281 lines
8.9 KiB
C
281 lines
8.9 KiB
C
/* GdkPixbuf library - convert X drawable information to RGB
|
|
*
|
|
* Copyright (C) 1999 Michael Zucchi
|
|
*
|
|
* Authors: Michael Zucchi <zucchi@zedzone.mmc.com.au>
|
|
* Cody Russell <bratsche@dfw.net>
|
|
* 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 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.
|
|
*/
|
|
|
|
#include "config.h"
|
|
|
|
#include "gdkpixbuf.h"
|
|
|
|
#include "gdkcolor.h"
|
|
#include "gdkwindow.h"
|
|
#include "gdkinternals.h"
|
|
|
|
#include <gdk-pixbuf/gdk-pixbuf.h>
|
|
|
|
/**
|
|
* SECTION:pixbufs
|
|
* @Short_description: Functions for obtaining pixbufs
|
|
* @Title: Pixbufs
|
|
*
|
|
* Pixbufs are client-side images. For details on how to create
|
|
* and manipulate pixbufs, see the #GdkPixbuf API documentation.
|
|
*
|
|
* The functions described here allow to obtain pixbufs from
|
|
* #GdkWindows and cairo surfaces.
|
|
*/
|
|
|
|
|
|
/**
|
|
* gdk_pixbuf_get_from_window:
|
|
* @window: Source window
|
|
* @src_x: Source X coordinate within @window
|
|
* @src_y: Source Y coordinate within @window
|
|
* @width: Width in pixels of region to get
|
|
* @height: Height in pixels of region to get
|
|
*
|
|
* Transfers image data from a #GdkWindow and converts it to an RGB(A)
|
|
* representation inside a #GdkPixbuf. In other words, copies
|
|
* image data from a server-side drawable to a client-side RGB(A) buffer.
|
|
* This allows you to efficiently read individual pixels on the client side.
|
|
*
|
|
* This function will create an RGB pixbuf with 8 bits per channel with
|
|
* the same size specified by the @width and @height arguments. The pixbuf
|
|
* will contain an alpha channel if the @window contains one.
|
|
*
|
|
* If the window is off the screen, then there is no image data in the
|
|
* obscured/offscreen regions to be placed in the pixbuf. The contents of
|
|
* portions of the pixbuf corresponding to the offscreen region are undefined.
|
|
*
|
|
* If the window you're obtaining data from is partially obscured by
|
|
* other windows, then the contents of the pixbuf areas corresponding
|
|
* to the obscured regions are undefined.
|
|
*
|
|
* If the window is not mapped (typically because it's iconified/minimized
|
|
* or not on the current workspace), then %NULL will be returned.
|
|
*
|
|
* If memory can't be allocated for the return value, %NULL will be returned
|
|
* instead.
|
|
*
|
|
* (In short, there are several ways this function can fail, and if it fails
|
|
* it returns %NULL; so check the return value.)
|
|
*
|
|
* Return value: (transfer full): A newly-created pixbuf with a reference
|
|
* count of 1, or %NULL on error
|
|
*/
|
|
GdkPixbuf *
|
|
gdk_pixbuf_get_from_window (GdkWindow *src,
|
|
gint src_x,
|
|
gint src_y,
|
|
gint width,
|
|
gint height)
|
|
{
|
|
cairo_surface_t *surface;
|
|
GdkPixbuf *dest;
|
|
|
|
g_return_val_if_fail (GDK_IS_WINDOW (src), NULL);
|
|
g_return_val_if_fail (gdk_window_is_viewable (src), NULL);
|
|
|
|
surface = _gdk_window_ref_cairo_surface (src);
|
|
dest = gdk_pixbuf_get_from_surface (surface,
|
|
src_x, src_y,
|
|
width, height);
|
|
cairo_surface_destroy (surface);
|
|
|
|
return dest;
|
|
}
|
|
|
|
static cairo_format_t
|
|
gdk_cairo_format_for_content (cairo_content_t content)
|
|
{
|
|
switch (content)
|
|
{
|
|
case CAIRO_CONTENT_COLOR:
|
|
return CAIRO_FORMAT_RGB24;
|
|
case CAIRO_CONTENT_ALPHA:
|
|
return CAIRO_FORMAT_A8;
|
|
case CAIRO_CONTENT_COLOR_ALPHA:
|
|
default:
|
|
return CAIRO_FORMAT_ARGB32;
|
|
}
|
|
}
|
|
|
|
static cairo_surface_t *
|
|
gdk_cairo_surface_coerce_to_image (cairo_surface_t *surface,
|
|
cairo_content_t content,
|
|
int src_x,
|
|
int src_y,
|
|
int width,
|
|
int height)
|
|
{
|
|
cairo_surface_t *copy;
|
|
cairo_t *cr;
|
|
|
|
copy = cairo_image_surface_create (gdk_cairo_format_for_content (content),
|
|
width,
|
|
height);
|
|
|
|
