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gtk2/gdk-pixbuf/gnome-canvas-pixbuf.c
Arturo Espinosa 9d8da16ee9 More docs work - Federico
1999-11-04 21:52:08 +00:00

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/* GNOME libraries - GdkPixbuf item for the GNOME canvas
*
* Copyright (C) 1999 The Free Software Foundation
*
* Author: Federico Mena-Quintero <federico@gimp.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library 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.
*/
#include <config.h>
#include <math.h>
#include <libgnomeui/gnome-canvas.h>
#include <libgnomeui/gnome-canvas-util.h>
#include "gdk-pixbuf.h"
#include "gnome-canvas-pixbuf.h"
#include "libart_lgpl/art_rgb_pixbuf_affine.h"
/* Private part of the GnomeCanvasPixbuf structure */
typedef struct {
/* Our gdk-pixbuf */
GdkPixbuf *pixbuf;
/* Width value */
double width;
/* Height value */
double height;
/* X translation */
double x;
/* Y translation */
double y;
/* Whether dimensions are set and whether they are in pixels or units */
guint width_set : 1;
guint width_pixels : 1;
guint height_set : 1;
guint height_pixels : 1;
guint x_set : 1;
guint x_pixels : 1;
guint y_set : 1;
guint y_pixels : 1;
/* Whether the pixbuf has changed */
guint need_pixbuf_update : 1;
/* Whether the transformation or size have changed */
guint need_xform_update : 1;
} PixbufPrivate;
/* Object argument IDs */
enum {
ARG_0,
ARG_PIXBUF,
ARG_WIDTH,
ARG_WIDTH_SET,
ARG_WIDTH_PIXELS,
ARG_HEIGHT,
ARG_HEIGHT_SET,
ARG_HEIGHT_PIXELS,
ARG_X,
ARG_X_SET,
ARG_X_PIXELS,
ARG_Y,
ARG_Y_SET,
ARG_Y_PIXELS
};
static void gnome_canvas_pixbuf_class_init (GnomeCanvasPixbufClass *class);
static void gnome_canvas_pixbuf_init (GnomeCanvasPixbuf *cpb);
static void gnome_canvas_pixbuf_destroy (GtkObject *object);
static void gnome_canvas_pixbuf_set_arg (GtkObject *object, GtkArg *arg, guint arg_id);
static void gnome_canvas_pixbuf_get_arg (GtkObject *object, GtkArg *arg, guint arg_id);
static void gnome_canvas_pixbuf_update (GnomeCanvasItem *item, double *affine,
ArtSVP *clip_path, int flags);
static void gnome_canvas_pixbuf_draw (GnomeCanvasItem *item, GdkDrawable *drawable,
int x, int y, int width, int height);
static void gnome_canvas_pixbuf_render (GnomeCanvasItem *item, GnomeCanvasBuf *buf);
static double gnome_canvas_pixbuf_point (GnomeCanvasItem *item, double x, double y, int cx, int cy,
GnomeCanvasItem **actual_item);
static void gnome_canvas_pixbuf_bounds (GnomeCanvasItem *item,
double *x1, double *y1, double *x2, double *y2);
static GnomeCanvasItemClass *parent_class;
/**
* gnome_canvas_pixbuf_get_type:
* @void:
*
* Registers the #GnomeCanvasPixbuf class if necessary, and returns the type ID
* associated to it.
*
* Return value: The type ID of the #GnomeCanvasPixbuf class.
