From Scott Percival
Okay, I think I have something for this. Tested it on GL and GLES
machines, it seems to work okay.
- Add a new SDL GL attribute SDL_GL_CONTEXT_EGL:
- Only useful for the X11 video driver at the moment
- Set to 1 for an EGL context, 0 to use the default for the video driver
- Default is 0, unless library is built for EGL only
- Should be set after SDL init, but before window/context
creation (i.e. same place you'd specify attributes for major/minor GL
version)
- After a lot of agony pondering the least-terrible way to go about
it, made it so that X11_GL_LoadLibrary and X11_GLES_LoadLibrary check
SDL_GL_CONTEXT_EGL. If no GL context exists yet, and the attribute
choice doesn't match with the checking function, then it changes all
the function pointers in the video driver and passes control on to the
new LoadLibrary method.
- Likewise, make X11_CreateWindow check this attribute before firing
off a call to X11_GL_GetVisual/X11_GLES_GetVisual
- Added a sanity check to the start of X11_GL_LoadLibrary
- Tidied up SDL_x11opengles.h
- Moved ownership of the gles_data structure over to
X11_GLES_LoadLibrary/UnloadLibrary
- Should incorporate the 3 fixes posted by Andre Heider
This is obviously quite a bit to take in, but is (at least) a proof of
concept for the approach I think EGL/GLX mingling should take. Any
comments/criticism is much appreciated.
We cannot use SDL_VIDEO_GL_DRIVER for both EGL and GLES1/2, so rename
the envvar for EGL to SDL_VIDEO_EGL_DRIVER and keep SDL_VIDEO_GL_DRIVER
for GLES1/2.
Contributed by Andre Heider
Scott Percival 2012-01-08 04:21:22 PST
I tested the new build on my two ARM machines, and fixed a few bugs:
- if SDL_VIDEO_DRIVER_UIKIT, SDL_VIDEO_DRIVER_ANDROID or
SDL_VIDEO_DRIVER_PANDORA are specified, function pointers are grabbed from the
compile-linked library instead of through SDL_GL_GetProcAddress. (not sure if
this is the best way to go about it)
- removing "/usr/lib/" from all the library names (hey, with multiarch you
can't be too sure anymore)
- added glFinish to glesfuncs.h
- changed the eglGetProcAddress arg type to "const char *" as per the EGL spec
- filled in the stubs for X11_GLES_SetSwapInterval and X11_GLES_GetSwapInterval
Scott Percival 2011-07-03 06:41:51 PDT
This submission is aimed at making life easier for OpenGL ES capable devices
running a X11 stack (e.g. Maemo, Meego, TrimSlice, other ARM SoC boards not
running Android). SDL's Pandora support already has the neccesary GLES-to-X11
glue code, however it's all ghetto'd off in Makefile.pandora and not very
flexible.
The patch:
- adds an awesome --enable-video-opengles option to configure
- re-modifies the opengles and opengles2 SDL_renderers to use function pointers
- no idea why this was removed?
- for SDL_Renderers, links in libGLESv1_CM, libGLES_CM (for PowerVR fans) or
libGLESv2 at runtime
- links in libEGL.so at runtime - the old code made an assumption that
eglFunctions could be pulled from the active GLES library, PowerVR for one
doesn't let you do that with their libGLESv2
- allows you to pick which of GLES v1 or v2 to load via
SDL_GL_CONTEXT_MAJOR_VERSION
So far I've tested this on a Nokia N900 (OMAP 3430/SGX 530 running Maemo 5) and
a Toshiba AC100 (Tegra 2 running Ubuntu 10.10). I haven't tested it on... well,
everything that isn't those two, such as a Pandora, iOS or Android device. The
Pandora specific code should be kept intact (fingers crossed), and nothing
painfully drastic has been added to the SDL_renderers. The library loading
sequence in SDL_x11opengles has been updated to accomodate both NVIDIA's
propensity to let developers get away with murder and PowerVR's alternative of
punishing every missed step.
The test apps work okay with GLES or GLES2 as the renderer. For some reason
alpha blending doesn't seem to work on the Tegra 2; last week NVIDIA pushed out
a new set of X11 GLES drivers, so I'll try and investigate once I upgrade
those. Also, this patch adds things to configure.in, include/SDL_config.h.in
and test/configure.in. I didn't know what the policy was re. committing
generated spaghetti from autotools, so ./autogen.sh has to be run again. Sorry.
I think that's about everything, let me know if there's anything I've
overlooked.
I fixed a bug in the "SDL_DestroyRenderer()" function in the pandora x11 renderer (in fact the bug was in the "X11_GLES_MakeCurrent()" function) that was causing a crash when exiting SDL.
There was a problem while terminating the x11 egl window, that was preventing to quit/close SDL/SDL-window then reload SDL/SDL-window inside the same application.
--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%403715
