gstreamer/gst-libs/gst/gl/gstglfeature.c
2017-12-09 19:31:27 +00:00

200 lines
6.3 KiB
C

/*
* GStreamer
* Copyright (C) 2012 Matthew Waters <ystreet00@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include "gstglfeature.h"
#include "gstglapi.h"
gboolean
gst_gl_check_extension (const char *name, const gchar * ext)
{
char *end;
int name_len, n;
if (name == NULL || ext == NULL)
return FALSE;
end = (char *) (ext + strlen (ext));
name_len = strlen (name);
while (ext < end) {
n = strcspn (ext, " ");
if ((name_len == n) && (!strncmp (name, ext, n)))
return TRUE;
ext += (n + 1);
}
return FALSE;
}
/* Define a set of arrays containing the functions required from GL
for each feature */
#define GST_GL_EXT_BEGIN(name, \
min_gl_major, min_gl_minor, \
gles_availability, \
namespaces, extension_names) \
static const GstGLFeatureFunction gst_gl_ext_ ## name ## _funcs[] = {
#define GST_GL_EXT_FUNCTION(ret, name, args) \
{ G_STRINGIFY (name), G_STRUCT_OFFSET (GstGLFuncs, name) },
#define GST_GL_EXT_END() \
{ NULL, 0 }, \
};
#include "glprototypes/all_functions.h"
#undef GST_GL_EXT_BEGIN
#define GST_GL_EXT_BEGIN(name, \
min_gl_major, min_gl_minor, \
gles_availability, \
namespaces, extension_names) \
{ min_gl_major, min_gl_minor, gles_availability, namespaces, \
extension_names, \
gst_gl_ext_ ## name ## _funcs },
#undef GST_GL_EXT_FUNCTION
#define GST_GL_EXT_FUNCTION(ret, name, args)
#undef GST_GL_EXT_END
#define GST_GL_EXT_END()
static const GstGLFeatureData gst_gl_feature_ext_functions_data[] = {
#include "glprototypes/all_functions.h"
};
#undef GST_GL_EXT_BEGIN
#undef GST_GL_EXT_FUNCTION
#undef GST_GL_EXT_END
gboolean
_gst_gl_feature_check (GstGLDisplay * display,
const char *driver_prefix,
const GstGLFeatureData * data,
int gl_major, int gl_minor, const char *extensions_string)
{
const char *suffix = NULL;
int func_num;
GstGLFuncs *gst_gl = display->gl_vtable;
/* First check whether the functions should be directly provided by
GL */
if (((display->gl_api & GST_GL_API_OPENGL) &&
GST_GL_CHECK_GL_VERSION (gl_major, gl_minor,
data->min_gl_major, data->min_gl_minor)) ||
((display->gl_api & GST_GL_API_GLES2) &&
(data->gl_availability & GST_GL_API_GLES2))) {
suffix = "";
} else {
/* Otherwise try all of the extensions */
const char *namespace, *namespace_suffix;
unsigned int namespace_len;
for (namespace = data->namespaces; *namespace;
namespace += strlen (namespace) + 1) {
const char *extension;
GString *full_extension_name = g_string_new ("");
/* If the namespace part contains a ':' then the suffix for
the function names is different from the name space */
if ((namespace_suffix = strchr (namespace, ':'))) {
namespace_len = namespace_suffix - namespace;
namespace_suffix++;
} else {
namespace_len = strlen (namespace);
namespace_suffix = namespace;
}
for (extension = data->extension_names; *extension;
extension += strlen (extension) + 1) {
g_string_assign (full_extension_name, driver_prefix);
g_string_append_c (full_extension_name, '_');
g_string_append_len (full_extension_name, namespace, namespace_len);
g_string_append_c (full_extension_name, '_');
g_string_append (full_extension_name, extension);
if (gst_gl_check_extension (full_extension_name->str,
extensions_string))
break;
}
g_string_free (full_extension_name, TRUE);
/* If we found an extension with this namespace then use it
as the suffix */
if (*extension) {
suffix = namespace_suffix;
break;
}
}
}
/* If we couldn't find anything that provides the functions then
give up */
if (suffix == NULL)
goto error;
/* Try to get all of the entry points */
for (func_num = 0; data->functions[func_num].name; func_num++) {
void *func;
char *full_function_name;
full_function_name = g_strconcat ("gl", data->functions[func_num].name,
suffix, NULL);
func =
gst_gl_window_get_proc_address (display->gl_window, full_function_name);
g_free (full_function_name);
if (func == NULL)
goto error;
/* Set the function pointer in the context */
*(void **) ((guint8 *) gst_gl +
data->functions[func_num].pointer_offset) = func;
}
return TRUE;
/* If the extension isn't found or one of the functions wasn't found
* then set all of the functions pointers to NULL so we can safely
* do feature testing by just looking at the function pointers */
error:
for (func_num = 0; data->functions[func_num].name; func_num++) {
*(void **) ((guint8 *) gst_gl +
data->functions[func_num].pointer_offset) = NULL;
}
return FALSE;
}
void
_gst_gl_feature_check_ext_functions (GstGLDisplay * display,
int gl_major, int gl_minor, const char *gl_extensions)
{
int i;
for (i = 0; i < G_N_ELEMENTS (gst_gl_feature_ext_functions_data); i++) {
_gst_gl_feature_check (display, "GL",
gst_gl_feature_ext_functions_data + i, gl_major, gl_minor,
gl_extensions);
}
}