**/
GtkType
gnome_canvas_pixbuf_get_type (void)
{
static GtkType canvas_pixbuf_type = 0;
if (!canvas_pixbuf_type) {
static const GtkTypeInfo canvas_pixbuf_info = {
"GnomeCanvasPixbuf",
sizeof (GnomeCanvasPixbuf),
sizeof (GnomeCanvasPixbufClass),
(GtkClassInitFunc) gnome_canvas_pixbuf_class_init,
(GtkObjectInitFunc) gnome_canvas_pixbuf_init,
NULL, /* reserved_1 */
NULL, /* reserved_2 */
(GtkClassInitFunc) NULL
};
canvas_pixbuf_type = gtk_type_unique (gnome_canvas_item_get_type (),
&canvas_pixbuf_info);
}
return canvas_pixbuf_type;
}
/* Class initialization function for the pixbuf canvas item */
static void
gnome_canvas_pixbuf_class_init (GnomeCanvasPixbufClass *class)
{
GtkObjectClass *object_class;
GnomeCanvasItemClass *item_class;
object_class = (GtkObjectClass *) class;
item_class = (GnomeCanvasItemClass *) class;
parent_class = gtk_type_class (gnome_canvas_item_get_type ());
gtk_object_add_arg_type ("GnomeCanvasPixbuf::pixbuf",
GTK_TYPE_POINTER, GTK_ARG_READWRITE, ARG_PIXBUF);
gtk_object_add_arg_type ("GnomeCanvasPixbuf::width",
GTK_TYPE_DOUBLE, GTK_ARG_READWRITE, ARG_WIDTH);
gtk_object_add_arg_type ("GnomeCanvasPixbuf::width_set",
GTK_TYPE_BOOL, GTK_ARG_READWRITE, ARG_WIDTH_SET);
gtk_object_add_arg_type ("GnomeCanvasPixbuf::width_pixels",
GTK_TYPE_BOOL, GTK_ARG_READWRITE, ARG_WIDTH_PIXELS);
gtk_object_add_arg_type ("GnomeCanvasPixbuf::height",
GTK_TYPE_DOUBLE, GTK_ARG_READWRITE, ARG_HEIGHT);
gtk_object_add_arg_type ("GnomeCanvasPixbuf::height_set",
GTK_TYPE_BOOL, GTK_ARG_READWRITE, ARG_HEIGHT_SET);
gtk_object_add_arg_type ("GnomeCanvasPixbuf::height_pixels",
GTK_TYPE_BOOL, GTK_ARG_READWRITE, ARG_HEIGHT_PIXELS);
gtk_object_add_arg_type ("GnomeCanvasPixbuf::x",
GTK_TYPE_DOUBLE, GTK_ARG_READWRITE, ARG_X);
gtk_object_add_arg_type ("GnomeCanvasPixbuf::x_set",
GTK_TYPE_BOOL, GTK_ARG_READWRITE, ARG_X_SET);
gtk_object_add_arg_type ("GnomeCanvasPixbuf::x_pixels",
GTK_TYPE_BOOL, GTK_ARG_READWRITE, ARG_X_PIXELS);
gtk_object_add_arg_type ("GnomeCanvasPixbuf::y",
GTK_TYPE_DOUBLE, GTK_ARG_READWRITE, ARG_Y);
gtk_object_add_arg_type ("GnomeCanvasPixbuf::y_set",
GTK_TYPE_BOOL, GTK_ARG_READWRITE, ARG_Y_SET);
gtk_object_add_arg_type ("GnomeCanvasPixbuf::y_pixels",
GTK_TYPE_BOOL, GTK_ARG_READWRITE, ARG_Y_PIXELS);
object_class->destroy = gnome_canvas_pixbuf_destroy;
object_class->set_arg = gnome_canvas_pixbuf_set_arg;
object_class->get_arg = gnome_canvas_pixbuf_get_arg;
item_class->update = gnome_canvas_pixbuf_update;
item_class->draw = gnome_canvas_pixbuf_draw;
item_class->render = gnome_canvas_pixbuf_render;
item_class->point = gnome_canvas_pixbuf_point;
item_class->bounds = gnome_canvas_pixbuf_bounds;
}
/* Object initialization function for the pixbuf canvas item */
static void
gnome_canvas_pixbuf_init (GnomeCanvasPixbuf *gcp)
{
PixbufPrivate *priv;
priv = g_new0 (PixbufPrivate, 1);
gcp->priv = priv;
priv->width = 0.0;
priv->height = 0.0;
priv->x = 0.0;
priv->y = 0.0;
}
/* Destroy handler for the pixbuf canvas item */
static void
gnome_canvas_pixbuf_destroy (GtkObject *object)
{
GnomeCanvasItem *item;
GnomeCanvasPixbuf *gcp;
PixbufPrivate *priv;
g_return_if_fail (object != NULL);
g_return_if_fail (GNOME_IS_CANVAS_PIXBUF (object));
item = GNOME_CANVAS_ITEM (object);
gcp = (GNOME_CANVAS_PIXBUF (object));
priv = gcp->priv;
gnome_canvas_request_redraw (item->canvas, item->x1, item->y1, item->x2, item->y2);
if (priv->pixbuf)
