Name
Utilities -- Utility and miscellaneous convenience functions.
Synopsis
#include <gdk-pixbuf/gdk-pixbuf.h>
GdkPixbuf* gdk_pixbuf_add_alpha (const GdkPixbuf *pixbuf,
gboolean substitute_color,
guchar r,
guchar g,
guchar b);
void gdk_pixbuf_copy_area (const GdkPixbuf *src_pixbuf,
int src_x,
int src_y,
int width,
int height,
GdkPixbuf *dest_pixbuf,
int dest_x,
int dest_y);
void gdk_pixbuf_saturate_and_pixelate
(const GdkPixbuf *src,
GdkPixbuf *dest,
gfloat saturation,
gboolean pixelate); |
Description
These functions provide miscellaneous utilities for manipulating
pixbufs. The pixel data in pixbufs may of course be manipulated
directly by applications, but several common operations can be
performed by these functions instead.
Details
gdk_pixbuf_add_alpha ()
GdkPixbuf* gdk_pixbuf_add_alpha (const GdkPixbuf *pixbuf,
gboolean substitute_color,
guchar r,
guchar g,
guchar b); |
Takes an existing pixbuf and adds an alpha channel to it.
If the existing pixbuf already had an alpha channel, the channel
values are copied from the original; otherwise, the alpha channel
is initialized to 255 (full opacity).
If substitute_color is TRUE, then the color specified by (r, g, b) will be
assigned zero opacity. That is, if you pass (255, 255, 255) for the
substitute color, all white pixels will become fully transparent.
gdk_pixbuf_copy_area ()
void gdk_pixbuf_copy_area (const GdkPixbuf *src_pixbuf,
int src_x,
int src_y,
int width,
int height,
GdkPixbuf *dest_pixbuf,
int dest_x,
int dest_y); |
Copies a rectangular area from src_pixbuf to dest_pixbuf. Conversion of
pixbuf formats is done automatically.
gdk_pixbuf_saturate_and_pixelate ()
void gdk_pixbuf_saturate_and_pixelate
(const GdkPixbuf *src,
GdkPixbuf *dest,
gfloat saturation,
gboolean pixelate); |
Modifies saturation and optionally pixelates src, placing the
result in dest. src and dest may be the same pixbuf with no ill
effects. If saturation is 1.0 then saturation is not changed. If
it's less than 1.0, saturation is reduced (the image is darkened);
if greater than 1.0, saturation is increased (the image is
brightened). If pixelate is TRUE, then pixels are faded in a
checkerboard pattern to create a pixelated image. src and dest
must have the same image format, size, and rowstride.