Commit Graph

16 Commits

Author SHA1 Message Date
Neil Roberts
df77e8565e Don't use eglGetProcAddress to retrieve core functions
According to the EGL spec, eglGetProcAddress should only be used to
retrieve extension functions. It also says that returning non-NULL
does not mean the extension is available so you could interpret this
as saying that the function is allowed to return garbage for core
functions. This seems to happen at least for the Android
implementation of EGL.

To workaround this the winsys's are now passed down a flag to say
whether the function is from the core API. This information is already
in the gl-prototypes headers as the minimum core GL version and as a
pair of flags to specify whether it is available in core GLES1 and
GLES2. If the function is in core the EGL winsys will now avoid using
eglGetProcAddress and always fallback to querying the library directly
with the GModule API.

The GLX winsys is left alone because glXGetProcAddress apparently
supports querying core API and extension functions.

The WGL winsys could ideally be changed because wglGetProcAddress
should also only be used for extension functions but the situation is
slightly different because WGL considers anything from GL > 1.1 to be
an extension so it would need a bit more information to determine
whether to query the function directly from the library.

The SDL winsys is also left alone because it's not as easy to portably
determine which GL library SDL has chosen to load in order to resolve
the symbols directly.

Reviewed-by: Robert Bragg <robert@linux.intel.com>

(cherry picked from commit 72089730ad06ccdd38a344279a893965ae68cec1)

  Since we aren't able to break API on the 1.12 branch
  cogl_get_proc_address is still supported but isn't easily able to
  determine whether the given name corresponds to a core symbol or
  not.  For now we just assume the symbol being queried isn't part
  of the core GL api and update the documentation accordingly.
2012-08-06 14:27:45 +01:00
Robert Bragg
54735dec84 Switch use of primitive glib types to c99 equivalents
The coding style has for a long time said to avoid using redundant glib
data types such as gint or gchar etc because we feel that they make the
code look unnecessarily foreign to developers coming from outside of the
Gnome developer community.

Note: When we tried to find the historical rationale for the types we
just found that they were apparently only added for consistent syntax
highlighting which didn't seem that compelling.

Up until now we have been continuing to use some of the platform
specific type such as gint{8,16,32,64} and gsize but this patch switches
us over to using the standard c99 equivalents instead so we can further
ensure that our code looks familiar to the widest range of C developers
who might potentially contribute to Cogl.

So instead of using the gint{8,16,32,64} and guint{8,16,32,64} types this
switches all Cogl code to instead use the int{8,16,32,64}_t and
uint{8,16,32,64}_t c99 types instead.

Instead of gsize we now use size_t

For now we are not going to use the c99 _Bool type and instead we have
introduced a new CoglBool type to use instead of gboolean.

Reviewed-by: Neil Roberts <neil@linux.intel.com>

(cherry picked from commit 5967dad2400d32ca6319cef6cb572e81bf2c15f0)
2012-08-06 14:27:39 +01:00
Robert Bragg
9a1f1df83f Rework sdl integration api
This re-works the SDL integration api to simplify the integration for
application developers and also allow Cogl to know when the application
is about to go idle waiting for events so it can perform idle
book-keeping work.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2012-04-12 12:31:46 +01:00
Robert Bragg
be237cc2b7 renderer: Adds getters/setters for driver preference
This adds api for explicitly choosing what underlying driver cogl should
use internally for rendering as well as api for querying back what
driver is actually in use.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2012-02-24 14:42:31 +00:00
Robert Bragg
a8513c1d77 renderer: Adds api to add/remove selection constraints
This allows applications to specify certain constraints that feed into
the process of selecting a CoglRenderer backend. For example
applications might depend on x11 for handling input and so they require
a backend that's also based on x11.
2012-01-16 18:27:19 +00:00
Neil Roberts
181b875a3d xlib: Internally retrieve XEvents
Previously we relied on the application to send all X events through
Cogl using cogl_xlib_renderer_handle_event. This breaks the
abstraction that an application shouldn't need to know what winsys
Cogl is using. Now that we have main loop integreation in Cogl, the
Xlib-based winsys's can report that Cogl needs to block on the file
descriptor of the X connection and it can manually handle the
events.

The event retrieval can be disabled by an application if it calls the
new cogl_xlib_renderer_set_event_retrieval_enabled() function. The
event retrieval will also automatically be disabled if the application
sets a foreign display.

