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The gdk-pixbuf Library | |
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XlibRGBXlibRGB — Rendering RGB buffers to X drawables. |
#include <gdk-pixbuf/gdk-pixbuf.h>
XlibRgbCmap;
enum XlibRgbDither;
void xlib_rgb_init (Display *display,
Screen *screen);
void xlib_rgb_init_with_depth (Display *display,
Screen *screen,
int prefDepth);
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.
typedef struct {
unsigned int colors[256];
unsigned char lut[256]; /* for 8-bit modes */
} XlibRgbCmap;
FIXME: Describe this.
unsigned int colors[256]; |
FIXME. |
unsigned char lut[256]; |
FIXME. |
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.
XLIB_RGB_DITHER_NONE |
Specifies no dithering. |
XLIB_RGB_DITHER_NORMAL |
Specifies dithering only on pseudocolor displays. |
XLIB_RGB_DITHER_MAX |
Specifies dithering on 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.
display : |
X Display to use. |
screen : |
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.
display : |
X display to use. |
screen : |
Screen to use. |
prefDepth : |
Visual depth to use for color substitution tables. This must
be one of the supported visual depths in the specified display.
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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.
gc : |
A graphic context. |
rgb : |
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.
gc : |
A graphic context. |
rgb : |
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.
drawable : |
Destination drawable. |
gc : |
A graphic context. |
x : |
Leftmost coordinate of the destination rectangle. |
y : |
Upper coordinate of the destination rectangle. |
width : |
Width of the destination rectangle, in pixels. |
height : |
Height of the destination rectangle, in pixels. |
dith : |
Dithering method to use. |
rgb_buf : |
Pointer to the pixel in the RGB buffer that corresponds to the upper-left corner of the rectangular region to render. |
rowstride : |
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.
drawable : |
Destination drawable. |
gc : |
A graphic context. |
x : |
Leftmost coordinate of the destination rectangle. |
y : |
Upper coordinate of the destination rectangle. |
width : |
Width of the destination rectangle, in pixels. |
height : |
Height of the destination rectangle, in pixels. |
dith : |
Dithering method to use. |
rgb_buf : |
Pointer to the pixel in the RGB buffer that corresponds to the upper-left corner of the rectangular region to render. |
rowstride : |
Offset between pixel rows in the RGB buffer, in bytes. |
xdith : |
X offset for the dither mask. |
ydith : |
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.
drawable : |
Destination drawable. |
gc : |
A graphic context. |
x : |
Leftmost coordinate of the destination rectangle. |
y : |
Upper coordinate of the destination rectangle. |
width : |
Width of the destination rectangle, in pixels. |
height : |
Height of the destination rectangle, in pixels. |
dith : |
Dithering method to use. |
buf : |
Pointer to the pixel in the RGB buffer that corresponds to the upper-left corner of the rectangular region to render. |
rowstride : |
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.
drawable : |
Destination drawable. |
gc : |
A graphic context. |
x : |
Leftmost coordinate of the destination rectangle. |
y : |
Upper coordinate of the destination rectangle. |
width : |
Width of the destination rectangle, in pixels. |
height : |
Height of thd destination rectangle, in pixels. |
dith : |
Dithering method to use. |
buf : |
Pointer to the pixel in the grayscale buffer that corresponds to the upper-left corner of the rectangular region to render. |
rowstride : |
Offset between pixel rows in the grayscale buffer, in pixels. |
XlibRgbCmap* xlib_rgb_cmap_new (guint32 *colors, int n_colors);
FIXME
colors : |
FIXME |
n_colors : |
FIXME |
| Returns : | FIXME |
void xlib_rgb_cmap_free (XlibRgbCmap *cmap);
Frees an XlibRGB colormap.
cmap : |
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
drawable : |
FIXME |
gc : |
FIXME |
x : |
FIXME |
y : |
FIXME |
width : |
FIXME |
height : |
FIXME |
dith : |
FIXME |
buf : |
FIXME |
rowstride : |
FIXME |
cmap : |
FIXME |
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.
verbose : |
True to be verbose
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void xlib_rgb_set_install (Bool install);
Sets whether we install an RGB colormap.
install : |
True to install a colormap
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void xlib_rgb_set_min_colors (int min_colors);
Sets the minimum number of colors in the color cube.
min_colors : |
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. |
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