/*
* 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 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
#define CLUTTER_ENABLE_EXPERIMENTAL_API
#include "clutter-blur-effect.h"
#include "cogl/cogl.h"
#include "clutter-debug.h"
#include "clutter-offscreen-effect.h"
#include "clutter-private.h"
#define BLUR_PADDING 2
/* FIXME - lame shader; we should really have a decoupled
* horizontal/vertical two pass shader for the gaussian blur
*/
static const gchar *box_blur_glsl_declarations =
"uniform vec2 pixel_step;\n";
#define SAMPLE(offx, offy) \
"cogl_texel += texture2D (cogl_sampler, cogl_tex_coord.st + pixel_step * " \
"vec2 (" G_STRINGIFY (offx) ", " G_STRINGIFY (offy) "));\n"
static const gchar *box_blur_glsl_shader =
" cogl_texel = texture2D (cogl_sampler, cogl_tex_coord.st);\n"
SAMPLE (-1.0, -1.0)
SAMPLE ( 0.0, -1.0)
SAMPLE (+1.0, -1.0)
SAMPLE (-1.0, 0.0)
SAMPLE (+1.0, 0.0)
SAMPLE (-1.0, +1.0)
SAMPLE ( 0.0, +1.0)
SAMPLE (+1.0, +1.0)
" cogl_texel /= 9.0;\n";
#undef SAMPLE
struct _ClutterBlurEffect
{
ClutterOffscreenEffect parent_instance;
/* a back pointer to our actor, so that we can query it */
ClutterActor *actor;
gint pixel_step_uniform;
gint tex_width;
gint tex_height;
CoglPipeline *pipeline;
};
struct _ClutterBlurEffectClass
{
ClutterOffscreenEffectClass parent_class;
CoglPipeline *base_pipeline;
};
G_DEFINE_TYPE (ClutterBlurEffect,
clutter_blur_effect,
CLUTTER_TYPE_OFFSCREEN_EFFECT);
static gboolean
clutter_blur_effect_pre_paint (ClutterEffect *effect)
{
ClutterBlurEffect *self = CLUTTER_BLUR_EFFECT (effect);
ClutterEffectClass *parent_class;
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;
if (!clutter_feature_available (CLUTTER_FEATURE_SHADERS_GLSL))
{
/* if we don't have support for GLSL shaders then we
* forcibly disable the ActorMeta
*/
g_warning ("Unable to use the ShaderEffect: the graphics hardware "
"or the current GL driver does not implement support "
"for the GLSL shading language.");
clutter_actor_meta_set_enabled (CLUTTER_ACTOR_META (effect), FALSE);
return FALSE;
}
parent_class = CLUTTER_EFFECT_CLASS (clutter_blur_effect_parent_class);
if (parent_class->pre_paint (effect))
{
ClutterOffscreenEffect *offscreen_effect =
CLUTTER_OFFSCREEN_EFFECT (effect);
CoglHandle texture;
texture = clutter_offscreen_effect_get_texture (offscreen_effect);
self->tex_width = cogl_texture_get_width (texture);
self->tex_height = cogl_texture_get_height (texture);
if (self->pixel_step_uniform > -1)
{
gfloat pixel_step[2];
pixel_step[0] = 1.0f / self->tex_width;
pixel_step[1] = 1.0f / self->tex_height;
cogl_pipeline_set_uniform_float (self->pipeline,
self->pixel_step_uniform,
2, /* n_components */
1, /* count */
pixel_step);
}
cogl_pipeline_set_layer_texture (self->pipeline, 0, texture);
return TRUE;
}
else
return FALSE;
}
static void
clutter_blur_effect_paint_target (ClutterOffscreenEffect *effect)
{
ClutterBlurEffect *self = CLUTTER_BLUR_EFFECT (effect);
guint8 paint_opacity;
paint_opacity = clutter_actor_get_paint_opacity (self->actor);
cogl_pipeline_set_color4ub (self->pipeline,
paint_opacity,
paint_opacity,
paint_opacity,
paint_opacity);
cogl_push_source (self->pipeline);
cogl_rectangle (0, 0, self->tex_width, self->tex_height);
cogl_pop_source ();
}
static gboolean
clutter_blur_effect_get_paint_volume (ClutterEffect *effect,
ClutterPaintVolume *volume)
{
gfloat cur_width, cur_height;
ClutterVertex origin;
clutter_paint_volume_get_origin (volume, &origin);
cur_width = clutter_paint_volume_get_width (volume);
cur_height = clutter_paint_volume_get_height (volume);
origin.x -= BLUR_PADDING;
origin.y -= BLUR_PADDING;
cur_width += 2 * BLUR_PADDING;
cur_height += 2 * BLUR_PADDING;
clutter_paint_volume_set_origin (volume, &origin);
clutter_paint_volume_set_width (volume, cur_width);
clutter_paint_volume_set_height (volume, cur_height);
return TRUE;
}
static void
clutter_blur_effect_dispose (GObject *gobject)
{
ClutterBlurEffect *self = CLUTTER_BLUR_EFFECT (gobject);
if (self->pipeline != NULL)
{
cogl_object_unref (self->pipeline);
self->pipeline = NULL;
}
G_OBJECT_CLASS (clutter_blur_effect_parent_class)->dispose (gobject);
}
static void
clutter_blur_effect_class_init (ClutterBlurEffectClass *klass)
{
ClutterEffectClass *effect_class = CLUTTER_EFFECT_CLASS (klass);
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
ClutterOffscreenEffectClass *offscreen_class;
gobject_class->dispose = clutter_blur_effect_dispose;
effect_class->pre_paint = clutter_blur_effect_pre_paint;
effect_class->get_paint_volume = clutter_blur_effect_get_paint_volume;
offscreen_class = CLUTTER_OFFSCREEN_EFFECT_CLASS (klass);
offscreen_class->paint_target = clutter_blur_effect_paint_target;
}
static void
clutter_blur_effect_init (ClutterBlurEffect *self)
{
ClutterBlurEffectClass *klass = CLUTTER_BLUR_EFFECT_GET_CLASS (self);
if (G_UNLIKELY (klass->base_pipeline == NULL))
{
CoglSnippet *snippet;
CoglContext *ctx =
clutter_backend_get_cogl_context (clutter_get_default_backend ());
klass->base_pipeline = cogl_pipeline_new (ctx);
snippet = cogl_snippet_new (COGL_SNIPPET_HOOK_TEXTURE_LOOKUP,
box_blur_glsl_declarations,
NULL);
cogl_snippet_set_replace (snippet, box_blur_glsl_shader);
cogl_pipeline_add_layer_snippet (klass->base_pipeline, 0, snippet);
cogl_object_unref (snippet);
cogl_pipeline_set_layer_null_texture (klass->base_pipeline,
0, /* layer number */
COGL_TEXTURE_TYPE_2D);
}
self->pipeline = cogl_pipeline_copy (klass->base_pipeline);
self->pixel_step_uniform =
cogl_pipeline_get_uniform_location (self->pipeline, "pixel_step");
}
/**
* 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);
}