mutter/clutter/clutter-cairo-texture.c

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/*
* Clutter
*
* An OpenGL based 'interactive canvas' library.
*
* Authored By: Emmanuele Bassi <ebassi@linux.intel.com>
* Matthew Allum <mallum@o-hand.com>
* Chris Lord <chris@o-hand.com>
* Iain Holmes <iain@o-hand.com>
* Neil Roberts <neil@linux.intel.com>
*
* Copyright (C) 2008, 2009, 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/>.
*/
/**
* SECTION:clutter-cairo-texture
* @short_description: Texture with Cairo integration
*
* #ClutterCairoTexture is a #ClutterTexture that displays the contents
* of a Cairo context. The #ClutterCairoTexture actor will create a
* Cairo image surface which will then be uploaded to a GL texture when
* needed.
*
* #ClutterCairoTexture will provide a #cairo_t context by using the
* clutter_cairo_texture_create() and clutter_cairo_texture_create_region()
* functions; you can use the Cairo API to draw on the context and then
* call cairo_destroy() when done.
*
* As soon as the context is destroyed with cairo_destroy(), the contents
* of the surface will be uploaded into the #ClutterCairoTexture actor:
*
* |[
* cairo_t *cr;
*
* cr = clutter_cairo_texture_create (CLUTTER_CAIRO_TEXTURE (texture));
*
* /&ast; draw on the context &ast;/
*
* cairo_destroy (cr);
* ]|
*
* Although a new #cairo_t is created each time you call
* clutter_cairo_texture_create() or
* clutter_cairo_texture_create_region(), it uses the same
* #cairo_surface_t each time. You can call
* clutter_cairo_texture_clear() to erase the contents between calls.
*
* <warning><para>Note that you should never use the code above inside the
* #ClutterActor::paint or #ClutterActor::pick virtual functions or
* signal handlers because it will lead to performance
* degradation.</para></warning>
*
* <note><para>Since #ClutterCairoTexture uses a Cairo image surface
* internally all the drawing operations will be performed in
* software and not using hardware acceleration. This can lead to
* performance degradation if the contents of the texture change
* frequently.</para></note>
*
* #ClutterCairoTexture is available since Clutter 1.0.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include <cairo-gobject.h>
#include "clutter-cairo-texture.h"
#include "clutter-actor-private.h"
#include "clutter-debug.h"
#include "clutter-marshal.h"
#include "clutter-private.h"
G_DEFINE_TYPE (ClutterCairoTexture,
clutter_cairo_texture,
CLUTTER_TYPE_TEXTURE);
enum
{
PROP_0,
PROP_SURFACE_WIDTH,
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PROP_SURFACE_HEIGHT,
PROP_LAST
};
enum
{
CREATE_SURFACE,
LAST_SIGNAL
};
static GParamSpec *obj_props[PROP_LAST] = { NULL, };
static guint cairo_signals[LAST_SIGNAL] = { 0, };
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#ifdef CLUTTER_ENABLE_DEBUG
#define clutter_warn_if_paint_fail(obj) G_STMT_START { \
if (CLUTTER_ACTOR_IN_PAINT (obj)) { \
g_warning ("%s should not be called during the paint sequence " \
"of a ClutterCairoTexture as it will likely cause " \
"performance issues.", G_STRFUNC); \
} } G_STMT_END
#else
#define clutter_warn_if_paint_fail(obj) /* void */
#endif /* CLUTTER_ENABLE_DEBUG */
#define CLUTTER_CAIRO_TEXTURE_GET_PRIVATE(obj) (G_TYPE_INSTANCE_GET_PRIVATE ((obj), CLUTTER_TYPE_CAIRO_TEXTURE, ClutterCairoTexturePrivate))
/* Cairo stores the data in native byte order as ARGB but Cogl's pixel
formats specify the actual byte order. Therefore we need to use a
different format depending on the architecture */
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
#define CLUTTER_CAIRO_TEXTURE_PIXEL_FORMAT COGL_PIXEL_FORMAT_BGRA_8888_PRE
#else
#define CLUTTER_CAIRO_TEXTURE_PIXEL_FORMAT COGL_PIXEL_FORMAT_ARGB_8888_PRE
#endif
struct _ClutterCairoTexturePrivate
{
cairo_surface_t *cr_surface;
gint surface_width;
gint surface_height;
guint width;
guint height;
};
typedef struct {
ClutterCairoTexture *cairo;
cairo_rectangle_int_t rect;
} ClutterCairoTextureContext;
