mutter/clutter/clutter-util.c
Emmanuele Bassi 2b81d90dd7 Eliminate G_CONST_RETURN
The G_CONST_RETURN define in GLib is, and has always been, a bit fuzzy.

We always used it to conform to the platform, at least for public-facing
API.

At first I assumed it has something to do with brain-damaged compilers
or with weird platforms where const was not really supported; sadly,
it's something much, much worse: it's a define that can be toggled at
compile-time to remove const from the signature of public API. This is a
truly terrifying feature that I assume was added in the past century,
and whose inception clearly had something to do with massive doses of
absynthe and opium — because any other explanation would make the
existence of such a feature even worse than assuming drugs had anything
to do with it.

Anyway, and pleasing the gods, this dubious feature is being
removed/deprecated in GLib; see bug:

  https://bugzilla.gnome.org/show_bug.cgi?id=644611

Before deprecation, though, we should just remove its usage from the
whole API. We should especially remove its usage from Cally's internals,
since there it never made sense in the first place.
2011-06-07 16:06:24 +01:00

151 lines
4.4 KiB
C

/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Authored By Matthew Allum <mallum@openedhand.com>
*
* Copyright (C) 2006 OpenedHand
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*
*
*/
/**
* SECTION:clutter-util
* @short_description: Utility functions
*
* Various miscellaneous utilility functions.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <glib/gi18n-lib.h>
#include "clutter-util.h"
#include "clutter-main.h"
/**
* clutter_util_next_p2:
* @a: Value to get the next power
*
* Calculates the nearest power of two, greater than or equal to @a.
*
* Return value: The nearest power of two, greater or equal to @a.
*
* Deprecated: 1.2
*/
gint
clutter_util_next_p2 (gint a)
{
int rval = 1;
while (rval < a)
rval <<= 1;
return rval;
}
/*< private >
* _clutter_gettext:
* @str: a string to localize
*
* Retrieves the localized version of @str, using the Clutter domain
*
* Return value: the translated string
*/
const gchar *
_clutter_gettext (const gchar *str)
{
return g_dgettext (GETTEXT_PACKAGE, str);
}
/* Help macros to scale from OpenGL <-1,1> coordinates system to
* window coordinates ranging [0,window-size]
*/
#define MTX_GL_SCALE_X(x,w,v1,v2) ((((((x) / (w)) + 1.0f) / 2.0f) * (v1)) + (v2))
#define MTX_GL_SCALE_Y(y,w,v1,v2) ((v1) - (((((y) / (w)) + 1.0f) / 2.0f) * (v1)) + (v2))
#define MTX_GL_SCALE_Z(z,w,v1,v2) (MTX_GL_SCALE_X ((z), (w), (v1), (v2)))
typedef struct _ClutterVertex4
{
float x;
float y;
float z;
float w;
} ClutterVertex4;
void
_clutter_util_fully_transform_vertices (const CoglMatrix *modelview,
const CoglMatrix *projection,
const float *viewport,
const ClutterVertex *vertices_in,
ClutterVertex *vertices_out,
int n_vertices)
{
CoglMatrix modelview_projection;
ClutterVertex4 *vertices_tmp;
int i;
vertices_tmp = g_alloca (sizeof (ClutterVertex4) * n_vertices);
if (n_vertices >= 4)
{
/* XXX: we should find a way to cache this per actor */
cogl_matrix_multiply (&modelview_projection,
projection,
modelview);
cogl_matrix_project_points (&modelview_projection,
3,
sizeof (ClutterVertex),
vertices_in,
sizeof (ClutterVertex4),
vertices_tmp,
n_vertices);
}
else
{
cogl_matrix_transform_points (modelview,
3,
sizeof (ClutterVertex),
vertices_in,
sizeof (ClutterVertex4),
vertices_tmp,
n_vertices);
cogl_matrix_project_points (projection,
3,
sizeof (ClutterVertex4),
vertices_tmp,
sizeof (ClutterVertex4),
vertices_tmp,
n_vertices);
}
for (i = 0; i < n_vertices; i++)
{
ClutterVertex4 vertex_tmp = vertices_tmp[i];
ClutterVertex *vertex_out = &vertices_out[i];
/* Finally translate from OpenGL coords to window coords */
vertex_out->x = MTX_GL_SCALE_X (vertex_tmp.x, vertex_tmp.w,
viewport[2], viewport[0]);
vertex_out->y = MTX_GL_SCALE_Y (vertex_tmp.y, vertex_tmp.w,
viewport[3], viewport[1]);
}
}