mutter/examples/cogl-info.c
Robert Bragg df21e20f65 Adds CoglError api
Although we use GLib internally in Cogl we would rather not leak GLib
api through Cogl's own api, except through explicitly namespaced
cogl_glib_ / cogl_gtype_ feature apis.

One of the benefits we see to not leaking GLib through Cogl's public API
is that documentation for Cogl won't need to first introduce the Glib
API to newcomers, thus hopefully lowering the barrier to learning Cogl.

This patch provides a Cogl specific typedef for reporting runtime errors
which by no coincidence matches the typedef for GError exactly.  If Cogl
is built with --enable-glib (default) then developers can even safely
assume that a CoglError is a GError under the hood.

This patch also enforces a consistent policy for when NULL is passed as
an error argument and an error is thrown. In this case we log the error
and abort the application, instead of silently ignoring it. In common
cases where nothing has been implemented to handle a particular error
and/or where applications are just printing the error and aborting
themselves then this saves some typing. This also seems more consistent
with language based exceptions which usually cause a program to abort if
they are not explicitly caught (which passing a non-NULL error signifies
in this case)

Since this policy for NULL error pointers is stricter than the standard
GError convention, there is a clear note in the documentation to warn
developers that are used to using the GError api.

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

(cherry picked from commit b068d5ea09ab32c37e8c965fc8582c85d1b2db46)

Note: Since we can't change the Cogl 1.x api the patch was changed to
not rename _error_quark() functions to be _error_domain() functions and
although it's a bit ugly, instead of providing our own CoglError type
that's compatible with GError we simply #define CoglError to GError
unless Cogl is built with glib disabled.

Note: this patch does technically introduce an API break since it drops
the cogl_error_get_type() symbol generated by glib-mkenum (Since the
CoglError enum was replaced by a CoglSystemError enum) but for now we
are assuming that this will not affect anyone currently using the Cogl
API. If this does turn out to be a problem in practice then we would be
able to fix this my manually copying an implementation of
cogl_error_get_type() generated by glib-mkenum into a compatibility
source file and we could also define the original COGL_ERROR_ enums for
compatibility too.

Note: another minor concern with cherry-picking this patch to the 1.14
branch is that an api scanner would be lead to believe that some APIs
have changed, and for example the gobject-introspection parser which
understands the semantics of GError will not understand the semantics of
CoglError. We expect most people that have tried to use
gobject-introspection with Cogl already understand though that it is not
well suited to generating bindings of the Cogl api anyway and we aren't
aware or anyone depending on such bindings for apis involving GErrors.
(GnomeShell only makes very-very minimal use of Cogl via the gjs
bindings for the cogl_rectangle and cogl_color apis.)

The main reason we have cherry-picked this patch to the 1.14 branch
even given the above concerns is that without it it would become very
awkward for us to cherry-pick other beneficial patches from master.
2013-01-22 17:47:39 +00:00