static const cairo_user_data_key_t clutter_cairo_texture_context_key;
static void
clutter_cairo_texture_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
ClutterCairoTexturePrivate *priv;
priv = CLUTTER_CAIRO_TEXTURE (object)->priv;
switch (prop_id)
{
case PROP_SURFACE_WIDTH:
priv->width = g_value_get_uint (value);
break;
case PROP_SURFACE_HEIGHT:
priv->height = g_value_get_uint (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
clutter_cairo_texture_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
ClutterCairoTexturePrivate *priv;
priv = CLUTTER_CAIRO_TEXTURE (object)->priv;
switch (prop_id)
{
case PROP_SURFACE_WIDTH:
g_value_set_uint (value, priv->width);
break;
case PROP_SURFACE_HEIGHT:
g_value_set_uint (value, priv->height);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
clutter_cairo_texture_finalize (GObject *object)
{
ClutterCairoTexturePrivate *priv = CLUTTER_CAIRO_TEXTURE (object)->priv;
if (priv->cr_surface != NULL)
{
cairo_surface_t *surface = priv->cr_surface;
priv->cr_surface = NULL;
cairo_surface_finish (surface);
cairo_surface_destroy (surface);
}
G_OBJECT_CLASS (clutter_cairo_texture_parent_class)->finalize (object);
}
static cairo_surface_t *
get_surface (ClutterCairoTexture *self)
{
ClutterCairoTexturePrivate *priv = self->priv;
if (priv->cr_surface == NULL)
{
g_signal_emit (self, cairo_signals[CREATE_SURFACE], 0,
priv->width,
priv->height,
&priv->cr_surface);
}
return priv->cr_surface;
}
static inline void
clutter_cairo_texture_surface_resize_internal (ClutterCairoTexture *cairo)
{
ClutterCairoTexturePrivate *priv = cairo->priv;
if (priv->cr_surface != NULL)
{
cairo_surface_t *surface = priv->cr_surface;
/* if the surface is an image one, and the size is already the
* same, then we don't need to do anything
*/
if (cairo_surface_get_type (surface) != CAIRO_SURFACE_TYPE_IMAGE)
{
gint surface_width = cairo_image_surface_get_width (surface);
gint surface_height = cairo_image_surface_get_height (surface);
if (priv->width == surface_width &&
priv->height == surface_height)
return;
}
cairo_surface_finish (surface);
cairo_surface_destroy (surface);
priv->cr_surface = NULL;
}
if (priv->width == 0 || priv->height == 0)
return;
g_signal_emit (cairo, cairo_signals[CREATE_SURFACE], 0,
priv->width,
priv->height,
&priv->cr_surface);
}
static void
clutter_cairo_texture_notify (GObject *object,
GParamSpec *pspec)
{
/* When the surface width or height changes then resize the cairo
surface. This is done here instead of directly in set_property so
that if both the width and height properties are set using a
single call to g_object_set then the surface will only be resized
once because the notifications will be frozen in between */
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if (strcmp ("surface-width", pspec->name) == 0 ||
strcmp ("surface-height", pspec->name) == 0)
{
ClutterCairoTexture *cairo = CLUTTER_CAIRO_TEXTURE (object);
clutter_cairo_texture_surface_resize_internal (cairo);
}
if (G_OBJECT_CLASS (clutter_cairo_texture_parent_class)->notify)
G_OBJECT_CLASS (clutter_cairo_texture_parent_class)->notify (object, pspec);
}
static void
clutter_cairo_texture_get_preferred_width (ClutterActor *actor,
Remove Units from the public API With the recent change to internal floating point values, ClutterUnit has become a redundant type, defined to be a float. All integer entry points are being internally converted to floating point values to be passed to the GL pipeline with the least amount of conversion. ClutterUnit is thus exposed as just a "pixel with fractionary bits", and not -- as users might think -- as generic, resolution and device independent units. not that it was the case, but a definitive amount of people was convinced it did provide this "feature", and was flummoxed about the mere existence of this type. So, having ClutterUnit exposed in the public API doubles the entry points and has the following disadvantages: - we have to maintain twice the amount of entry points in ClutterActor - we still do an