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mutter/clutter/clutter-offscreen-effect.c

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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.
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/*
* 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/>.
*
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
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* Authors:
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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* Emmanuele Bassi <ebassi@linux.intel.com>
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
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* Robert Bragg <robert@linux.intel.com>
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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*/
/**
* SECTION:clutter-offscreen-effect
* @short_description: Base class for effects using offscreen buffers
* @see_also: #ClutterBlurEffect, #ClutterEffect
*
* #ClutterOffscreenEffect is an abstract class that can be used by
* #ClutterEffect sub-classes requiring access to an offscreen buffer.
*
* Some effects, like the fragment shader based effects, can only use GL
* textures, and in order to apply those effects to any kind of actor they
* require that all drawing operations are applied to an offscreen framebuffer
* that gets redirected to a texture.
*
* #ClutterOffscreenEffect provides all the heavy-lifting for creating the
* offscreen framebuffer, the redirection and the final paint of the texture on
* the desired stage.
*
* <refsect2 id="ClutterOffscreenEffect-implementing">
* <title>Implementing a ClutterOffscreenEffect</title>
* <para>Creating a sub-class of #ClutterOffscreenEffect requires, in case
* of overriding the #ClutterEffect virtual functions, to chain up to the
* #ClutterOffscreenEffect's implementation.</para>
* <para>On top of the #ClutterEffect's virtual functions,
* #ClutterOffscreenEffect also provides a <function>paint_target()</function>
* function, which encapsulates the effective painting of the texture that
* contains the result of the offscreen redirection.</para>
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
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* <para>The size of the target material is defined to be as big as the
* transformed size of the #ClutterActor using the offscreen effect.
* Sub-classes of #ClutterOffscreenEffect can change the texture creation
* code to provide bigger textures by overriding the
* <function>create_target()</function> virtual function; no chain up
* to the #ClutterOffscreenEffect implementation is required in this
* case.</para>
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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* </refsect2>
*
* #ClutterOffscreenEffect is available since Clutter 1.4
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "clutter-offscreen-effect.h"
#include "cogl/cogl.h"
#include "clutter-debug.h"
#include "clutter-private.h"
struct _ClutterOffscreenEffectPrivate
{
CoglHandle offscreen;
CoglHandle target;
ClutterActor *actor;
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
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ClutterActor *stage;
gfloat x_offset;
gfloat y_offset;
gfloat target_width;
gfloat target_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_DEFINE_ABSTRACT_TYPE (ClutterOffscreenEffect,
clutter_offscreen_effect,
CLUTTER_TYPE_EFFECT);
static void
clutter_offscreen_effect_set_actor (ClutterActorMeta *meta,
ClutterActor *actor)
{
ClutterOffscreenEffect *self = CLUTTER_OFFSCREEN_EFFECT (meta);
ClutterOffscreenEffectPrivate *priv = self->priv;
ClutterActorMetaClass *meta_class;
meta_class = CLUTTER_ACTOR_META_CLASS (clutter_offscreen_effect_parent_class);
meta_class->set_actor (meta, actor);
/* clear out the previous state */
if (priv->offscreen != COGL_INVALID_HANDLE)
{
cogl_handle_unref (priv->offscreen);
priv->offscreen = COGL_INVALID_HANDLE;
}
if (priv->target != COGL_INVALID_HANDLE)
{
cogl_handle_unref (priv->target);
priv->target = COGL_INVALID_HANDLE;
}
/* we keep a back pointer here, to avoid going through the ActorMeta */
priv->actor = clutter_actor_meta_get_actor (meta);
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
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}
static CoglHandle
clutter_offscreen_effect_real_create_target (ClutterOffscreenEffect *effect,
gfloat width,
gfloat height)
{
return cogl_texture_new_with_size (MAX (width, 1), MAX (height, 1),
COGL_TEXTURE_NO_SLICING,
COGL_PIXEL_FORMAT_RGBA_8888_PRE);
}
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 10:39:27 +00:00
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
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static gboolean
update_fbo (ClutterEffect *effect)
{
ClutterOffscreenEffect *self = CLUTTER_OFFSCREEN_EFFECT (effect);
ClutterOffscreenEffectPrivate *priv = self->priv;
gfloat width, height;
CoglHandle texture;
priv->stage = clutter_actor_get_stage (priv->actor);
if (priv->stage == NULL)
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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{
CLUTTER_NOTE (MISC, "The actor '%s' is not part of a stage",
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
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clutter_actor_get_name (priv->actor) == NULL
? G_OBJECT_TYPE_NAME (priv->actor)
: clutter_actor_get_name (priv->actor));