gdk_pixbuf_unref (priv->pixbuf);
g_free (priv);
if (GTK_OBJECT_CLASS (parent_class)->destroy)
(* GTK_OBJECT_CLASS (parent_class)->destroy) (object);
}
/* Set_arg handler for the pixbuf canvas item */
static void
gnome_canvas_pixbuf_set_arg (GtkObject *object, GtkArg *arg, guint arg_id)
{
GnomeCanvasItem *item;
GnomeCanvasPixbuf *gcp;
PixbufPrivate *priv;
GdkPixbuf *pixbuf;
double val;
item = GNOME_CANVAS_ITEM (object);
gcp = GNOME_CANVAS_PIXBUF (object);
priv = gcp->priv;
switch (arg_id) {
case ARG_PIXBUF:
pixbuf = GTK_VALUE_POINTER (*arg);
if (pixbuf != priv->pixbuf) {
if (pixbuf) {
g_return_if_fail (pixbuf->art_pixbuf->format == ART_PIX_RGB);
g_return_if_fail (pixbuf->art_pixbuf->n_channels == 3
|| pixbuf->art_pixbuf->n_channels == 4);
g_return_if_fail (pixbuf->art_pixbuf->bits_per_sample == 8);
gdk_pixbuf_ref (pixbuf);
}
if (priv->pixbuf)
gdk_pixbuf_unref (priv->pixbuf);
priv->pixbuf = pixbuf;
}
priv->need_pixbuf_update = TRUE;
gnome_canvas_item_request_update (item);
break;
case ARG_WIDTH:
val = GTK_VALUE_DOUBLE (*arg);
g_return_if_fail (val >= 0.0);
priv->width = val;
priv->need_xform_update = TRUE;
gnome_canvas_item_request_update (item);
break;
case ARG_WIDTH_SET:
priv->width_set = GTK_VALUE_BOOL (*arg) ? TRUE : FALSE;
priv->need_xform_update = TRUE;
gnome_canvas_item_request_update (item);
break;
case ARG_WIDTH_PIXELS:
priv->width_pixels = GTK_VALUE_BOOL (*arg) ? TRUE : FALSE;
priv->need_xform_update = TRUE;
gnome_canvas_item_request_update (item);
break;
case ARG_HEIGHT:
val = GTK_VALUE_DOUBLE (*arg);
g_return_if_fail (val >= 0.0);
priv->height = val;
priv->need_xform_update = TRUE;
gnome_canvas_item_request_update (item);
break;
case ARG_HEIGHT_SET:
priv->height_set = GTK_VALUE_BOOL (*arg) ? TRUE : FALSE;
priv->need_xform_update = TRUE;
gnome_canvas_item_request_update (item);
break;
case ARG_HEIGHT_PIXELS:
priv->height_pixels = GTK_VALUE_BOOL (*arg) ? TRUE : FALSE;
priv->need_xform_update = TRUE;
gnome_canvas_item_request_update (item);
break;
case ARG_X:
priv->x = GTK_VALUE_DOUBLE (*arg);
priv->need_xform_update = TRUE;
gnome_canvas_item_request_update (item);
break;
case ARG_X_SET:
priv->x_set = GTK_VALUE_BOOL (*arg) ? TRUE : FALSE;
priv->need_xform_update = TRUE;
gnome_canvas_item_request_update (item);
break;
case ARG_X_PIXELS:
priv->x_pixels = GTK_VALUE_BOOL (*arg) ? TRUE : FALSE;
priv->need_xform_update = TRUE;
gnome_canvas_item_request_update (item);
break;
case ARG_Y:
priv->y = GTK_VALUE_DOUBLE (*arg);
priv->need_xform_update = TRUE;
gnome_canvas_item_request_update (item);
break;
case ARG_Y_SET:
priv->y_set = GTK_VALUE_BOOL (*arg) ? TRUE : FALSE;
priv->need_xform_update = TRUE;
gnome_canvas_item_request_update (item);
break;
case ARG_Y_PIXELS:
priv->y_pixels = GTK_VALUE_BOOL (*arg) ? TRUE : FALSE;
priv->need_xform_update = TRUE;
gnome_canvas_item_request_update (item);
break;
default:
break;
}
}
/* Get_arg handler for the pixbuf canvasi item */
static void
gnome_canvas_pixbuf_get_arg (GtkObject *object, GtkArg *arg, guint arg_id)
{
GnomeCanvasItem *item;
GnomeCanvasPixbuf *gcp;
PixbufPrivate *priv;
item = GNOME_CANVAS_ITEM (object);
gcp = GNOME_CANVAS_PIXBUF (object);
priv = gcp->priv;
switch (arg_id) {
case ARG_PIXBUF:
GTK_VALUE_POINTER (*arg) = priv->pixbuf;
break;
case ARG_WIDTH:
GTK_VALUE_DOUBLE (*arg) = priv->width;
break;
case ARG_WIDTH_SET:
GTK_VALUE_BOOL (*arg) = priv->width_set;
break;
case ARG_WIDTH_PIXELS:
GTK_VALUE_BOOL (*arg) = priv->width_pixels;
break;
case ARG_HEIGHT:
GTK_VALUE_DOUBLE (*arg) = priv->height;
break;
case ARG_HEIGHT_SET:
GTK_VALUE_BOOL (*arg) = priv->height_set;
break;
case ARG_HEIGHT_PIXELS:
GTK_VALUE_BOOL (*arg) = priv->height_pixels;
break;
case ARG_X:
GTK_VALUE_DOUBLE (*arg) = priv->x;
break;
case ARG_X_SET:
GTK_VALUE_BOOL (*arg) = priv->x_set;
break;
case ARG_X_PIXELS:
GTK_VALUE_BOOL (*arg) = priv->x_pixels;
break;
case ARG_Y:
GTK_VALUE_DOUBLE (*arg) = priv->y;
break;
case ARG_Y_SET:
GTK_VALUE_BOOL (*arg) = priv->y_set;
break;
case ARG_Y_PIXELS:
GTK_VALUE_BOOL (*arg) = priv->y_pixels;
break;
default:
arg->type = GTK_TYPE_INVALID;
break;
}
}
/* Bounds and utilities */
/* Computes the amount by which the unit horizontal and vertical vectors will be
* scaled by an affine transformation.
*/
static void
compute_xform_scaling (double *affine, ArtPoint *i_c, ArtPoint *j_c)
{
ArtPoint orig, orig_c;
ArtPoint i, j;
/* Origin */
orig.x = 0.0;
orig.y = 0.0;
art_affine_point (&orig_c, &orig, affine);
/* Horizontal and vertical vectors */
i.x = 1.0;
i.y = 0.0;
art_affine_point (i_c, &i, affine);
i_c->x -= orig_c.x;
i_c->y -= orig_c.y;
j.x = 0.0;
j.y = 1.0;
art_affine_point (j_c, &j, affine);
j_c->x -= orig_c.x;
j_c->y -= orig_c.y;
}
/* Computes the affine transformation with which the pixbuf needs to be
* transformed to render it on the canvas. This is not the same as the
* item_to_canvas transformation because we may need to scale the pixbuf by some
* other amount.
*/
static void
compute_render_affine (GnomeCanvasPixbuf *gcp, double *render_affine, double *i2c)
{
PixbufPrivate *priv;
ArtPoint i_c, j_c;
double i_len, j_len;
double si_len, sj_len;
double ti_len, tj_len;
double scale[6], translate[6], composite[6];
double w, h;
double x, y;
priv = gcp->priv;
/* Compute scaling vectors and required width/height */
compute_xform_scaling (i2c, &i_c, &j_c);
i_len = sqrt (i_c.x * i_c.x + i_c.y * i_c.y);
j_len = sqrt (j_c.x * j_c.x + j_c.y * j_c.y);
if (priv->width_set)
w = priv->width;
else
w = priv->pixbuf->art_pixbuf->width;
if (priv->height_set)
h = priv->height;
else
h = priv->pixbuf->art_pixbuf->height;
if (priv->x_set)
x = priv->x;
else
x = 0.0;
if (priv->y_set)
y = priv->y;
else
y = 0.0;
/* Convert i_len and j_len into scaling factors */
if (priv->width_pixels) {
if (i_len > GNOME_CANVAS_EPSILON)
si_len = 1.0 / i_len;
else
si_len = 0.0;
} else
si_len = 1.0;
si_len *= w / priv->pixbuf->art_pixbuf->width;
if (priv->height_pixels) {
if (j_len > GNOME_CANVAS_EPSILON)
sj_len = 1.0 / j_len;
else
sj_len = 0.0;
} else
sj_len = 1.0;
sj_len *= h / priv->pixbuf->art_pixbuf->height;
/* Calculate translation offsets */
if (priv->x_pixels) {
if (i_len > GNOME_CANVAS_EPSILON)
ti_len = 1.0 / i_len;
else
ti_len = 0.0;
} else
ti_len = 1.0;
ti_len *= x;
if (priv->y_pixels) {
if (j_len > GNOME_CANVAS_EPSILON)
tj_len = 1.0 / j_len;
else
tj_len = 0.0;
} else
tj_len = 1.0;
tj_len *= y;
/* Compute the final affine */
art_affine_scale (scale, si_len, sj_len);
art_affine_translate (translate, ti_len, tj_len);
art_affine_multiply (composite, scale, translate);
art_affine_multiply (render_affine, composite, i2c);
}
/* Recomputes the bounding box of a pixbuf canvas item. The horizontal and
* vertical dimensions may be specified in units or pixels, separately, so we
* have to compute the components individually for each dimension.