194 lines
5.2 KiB
C

#include <cogl/cogl.h>
#include <glib.h>
#include <stdio.h>
struct {
CoglFeatureID feature;
const char *short_description;
const char *long_description;
} features[] =
{
{
COGL_FEATURE_ID_TEXTURE_NPOT_BASIC,
"Non power of two textures (basic)",
"The hardware supports non power of two textures, but you also "
"need to check the COGL_FEATURE_ID_TEXTURE_NPOT_MIPMAP and "
"COGL_FEATURE_ID_TEXTURE_NPOT_REPEAT features to know if the "
"hardware supports npot texture mipmaps or repeat modes other "
"than COGL_RENDERER_PIPELINE_WRAP_MODE_CLAMP_TO_EDGE respectively."
},
{
COGL_FEATURE_ID_TEXTURE_NPOT_MIPMAP,
"Non power of two textures (+ mipmap)",
"Mipmapping is supported in conjuntion with non power of two "
"textures."
},
{
COGL_FEATURE_ID_TEXTURE_NPOT_REPEAT,
"Non power of two textures (+ repeat modes)",
"Repeat modes other than "
"COGL_RENDERER_PIPELINE_WRAP_MODE_CLAMP_TO_EDGE are supported by "
"the hardware in conjunction with non power of two textures."
},
{
COGL_FEATURE_ID_TEXTURE_NPOT,
"Non power of two textures (fully featured)",
"Non power of two textures are supported by the hardware. This "
"is a equivalent to the COGL_FEATURE_ID_TEXTURE_NPOT_BASIC, "
"COGL_FEATURE_ID_TEXTURE_NPOT_MIPMAP and "
"COGL_FEATURE_ID_TEXTURE_NPOT_REPEAT features combined."
},
{
COGL_FEATURE_ID_TEXTURE_RECTANGLE,
"Unnormalized coordinate, rectangle textures",
"Support for rectangular textures with non-normalized texture "
"coordinates."
},
{
COGL_FEATURE_ID_TEXTURE_3D,
"3D texture support",
"3D texture support"
},
{
COGL_FEATURE_ID_OFFSCREEN,
"Offscreen rendering support",
"Offscreen rendering support"
},
{
COGL_FEATURE_ID_OFFSCREEN_MULTISAMPLE,
"Offscreen rendering with multisampling support",
"Offscreen rendering with multisampling support"
},
{
COGL_FEATURE_ID_ONSCREEN_MULTIPLE,
"Multiple onscreen framebuffers supported",
"Multiple onscreen framebuffers supported"
},
{
COGL_FEATURE_ID_GLSL,
"GLSL support",
"GLSL support"
},
{
COGL_FEATURE_ID_ARBFP,
"ARBFP support",
"ARBFP support"
},
{
COGL_FEATURE_ID_UNSIGNED_INT_INDICES,
"Unsigned integer indices",
"COGL_RENDERER_INDICES_TYPE_UNSIGNED_INT is supported in cogl_indices_new()."
},
{
COGL_FEATURE_ID_DEPTH_RANGE,
"cogl_pipeline_set_depth_range() support",
"cogl_pipeline_set_depth_range() support",
},
{
COGL_FEATURE_ID_POINT_SPRITE,
"Point sprite coordinates",
"cogl_pipeline_set_layer_point_sprite_coords_enabled() is supported"
},
{
COGL_FEATURE_ID_MAP_BUFFER_FOR_READ,
"Mapping buffers for reading",
"Mapping buffers for reading"
},
{
COGL_FEATURE_ID_MAP_BUFFER_FOR_WRITE,
"Mapping buffers for writing",
"Mapping buffers for writing"
},
{
COGL_FEATURE_ID_MIRRORED_REPEAT,
"Mirrored repeat wrap modes",
"Mirrored repeat wrap modes"
},
{
COGL_FEATURE_ID_GLES2_CONTEXT,
"GLES2 API integration supported",
"Support for creating a GLES2 context for using the GLES2 API in a "
"way that's integrated with Cogl."
},
{
COGL_FEATURE_ID_DEPTH_TEXTURE,
"Depth Textures",
"CoglFramebuffers can be configured to render their depth buffer into "
"a texture"
}
};
static const char *
get_winsys_name_for_id (CoglWinsysID winsys_id)
{
switch (winsys_id)
{
case COGL_WINSYS_ID_ANY:
g_return_val_if_reached ("ERROR");
case COGL_WINSYS_ID_STUB:
return "Stub";
case COGL_WINSYS_ID_GLX:
return "GLX";
case COGL_WINSYS_ID_EGL_XLIB:
return "EGL + Xlib platform";
case COGL_WINSYS_ID_EGL_NULL:
return "EGL + NULL window system platform";
case COGL_WINSYS_ID_EGL_GDL:
return "EGL + GDL platform";
case COGL_WINSYS_ID_EGL_WAYLAND:
return "EGL + Wayland platform";
case COGL_WINSYS_ID_EGL_KMS:
return "EGL + KMS platform";
case COGL_WINSYS_ID_EGL_ANDROID:
return "EGL + Android platform";
case COGL_WINSYS_ID_WGL:
return "EGL + Windows WGL platform";
case COGL_WINSYS_ID_SDL:
return "EGL + SDL platform";
}
g_return_val_if_reached ("Unknown");
}
static void
feature_cb (CoglFeatureID feature, void *user_data)
{
int i;
for (i = 0; i < sizeof(features) / sizeof(features[0]); i++)
{
if (features[i].feature == feature)
{
printf (" » %s\n", features[i].short_description);
return;
}
}
printf (" » Unknown feature %d\n", feature);
}
int
main (int argc, char **argv)
{
CoglRenderer *renderer;
CoglDisplay *display;
CoglContext *ctx;
CoglError *error = NULL;
CoglWinsysID winsys_id;
const char *winsys_name;
ctx = cogl_context_new (NULL, &error);
if (!ctx) {
fprintf (stderr, "Failed to create context: %s\n", error->message);
return 1;
}
display = cogl_context_get_display (ctx);
renderer = cogl_display_get_renderer (display);
winsys_id = cogl_renderer_get_winsys_id (renderer);
winsys_name = get_winsys_name_for_id (winsys_id);
g_print ("Renderer: %s\n\n", winsys_name);
g_print ("Features:\n");
cogl_foreach_feature (ctx, feature_cb, NULL);
return 0;
}