendercopyex (all backends), testgl2, testgles2,testintersections
SDL_GameControllerAddMappingsFromFile is now a convenience macro.
controllermap can now skip bindings by pressing space or clicking/touching the
screen.
Sam Lantinga
Gabriel Jacobo
Ryan C. Gordon