|
|
|
GIMP Library Reference Manual | |
|---|---|---|---|---|
| Top | Description | ||||
GimpPixelRgn; void gimp_pixel_rgn_init (GimpPixelRgn *pr,GimpDrawable *drawable,gint x,gint y,gint width,gint height,gint dirty,gint shadow); void gimp_pixel_rgn_resize (GimpPixelRgn *pr,gint x,gint y,gint width,gint height); void gimp_pixel_rgn_get_pixel (GimpPixelRgn *pr,guchar *buf,gint x,gint y); void gimp_pixel_rgn_get_row (GimpPixelRgn *pr,guchar *buf,gint x,gint y,gint width); void gimp_pixel_rgn_get_col (GimpPixelRgn *pr,guchar *buf,gint x,gint y,gint height); void gimp_pixel_rgn_get_rect (GimpPixelRgn *pr,guchar *buf,gint x,gint y,gint width,gint height); void gimp_pixel_rgn_set_pixel (GimpPixelRgn *pr,const guchar *buf,gint x,gint y); void gimp_pixel_rgn_set_row (GimpPixelRgn *pr,const guchar *buf,gint x,gint y,gint width); void gimp_pixel_rgn_set_col (GimpPixelRgn *pr,const guchar *buf,gint x,gint y,gint height); void gimp_pixel_rgn_set_rect (GimpPixelRgn *pr,const guchar *buf,gint x,gint y,gint width,gint height); gpointer gimp_pixel_rgns_register (gint nrgns,...); gpointer gimp_pixel_rgns_register2 (gint nrgns,GimpPixelRgn **prs); gpointer gimp_pixel_rgns_process (gpointer pri_ptr);
Functions for operating on pixel regions. These functions provide fast ways of accessing and modifying portions of a drawable.
typedef struct {
guchar *data; /* pointer to region data */
GimpDrawable *drawable; /* pointer to drawable */
gint bpp; /* bytes per pixel */
gint rowstride; /* bytes per pixel row */
gint x, y; /* origin */
gint w, h; /* width and height of region */
guint dirty : 1; /* will this region be dirtied? */
guint shadow : 1; /* will this region use the shadow or normal tiles */
gint process_count; /* used internally */
} GimpPixelRgn;
void gimp_pixel_rgn_init (GimpPixelRgn *pr,GimpDrawable *drawable,gint x,gint y,gint width,gint height,gint dirty,gint shadow);
Initialize the pixel region pointed by pr with the specified parameters.
The dirty and shadow flags can be used as follows:
dirty = FALSE, shadow = FALSE: the region will be used to read
the actual drawable datas. This
is useful for save plug-ins or for
filters.
dirty = FALSE, shadow = TRUE: the region will be used to read the
shadow tiles. This is used in
some filter plug-ins which operate
in two passes such as gaussian
blur. The first pass reads the
actual drawable data and writes to
the shadow tiles, and the second
one reads from and writes to the
shadow tiles.
dirty = TRUE, shadow = TRUE: the region will be used to write to
the shadow tiles. It is common
practice to write to the shadow
tiles and then use
gimp_drawable_merge_shadow() to
merge the changes from the shadow
tiles using the current selection
as a mask.
dirty = TRUE, shadow = FALSE: the region will be used to directly
change the drawable content. Don't
do this, since this could prevent
the Undo-System from working as
expected.
|
a pointer to a GimpPixelRgn variable. |
|
the GimpDrawable the new region will be attached to. |
|
the x coordinate of the top-left pixel of the region in the
drawable. |
|
the y coordinate of the top-left pixel of the region in the
drawable. |
|
the width of the region. |
|
the height of the region. |
|
a gboolean indicating whether the drawable should be marked
as "dirty". |
|
a gboolean indicating whether the region is attached to the
shadow tiles or the real drawable tiles. |
void gimp_pixel_rgn_resize (GimpPixelRgn *pr,gint x,gint y,gint width,gint height);
Change the position and size of a previously initialized pixel region.
|
a pointer to a previously initialized GimpPixelRgn. |
|
the x coordinate of the new position of the region's top-left corner. |
|
the y coordinate of the new position of the region's top-left corner. |
|
the new width of the region. |
|
the new height of the region. |
void gimp_pixel_rgn_get_pixel (GimpPixelRgn *pr,guchar *buf,gint x,gint y);
Fill the buffer pointed by buf with the value of the pixel at (x, y)
in the region pr. buf should be large enough to hold the pixel value
(1 guchar for an indexed or grayscale drawable, 2 guchar for
indexed with alpha or grayscale with alpha drawable, 3 guchar for
rgb drawable and 4 guchar for rgb with alpha drawable.
|
a pointer to a previously initialized GimpPixelRgn. |
|
a pointer to an array of guchar |
|
the x coordinate of the wanted pixel (relative to the drawable) |
|
the y coordinate of the wanted pixel (relative to the drawable) |
void gimp_pixel_rgn_get_row (GimpPixelRgn *pr,guchar *buf,gint x,gint y,gint width);
Get several pixels of a region in a row. This function fills the buffer
buf with the values of the pixels from (x, y) to (x+width-1, y).
