GDK Reference Manual

　　GDK_DIRECT_COLOR Each pixel value contains red, green, and blue components as for GDK_TRUE_COLOR, but the components are mapped via a color table into the final output table instead of being converted directly..

　　enum GdkByteOrder

typedef enum
{
GDK_LSB_FIRST,
GDK_MSB_FIRST
} GdkByteOrder; 

　　A set of values describing the possible byte-orders for storing pixel values in memory.

　　GDK_LSB_FIRST The values are stored with the least-significant byte first. For instance, the 32-bit value 0xffeecc would be stored in memory as 0xcc, 0xee, 0xff, 0x00.

　　GDK_MSB_FIRST The values are stored with the least-significant byte first. For instance, the 32-bit value 0xffeecc would be stored in memory as 0xff, 0xee, 0xcc, 0x00.

gdk_query_depths ()
voidgdk_query_depths(gint **depths,gint *count); 

　　Lists the available color depths. The returned values are pointers to static storage and should not be modified or freed.

　　depths : a location to store a pointer to an array holding the available color depths.

　　count : a location to store the number of values in depths.

gdk_query_visual_types ()
voidgdk_query_visual_types(GdkVisualType **visual_types,gint *count); 

　　Lists the available visual types. The returned values are pointers to static storage and should not be modified or freed.

　　visual_types : a location to store a pointer to an array holding the available visual types.

　　count : a location to store the number of values in visual types.

gdk_list_visuals ()
GList*gdk_list_visuals(void); 

　　Lists the available visuals.

　　Returns : A GList of the available visuals. The list should be freed this list with g_list_free().

gdk_visual_get_best_depth ()
gintgdk_visual_get_best_depth (void); 

　　Returns the best available color depth.

　　Returns : the best available color depth.

gdk_visual_get_best_type ()
GdkVisualType gdk_visual_get_best_type(void); 

　　Returns the best available visual type.

　　Returns : the best available visual type.

gdk_visual_get_system ()
GdkVisual*gdk_visual_get_system (void); 

　　Returns the system's default visual.

　　Returns : the system's default visual.

gdk_visual_get_best ()
GdkVisual*gdk_visual_get_best (void); 

　　Returns the best available visual.

　　Returns : the best available visual.

gdk_visual_get_best_with_depth ()
GdkVisual*gdk_visual_get_best_with_depth(gint depth); 

　　Returns the best available visual with a certain depth.

　　depth : the desired color depth

　　Returns : the best available visual with depth bits per pixel or NULL if no visuals with that type are available.

gdk_visual_get_best_with_type ()
GdkVisual*gdk_visual_get_best_with_type (GdkVisualType visual_type); 

　　Returns the best available visual of a certain visual type.

　　visual_type : the desired visual type.

　　Returns : the visual of the given type with the highest depth or NULL if no visuals of that type are available.

gdk_visual_get_best_with_both ()
GdkVisual*gdk_visual_get_best_with_both (gint depth,
GdkVisualType visual_type); 

　　Returns the best available visual

　　depth : the desired visual type.

　　visual_type : the desired depth.

　　Returns : the best available visual with the given depth and visual type, or NULL if no matching visuals are available.