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#include <gdk/gdk.h>
#include <gdk-pixbuf/gdk-pixbuf.h>
#include "gdk-pixbuf-extra.h"
#include "string.h"
/*************** gdk_pixbuf_is_subimage ()
simple test: is one image contained in the other ?
*/
void
gdk_pixbuf_clear(GdkPixbuf *pb)
{
int width = gdk_pixbuf_get_width(pb),
height = gdk_pixbuf_get_height(pb);
long size = width * height;
guchar *data = gdk_pixbuf_get_pixels(pb);
memset(data, 0, size * gdk_pixbuf_get_n_channels(pb) );
}
/******** measures square distance between images ***
* useful for matching subimages
*/
double long gdk_pixbuf_sqrdist(GdkPixbuf *p1,GdkPixbuf *p2)
{
int i,j, r1 , r2, w,w1,w2, h,h1,h2, c;
int r;
double res=0;
guchar * d1, * d2;
c=gdk_pixbuf_get_n_channels(p1);
g_assert (!gdk_pixbuf_get_has_alpha(p1)
|| !gdk_pixbuf_get_has_alpha(p2)
|| 8!=gdk_pixbuf_get_bits_per_sample(p2)
|| 8!=gdk_pixbuf_get_bits_per_sample(p1)
|| c != gdk_pixbuf_get_n_channels(p2)
);
d1=gdk_pixbuf_get_pixels(p1) ;
d2=gdk_pixbuf_get_pixels(p2) ;
r1= gdk_pixbuf_get_rowstride(p1);
r2= gdk_pixbuf_get_rowstride(p2);
w1=gdk_pixbuf_get_width(p1);
w2=gdk_pixbuf_get_width(p2);
h1=gdk_pixbuf_get_width(p1);
h2=gdk_pixbuf_get_width(p2);
w=MIN(w1,w2);
h=MIN(h1,h2);
for(j=h; j>=0; j--)
for(i=0; i < w*c ; i++){
r=(d1[ i + r1 * j] - d2[ i + r2 * j]);
res += r*r;
}
return res / (double)w / (double)h ;
}
static void
gdk_pixbuf_subimage_GdkPixbufDestroyNotify(guchar *pixels,
gpointer data)
{
gdk_pixbuf_unref( (GdkPixbuf*) data );
}
gboolean
gdk_pixbuf_is_subimage (
int src_x,
int src_y,
int width,
int height,
int dst_width,
int dst_height
)
{
if ( src_x < 0 || src_y < 0
|| src_x + width > dst_width
|| src_y + height > dst_height
)
return FALSE;
else
return TRUE;
}
/*
src_pixbuf :
Source pixbuf.
src_x :
Source X coordinate within src_pixbuf.
src_y :
Source Y coordinate within src_pixbuf.
width :
Width of the area to copy.
height :
Height of the area to copy.
returns : subimage pixbuf, or NULL if there is an error
This function is similar to gdk_pixbuf_copy_area()
but it uses the same buffer as the buffer in src_pixbuf
for this reason, the subimage must be contained in the given image
*/
GdkPixbuf*
gdk_pixbuf_subimage (GdkPixbuf *src_pixbuf,
int src_x,
int src_y,
int width,
int height)
{
if( src_pixbuf == NULL)
{
g_warning( "%s (in %s:%d): %s\n",
__FUNCTION__ , __FILE__ , __LINE__ ,
( "src_pixbuf is null" ));
return NULL;
}
if ( width < 1 || height < 1 ) {
g_warning( "%s (in %s:%d): %s\n",
__FUNCTION__ , __FILE__ , __LINE__ ,
( "subimage has zero size" ));
return NULL;
}
if ( ! gdk_pixbuf_is_subimage ( src_x,
src_y,
width,
height,
gdk_pixbuf_get_width(src_pixbuf),
gdk_pixbuf_get_height(src_pixbuf)) ) {
g_warning( "%s (in %s:%d): %s\n",
__FUNCTION__ , __FILE__ , __LINE__ ,
( "subimage is not contained in image" ));
return NULL;
}
{
/* bytes per sample */
int b= gdk_pixbuf_get_n_channels(src_pixbuf) *
gdk_pixbuf_get_bits_per_sample(src_pixbuf) / 8;
/* increment the reference count.
this way, we are sure that the buffer will not disappear
beneath this pixbuf
*/
gdk_pixbuf_ref( src_pixbuf);
/* the ref count will be decremented when the
subimage pixbuf will be destroyed
*/
return gdk_pixbuf_new_from_data
(gdk_pixbuf_get_pixels(src_pixbuf) //+
+ gdk_pixbuf_get_rowstride(src_pixbuf) * src_y + src_x * b,
gdk_pixbuf_get_colorspace(src_pixbuf),
gdk_pixbuf_get_has_alpha(src_pixbuf),
gdk_pixbuf_get_bits_per_sample(src_pixbuf),
width,
height,
gdk_pixbuf_get_rowstride(src_pixbuf), //rowstride
gdk_pixbuf_subimage_GdkPixbufDestroyNotify,
(gpointer)src_pixbuf//gpointer destroy_fn_data
);
}
}
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