integer-to-float implicit conversion - we introduce a weird impedance between pixels and "pixels with fractionary bits" - language bindings will have to choose what to bind, and resort to manually overriding the API + *except* for language bindings based on GObject-Introspection, as they cannot do manual overrides, thus will replicate the entire set of entry points For these reason, we should coalesces every Actor entry point for pixels and for ClutterUnit into a single entry point taking a float, like: void clutter_actor_set_x (ClutterActor *self, gfloat x); void clutter_actor_get_size (ClutterActor *self, gfloat *width, gfloat *height); gfloat clutter_actor_get_height (ClutterActor *self); etc. The issues I have identified are: - we'll have a two cases of compiler warnings: - printf() format of the return values from %d to %f - clutter_actor_get_size() taking floats instead of unsigned ints - we'll have a problem with varargs when passing an integer instead of a floating point value, except on 64bit platforms where the size of a float is the same as the size of an int To be clear: the *intent* of the API should not change -- we still use pixels everywhere -- but: - we remove ambiguity in the API with regard to pixels and units - we remove entry points we get to maintain for the whole 1.0 version of the API - we make things simpler to bind for both manual language bindings and automatic (gobject-introspection based) ones - we have the simplest API possible while still exposing the capabilities of the underlying GL implementation
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gfloat for_height,
gfloat *min_width,
gfloat *natural_width)
{
ClutterCairoTexturePrivate *priv = CLUTTER_CAIRO_TEXTURE (actor)->priv;
if (min_width)
*min_width = 0;
if (natural_width)
Remove Units from the public API With the recent change to internal floating point values, ClutterUnit has become a redundant type, defined to be a float. All integer entry points are being internally converted to floating point values to be passed to the GL pipeline with the least amount of conversion. ClutterUnit is thus exposed as just a "pixel with fractionary bits", and not -- as users might think -- as generic, resolution and device independent units. not that it was the case, but a definitive amount of people was convinced it did provide this "feature", and was flummoxed about the mere existence of this type. So, having ClutterUnit exposed in the public API doubles the entry points and has the following disadvantages: - we have to maintain twice the amount of entry points in ClutterActor - we still do an integer-to-float implicit conversion - we introduce a weird impedance between pixels and "pixels with fractionary bits" - language bindings will have to choose what to bind, and resort to manually overriding the API + *except* for language bindings based on GObject-Introspection, as they cannot do manual overrides, thus will replicate the entire set of entry points For these reason, we should coalesces every Actor entry point for pixels and for ClutterUnit into a single entry point taking a float, like: void clutter_actor_set_x (ClutterActor *self, gfloat x); void clutter_actor_get_size (ClutterActor *self, gfloat *width, gfloat *height); gfloat clutter_actor_get_height (ClutterActor *self); etc. The issues I have identified are: - we'll have a two cases of compiler warnings: - printf() format of the return values from %d to %f - clutter_actor_get_size() taking floats instead of unsigned ints - we'll have a problem with varargs when passing an integer instead of a floating point value, except on 64bit platforms where the size of a float is the same as the size of an int To be clear: the *intent* of the API should not change -- we still use pixels everywhere -- but: - we remove ambiguity in the API with regard to pixels and units - we remove entry points we get to maintain for the whole 1.0 version of the API - we make things simpler to bind for both manual language bindings and automatic (gobject-introspection based) ones - we have the simplest API possible while still exposing the capabilities of the underlying GL implementation