*/
static void
recompute_bounding_box (GnomeCanvasPixbuf *gcp)
{
GnomeCanvasItem *item;
PixbufPrivate *priv;
double i2c[6], render_affine[6];
ArtDRect rect;
item = GNOME_CANVAS_ITEM (gcp);
priv = gcp->priv;
if (!priv->pixbuf) {
item->x1 = item->y1 = item->x2 = item->y2 = 0.0;
return;
}
rect.x0 = 0.0;
rect.x1 = priv->pixbuf->art_pixbuf->width;
rect.y0 = 0.0;
rect.y1 = priv->pixbuf->art_pixbuf->height;
gnome_canvas_item_i2c_affine (item, i2c);
compute_render_affine (gcp, render_affine, i2c);
art_drect_affine_transform (&rect, &rect, render_affine);
item->x1 = floor (rect.x0);
item->y1 = floor (rect.y0);
item->x2 = ceil (rect.x1);
item->y2 = ceil (rect.y1);
}
/* Update sequence */
/* Update handler for the pixbuf canvas item */
static void
gnome_canvas_pixbuf_update (GnomeCanvasItem *item, double *affine, ArtSVP *clip_path, int flags)
{
GnomeCanvasPixbuf *gcp;
PixbufPrivate *priv;
gcp = GNOME_CANVAS_PIXBUF (item);
priv = gcp->priv;
if (parent_class->update)
(* parent_class->update) (item, affine, clip_path, flags);
if (((flags & GNOME_CANVAS_UPDATE_VISIBILITY)
&& !(GTK_OBJECT_FLAGS (item) & GNOME_CANVAS_ITEM_VISIBLE))
|| (flags & GNOME_CANVAS_UPDATE_AFFINE)
|| priv->need_pixbuf_update
|| priv->need_xform_update)
gnome_canvas_request_redraw (item->canvas, item->x1, item->y1, item->x2, item->y2);
/* If we need a pixbuf update, or if the item changed visibility to
* shown, recompute the bounding box.
*/
if (priv->need_pixbuf_update
|| priv->need_xform_update
|| ((flags & GNOME_CANVAS_UPDATE_VISIBILITY)
&& (GTK_OBJECT_FLAGS (gcp) & GNOME_CANVAS_ITEM_VISIBLE))
|| (flags & GNOME_CANVAS_UPDATE_AFFINE)) {
recompute_bounding_box (gcp);
gnome_canvas_request_redraw (item->canvas, item->x1, item->y1, item->x2, item->y2);
priv->need_pixbuf_update = FALSE;
priv->need_xform_update = FALSE;
}
}
/* Rendering */
/* This is private to libart, but we need it. Sigh. */
extern void art_rgb_affine_run (int *p_x0, int *p_x1, int y, int src_width, int src_height,
const double affine[6]);
/* Fills the specified buffer with the transformed version of a pixbuf */
static void
transform_pixbuf (guchar *dest, int x, int y, int width, int height, int rowstride,
GdkPixbuf *pixbuf, double *affine)
{
ArtPixBuf *apb;
int xx, yy;
double inv[6];
guchar *src, *d;
ArtPoint src_p, dest_p;
int run_x1, run_x2;
int src_x, src_y;
int i;
apb = pixbuf->art_pixbuf;
art_affine_invert (inv, affine);
for (yy = 0; yy < height; yy++) {
dest_p.y = y + yy + 0.5;
run_x1 = x;
run_x2 = x + width;
art_rgb_affine_run (&run_x1, &run_x2, yy + y,
apb->width, apb->height,
inv);
d = dest + yy * rowstride + (run_x1 - x) * 4;
for (xx = run_x1; xx < run_x2; xx++) {
dest_p.x = xx + 0.5;
art_affine_point (&src_p, &dest_p, inv);
src_x = floor (src_p.x);
src_y = floor (src_p.y);
src = apb->pixels + src_y * apb->rowstride + src_x * apb->n_channels;
for (i = 0; i < apb->n_channels; i++)
*d++ = *src++;
if (!apb->has_alpha)
*d++ = 255; /* opaque */
}
}
}
/* Draw handler for the pixbuf canvas item */
