mutter/clutter/clutter-cairo-texture.c
Emmanuele Bassi c93cd4a096 [docs] Documentation fixes for CairoTexture
Sync up the arguments name inside the gtk-doc annotations with their
name inside the function declaration in the header file.
2008-12-19 17:48:30 +00:00

763 lines
22 KiB
C

/*
* 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 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, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* 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);
* ]|
*
* <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 "clutter-cairo-texture.h"
#include "clutter-debug.h"
#include "clutter-private.h"
G_DEFINE_TYPE (ClutterCairoTexture,
clutter_cairo_texture,
CLUTTER_TYPE_TEXTURE);
enum
{
PROP_0,
PROP_SURFACE_WIDTH,
PROP_SURFACE_HEIGHT
};
#ifdef CLUTTER_ENABLE_DEBUG
#define clutter_warn_if_paint_fail(obj) G_STMT_START { \
if (CLUTTER_PRIVATE_FLAGS ((obj)) & CLUTTER_ACTOR_IN_PAINT) { \
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))
struct _ClutterCairoTexturePrivate
{
cairo_format_t format;
cairo_surface_t *cr_surface;
guchar *cr_surface_data;
guint width;
guint height;
guint rowstride;
};
typedef struct
{
gint x;
gint y;
guint width;
guint height;
} ClutterCairoTextureRectangle;
typedef struct
{
ClutterCairoTexture *cairo;
ClutterCairoTextureRectangle rect;
} ClutterCairoTextureContext;
static const cairo_user_data_key_t clutter_cairo_texture_surface_key;
static const cairo_user_data_key_t clutter_cairo_texture_context_key;
static void
clutter_cairo_texture_surface_destroy (void *data)
{
ClutterCairoTexture *cairo = data;
cairo->priv->cr_surface = NULL;
}
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)
{
cairo_surface_t *surface = priv->cr_surface;
cairo_surface_finish (priv->cr_surface);
cairo_surface_set_user_data (priv->cr_surface,
&clutter_cairo_texture_surface_key,
NULL, NULL);
cairo_surface_destroy (surface);
priv->cr_surface = NULL;
}
if (priv->cr_surface_data)
{
g_free (priv->cr_surface_data);
priv->cr_surface_data = NULL;
}
G_OBJECT_CLASS (clutter_cairo_texture_parent_class)->finalize (object);
}
static inline void
clutter_cairo_texture_surface_resize_internal (ClutterCairoTexture *cairo)
{
ClutterCairoTexturePrivate *priv = cairo->priv;
if (priv->cr_surface)
{
cairo_surface_t *surface = priv->cr_surface;
/* If the surface is already the right size then don't bother
doing anything */
if (priv->width == cairo_image_surface_get_width (priv->cr_surface)
&& priv->height == cairo_image_surface_get_height (priv->cr_surface))
return;
cairo_surface_finish (surface);
cairo_surface_set_user_data (surface,
&clutter_cairo_texture_surface_key,
NULL, NULL);
cairo_surface_destroy (surface);
priv->cr_surface = NULL;
}
if (priv->cr_surface_data)
{
g_free (priv->cr_surface_data);
priv->cr_surface_data = NULL;
}
if (priv->width == 0 || priv->height == 0)
return;
#if CAIRO_VERSION > 106000
priv->rowstride = cairo_format_stride_for_width (priv->format, priv->width);
#else
/* poor man's version of cairo_format_stride_for_width() */
switch (priv->format)
{
case CAIRO_FORMAT_ARGB32:
case CAIRO_FORMAT_RGB24:
priv->rowstride = priv->width * 4;
break;
case CAIRO_FORMAT_A8:
case CAIRO_FORMAT_A1:
priv->rowstride = priv->width;
break;
default:
g_assert_not_reached ();
break;
}
#endif /* CAIRO_VERSION > 106000 */
priv->cr_surface_data = g_malloc0 (priv->height * priv->rowstride);
priv->cr_surface =
cairo_image_surface_create_for_data (priv->cr_surface_data,
priv->format,
priv->width, priv->height,
priv->rowstride);
cairo_surface_set_user_data (priv->cr_surface,
&clutter_cairo_texture_surface_key,
cairo,
clutter_cairo_texture_surface_destroy);
/* The texture data will be all zeroes so we can use it to create a
* blank Cogl texture even though its in a different format
*/
clutter_texture_set_from_rgb_data (CLUTTER_TEXTURE (cairo),
priv->cr_surface_data,
TRUE, priv->width, priv->height,
priv->rowstride,
4, 0, NULL);
}
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 */
if (!strcmp ("surface-width", pspec->name)