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*natural_width = (gfloat) priv->width;
}
static void
clutter_cairo_texture_get_preferred_height (ClutterActor *actor,
Remove Units from the public API With the recent change to internal floating point values, ClutterUnit has become a redundant type, defined to be a float. All integer entry points are being internally converted to floating point values to be passed to the GL pipeline with the least amount of conversion. ClutterUnit is thus exposed as just a "pixel with fractionary bits", and not -- as users might think -- as generic, resolution and device independent units. not that it was the case, but a definitive amount of people was convinced it did provide this "feature", and was flummoxed about the mere existence of this type. So, having ClutterUnit exposed in the public API doubles the entry points and has the following disadvantages: - we have to maintain twice the amount of entry points in ClutterActor - we still do an integer-to-float implicit conversion - we introduce a weird impedance between pixels and "pixels with fractionary bits" - language bindings will have to choose what to bind, and resort to manually overriding the API + *except* for language bindings based on GObject-Introspection, as they cannot do manual overrides, thus will replicate the entire set of entry points For these reason, we should coalesces every Actor entry point for pixels and for ClutterUnit into a single entry point taking a float, like: void clutter_actor_set_x (ClutterActor *self, gfloat x); void clutter_actor_get_size (ClutterActor *self, gfloat *width, gfloat *height); gfloat clutter_actor_get_height (ClutterActor *self); etc. The issues I have identified are: - we'll have a two cases of compiler warnings: - printf() format of the return values from %d to %f - clutter_actor_get_size() taking floats instead of unsigned ints - we'll have a problem with varargs when passing an integer instead of a floating point value, except on 64bit platforms where the size of a float is the same as the size of an int To be clear: the *intent* of the API should not change -- we still use pixels everywhere -- but: - we remove ambiguity in the API with regard to pixels and units - we remove entry points we get to maintain for the whole 1.0 version of the API - we make things simpler to bind for both manual language bindings and automatic (gobject-introspection based) ones - we have the simplest API possible while still exposing the capabilities of the underlying GL implementation
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gfloat for_width,
gfloat *min_height,
gfloat *natural_height)
{
ClutterCairoTexturePrivate *priv = CLUTTER_CAIRO_TEXTURE (actor)->priv;
if (min_height)
*min_height = 0;
if (natural_height)
Remove Units from the public API With the recent change to internal floating point values, ClutterUnit has become a redundant type, defined to be a float. All integer entry points are being internally converted to floating point values to be passed to the GL pipeline with the least amount of conversion. ClutterUnit is thus exposed as just a "pixel with fractionary bits", and not -- as users might think -- as generic, resolution and device independent units. not that it was the case, but a definitive amount of people was convinced it did provide this "feature", and was flummoxed about the mere existence of this type. So, having ClutterUnit exposed in the public API doubles the entry points and has the following disadvantages: - we have to maintain twice the amount of entry points in ClutterActor - we still do an integer-to-float implicit conversion - we introduce a weird impedance between pixels and "pixels with fractionary bits" - language bindings will have to choose what to bind, and resort