static void
gnome_canvas_pixbuf_draw (GnomeCanvasItem *item, GdkDrawable *drawable,
int x, int y, int width, int height)
{
GnomeCanvasPixbuf *gcp;
PixbufPrivate *priv;
double i2c[6], render_affine[6];
guchar *buf;
GdkPixbuf *pixbuf;
gcp = GNOME_CANVAS_PIXBUF (item);
priv = gcp->priv;
if (!priv->pixbuf)
return;
gnome_canvas_item_i2c_affine (item, i2c);
compute_render_affine (gcp, render_affine, i2c);
buf = g_new0 (guchar, width * height * 4);
transform_pixbuf (buf, x, y, width, height, width * 4, priv->pixbuf, render_affine);
pixbuf = gdk_pixbuf_new_from_data (buf, ART_PIX_RGB, TRUE,
width, height, width * 4,
NULL, NULL);
gdk_pixbuf_render_to_drawable_alpha (pixbuf, drawable,
0, 0,
0, 0,
width, height,
GDK_PIXBUF_ALPHA_BILEVEL,
128,
GDK_RGB_DITHER_MAX,
x, y);
gdk_pixbuf_unref (pixbuf);
g_free (buf);
}
/* Render handler for the pixbuf canvas item */
static void
gnome_canvas_pixbuf_render (GnomeCanvasItem *item, GnomeCanvasBuf *buf)
{
GnomeCanvasPixbuf *gcp;
PixbufPrivate *priv;
double i2c[6], render_affine[6];
gcp = GNOME_CANVAS_PIXBUF (item);
priv = gcp->priv;
if (!priv->pixbuf)
return;
gnome_canvas_item_i2c_affine (item, i2c);
compute_render_affine (gcp, render_affine, i2c);
gnome_canvas_buf_ensure_buf (buf);
art_rgb_pixbuf_affine (buf->buf,
buf->rect.x0, buf->rect.y0, buf->rect.x1, buf->rect.y1,
buf->buf_rowstride,
priv->pixbuf->art_pixbuf,
render_affine,
ART_FILTER_NEAREST, NULL);
buf->is_bg = 0;
}
/* Point handler for the pixbuf canvas item */
static double
gnome_canvas_pixbuf_point (GnomeCanvasItem *item, double x, double y, int cx, int cy,
GnomeCanvasItem **actual_item)
{
GnomeCanvasPixbuf *gcp;
PixbufPrivate *priv;
double i2c[6], render_affine[6], inv[6];
ArtPoint c, p;
int px, py;
double no_hit;
ArtPixBuf *apb;
guchar *src;
gcp = GNOME_CANVAS_PIXBUF (item);
priv = gcp->priv;
*actual_item = item;
no_hit = item->canvas->pixels_per_unit * 2 + 10;
if (!priv->pixbuf)
return no_hit;
apb = priv->pixbuf->art_pixbuf;
gnome_canvas_item_i2c_affine (item, i2c);
compute_render_affine (gcp, render_affine, i2c);
art_affine_invert (inv, render_affine);
c.x = cx;
c.y = cy;
art_affine_point (&p, &c, inv);
px = p.x;
py = p.y;
if (px < 0 || px >= apb->width || py < 0 || py >= apb->height)
return no_hit;
if (!apb->has_alpha)
return 0.0;
src = apb->pixels + py * apb->rowstride + px * apb->n_channels;
if (src[3] < 128)
return no_hit;
else
return 0.0;
}
/* Bounds handler for the pixbuf canvas item */
static void
gnome_canvas_pixbuf_bounds (GnomeCanvasItem *item, double *x1, double *y1, double *x2, double *y2)
{
GnomeCanvasPixbuf *gcp;
PixbufPrivate *priv;
gcp = GNOME_CANVAS_PIXBUF (item);
priv = gcp->priv;
*x1 = 0.0;
*y1 = 0.0;
if (priv->pixbuf) {
if (priv->width_set)
*x2 = priv->width;
else
*x2 = priv->pixbuf->art_pixbuf->width;
if (priv->height_set)
*y2 = priv->height;
else
*y2 = priv->pixbuf->art_pixbuf->height;
} else {
*x2 = 0.0;
*y2 = 0.0;
}
}
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