cr = cairo_create (copy);
|
|
cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE);
|
|
cairo_set_source_surface (cr, surface, -src_x, -src_y);
|
|
cairo_paint (cr);
|
|
cairo_destroy (cr);
|
|
|
|
return copy;
|
|
}
|
|
|
|
static void
|
|
convert_alpha (guchar *dest_data,
|
|
int dest_stride,
|
|
guchar *src_data,
|
|
int src_stride,
|
|
int src_x,
|
|
int src_y,
|
|
int width,
|
|
int height)
|
|
{
|
|
int x, y;
|
|
|
|
src_data += src_stride * src_y + src_x * 4;
|
|
|
|
for (y = 0; y < height; y++) {
|
|
guint32 *src = (guint32 *) src_data;
|
|
|
|
for (x = 0; x < width; x++) {
|
|
guint alpha = src[x] >> 24;
|
|
|
|
if (alpha == 0)
|
|
{
|
|
dest_data[x * 4 + 0] = 0;
|
|
dest_data[x * 4 + 1] = 0;
|
|
dest_data[x * 4 + 2] = 0;
|
|
}
|
|
else
|
|
{
|
|
dest_data[x * 4 + 0] = (((src[x] & 0xff0000) >> 16) * 255 + alpha / 2) / alpha;
|
|
dest_data[x * 4 + 1] = (((src[x] & 0x00ff00) >> 8) * 255 + alpha / 2) / alpha;
|
|
dest_data[x * 4 + 2] = (((src[x] & 0x0000ff) >> 0) * 255 + alpha / 2) / alpha;
|
|
}
|
|
dest_data[x * 4 + 3] = alpha;
|
|
}
|
|
|
|
src_data += src_stride;
|
|
dest_data += dest_stride;
|
|
}
|
|
}
|
|
|
|
static void
|
|
convert_no_alpha (guchar *dest_data,
|
|
int dest_stride,
|
|
guchar *src_data,
|
|
int src_stride,
|
|
int src_x,
|
|
int src_y,
|
|
int width,
|
|
int height)
|
|
{
|
|
int x, y;
|
|
|
|
src_data += src_stride * src_y + src_x * 4;
|
|
|
|
for (y = 0; y < height; y++) {
|
|
guint32 *src = (guint32 *) src_data;
|
|
|
|
for (x = 0; x < width; x++) {
|
|
dest_data[x * 3 + 0] = src[x] >> 16;
|
|
dest_data[x * 3 + 1] = src[x] >> 8;
|
|
dest_data[x * 3 + 2] = src[x];
|
|
}
|
|
|
|
src_data += src_stride;
|
|
dest_data += dest_stride;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gdk_pixbuf_get_from_surface:
|
|
* @surface: surface to copy from
|
|
* @src_x: Source X coordinate within @surface
|
|
* @src_y: Source Y coordinate within @surface
|
|
* @width: Width in pixels of region to get
|
|
* @height: Height in pixels of region to get
|
|
*
|
|
* Transfers image data from a #cairo_surface_t and converts it to an RGB(A)
|
|
* representation inside a #GdkPixbuf. This allows you to efficiently read
|
|
* individual pixels from cairo surfaces. For #GdkWindows, use
|
|
* gdk_pixbuf_get_from_window() instead.
|
|
*
|
|
* This function will create an RGB pixbuf with 8 bits per channel.
|
|
* The pixbuf will contain an alpha channel if the @surface contains one.
|
|
*
|
|
* Return value: (transfer full): A newly-created pixbuf with a reference
|
|
* count of 1, or %NULL on error
|
|
*/
|
|
GdkPixbuf *
|
|
gdk_pixbuf_get_from_surface (cairo_surface_t *surface,
|
|
gint src_x,
|
|
gint src_y,
|
|
gint width,
|
|
gint height)
|
|
{
|
|
cairo_content_t content;
|
|
GdkPixbuf *dest;
|
|
|
|
/* General sanity checks */
|
|
g_return_val_if_fail (surface != NULL, NULL);
|
|
g_return_val_if_fail (width > 0 && height > 0, NULL);
|
|
|
|
content = cairo_surface_get_content (surface) | CAIRO_CONTENT_COLOR;
|
|
dest = gdk_pixbuf_new (GDK_COLORSPACE_RGB,
|
|
!!(content & CAIRO_CONTENT_ALPHA),
|
|
8,
|
|
width, height);
|
|
|
|
surface = gdk_cairo_surface_coerce_to_image (surface, content,
|
|
src_x, src_y,
|
|
width, height);
|
|
cairo_surface_flush (surface);
|
|
if (cairo_surface_status (surface) || dest == NULL)
|
|
{
|
|
cairo_surface_destroy (surface);
|
|
return NULL;
|
|
}
|
|
|
|
if (gdk_pixbuf_get_has_alpha (dest))
|
|
convert_alpha (gdk_pixbuf_get_pixels (dest),
|
|
gdk_pixbuf_get_rowstride (dest),
|
|
cairo_image_surface_get_data (surface),
|
|
cairo_image_surface_get_stride (surface),
|
|
0, 0,
|
|
width, height);
|
|
else
|
|
convert_no_alpha (gdk_pixbuf_get_pixels (dest),
|
|
gdk_pixbuf_get_rowstride (dest),
|
|
cairo_image_surface_get_data (surface),
|
|
cairo_image_surface_get_stride (surface),
|
|
0, 0,
|
|
width, height);
|
|
|
|
cairo_surface_destroy (surface);
|
|
return dest;
|
|
}
|