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mutter/clutter/clutter-offscreen-effect.h

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effect: Add OffscreenEffect The OffscreenEffect class is meant to be used to implement Effect sub-classes that create an offscreen framebuffer and redirect the actor's paint sequence there. The OffscreenEffect is useful for effects using fragment shaders. Any shader-based effect being applied to an actor through an offscreen buffer should be used before painting the resulting target material and not for every actor. This means that doing: pre_paint: cogl_program_use(program) set up offscreen buffer paint: [ actors ] → offscreen buffer → target material post_paint: paint target material cogl_program_use(null) Is not correct. Unfortunately, we cannot really do: post_paint: cogl_program_use(program) paint target material cogl_program_use(null) Because the OffscreenEffect::post_paint() implementation also pops the offscreen buffer and re-instates the previous framebuffer: post_paint: cogl_program_use(program) change frame buffer ← ouch! paint target material cogl_program_use(null) One way to fix it is to allow using the shader right before painting the target material - which means adding a new virtual inside the OffscreenEffect class vtable in additions to the ones defined by the parent Effect class. The newly-added paint_target() virtual allows the correct sequence of actions by adding an entry point for sub-classes to wrap the "paint target material" operation with custom code, in order to implement the case above correctly as: post_paint: change frame buffer cogl_program_use(program) paint target material cogl_program_use(null) The added upside is that sub-classes of OffscreenEffect involving shaders really just need to override the prepare() and paint_target() virtuals, since the pre_paint() and post_paint() do all that's needed.
2010-05-17 06:39:27 -04:00
/*
* 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>
*/
#if !defined(__CLUTTER_H_INSIDE__) && !defined(CLUTTER_COMPILATION)
#error "Only <clutter/clutter.h> can be included directly."
#endif
#ifndef __CLUTTER_OFFSCREEN_EFFECT_H__
#define __CLUTTER_OFFSCREEN_EFFECT_H__
build: Re-arrange headers Try to minimize the included headers, especially in clutter-actor.h.
2010-11-18 13:23:49 -05:00
#include <cogl/cogl.h>
effect: Add OffscreenEffect The OffscreenEffect class is meant to be used to implement Effect sub-classes that create an offscreen framebuffer and redirect the actor's paint sequence there. The OffscreenEffect is useful for effects using fragment shaders. Any shader-based effect being applied to an actor through an offscreen buffer should be used before painting the resulting target material and not for every actor. This means that doing: pre_paint: cogl_program_use(program) set up offscreen buffer paint: [ actors ] → offscreen buffer → target material post_paint: paint target material cogl_program_use(null) Is not correct. Unfortunately, we cannot really do: post_paint: cogl_program_use(program) paint target material cogl_program_use(null) Because the OffscreenEffect::post_paint() implementation also pops the offscreen buffer and re-instates the previous framebuffer: post_paint: cogl_program_use(program) change frame buffer ← ouch! paint target material cogl_program_use(null) One way to fix it is to allow using the shader right before painting the target material - which means adding a new virtual inside the OffscreenEffect class vtable in additions to the ones defined by the parent Effect class. The newly-added paint_target() virtual allows the correct sequence of actions by adding an entry point for sub-classes to wrap the "paint target material" operation with custom code, in order to implement the case above correctly as: post_paint: change frame buffer cogl_program_use(program) paint target material cogl_program_use(null) The added upside is that sub-classes of OffscreenEffect involving shaders really just need to override the prepare() and paint_target() virtuals, since the pre_paint() and post_paint() do all that's needed.