to manually overriding the API + *except* for language bindings based on GObject-Introspection, as they cannot do manual overrides, thus will replicate the entire set of entry points For these reason, we should coalesces every Actor entry point for pixels and for ClutterUnit into a single entry point taking a float, like: void clutter_actor_set_x (ClutterActor *self, gfloat x); void clutter_actor_get_size (ClutterActor *self, gfloat *width, gfloat *height); gfloat clutter_actor_get_height (ClutterActor *self); etc. The issues I have identified are: - we'll have a two cases of compiler warnings: - printf() format of the return values from %d to %f - clutter_actor_get_size() taking floats instead of unsigned ints - we'll have a problem with varargs when passing an integer instead of a floating point value, except on 64bit platforms where the size of a float is the same as the size of an int To be clear: the *intent* of the API should not change -- we still use pixels everywhere -- but: - we remove ambiguity in the API with regard to pixels and units - we remove entry points we get to maintain for the whole 1.0 version of the API - we make things simpler to bind for both manual language bindings and automatic (gobject-introspection based) ones - we have the simplest API possible while still exposing the capabilities of the underlying GL implementation
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*natural_height = (gfloat) priv->height;
}
static gboolean
clutter_cairo_texture_get_paint_volume (ClutterActor *self,
ClutterPaintVolume *volume)
{
return _clutter_actor_set_default_paint_volume (self,
CLUTTER_TYPE_CAIRO_TEXTURE,
volume);
}
static cairo_surface_t *
clutter_cairo_texture_create_surface (ClutterCairoTexture *self,
guint width,
guint height)
{
cairo_surface_t *surface;
guint cairo_stride;
guint8 *cairo_data;
CoglHandle cogl_texture;
surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
width,
height);
cairo_stride = cairo_image_surface_get_stride (surface);
cairo_data = cairo_image_surface_get_data (surface);
self->priv->surface_width = width;
self->priv->surface_height = height;
/* create a backing Cogl texture */
cogl_texture = cogl_texture_new_from_data (width, height,
COGL_TEXTURE_NONE,
CLUTTER_CAIRO_TEXTURE_PIXEL_FORMAT,
COGL_PIXEL_FORMAT_ANY,
cairo_stride,
cairo_data);
clutter_texture_set_cogl_texture (CLUTTER_TEXTURE (self), cogl_texture);
cogl_handle_unref (cogl_texture);
return surface;
}
static gboolean
create_surface_accum (GSignalInvocationHint *ihint,
GValue *return_accu,
const GValue *handler_return,
gpointer data)
{
g_value_copy (handler_return, return_accu);
/* stop on the first non-NULL return value */
return g_value_get_boxed (handler_return) == NULL;
}
static void
clutter_cairo_texture_class_init (ClutterCairoTextureClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
ClutterActorClass *actor_class = CLUTTER_ACTOR_CLASS (klass);
gobject_class->finalize = clutter_cairo_texture_finalize;
gobject_class->set_property = clutter_cairo_texture_set_property;
gobject_class->get_property = clutter_cairo_texture_get_property;
gobject_class->notify = clutter_cairo_texture_notify;
actor_class->get_paint_volume =
clutter_cairo_texture_get_paint_volume;
actor_class->get_preferred_width =
clutter_cairo_texture_get_preferred_width;
actor_class->get_preferred_height =
clutter_cairo_texture_get_preferred_height;
klass->create_surface = clutter_cairo_texture_create_surface;
g_type_class_add_private (gobject_class, sizeof (ClutterCairoTexturePrivate));
/**
* ClutterCairoTexture:surface-width:
*
* The width of the Cairo surface used by the #ClutterCairoTexture
* actor, in pixels.
*
* Since: 1.0
*/
obj_props[PROP_SURFACE_WIDTH] =
g_param_spec_uint ("surface-width",
P_("Surface Width"),
P_("The width of the Cairo surface"),
0, G_MAXUINT,
0,
CLUTTER_PARAM_READWRITE);
/**
* ClutterCairoTexture:surface-height:
*
* The height of the Cairo surface used by the #ClutterCairoTexture
* actor, in pixels.