return FALSE;
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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}
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
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/* the target should at least be big enough to contain the
* transformed allocation of the actor
*
* FIXME - this is actually not enough: we need the paint area
* to make this work reliably
*/
clutter_actor_get_transformed_size (priv->actor, &width, &height);
if (fabsf (priv->target_width - width) < 0.00001f &&
fabsf (priv->target_height - height) < 0.0001f)
return TRUE;
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 10:39:27 +00:00
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
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if (priv->target != COGL_INVALID_HANDLE)
{
cogl_handle_unref (priv->target);
cogl_handle_unref (priv->offscreen);
}
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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priv->target = cogl_material_new ();
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
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texture = clutter_offscreen_effect_create_target (self, width, height);
if (texture == COGL_INVALID_HANDLE)
return FALSE;
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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cogl_material_set_layer (priv->target, 0, texture);
cogl_handle_unref (texture);
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
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/* we need to use the size of the texture target and not the minimum
* size we passed to the create_target() vfunc, as any sub-class might
* give use a bigger texture
*/
priv->target_width = cogl_texture_get_width (texture);
priv->target_height = cogl_texture_get_height (texture);
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 10:39:27 +00:00
priv->offscreen = cogl_offscreen_new_to_texture (texture);
if (priv->offscreen == COGL_INVALID_HANDLE)
{
g_warning ("%s: Unable to create an Offscreen buffer", G_STRLOC);
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
cogl_handle_unref (priv->target);
priv->target = COGL_INVALID_HANDLE;
priv->target_width = 0;
priv->target_height = 0;
return FALSE;
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 10:39:27 +00:00
}
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
return TRUE;
}
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 10:39:27 +00:00
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
static void
get_screen_offsets (ClutterActor *actor,
gfloat *x_offset,
gfloat *y_offset)
{
ClutterVertex verts[4];
gfloat x_min = G_MAXFLOAT, y_min = G_MAXFLOAT;
effects: Fix stacking of offscreen-based effects Stacking multiple effects sub-classing ClutterOffscreenEffect requires a small fix in the code that computes the screen coordinates of the actor to position the FBO correctly with regards to the stage.
2010-06-03 13:08:59 +00:00
gfloat v[4] = { 0, };
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
gint i;
/* Get the actors allocation transformed into screen coordinates.
*
* XXX: Note: this may not be a bounding box for the actor, since an
* actor with depth may escape the box due to its perspective
* projection. */
clutter_actor_get_abs_allocation_vertices (actor, verts);
for (i = 0; i < G_N_ELEMENTS (verts); ++i)
{
if (verts[i].x < x_min)
x_min = verts[i].x;
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 10:39:27 +00:00
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
if (verts[i].y < y_min)
y_min = verts[i].y;
}
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 10:39:27 +00:00
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
/* XXX: It's not good enough to round by simply truncating the fraction here
* via a cast, as it results in offscreen rendering being offset by 1 pixel
* in many cases... */
#define ROUND(x) ((x) >= 0 ? (long)((x) + 0.5) : (long)((x) - 0.5))
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 10:39:27 +00:00
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
*x_offset = ROUND (x_min);
*y_offset = ROUND (y_min);
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 10:39:27 +00:00
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
#undef ROUND
effects: Fix stacking of offscreen-based effects Stacking multiple effects sub-classing ClutterOffscreenEffect requires a small fix in the code that computes the screen coordinates of the actor to position the FBO correctly with regards to the stage.
2010-06-03 13:08:59 +00:00
/* since we're setting up a viewport with a negative offset to paint
* in an FBO with the same modelview and projection matrices as the
* stage, we need to offset the computed absolute allocation vertices
* with the current viewport's X and Y offsets. this works even with
* the default case where the viewport is set up by Clutter to be
* (0, 0, stage_width, stage_height)
*/
cogl_get_viewport (v);
*x_offset -= v[0];
*y_offset -= v[1];
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 10:39:27 +00:00
}
static gboolean
clutter_offscreen_effect_pre_paint (ClutterEffect *effect)
{
ClutterOffscreenEffect *self = CLUTTER_OFFSCREEN_EFFECT (effect);
ClutterOffscreenEffectPrivate *priv = self->priv;
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
ClutterPerspective perspective;
CoglColor transparent;
CoglMatrix modelview;
gfloat width, 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.
