| Top | Description |  |  |  |  | 
#include <gdk-pixbuf/gdk-pixbuf.h> struct XlibRgbCmap; enum XlibRgbDither; void xlib_rgb_init (Display *display,Screen *screen); void xlib_rgb_init_with_depth (Display *display,Screen *screen,int prefDepth); unsigned long xlib_rgb_xpixel_from_rgb (guint32 rgb); void xlib_rgb_gc_set_foreground (GC gc,guint32 rgb); void xlib_rgb_gc_set_background (GC gc,guint32 rgb); void xlib_draw_rgb_image (Drawable drawable,GC gc,int x,int y,int width,int height,XlibRgbDither dith,unsigned char *rgb_buf,int rowstride); void xlib_draw_rgb_image_dithalign (Drawable drawable,GC gc,int x,int y,int width,int height,XlibRgbDither dith,unsigned char *rgb_buf,int rowstride,int xdith,int ydith); void xlib_draw_rgb_32_image (Drawable drawable,GC gc,int x,int y,int width,int height,XlibRgbDither dith,unsigned char *buf,int rowstride); void xlib_draw_gray_image (Drawable drawable,GC gc,int x,int y,int width,int height,XlibRgbDither dith,unsigned char *buf,int rowstride); XlibRgbCmap * xlib_rgb_cmap_new (guint32 *colors,int n_colors); void xlib_rgb_cmap_free (XlibRgbCmap *cmap); void xlib_draw_indexed_image (Drawable drawable,GC gc,int x,int y,int width,int height,XlibRgbDither dith,unsigned char *buf,int rowstride,XlibRgbCmap *cmap); Bool xlib_rgb_ditherable (void); void xlib_rgb_set_verbose (Bool verbose); void xlib_rgb_set_install (Bool install); void xlib_rgb_set_min_colors (int min_colors); Colormap xlib_rgb_get_cmap (void); Visual * xlib_rgb_get_visual (void); XVisualInfo * xlib_rgb_get_visual_info (void); int xlib_rgb_get_depth (void); Display * xlib_rgb_get_display (void); Screen * xlib_rgb_get_screen (void);
The XlibRGB set of functions is a port of the GdkRGB library to use plain Xlib and X drawables. You can use these functions to render RGB buffers into drawables very quickly with high-quality dithering.
struct XlibRgbCmap {
  unsigned int colors[256];
  unsigned char lut[256]; /* for 8-bit modes */
};
FIXME: Describe this.
typedef enum {
  XLIB_RGB_DITHER_NONE,
  XLIB_RGB_DITHER_NORMAL,
  XLIB_RGB_DITHER_MAX
} XlibRgbDither;
These values are used to specify which dithering method should be used. XLIB_RGB_DITHER_NONE will use no dithering and simply map the colors in an RGB buffer to the closest colors that the display can provide. XLIB_RGB_DITHER_NORMAL will provide dithering only on pseudocolor displays. XLIB_RGB_DITHER_MAX will provide dithering on pseudocolor and 16-bit truecolor or “high color” displays.
void xlib_rgb_init (Display *display,Screen *screen);
Initializes the XlibRGB machinery with the default depth.  If you use this
function XlibRGB will automatically pick the best visual available on your
display.  This function or xlib_rgb_init_with_depth() must be called before
using any of the other functions in XlibRGB.
| 
 | X Display to use. | 
| 
 | Screen to use. | 
void xlib_rgb_init_with_depth (Display *display,Screen *screen,int prefDepth);
Initializes the XlibRGB machinery with a particular depth you specify,
instead of automatically picking the best depth in the display.  This
function or xlib_rgb_init() must be called before using any of the other
functions in XlibRGB.
| 
 | X display to use. | 
| 
 | Screen to use. | 
| 
 | Visual depth to use for color substitution tables.  This must
be one of the supported visual depths in the specified display. | 
unsigned long       xlib_rgb_xpixel_from_rgb            (guint32 rgb);
Converts an RGB triplet into the closest color that XlibRGB visual can handle.
| 
 | 32-bit representation of an RGB value, specified as 0x00RRGGBB. | 
| Returns : | X pixel value that corresponds to the closest color in the XlibRGB visual and colormap. | 
void xlib_rgb_gc_set_foreground (GC gc,guint32 rgb);
This is a convenience function to set the foreground of a GC from an RGB
triplet.  It calls xlib_rgb_xpixel_from_rgb() internally and uses the
returned pixel value to set the GC's foreground.
| 
 | A graphic context. | 
| 
 | 32-bit representation of an RGB value, specified as 0x00RRGGBB. | 
void xlib_rgb_gc_set_background (GC gc,guint32 rgb);
This is a convenience function to set the background of a GC from an RGB
triplet.  It calls xlib_rgb_xpixel_from_rgb() internally and uses the
returned pixel value to set the GC's background.
| 
 | A graphic context. | 
| 
 | 32-bit representation of an RGB value, specified as 0x00RRGGBB. | 
void xlib_draw_rgb_image (Drawable drawable,GC gc,int x,int y,int width,int height,XlibRgbDither dith,unsigned char *rgb_buf,int rowstride);
Renders an RGB buffer to a drawable.  Pixels are specified as RGB triplets
with 8 bits per channel.  An image will thus look like an RGBRGBRGBRGB
sequence of 8-bit values.  This function does not let you specify dither
offsets; applications that need to render partial regions of a buffer to
build the final image should use xlib_draw_rgb_image_dithalign() instead.