*
* Since: 1.0
*/
obj_props[PROP_SURFACE_HEIGHT] =
g_param_spec_uint ("surface-height",
P_("Surface Height"),
P_("The height of the Cairo surface"),
0, G_MAXUINT,
0,
CLUTTER_PARAM_READWRITE);
_clutter_object_class_install_properties (gobject_class,
PROP_LAST,
obj_props);
/**
* ClutterCairoTexture::create_surface:
* @texture: the #ClutterCairoTexture that emitted the signal
* @width: the width of the surface to create
* @height: the height of the surface to create
*
* The ::create-surface signal is emitted when a #ClutterCairoTexture
* news its surface (re)created, which happens either when the Cairo
* context is created with clutter_cairo_texture_create() or
* clutter_cairo_texture_create_region(), or when the surface is resized
* through clutter_cairo_texture_set_surface_size().
*
* The first signal handler that returns a non-%NULL, valid surface will
* stop any further signal emission, and the returned surface will be
* the one used.
*
* Return value: the newly created #cairo_surface_t for the texture
*
* Since: 1.6
*/
cairo_signals[CREATE_SURFACE] =
g_signal_new (I_("create-surface"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (ClutterCairoTextureClass, create_surface),
create_surface_accum, NULL,
_clutter_marshal_BOXED__UINT_UINT,
CAIRO_GOBJECT_TYPE_SURFACE, 2,
G_TYPE_UINT,
G_TYPE_UINT);
}
static void
clutter_cairo_texture_init (ClutterCairoTexture *self)
{
ClutterCairoTexturePrivate *priv;
self->priv = priv = CLUTTER_CAIRO_TEXTURE_GET_PRIVATE (self);
/* FIXME - we are hardcoding the format; it would be good to have
* a :surface-format construct-only property for creating
* textures with a different format and have the cairo surface
* match that format
*
* priv->format = CAIRO_FORMAT_ARGB32;
*/
/* the Cairo surface is responsible for driving the size of
* the texture; if we let sync_size to its default of TRUE,
* the Texture will try to queue a relayout every time we
* change the size of the Cairo surface - which is not what
* we want
*/
clutter_texture_set_sync_size (CLUTTER_TEXTURE (self), FALSE);
}
/**
* clutter_cairo_texture_new:
* @width: the width of the surface
* @height: the height of the surface
*
* Creates a new #ClutterCairoTexture actor, with a surface of @width by
* @height pixels.
*
* Return value: the newly created #ClutterCairoTexture actor
*
* Since: 1.0
*/
ClutterActor*
clutter_cairo_texture_new (guint width,
guint height)
{
return g_object_new (CLUTTER_TYPE_CAIRO_TEXTURE,
"surface-width", width,
"surface-height", height,
NULL);
}
static void
clutter_cairo_texture_context_destroy (void *data)
{
ClutterCairoTextureContext *ctxt = data;
ClutterCairoTexture *cairo = ctxt->cairo;
ClutterCairoTexturePrivate *priv = cairo->priv;
guint8 *cairo_data;
gint cairo_width, cairo_height, cairo_stride;
gint surface_width, surface_height;
CoglHandle cogl_texture;
if (priv->cr_surface == NULL)
return;
/* for any other surface type, we presume that there exists a native
* communication between Cairo and GL that is triggered by cairo_destroy().
*
* for instance, cairo-drm will flush the outstanding modifications to the
* surface upon context destruction and so the texture is automatically
* updated.