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#include <clutter/clutter-effect.h>
G_BEGIN_DECLS
#define CLUTTER_TYPE_OFFSCREEN_EFFECT (clutter_offscreen_effect_get_type ())
#define CLUTTER_OFFSCREEN_EFFECT(o) (G_TYPE_CHECK_INSTANCE_CAST ((o), CLUTTER_TYPE_OFFSCREEN_EFFECT, ClutterOffscreenEffect))
#define CLUTTER_IS_OFFSCREEN_EFFECT(o) (G_TYPE_CHECK_INSTANCE_TYPE ((o), CLUTTER_TYPE_OFFSCREEN_EFFECT))
#define CLUTTER_OFFSCREEN_EFFECT_CLASS(k) (G_TYPE_CHECK_CLASS_CAST ((k), CLUTTER_TYPE_OFFSCREEN_EFFECT, ClutterOffscreenEffectClass))
#define CLUTTER_IS_OFFSCREEN_EFFECT_CLASS(k) (G_TYPE_CHECK_CLASS_TYPE ((k), CLUTTER_TYPE_OFFSCREEN_EFFECT))
#define CLUTTER_OFFSCREEN_EFFECT_GET_CLASS(o) (G_TYPE_INSTANCE_GET_CLASS ((o), CLUTTER_TYPE_OFFSCREEN_EFFECT, ClutterOffscreenEffectClass))
typedef struct _ClutterOffscreenEffect ClutterOffscreenEffect;
typedef struct _ClutterOffscreenEffectPrivate ClutterOffscreenEffectPrivate;
typedef struct _ClutterOffscreenEffectClass ClutterOffscreenEffectClass;
/**
* ClutterOffscreenEffect:
*
* The #ClutterOffscreenEffect structure contains only private data
* and should be accessed using the provided API
*
* Since: 1.4
*/
struct _ClutterOffscreenEffect
{
/*< private >*/
ClutterEffect parent_instance;
ClutterOffscreenEffectPrivate *priv;
};
/**
* ClutterOffscreenEffectClass:
offscreen-effect: Rename create_target to create_buffer *** This is an API change *** The create_target() virtual function should return a CoglHandle to a texture; clutter_offscreen_effect_get_target(), instead, returns a CoglMaterial to be painted in the implementation of the paint_target() virtual function. Instead of equating textures with materials, and confusing the user of the API, we should mark the difference more prominently. First of all, we should return a CoglMaterial* (now that we have that as a public type) in get_target(); having handles all over the place does not make it easier to distinguish the semantics of the virtual functions. Then we should rename create_target() to create_texture(), to make it clear that what should be returned is a texture that is used as the backing for the offscreen framebuffer.
2010-09-01 12:56:15 -04:00
* @create_texture: virtual function
effect: Add OffscreenEffect The OffscreenEffect class is meant to be used to implement Effect sub-classes that create an offscreen framebuffer and redirect the actor's paint sequence there. The OffscreenEffect is useful for effects using fragment shaders. Any shader-based effect being applied to an actor through an offscreen buffer should be used before painting the resulting target material and not for every actor. This means that doing: pre_paint: cogl_program_use(program) set up offscreen buffer paint: [ actors ] → offscreen buffer → target material post_paint: paint target material cogl_program_use(null) Is not correct. Unfortunately, we cannot really do: post_paint: cogl_program_use(program) paint target material cogl_program_use(null) Because the OffscreenEffect::post_paint() implementation also pops the offscreen buffer and re-instates the previous framebuffer: post_paint: cogl_program_use(program) change frame buffer ← ouch! paint target material cogl_program_use(null) One way to fix it is to allow using the shader right before painting the target material - which means adding a new virtual inside the OffscreenEffect class vtable in additions to the ones defined by the parent Effect class. The newly-added paint_target() virtual allows the correct sequence of actions by adding an entry point for sub-classes to wrap the "paint target material" operation with custom code, in order to implement the case above correctly as: post_paint: change frame buffer cogl_program_use(program) paint target material cogl_program_use(null) The added upside is that sub-classes of OffscreenEffect involving shaders really just need to override the prepare() and paint_target() virtuals, since the pre_paint() and post_paint() do all that's needed.
2010-05-17 06:39:27 -04:00
* @paint_target: virtual function
*
* The #ClutterOffscreenEffectClass structure contains only private data
*
* Since: 1.4
*/
struct _ClutterOffscreenEffectClass
{
/*< private >*/
ClutterEffectClass parent_class;
/*< public >*/
offscreen-effect: Rename create_target to create_buffer *** This is an API change *** The create_target() virtual function should return a CoglHandle to a texture; clutter_offscreen_effect_get_target(), instead, returns a CoglMaterial to be painted in the implementation of the paint_target() virtual function. Instead of equating textures with materials, and confusing the user of the API, we should mark the difference more prominently. First of all, we should return a CoglMaterial* (now that we have that as a public type) in get_target(); having handles all over the place does not make it easier to distinguish the semantics of the virtual functions. Then we should rename create_target() to create_texture(), to make it clear that what should be returned is a texture that is used as the backing for the offscreen framebuffer.
2010-09-01 12:56:15 -04:00
CoglHandle (* create_texture) (ClutterOffscreenEffect *effect,
Reduce the amount of g-ir-scanner warnings As much as we can; the remaining warnings are mostly valid things that the introspection scanner still flags as potential issues.