| 
 | Destination drawable. | 
| 
 | A graphic context. | 
| 
 | Leftmost coordinate of the destination rectangle. | 
| 
 | Upper coordinate of the destination rectangle. | 
| 
 | Width of the destination rectangle, in pixels. | 
| 
 | Height of the destination rectangle, in pixels. | 
| 
 | Dithering method to use. | 
| 
 | Pointer to the pixel in the RGB buffer that corresponds to the upper-left corner of the rectangular region to render. | 
| 
 | Offset between pixel rows in the RGB buffer, in bytes. | 
void xlib_draw_rgb_image_dithalign (Drawable drawable,GC gc,int x,int y,int width,int height,XlibRgbDither dith,unsigned char *rgb_buf,int rowstride,int xdith,int ydith);
Renders an RGB buffer to a drawable. Pixels are specified as RGB triplets with 8 bits per channel. An image will thus look like an RGBRGBRGBRGB sequence of 8-bit values. This function lets you specify a pair of dither offsets. It should be used when you need to render regions of an RGB buffer separately to form the final image; the dither offsets let you align the dither mask appropriately.
| 
 | Destination drawable. | 
| 
 | A graphic context. | 
| 
 | Leftmost coordinate of the destination rectangle. | 
| 
 | Upper coordinate of the destination rectangle. | 
| 
 | Width of the destination rectangle, in pixels. | 
| 
 | Height of the destination rectangle, in pixels. | 
| 
 | Dithering method to use. | 
| 
 | Pointer to the pixel in the RGB buffer that corresponds to the upper-left corner of the rectangular region to render. | 
| 
 | Offset between pixel rows in the RGB buffer, in bytes. | 
| 
 | X offset for the dither mask. | 
| 
 | Y offset for the dither mask. | 
void xlib_draw_rgb_32_image (Drawable drawable,GC gc,int x,int y,int width,int height,XlibRgbDither dith,unsigned char *buf,int rowstride);
This function is analogous to xlib_draw_rgb_image(), but it lets you use
32-bit RGB buffers with pixels specified as 0xRRGGBB00.  The
least-significant 8 bits are actually discarded.  This function can lead to
faster results than xlib_draw_rgb_image() since the pixels are aligned on
32-bit boundaries.
| 
 | Destination drawable. | 
| 
 | A graphic context. | 
| 
 | Leftmost coordinate of the destination rectangle. | 
| 
 | Upper coordinate of the destination rectangle. | 
| 
 | Width of the destination rectangle, in pixels. | 
| 
 | Height of the destination rectangle, in pixels. | 
| 
 | Dithering method to use. | 
| 
 | Pointer to the pixel in the RGB buffer that corresponds to the upper-left corner of the rectangular region to render. | 
| 
 | Offset between pixel rows in the RGB buffer, in bytes. | 
void xlib_draw_gray_image (Drawable drawable,GC gc,int x,int y,int width,int height,XlibRgbDither dith,unsigned char *buf,int rowstride);
Renders a grayscale buffer to a drawable. Pixels are specified as 8-bit intensity values. An image will thus look as a GGGGGG sequence of 8-bit values.
| 
 | Destination drawable. | 
| 
 | A graphic context. | 
| 
 | Leftmost coordinate of the destination rectangle. | 
| 
 | Upper coordinate of the destination rectangle. | 
| 
 | Width of the destination rectangle, in pixels. | 
| 
 | Height of thd destination rectangle, in pixels. | 
| 
 | Dithering method to use. | 
| 
 | Pointer to the pixel in the grayscale buffer that corresponds to the upper-left corner of the rectangular region to render. | 
| 
 | Offset between pixel rows in the grayscale buffer, in pixels. | 
XlibRgbCmap * xlib_rgb_cmap_new (guint32 *colors,int n_colors);
FIXME
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 | FIXME | 
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| Returns : | FIXME | 
void                xlib_rgb_cmap_free                  (XlibRgbCmap *cmap);
Frees an XlibRGB colormap.
| 
 | An XlibRGB colormap. | 
void xlib_draw_indexed_image (Drawable drawable,GC gc,int x,int y,int width,int height,XlibRgbDither dith,unsigned char *buf,int rowstride,XlibRgbCmap *cmap);
FIXME
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Bool                xlib_rgb_ditherable                 (void);
Queries whether XlibRGB supports dithering for its chosen visual.
| Returns : | TRUE if dithering can be performed for the visual that XlibRGB is using, FALSE otherwise. | 
void                xlib_rgb_set_verbose                (Bool verbose);
Enables/disables debug spew.
| 
 | True to be verbose | 
void                xlib_rgb_set_install                (Bool install);
Sets whether we install an RGB colormap.
| 
 | True to install a colormap | 
void                xlib_rgb_set_min_colors             (int min_colors);
Sets the minimum number of colors in the color cube.
| 
 | minimum colors to use | 
Colormap            xlib_rgb_get_cmap                   (void);
Queries the X colormap that XlibRGB is using.
| Returns : | An X colormap. | 
Visual *            xlib_rgb_get_visual                 (void);
Queries the visual that XlibRGB is using.
| Returns : | An X visual. | 
XVisualInfo *       xlib_rgb_get_visual_info            (void);
Queries the visual info structure for the visual that XlibRGB is using.
| Returns : | An XVisualInfo structure. | 
int                 xlib_rgb_get_depth                  (void);
Queries the depth of the visual that XlibRGB is using.
| Returns : | Bit depth. | 
Display *           xlib_rgb_get_display                (void);
Queries the X display that XlibRGB is using.
| Returns : | An X display. |