mirror of https://gitlab.freedesktop.org/mesa/mesa
551d459af4
This extension provides a way for an application to render to multiple surfaces with different buffer formats without having to use multiple contexts. An EGLContext can be created without an EGLConfig by passing EGL_NO_CONFIG_MESA. In that case there are no restrictions on the surfaces that can be used with the context apart from that they must be using the same EGLDisplay. _mesa_initialze_context can now take a NULL gl_config which will mark the context as ‘configless’. It will memset the visual to zero in that case. Previously the i965 and i915 drivers were explicitly creating a zeroed visual whenever 0 is passed for the EGLConfig. Mesa needs to be aware that the context is configless because it affects the initial value to use for glDrawBuffer. The first time the context is bound it will set the initial value for configless contexts depending on whether the framebuffer used is double-buffered. Reviewed-by: Kristian Høgsberg <krh@bitplanet.net> |
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| .. | ||
| Android.mk | ||
| Makefile.am | ||
| README.txt | ||
| SConscript | ||
| egl.def | ||
| egl.pc.in | ||
| eglapi.c | ||
| eglapi.h | ||
| eglarray.c | ||
| eglarray.h | ||
| eglcompiler.h | ||
| eglconfig.c | ||
| eglconfig.h | ||
| eglcontext.c | ||
| eglcontext.h | ||
| eglcurrent.c | ||
| eglcurrent.h | ||
| egldefines.h | ||
| egldisplay.c | ||
| egldisplay.h | ||
| egldriver.c | ||
| egldriver.h | ||
| eglfallbacks.c | ||
| eglglobals.c | ||
| eglglobals.h | ||
| eglimage.c | ||
| eglimage.h | ||
| egllog.c | ||
| egllog.h | ||
| eglmisc.c | ||
| eglmisc.h | ||
| eglmode.c | ||
| eglmode.h | ||
| eglmutex.h | ||
| eglscreen.c | ||
| eglscreen.h | ||
| eglstring.c | ||
| eglstring.h | ||
| eglsurface.c | ||
| eglsurface.h | ||
| eglsync.c | ||
| eglsync.h | ||
| egltypedefs.h | ||
README.txt
Notes about the EGL library: The EGL code here basically consists of two things: 1. An EGL API dispatcher. This directly routes all the eglFooBar() API calls into driver-specific functions. 2. Fallbacks for EGL API functions. A driver _could_ implement all the EGL API calls from scratch. But in many cases, the fallbacks provided in libEGL (such as eglChooseConfig()) will do the job. Bootstrapping: When the apps calls eglOpenDisplay() a device driver is selected and loaded (look for dlsym() or LoadLibrary() in egldriver.c). The driver's _eglMain() function is then called. This driver function allocates, initializes and returns a new _EGLDriver object (usually a subclass of that type). As part of initialization, the dispatch table in _EGLDriver->API must be populated with all the EGL entrypoints. Typically, _eglInitDriverFallbacks() can be used to plug in default/fallback functions. Some functions like driver->API.Initialize and driver->API.Terminate _must_ be implemented with driver-specific code (no default/fallback function is possible). A bit later, the app will call eglInitialize(). This will get routed to the driver->API.Initialize() function. Any additional driver initialization that wasn't done in _eglMain() should be done at this point. Typically, this will involve setting up visual configs, etc. Special Functions: Certain EGL functions _must_ be implemented by the driver. This includes: eglCreateContext eglCreateWindowSurface eglCreatePixmapSurface eglCreatePBufferSurface eglMakeCurrent eglSwapBuffers Most of the EGLConfig-related functions can be implemented with the defaults/fallbacks. Same thing for the eglGet/Query functions. Teardown: When eglTerminate() is called, the driver->API.Terminate() function is called. The driver should clean up after itself. eglTerminate() will then close/unload the driver (shared library). Subclassing: The internal libEGL data structures such as _EGLDisplay, _EGLContext, _EGLSurface, etc should be considered base classes from which drivers will derive subclasses.