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GDK-PixBuf Reference Manual | |
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#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.
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X Display to use. |
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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.
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X display to use. |
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Screen to use. |
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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.
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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.
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A graphic context. |
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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.
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A graphic context. |
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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.
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Destination drawable. |
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A graphic context. |
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Leftmost coordinate of the destination rectangle. |
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Upper coordinate of the destination rectangle. |
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Width of the destination rectangle, in pixels. |
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Height of the destination rectangle, in pixels. |
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Dithering method to use. |
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Pointer to the pixel in the RGB buffer that corresponds to the upper-left corner of the rectangular region to render. |
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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.
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Destination drawable. |
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A graphic context. |
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Leftmost coordinate of the destination rectangle. |
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Upper coordinate of the destination rectangle. |
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Width of the destination rectangle, in pixels. |
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Height of the destination rectangle, in pixels. |
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Dithering method to use. |
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Pointer to the pixel in the RGB buffer that corresponds to the upper-left corner of the rectangular region to render. |
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Offset between pixel rows in the RGB buffer, in bytes. |
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X offset for the dither mask. |
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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.
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Destination drawable. |
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A graphic context. |
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Leftmost coordinate of the destination rectangle. |
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Upper coordinate of the destination rectangle. |
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Width of the destination rectangle, in pixels. |
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Height of the destination rectangle, in pixels. |
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Dithering method to use. |
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Pointer to the pixel in the RGB buffer that corresponds to the upper-left corner of the rectangular region to render. |
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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.
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Destination drawable. |
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A graphic context. |
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Leftmost coordinate of the destination rectangle. |
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Upper coordinate of the destination rectangle. |
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Width of the destination rectangle, in pixels. |
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Height of thd destination rectangle, in pixels. |
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Dithering method to use. |
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Pointer to the pixel in the grayscale buffer that corresponds to the upper-left corner of the rectangular region to render. |
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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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Returns : |
FIXME |
void xlib_rgb_cmap_free (XlibRgbCmap *cmap);
Frees an XlibRGB colormap.
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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.
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True to be verbose |
void xlib_rgb_set_install (Bool install);
Sets whether we install an RGB colormap.
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True to install a colormap |
void xlib_rgb_set_min_colors (int min_colors);
Sets the minimum number of colors in the color cube.
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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. |