mutter/clutter/clutter-blur-effect.c
Emmanuele Bassi d10ebe9fca effects: Check before using the cogl_shader_* API
Since BlurEffect and DesaturateEffect are using the shader API
implicitly and not using ClutterShaderEffect, we need to check if the
underlying GL implementation supports the GLSL shading language and warn
if not.
2010-08-11 17:25:17 +01:00

296 lines
8.4 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"
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
{
ClutterOffscreenEffect 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;
CoglHandle shader;
CoglHandle program;
gint tex_uniform;
gint x_step_uniform;
gint y_step_uniform;
guint is_compiled : 1;
};
struct _ClutterBlurEffectClass
{
ClutterOffscreenEffectClass parent_class;
};
G_DEFINE_TYPE (ClutterBlurEffect,
clutter_blur_effect,
CLUTTER_TYPE_OFFSCREEN_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);
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;
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;
}
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);
if (self->shader == COGL_INVALID_HANDLE)
{
self->shader = cogl_create_shader (COGL_SHADER_TYPE_FRAGMENT);
cogl_shader_source (self->shader, box_blur_glsl_shader);
self->is_compiled = FALSE;
self->tex_uniform = -1;
self->x_step_uniform = -1;
self->y_step_uniform = -1;
}
if (self->program == COGL_INVALID_HANDLE)
self->program = cogl_create_program ();
if (!self->is_compiled)
{
g_assert (self->shader != COGL_INVALID_HANDLE);
g_assert (self->program != COGL_INVALID_HANDLE);
cogl_shader_compile (self->shader);
if (!cogl_shader_is_compiled (self->shader))
{
gchar *log_buf = cogl_shader_get_info_log (self->shader);
g_warning (G_STRLOC ": Unable to compile the box blur shader: %s",
log_buf);
g_free (log_buf);
cogl_handle_unref (self->shader);
cogl_handle_unref (self->program);
self->shader = COGL_INVALID_HANDLE;
self->program = COGL_INVALID_HANDLE;
}
else
{
cogl_program_attach_shader (self->program, self->shader);
cogl_program_link (self->program);
cogl_handle_unref (self->shader);
self->is_compiled = TRUE;
self->tex_uniform =
cogl_program_get_uniform_location (self->program, "tex");
self->x_step_uniform =
cogl_program_get_uniform_location (self->program, "x_step");
self->y_step_uniform =
cogl_program_get_uniform_location (self->program, "y_step");
}
}
parent_class = CLUTTER_EFFECT_CLASS (clutter_blur_effect_parent_class);
return parent_class->pre_paint (effect);
}
static void
clutter_blur_effect_paint_target (ClutterOffscreenEffect *effect)
{
ClutterBlurEffect *self = CLUTTER_BLUR_EFFECT (effect);
ClutterOffscreenEffectClass *parent;
CoglHandle material;
if (self->program == COGL_INVALID_HANDLE)
goto out;
cogl_program_use (self->program);
if (self->tex_uniform > -1)
cogl_program_uniform_1i (self->tex_uniform, 0);
if (self->x_step_uniform > -1)
cogl_program_uniform_1f (self->x_step_uniform, self->x_step);
if (self->y_step_uniform > -1)
cogl_program_uniform_1f (self->y_step_uniform, self->y_step);
cogl_program_use (COGL_INVALID_HANDLE);
material = clutter_offscreen_effect_get_target (effect);
cogl_material_set_user_program (material, self->program);
out:
parent = CLUTTER_OFFSCREEN_EFFECT_CLASS (clutter_blur_effect_parent_class);
parent->paint_target (effect);
}
static void
clutter_blur_effect_dispose (GObject *gobject)
{
ClutterBlurEffect *self = CLUTTER_BLUR_EFFECT (gobject);
if (self->program != COGL_INVALID_HANDLE)
{
cogl_handle_unref (self->program);
self->program = COGL_INVALID_HANDLE;
self->shader = COGL_INVALID_HANDLE;
}
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;
offscreen_class = CLUTTER_OFFSCREEN_EFFECT_CLASS (klass);
offscreen_class->paint_target = clutter_blur_effect_paint_target;
}
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);
}