|| !strcmp ("surface-height", pspec->name))
{
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,
ClutterUnit for_height,
ClutterUnit *min_width,
ClutterUnit *natural_width)
{
ClutterCairoTexturePrivate *priv = CLUTTER_CAIRO_TEXTURE (actor)->priv;
if (min_width)
*min_width = 0;
if (natural_width)
*natural_width = CLUTTER_UNITS_FROM_DEVICE (priv->width);
}
static void
clutter_cairo_texture_get_preferred_height (ClutterActor *actor,
ClutterUnit for_width,
ClutterUnit *min_height,
ClutterUnit *natural_height)
{
ClutterCairoTexturePrivate *priv = CLUTTER_CAIRO_TEXTURE (actor)->priv;
if (min_height)
*min_height = 0;
if (natural_height)
*natural_height = CLUTTER_UNITS_FROM_DEVICE (priv->height);
}
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_preferred_width =
clutter_cairo_texture_get_preferred_width;
actor_class->get_preferred_height =
clutter_cairo_texture_get_preferred_height;
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
*/
g_object_class_install_property (gobject_class,
PROP_SURFACE_WIDTH,
g_param_spec_uint ("surface-width",
"Surface-Width",
"Surface Width",
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
*/
g_object_class_install_property (gobject_class,
PROP_SURFACE_HEIGHT,
g_param_spec_uint ("surface-height",
"Surface-Height",
"Surface Height",
0, G_MAXUINT,
0,
CLUTTER_PARAM_READWRITE));
}
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;
}
/**
* 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;
gint cairo_width, cairo_height, cairo_rowstride;
gint surface_width, surface_height;
guchar *pixbuf_data, *dst, *cairo_data;
guint *src, pixbuf_rowstride;
gint x, y;
priv = CLUTTER_CAIRO_TEXTURE_GET_PRIVATE (cairo);
if (!priv->cr_surface)
return;
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);
if (!cairo_width || !cairo_height)
{
g_free (ctxt);
return;
}
cairo_rowstride = priv->rowstride;
cairo_data = priv->cr_surface_data;
pixbuf_data = g_malloc (cairo_width * cairo_height * 4);
pixbuf_rowstride = cairo_width * 4;
/* BAH BAH BAH ! un-pre-multiply alpha...
*
* FIXME: Need to figure out if GL has a premult texture
* format, or we need to change the order of the
* paint sequence in Clutter. or go back to battling
* glitz (ugh).
*
* in theory, this could be moved to a shader, but apparently
* the performance gain is not really worth it.
*/
for (y = 0; y < cairo_height; y++)
{
src = (unsigned int *) (cairo_data
+ ((y + ctxt->rect.y) * cairo_rowstride)
+ (ctxt->rect.x * 4));
dst = pixbuf_data + y * pixbuf_rowstride;
for (x = 0; x < cairo_width; x++)
{
guchar alpha = (*src >> 24) & 0xff;
if (alpha == 0)
dst[0] = dst[1] = dst[2] = dst[3] = alpha;
else
{
dst[0] = (((*src >> 16) & 0xff) * 255 ) / alpha;
dst[1] = (((*src >> 8) & 0xff) * 255 ) / alpha;
dst[2] = (((*src >> 0) & 0xff) * 255 ) / alpha;
dst[3] = alpha;
}
dst += 4;
src++;
}
}
clutter_texture_set_area_from_rgb_data (CLUTTER_TEXTURE (cairo),
pixbuf_data,
TRUE,
ctxt->rect.x,
ctxt->rect.y,
cairo_width, cairo_height,
pixbuf_rowstride,
4, 0, NULL);
g_free (pixbuf_data);
g_free (ctxt);
if (CLUTTER_ACTOR_IS_VISIBLE (cairo))
clutter_actor_queue_redraw (CLUTTER_ACTOR (cairo));
}
static void
intersect_rectangles (ClutterCairoTextureRectangle *a,
ClutterCairoTextureRectangle *b,
ClutterCairoTextureRectangle *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;
ClutterCairoTextureRectangle region, area, inter;
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;
}
if (!priv->cr_surface)
return NULL;
ctxt = g_new0 (ClutterCairoTextureContext, 1);
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.x = inter.x;
ctxt->rect.y = inter.y;
ctxt->rect.width = inter.width;
ctxt->rect.height = inter.height;
cr = cairo_create (priv->cr_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;
g_object_notify (G_OBJECT (self), "surface-width");
}
if (priv->height != height)
{
priv->height = height;
g_object_notify (G_OBJECT (self), "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: return location for the surface width, or %NULL
* @height: 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;
}