mutter/clutter/clutter-blur-effect.c
Emmanuele Bassi b1ff53d980 effects: Delay the creation of the base pipeline
Unconditionally creating CoglPipeline and CoglSnippets inside the class
initialization functions does not seem to be enough when dealing with
headless builds.

Our last resort is to lazily create the base pipeline the first time we
try to copy it, during the instance initialization.
2012-02-15 09:34:27 +00:00

278 lines
8.2 KiB
C

/*
* 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 <http://www.gnu.org/licenses/>.
*
* Author:
* Emmanuele Bassi <ebassi@linux.intel.com>
*/
/**
* 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
#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";
/* FIXME: Is this shader right? It is doing 10 samples (ie, sampling
the middle texel twice) and then only dividing by 9 */
#define SAMPLE(offx, offy) \
"cogl_texel += texture2D (cogl_sampler, cogl_tex_coord.st + pixel_step * " \
"vec2 (" G_STRINGIFY (offx) ", " G_STRINGIFY (offy) ") * 2.0);\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 ( 0.0, 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;
klass->base_pipeline = cogl_pipeline_new ();
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);
}