Reviewed-by: Robert Bragg <robert@linux.intel.com>
2012-01-05 13:40:24 +00:00
Robert Bragg
14ddbd980b wayland: Add api to set a foreign shell
Since the wayland protocol doesn't currently provide a way to
retrospectively query the interfaces that get notified when a client
first connects then when using a foreign display with Cogl then we also
need api for telling cogl what compositor and shell objects to use. We
already had api for setting a foreign compositor so this patch just adds
api for setting a foreign shell.

This patch also adds documentation for all the wayland specific apis.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-12-07 15:53:05 +00:00
Philip Withnall
d51c3c423e Fix testing of undefined macro constants to check for definedness instead
Reviewed-By: Robert Bragg <robert@linux.intel.com>
2011-07-27 18:46:36 +01:00
Neil Roberts
d259a87602 Don't use the 'NULL' GModule to resolve GL symbols
Previously, _cogl_get_proc_address had a fallback to resolve the
symbol using g_module_open(NULL) to get the symbol from anywhere in
the address space. The EGL backend ends up using this on some drivers
because eglGetProcAddress isn't meant to return a pointer for core
functions. This causes problems if something in the process is linking
against a different GL library, for example Cairo may be linking
against libGL itself. In this case it may end up resolving symbols
from the GL library even if GLES is being used.

This patch removes the fallback. The EGL version now has its own
fallback instead which passes the existing libgl_module from the
renderer to g_module_symbol so that it should only get symbols from
that library or its dependency chain. The GLX and WGL winsys only call
glXGetProcAddress and wglGetProcAddress. The stub winsys does however
continue using the global symbol lookup.

The internal _cogl_get_proc_address function has been renamed to
_cogl_renderer_get_proc_address because it needs a connected renderer
to work so it could be considered to be a renderer method. The pointer
to the renderer is passed down to the winsys backends so that it can
use the data attached to the renderer to get the module pointers.

https://bugzilla.gnome.org/show_bug.cgi?id=655412

Reviewed-by: Robert Bragg <robert@linux.intel.com>
2011-07-27 16:10:02 +01:00
Neil Roberts
b2e735ff7f Dynamically load the GL or GLES library
The GL or GLES library is now dynamically loaded by the CoglRenderer
so that it can choose between GL, GLES1 and GLES2 at runtime. The
library is loaded by the renderer because it needs to be done before
calling eglInitialize. There is a new environment variable called
COGL_DRIVER to choose between gl, gles1 or gles2.

The #ifdefs for HAVE_COGL_GL, HAVE_COGL_GLES and HAVE_COGL_GLES2 have
been changed so that they don't assume the ifdefs are mutually
exclusive. They haven't been removed entirely so that it's possible to
compile the GLES backends without the the enums from the GL headers.

When using GLX the winsys additionally dynamically loads libGL because
that also contains the GLX API. It can't be linked in directly because
that would probably conflict with the GLES API if the EGL is
selected. When compiling with EGL support the library links directly
to libEGL because it doesn't contain any GL API so it shouldn't have
any conflicts.

When building for WGL or OSX Cogl still directly links against the GL
API so there is a #define in config.h so that Cogl won't try to dlopen
the library.

Cogl-pango previously had a #ifdef to detect when the GL backend is
used so that it can sneakily pass GL_QUADS to
cogl_vertex_buffer_draw. This is now changed so that it queries the
CoglContext for the backend. However to get this to work Cogl now
needs to export the _cogl_context_get_default symbol and cogl-pango
needs some extra -I flags to so that it can include
cogl-context-private.h
2011-07-11 12:57:38 +01:00
Robert Bragg
3b64a439f0 replace public native_event APIs with typesafe APIs
This adds Xlib and Win32 typesafe replacements for
cogl_renderer_handle_native_event, cogl_renderer_add_native_filter,
cogl_renderer_remove_native_filter. The old functions are kept as an
implementation detail so we can share code.

Signed-off-by: Neil Roberts <neil@linux.intel.com>
2011-06-30 14:33:13 +01:00
Robert Bragg
b3a105c576 renderer: Expose winsys ID setter/getters
This adds API to let you override the choice of Cogl's winsys backend.
Previously it was only possible to override the winsys using the
COGL_RENDERER environment variable, but it's useful for something like
Clutter to be able to control the winsys via API without needing
environment variable tricks. This also adds API to query back the
winsys chosen by Cogl, in case you don't set an explicit override.