2010-05-17 10:39:27 +00:00
if (!clutter_actor_meta_get_enabled (CLUTTER_ACTOR_META (effect)))
return FALSE;
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
if (priv->actor == NULL)
return FALSE;
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 10:39:27 +00:00
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
if (!update_fbo (effect))
return FALSE;
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 10:39:27 +00:00
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
/* get the current modelview matrix so that we can copy it
* on the new framebuffer
*/
cogl_get_modelview_matrix (&modelview);
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 10:39:27 +00:00
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
clutter_stage_get_perspective (CLUTTER_STAGE (priv->stage), &perspective);
clutter_actor_get_size (priv->stage, &width, &height);
get_screen_offsets (priv->actor, &priv->x_offset, &priv->y_offset);
/* let's draw offscreen */
cogl_push_framebuffer (priv->offscreen);
/* set up the viewport so that it has the same size of the stage,
* and it has its origin at the same position of the stage's; also
* set up the perspective to be the same as the stage's
*/
cogl_set_viewport (-priv->x_offset, -priv->y_offset, width, height);
cogl_perspective (perspective.fovy,
perspective.aspect,
perspective.z_near,
perspective.z_far);
cogl_color_set_from_4ub (&transparent, 0, 0, 0, 0);
cogl_clear (&transparent,
COGL_BUFFER_BIT_COLOR |
COGL_BUFFER_BIT_DEPTH);
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 10:39:27 +00:00
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
cogl_push_matrix ();
cogl_set_modelview_matrix (&modelview);
return TRUE;
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 10:39:27 +00:00
}
static void
clutter_offscreen_effect_real_paint_target (ClutterOffscreenEffect *effect)
{
ClutterOffscreenEffectPrivate *priv = effect->priv;
guint8 paint_opacity;
paint_opacity = clutter_actor_get_paint_opacity (priv->actor);
cogl_material_set_color4ub (priv->target,
paint_opacity,
paint_opacity,
paint_opacity,
paint_opacity);
cogl_set_source (priv->target);
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
/* paint the texture at the same position as the actor would be,
* in Stage coordinates, since we set up the modelview matrix to
offscreen-effect: Traslate the modelview with the offsets Instead of using the stage offsets when painting we can simply traslate the current modelview. This allows sub-classes to fully override the paint_target() virtual function without chaining up.
2010-06-10 16:35:56 +00:00
* be exactly as the stage sets it up, plus the eventual offsets
* due to offscreen effects stacking
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
*/
offscreen-effect: Traslate the modelview with the offsets Instead of using the stage offsets when painting we can simply traslate the current modelview. This allows sub-classes to fully override the paint_target() virtual function without chaining up.
2010-06-10 16:35:56 +00:00
cogl_rectangle_with_texture_coords (0, 0,
priv->target_width,
priv->target_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.
2010-05-17 10:39:27 +00:00
0.0, 0.0,
1.0, 1.0);
}
static void
clutter_offscreen_effect_post_paint (ClutterEffect *effect)
{
ClutterOffscreenEffect *self = CLUTTER_OFFSCREEN_EFFECT (effect);
ClutterOffscreenEffectPrivate *priv = self->priv;
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
ClutterPerspective perspective;
CoglMatrix modelview, matrix;
gfloat width, height;
gfloat z_camera;
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 10:39:27 +00:00
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
if (priv->offscreen == COGL_INVALID_HANDLE ||
priv->target == COGL_INVALID_HANDLE ||
priv->actor == NULL)
return;
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 10:39:27 +00:00
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
cogl_pop_matrix ();
cogl_pop_framebuffer ();
clutter_stage_get_perspective (CLUTTER_STAGE (priv->stage), &perspective);
clutter_actor_get_size (priv->stage, &width, &height);
cogl_get_modelview_matrix (&modelview);
cogl_get_projection_matrix (&matrix);
z_camera = 0.5f * matrix.xx;
/* obliterate the current modelview matrix and reset it to be
* the same as the stage's at the beginning of a paint run; this
* is done to paint the target material in screen coordinates at
* the same place as the actor would have been
*/
cogl_matrix_init_identity (&matrix);
cogl_matrix_translate (&matrix, -0.5f, -0.5f, -z_camera);
cogl_matrix_scale (&matrix, 1.0f / width, -1.0f / height, 1.0f / width);
cogl_matrix_translate (&matrix, 0.0f, -1.0f * height, 0.0f);
cogl_set_modelview_matrix (&matrix);
cogl_push_matrix ();
offscreen-effect: Traslate the modelview with the offsets Instead of using the stage offsets when painting we can simply traslate the current modelview. This allows sub-classes to fully override the paint_target() virtual function without chaining up.