*/
if (cairo_surface_get_type (priv->cr_surface) != CAIRO_SURFACE_TYPE_IMAGE)
goto out;
surface_width = cairo_image_surface_get_width (priv->cr_surface);
surface_height = cairo_image_surface_get_height (priv->cr_surface);
cairo_width = MIN (ctxt->rect.width, surface_width);
cairo_height = MIN (ctxt->rect.height, surface_height);
cogl_texture = clutter_texture_get_cogl_texture (CLUTTER_TEXTURE (cairo));
if (!cairo_width || !cairo_height || cogl_texture == COGL_INVALID_HANDLE)
{
g_slice_free (ClutterCairoTextureContext, ctxt);
return;
}
cairo_stride = cairo_image_surface_get_stride (priv->cr_surface);
cairo_data = cairo_image_surface_get_data (priv->cr_surface);
cairo_data += cairo_stride * ctxt->rect.y;
cairo_data += 4 * ctxt->rect.x;
cogl_texture_set_region (cogl_texture,
0, 0,
ctxt->rect.x, ctxt->rect.y,
cairo_width, cairo_height,
cairo_width, cairo_height,
CLUTTER_CAIRO_TEXTURE_PIXEL_FORMAT,
cairo_stride,
cairo_data);
out:
g_slice_free (ClutterCairoTextureContext, ctxt);
clutter_actor_queue_redraw (CLUTTER_ACTOR (cairo));
}
static void
intersect_rectangles (cairo_rectangle_int_t *a,
cairo_rectangle_int_t *b,
cairo_rectangle_int_t *inter)
{
gint dest_x, dest_y;
gint dest_width, dest_height;
dest_x = MAX (a->x, b->x);
dest_y = MAX (a->y, b->y);
dest_width = MIN (a->x + a->width, b->x + b->width) - dest_x;
dest_height = MIN (a->y + a->height, b->y + b->height) - dest_y;
if (dest_width > 0 && dest_height > 0)
{
inter->x = dest_x;
inter->y = dest_y;
inter->width = dest_width;
inter->height = dest_height;
}
else
{
inter->x = 0;
inter->y = 0;
inter->width = 0;
inter->height = 0;
}
}
/**
* clutter_cairo_texture_create_region:
* @self: a #ClutterCairoTexture
* @x_offset: offset of the region on the X axis
* @y_offset: offset of the region on the Y axis
* @width: width of the region, or -1 for the full surface width
* @height: height of the region, or -1 for the full surface height
*
* Creates a new Cairo context that will updat the region defined
* by @x_offset, @y_offset, @width and @height.
*
* <warning><para>Do not call this function within the paint virtual
* function or from a callback to the #ClutterActor::paint
* signal.</para></warning>
*
* Return value: a newly created Cairo context. Use cairo_destroy()
* to upload the contents of the context when done drawing
*
* Since: 1.0
*/
cairo_t *
clutter_cairo_texture_create_region (ClutterCairoTexture *self,
gint x_offset,
gint y_offset,
gint width,
gint height)
{
ClutterCairoTexturePrivate *priv;
ClutterCairoTextureContext *ctxt;
cairo_rectangle_int_t region, area, inter;
cairo_surface_t *surface;
cairo_t *cr;
g_return_val_if_fail (CLUTTER_IS_CAIRO_TEXTURE (self), NULL);
clutter_warn_if_paint_fail (self);
priv = self->priv;
if (width < 0)
width = priv->width;
if (height < 0)
height = priv->height;
if (width == 0 || height == 0)
{
g_warning ("Unable to create a context for an image surface of "
"width %d and height %d. Set the surface size to be "
"at least 1 pixel by 1 pixel.",
width, height);
return NULL;
}
surface = get_surface (self);
ctxt = g_slice_new0 (ClutterCairoTextureContext);
ctxt->cairo = self;
region.x = x_offset;
region.y = y_offset;
region.width = width;
region.height = height;
area.x = 0;
area.y = 0;
area.width = priv->width;
area.height = priv->height;
/* Limit the region to the visible rectangle */
intersect_rectangles (&area, &region, &inter);
ctxt->rect = inter;
cr = cairo_create (surface);
cairo_set_user_data (cr, &clutter_cairo_texture_context_key,
ctxt,
clutter_cairo_texture_context_destroy);
return cr;
}
/**
* clutter_cairo_texture_create:
* @self: a #ClutterCairoTexture
*
* Creates a new Cairo context for the @cairo texture. It is
* similar to using clutter_cairo_texture_create_region() with @x_offset
* and @y_offset of 0, @width equal to the @cairo texture surface width
* and @height equal to the @cairo texture surface height.