buf should be large enough to hold all these values.
|
a pointer to a previously initialized GimpPixelRgn. |
|
a pointer to an array of guchar |
|
the x coordinate of the first pixel (relative to the drawable). |
|
the y coordinate of the first pixel (relative to the drawable). |
|
the number of pixels to get. |
void gimp_pixel_rgn_get_col (GimpPixelRgn *pr,guchar *buf,gint x,gint y,gint height);
Get several pixels of a region's column. This function fills the buffer
buf with the values of the pixels from (x, y) to (x, y+height-1).
buf should be large enough to hold all these values.
|
a pointer to a previously initialized GimpPixelRgn. |
|
a pointer to an array of guchar |
|
the x coordinate of the first pixel (relative to the drawable). |
|
the y coordinate of the first pixel (relative to the drawable). |
|
the number of pixels to get. |
void gimp_pixel_rgn_get_rect (GimpPixelRgn *pr,guchar *buf,gint x,gint y,gint width,gint height);
Get all the pixel values from the rectangle defined by x, y, width and
height. This function fills the buffer buf with the values of the pixels
from (x, y) to (x+width-1, y+height-1).
buf should be large enough to hold all these values (width*height*bpp).
|
a pointer to a previously initialized GimpPixelRgn. |
|
a pointer to an array of guchar |
|
the x coordinate of the first pixel (relative to the drawable). |
|
the y coordinate of the first pixel (relative to the drawable). |
|
the width of the rectangle. |
|
the height of the rectangle. |
void gimp_pixel_rgn_set_pixel (GimpPixelRgn *pr,const guchar *buf,gint x,gint y);
Set the pixel at (x, y) to the values from buf.
|
a pointer to a previously initialized GimpPixelRgn. |
|
a pointer to an array of guchar. |
|
the x coordinate of the pixel (relative to the drawable). |
|
the y coordinate of the pixel (relative to the drawable). |
void gimp_pixel_rgn_set_row (GimpPixelRgn *pr,const guchar *buf,gint x,gint y,gint width);
Set several pixels of a region in a row. This function draws the pixels
from (x, y) to (x+width-1, y) using the values of the buffer buf.
buf should be large enough to hold all these values.
|
a pointer to a previously initialized GimpPixelRgn. |
|
a pointer to an array of guchar |
|
the x coordinate of the first pixel (relative to the drawable). |
|
the y coordinate of the first pixel (relative to the drawable). |
|
the number of pixels to set. |
void gimp_pixel_rgn_set_col (GimpPixelRgn *pr,const guchar *buf,gint x,gint y,gint height);
Set several pixels of a region's column. This function draws the pixels
from (x, y) to (x, y+height-1) using the values from the buffer buf.
buf should be large enough to hold all these values.
|
a pointer to a previously initialized GimpPixelRgn. |
|
a pointer to an array of guchar |
|
the x coordinate of the first pixel (relative to the drawable). |
|
the y coordinate of the first pixel (relative to the drawable). |
|
the number of pixels to set. |
void gimp_pixel_rgn_set_rect (GimpPixelRgn *pr,const guchar *buf,gint x,gint y,gint width,gint height);
Set all the pixel of the rectangle defined by x, y, width and
height. This function draws the rectangle from (x, y) to
(x+width-1, y+height-1), using the pixel values from the buffer buf.
buf should be large enough to hold all these values (width*height*bpp).
|
a pointer to a previously initialized GimpPixelRgn. |
|
a pointer to an array of guchar |
|
the x coordinate of the first pixel (relative to the drawable). |
|
the y coordinate of the first pixel (relative to the drawable). |
|
the width of the rectangle. |
|
the height of the rectangle. |
gpointer gimp_pixel_rgns_register (gint nrgns,...);
This is the varargs version of gimp_pixel_rgns_register2.
|
the number of regions to register. |
|
nrgns pointers to GimpPixelRgn. |
Returns : |
a gpointer to a regions iterator. |
gpointer gimp_pixel_rgns_register2 (gint nrgns,GimpPixelRgn **prs);
It takes a number of initialized regions of the same size and provides a pixel region iterator the iterator can be used to iterate over the registered pixel regions. While iterating the registered pixel regions will cover subsets of the original pixel regions, chosen for optimized access to the image data.
Note that the given regions themselves are changed by this function, so they are resized to the first subsets.
This function has to be used together with gimp_pixel_rgns_process in a loop.
|
the number of regions to register. |
|
an array of nrgns pointers to initialized GimpPixelRgn. |
Returns : |
a gpointer to a regions iterator. |
gpointer gimp_pixel_rgns_process (gpointer pri_ptr);
This function update the regions registered previously with one of the gimp_pixel_rgns_register* functions to their next tile.
|
a regions iterator returned by gimp_pixel_rgns_register, gimp_pixel_rgns_register2 or gimp_pixel_rgns_process. |
Returns : |
a gpointer to a new regions iterator or NULL if there isn't any tiles left. |