2010-12-09 07:36:50 -05:00
gfloat width,
gfloat height);
void (* paint_target) (ClutterOffscreenEffect *effect);
effect: Add OffscreenEffect The OffscreenEffect class is meant to be used to implement Effect sub-classes that create an offscreen framebuffer and redirect the actor's paint sequence there. The OffscreenEffect is useful for effects using fragment shaders. Any shader-based effect being applied to an actor through an offscreen buffer should be used before painting the resulting target material and not for every actor. This means that doing: pre_paint: cogl_program_use(program) set up offscreen buffer paint: [ actors ] → offscreen buffer → target material post_paint: paint target material cogl_program_use(null) Is not correct. Unfortunately, we cannot really do: post_paint: cogl_program_use(program) paint target material cogl_program_use(null) Because the OffscreenEffect::post_paint() implementation also pops the offscreen buffer and re-instates the previous framebuffer: post_paint: cogl_program_use(program) change frame buffer ← ouch! paint target material cogl_program_use(null) One way to fix it is to allow using the shader right before painting the target material - which means adding a new virtual inside the OffscreenEffect class vtable in additions to the ones defined by the parent Effect class. The newly-added paint_target() virtual allows the correct sequence of actions by adding an entry point for sub-classes to wrap the "paint target material" operation with custom code, in order to implement the case above correctly as: post_paint: change frame buffer cogl_program_use(program) paint target material cogl_program_use(null) The added upside is that sub-classes of OffscreenEffect involving shaders really just need to override the prepare() and paint_target() virtuals, since the pre_paint() and post_paint() do all that's needed.
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/*< private >*/
void (* _clutter_offscreen1) (void);
void (* _clutter_offscreen2) (void);
void (* _clutter_offscreen3) (void);
void (* _clutter_offscreen4) (void);
void (* _clutter_offscreen5) (void);
void (* _clutter_offscreen6) (void);
void (* _clutter_offscreen7) (void);
};
GType clutter_offscreen_effect_get_type (void) G_GNUC_CONST;
offscreen-effect: Add public accessor for target size The OffscreenEffect class needs to expose a way for sub-classes to track the size of FBO it creates, in case it has to do some geometry deformations like the DeformEffect sub-classes. Let's move the private symbol we used internally in 1.6 to fix DeformEffect to the list of public symbols of OffscreenEffect. http://bugzilla.clutter-project.org/show_bug.cgi?id=2570
2011-02-28 09:31:59 -05:00
CoglMaterial * clutter_offscreen_effect_get_target (ClutterOffscreenEffect *effect);
void clutter_offscreen_effect_paint_target (ClutterOffscreenEffect *effect);
CoglHandle clutter_offscreen_effect_create_texture (ClutterOffscreenEffect *effect,
gfloat width,
gfloat height);
gboolean clutter_offscreen_effect_get_target_size (ClutterOffscreenEffect *effect,
gfloat *width,
gfloat *height);
effect: Add OffscreenEffect The OffscreenEffect class is meant to be used to implement Effect sub-classes that create an offscreen framebuffer and redirect the actor's paint sequence there. The OffscreenEffect is useful for effects using fragment shaders. Any shader-based effect being applied to an actor through an offscreen buffer should be used before painting the resulting target material and not for every actor. This means that doing: pre_paint: cogl_program_use(program) set up offscreen buffer paint: [ actors ] → offscreen buffer → target material post_paint: paint target material cogl_program_use(null) Is not correct. Unfortunately, we cannot really do: post_paint: cogl_program_use(program) paint target material cogl_program_use(null) Because the OffscreenEffect::post_paint() implementation also pops the offscreen buffer and re-instates the previous framebuffer: post_paint: cogl_program_use(program) change frame buffer ← ouch! paint target material cogl_program_use(null) One way to fix it is to allow using the shader right before painting the target material - which means adding a new virtual inside the OffscreenEffect class vtable in additions to the ones defined by the parent Effect class. The newly-added paint_target() virtual allows the correct sequence of actions by adding an entry point for sub-classes to wrap the "paint target material" operation with custom code, in order to implement the case above correctly as: post_paint: change frame buffer cogl_program_use(program) paint target material cogl_program_use(null) The added upside is that sub-classes of OffscreenEffect involving shaders really just need to override the prepare() and paint_target() virtuals, since the pre_paint() and post_paint() do all that's needed.
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G_END_DECLS
#endif /* __CLUTTER_OFFSCREEN_EFFECT_H__ */
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