*
* <warning><para>Do not call this function within the paint virtual
* function or from a callback to the #ClutterActor::paint
* signal.</para></warning>
*
* Return value: a newly created Cairo context. Use cairo_destroy()
* to upload the contents of the context when done drawing
*
* Since: 1.0
*/
cairo_t *
clutter_cairo_texture_create (ClutterCairoTexture *self)
{
g_return_val_if_fail (CLUTTER_IS_CAIRO_TEXTURE (self), NULL);
clutter_warn_if_paint_fail (self);
return clutter_cairo_texture_create_region (self, 0, 0, -1, -1);
}
/**
* clutter_cairo_set_source_color:
* @cr: a Cairo context
* @color: a #ClutterColor
*
* Utility function for setting the source color of @cr using
* a #ClutterColor.
*
* Since: 1.0
*/
void
clutter_cairo_set_source_color (cairo_t *cr,
const ClutterColor *color)
{
g_return_if_fail (cr != NULL);
g_return_if_fail (color != NULL);
if (color->alpha == 0xff)
cairo_set_source_rgb (cr,
color->red / 255.0,
color->green / 255.0,
color->blue / 255.0);
else
cairo_set_source_rgba (cr,
color->red / 255.0,
color->green / 255.0,
color->blue / 255.0,
color->alpha / 255.0);
}
/**
* clutter_cairo_texture_set_surface_size:
* @self: a #ClutterCairoTexture
* @width: the new width of the surface
* @height: the new height of the surface
*
* Resizes the Cairo surface used by @self to @width and @height.
*
* Since: 1.0
*/
void
clutter_cairo_texture_set_surface_size (ClutterCairoTexture *self,
guint width,
guint height)
{
ClutterCairoTexturePrivate *priv;
g_return_if_fail (CLUTTER_IS_CAIRO_TEXTURE (self));
priv = self->priv;
if (width == priv->width && height == priv->height)
return;
g_object_freeze_notify (G_OBJECT (self));
if (priv->width != width)
{
priv->width = width;
2010-06-21 05:20:32 -04:00
_clutter_notify_by_pspec (G_OBJECT (self), obj_props[PROP_SURFACE_WIDTH]);
}
if (priv->height != height)
{
priv->height = height;
2010-06-21 05:20:32 -04:00
_clutter_notify_by_pspec (G_OBJECT (self), obj_props[PROP_SURFACE_HEIGHT]);
}
clutter_cairo_texture_surface_resize_internal (self);
g_object_thaw_notify (G_OBJECT (self));
}
/**
* clutter_cairo_texture_get_surface_size:
* @self: a #ClutterCairoTexture
* @width: (out): return location for the surface width, or %NULL
* @height: (out): return location for the surface height, or %NULL
*
* Retrieves the surface width and height for @self.
*
* Since: 1.0
*/
void
clutter_cairo_texture_get_surface_size (ClutterCairoTexture *self,
guint *width,
guint *height)
{
g_return_if_fail (CLUTTER_IS_CAIRO_TEXTURE (self));
if (width)
*width = self->priv->width;
if (height)
*height = self->priv->height;
}
/**
* clutter_cairo_texture_clear:
* @self: a #ClutterCairoTexture
*
* Clears @self's internal drawing surface, so that the next upload
* will replace the previous contents of the #ClutterCairoTexture
* rather than adding to it.
*
* Since: 1.0
*/
void
clutter_cairo_texture_clear (ClutterCairoTexture *self)
{
cairo_surface_t *surface;
cairo_t *cr;
g_return_if_fail (CLUTTER_IS_CAIRO_TEXTURE (self));
surface = get_surface (self);
cr = cairo_create (surface);
cairo_set_operator (cr, CAIRO_OPERATOR_CLEAR);
cairo_paint (cr);
cairo_destroy (cr);
}