Signed-off-by: Neil Roberts <neil@linux.intel.com>
2011-06-30 14:33:11 +01:00
Robert Bragg
e8b83f2880 Adds wayland support to the cogl EGL winsys
Wayland now supports integration via standard eglSurfaces which makes it
possible to share more code with other EGL platforms. (though at some
point cogl-winsys-egl.c really needs to gain a more formal
CoglEGLPlatform abstraction so we can rein back on the amount of #ifdefs
we have.)
2011-05-10 16:36:40 +01:00
Robert Bragg
dc7383b714 Add a vtable of indirection to the winsys code
So that we can dynamically select what winsys backend to use at runtime
we need to have some indirection to how code accesses the winsys instead
of simply calling _cogl_winsys* functions that would collide if we
wanted to compile more than one backend into Cogl.
2011-05-05 14:46:01 +01:00
Neil Roberts
f6ae9decaa cogl-renderer: Move the XEvent filters to be generic for all renderers
Instead of having cogl_renderer_xlib_add_filter and friends there is
now cogl_renderer_add_native_filter which can be used regardless of
the backend. The callback function for the filter now just takes a
void pointer instead of an XEvent pointer which should be interpreted
differently depending on the backend. For example, on Xlib it would
still be an XEvent but on Windows it could be a MSG. This simplifies
the code somewhat because the _cogl_xlib_add_filter no longer needs to
have its own filter list when a stub renderer is used because there is
always a renderer available.

cogl_renderer_xlib_handle_event has also been renamed to
cogl_renderer_handle_native_event. This just forwards the event on to
all of the listeners. The backend renderer is expected to register its
own event filter if it wants to process the events in some way.
2011-04-20 18:17:06 +01:00
Robert Bragg
bcd97f35ea Adds renderer,display,onscreen-template and swap-chain stubs
As part of the process of splitting Cogl out as a standalone graphics
API we need to introduce some API concepts that will allow us to
initialize a new CoglContext when Clutter isn't there to handle that for
us...

The new objects roughly in the order that they are (optionally) involved
in constructing a context are: CoglRenderer, CoglOnscreenTemplate,
CoglSwapChain and CoglDisplay.

Conceptually a CoglRenderer represents a means for rendering.  Cogl
supports rendering via OpenGL or OpenGL ES 1/2.0 and those APIs are
accessed through a number of different windowing APIs such as GLX, EGL,
SDL or WGL and more. Potentially in the future Cogl could render using
D3D or even by using libdrm and directly banging the hardware. All these
choices are wrapped up in the configuration of a CoglRenderer.

Conceptually a CoglDisplay represents a display pipeline for a renderer.
Although Cogl doesn't aim to provide a detailed abstraction of display
hardware, on some platforms we can give control over multiple display
planes (On TV platforms for instance video content may be on one plane
and 3D would be on another so a CoglDisplay lets you select the plane
up-front.)

Another aspect of CoglDisplay is that it lets us negotiate a display
pipeline that best supports the type of CoglOnscreen framebuffers we are
planning to create. For instance if you want transparent CoglOnscreen
framebuffers then we have to be sure the display pipeline wont discard
the alpha component of your framebuffers. Or if you want to use
double/tripple buffering that requires support from the display
pipeline.

CoglOnscreenTemplate and CoglSwapChain are how we describe our default
CoglOnscreen framebuffer configuration which can affect the
configuration of the display pipeline.

The default/simple way we expect most CoglContexts to be constructed
will be via something like:

 if (!cogl_context_new (NULL, &error))
   g_error ("Failed to construct a CoglContext: %s", error->message);

Where that NULL is for an optional "display" parameter and NULL says to
Cogl "please just try to do something sensible".

If you want some more control though you can manually construct a
CoglDisplay something like:

 display = cogl_display_new (NULL, NULL);
 cogl_gdl_display_set_plane (display, plane);
 if (!cogl_display_setup (display, &error))
   g_error ("Failed to setup a CoglDisplay: %s", error->message);

And in a similar fashion to cogl_context_new() you can optionally pass
a NULL "renderer" and/or a NULL "onscreen template" so Cogl will try to
just do something sensible.

If you need to change the CoglOnscreen defaults you can provide a
template something like:
  chain = cogl_swap_chain_new ();
  cogl_swap_chain_set_has_alpha (chain, TRUE);
  cogl_swap_chain_set_length (chain, 3);

  onscreen_template = cogl_onscreen_template_new (chain);
  cogl_onscreen_template_set_pixel_format (onscreen_template,
                                           COGL_PIXEL_FORMAT_RGB565);

  display = cogl_display_new (NULL, onscreen_template);
  if (!cogl_display_setup (display, &error))
    g_error ("Failed to setup a CoglDisplay: %s", error->message);
2011-04-11 17:54:35 +01:00