2010-06-10 16:35:56 +00:00
cogl_translate (priv->x_offset, priv->y_offset, 0.0f);
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
/* paint the target material; this is virtualized for
* sub-classes that require special hand-holding
*/
clutter_offscreen_effect_paint_target (self);
cogl_pop_matrix ();
/* reset the modelview matrix */
cogl_set_modelview_matrix (&modelview);
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 10:39:27 +00:00
}
static void
clutter_offscreen_effect_finalize (GObject *gobject)
{
ClutterOffscreenEffect *self = CLUTTER_OFFSCREEN_EFFECT (gobject);
ClutterOffscreenEffectPrivate *priv = self->priv;
if (priv->offscreen)
cogl_handle_unref (priv->offscreen);
if (priv->target)
cogl_handle_unref (priv->target);
G_OBJECT_CLASS (clutter_offscreen_effect_parent_class)->finalize (gobject);
}
static void
clutter_offscreen_effect_class_init (ClutterOffscreenEffectClass *klass)
{
ClutterActorMetaClass *meta_class = CLUTTER_ACTOR_META_CLASS (klass);
ClutterEffectClass *effect_class = CLUTTER_EFFECT_CLASS (klass);
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
g_type_class_add_private (klass, sizeof (ClutterOffscreenEffectPrivate));
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
klass->create_target = clutter_offscreen_effect_real_create_target;
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 10:39:27 +00:00
klass->paint_target = clutter_offscreen_effect_real_paint_target;
meta_class->set_actor = clutter_offscreen_effect_set_actor;
effect_class->pre_paint = clutter_offscreen_effect_pre_paint;
effect_class->post_paint = clutter_offscreen_effect_post_paint;
gobject_class->finalize = clutter_offscreen_effect_finalize;
}
static void
clutter_offscreen_effect_init (ClutterOffscreenEffect *self)
{
self->priv = G_TYPE_INSTANCE_GET_PRIVATE (self,
CLUTTER_TYPE_OFFSCREEN_EFFECT,
ClutterOffscreenEffectPrivate);
}
/**
* clutter_offscreen_effect_get_target:
* @effect: a #ClutterOffscreenEffect
*
* Retrieves the material used as a render target for the offscreen
* buffer created by @effect
*
* Return value: (transfer none): a handle for a #CoglMaterial, or
* %COGL_INVALID_HANDLE. The returned handle is owned by Clutter
* and it should not be modified or freed
*
* Since: 1.4
*/
CoglHandle
clutter_offscreen_effect_get_target (ClutterOffscreenEffect *effect)
{
g_return_val_if_fail (CLUTTER_IS_OFFSCREEN_EFFECT (effect),
COGL_INVALID_HANDLE);
return effect->priv->target;
}
/**
* clutter_offscreen_effect_paint_target:
* @effect: a #ClutterOffscreenEffect
*
* Calls the paint_target() virtual function of the @effect
*
* Since: 1.4
*/
void
clutter_offscreen_effect_paint_target (ClutterOffscreenEffect *effect)
{
g_return_if_fail (CLUTTER_IS_OFFSCREEN_EFFECT (effect));
CLUTTER_OFFSCREEN_EFFECT_GET_CLASS (effect)->paint_target (effect);
}
effect: Rework the OffscreenEffect painting The OffscreenEffect should set up the off screen draw buffer so that it has the same projection and modelview as if it where on screen; we achieve that by setting up the viewport to be the same size of the stage but with an initial offset given by the left-most vertex of the actor. When we paint the texture attached to the FBO we then set up the modelview matrix of the on screen draw buffer so that it's the same as the stage one: this way, the texture will be painted in screen coordinates and it will occupy the same area as the actor would have had.
2010-04-16 11:33:20 +00:00
/**
* clutter_offscreen_effect_create_target:
* @effect: a #ClutterOffscreenEffect
* @width: the minimum width of the target texture
* @height: the minimum height of the target texture
*
* Calls the create_target() virtual function of the @effect
*
* Return value: a handle to the target texture
*
* Since: 1.4
*/
CoglHandle
clutter_offscreen_effect_create_target (ClutterOffscreenEffect *effect,
gfloat width,
gfloat height)
{
g_return_val_if_fail (CLUTTER_IS_OFFSCREEN_EFFECT (effect),
COGL_INVALID_HANDLE);
return CLUTTER_OFFSCREEN_EFFECT_GET_CLASS (effect)->create_target (effect,
width,
height);
}
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