/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Copyright (C) 2010 Intel Corporation.
*
* 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 .
*
* Author:
* Emmanuele Bassi
*/
/**
* SECTION:clutter-blur-effect
* @short_description: A blur effect
* @see_also: #ClutterEffect, #ClutterOffscreenEffect
*
* #ClutterBlurEffect is a sub-class of #ClutterEffect that allows blurring a
* actor and its contents.
*
* #ClutterBlurEffect uses the programmable pipeline of the GPU and an
* offscreen buffer, so it is only available on graphics hardware that supports
* these two features.
*
* #ClutterBlurEffect is available since Clutter 1.4
*/
#define CLUTTER_BLUR_EFFECT_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), CLUTTER_TYPE_BLUR_EFFECT, ClutterBlurEffectClass))
#define CLUTTER_IS_BLUR_EFFECT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), CLUTTER_TYPE_BLUR_EFFECT))
#define CLUTTER_BLUR_EFFECT_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), CLUTTER_TYPE_BLUR_EFFECT, ClutterBlurEffectClass))
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "clutter-blur-effect.h"
#include "cogl/cogl.h"
#include "clutter-debug.h"
#include "clutter-private.h"
#include "clutter-shader-effect.h"
typedef struct _ClutterBlurEffectClass ClutterBlurEffectClass;
/* FIXME - lame shader; we should really have a decoupled
* horizontal/vertical two pass shader for the gaussian blur
*/
static const gchar *box_blur_glsl_shader =
"uniform sampler2D tex;\n"
"uniform float x_step, y_step;\n"
"\n"
"vec4 get_rgba_rel (sampler2D source, float dx, float dy)\n"
"{\n"
" return texture2D (tex, gl_TexCoord[0].st + vec2 (dx, dy) * 2.0);\n"
"}\n"
"\n"
"void main ()\n"
"{\n"
" vec4 color = gl_Color * texture2D (tex, vec2 (gl_TexCoord[0].xy));\n"
" float count = 1.0;\n"
" color += get_rgba_rel (tex, -x_step, -y_step); count++;\n"
" color += get_rgba_rel (tex, 0.0, -y_step); count++;\n"
" color += get_rgba_rel (tex, x_step, -y_step); count++;\n"
" color += get_rgba_rel (tex, -x_step, 0.0); count++;\n"
" color += get_rgba_rel (tex, 0.0, 0.0); count++;\n"
" color += get_rgba_rel (tex, x_step, 0.0); count++;\n"
" color += get_rgba_rel (tex, -x_step, y_step); count++;\n"
" color += get_rgba_rel (tex, 0.0, y_step); count++;\n"
" color += get_rgba_rel (tex, x_step, y_step); count++;\n"
" gl_FragColor = color / count;\n"
"}";
struct _ClutterBlurEffect
{
ClutterShaderEffect parent_instance;
/* a back pointer to our actor, so that we can query it */
ClutterActor *actor;
/* the parameters; x_step and y_step depend on
* the actor's allocation
*/
gfloat x_step;
gfloat y_step;
};
struct _ClutterBlurEffectClass
{
ClutterShaderEffectClass parent_class;
};
enum
{
PROP_0
};
G_DEFINE_TYPE (ClutterBlurEffect,
clutter_blur_effect,
CLUTTER_TYPE_SHADER_EFFECT);
static int
next_p2 (int a)
{
int rval = 1;
while (rval < a)
rval <<= 1;
return rval;
}
static gboolean
clutter_blur_effect_pre_paint (ClutterEffect *effect)
{
ClutterBlurEffect *self = CLUTTER_BLUR_EFFECT (effect);
ClutterShaderEffect *shader_effect;
ClutterEffectClass *parent_class;
ClutterActorBox allocation;
gfloat width, height;
if (!clutter_actor_meta_get_enabled (CLUTTER_ACTOR_META (effect)))
return FALSE;
self->actor = clutter_actor_meta_get_actor (CLUTTER_ACTOR_META (effect));
if (self->actor == NULL)
return FALSE;
clutter_actor_get_allocation_box (self->actor, &allocation);
clutter_actor_box_get_size (&allocation, &width, &height);
self->x_step = 1.0f / (float) next_p2 (width);
self->y_step = 1.0f / (float) next_p2 (height);
shader_effect = CLUTTER_SHADER_EFFECT (effect);
clutter_shader_effect_set_shader_source (shader_effect, box_blur_glsl_shader);
clutter_shader_effect_set_uniform (shader_effect,
"tex",
G_TYPE_INT, 1,
0);
clutter_shader_effect_set_uniform (shader_effect,
"x_step",
G_TYPE_FLOAT, 1,
self->x_step);
clutter_shader_effect_set_uniform (shader_effect,
"y_step",
G_TYPE_FLOAT, 1,
self->y_step);
parent_class = CLUTTER_EFFECT_CLASS (clutter_blur_effect_parent_class);
return parent_class->pre_paint (effect);
}
static void
clutter_blur_effect_finalize (GObject *gobject)
{
G_OBJECT_CLASS (clutter_blur_effect_parent_class)->finalize (gobject);
}
static void
clutter_blur_effect_set_property (GObject *gobject,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
switch (prop_id)
{
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
static void
clutter_blur_effect_get_property (GObject *gobject,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
switch (prop_id)
{
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
static void
clutter_blur_effect_class_init (ClutterBlurEffectClass *klass)
{
ClutterEffectClass *effect_class = CLUTTER_EFFECT_CLASS (klass);
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
effect_class->pre_paint = clutter_blur_effect_pre_paint;
gobject_class->set_property = clutter_blur_effect_set_property;
gobject_class->get_property = clutter_blur_effect_get_property;
gobject_class->finalize = clutter_blur_effect_finalize;
}
static void
clutter_blur_effect_init (ClutterBlurEffect *self)
{
}
/**
* clutter_blur_effect_new:
*
* Creates a new #ClutterBlurEffect to be used with
* clutter_actor_add_effect()
*
* Return value: the newly created #ClutterBlurEffect or %NULL
*
* Since: 1.4
*/
ClutterEffect *
clutter_blur_effect_new (void)
{
return g_object_new (CLUTTER_TYPE_BLUR_EFFECT, NULL);
}