asvisual - abstraction layer on top of X Visuals, focusing on color handling libAfterImage/asvisual.h

       Sasha Vasko <sasha at aftercode dot net>
       libAfterImage/alpha

       create_visual_ximage() will perform sanity checks on passed parameters, and it  will  attempt  to  create
       XImage  of sufficient size, and specified colordepth. It will also setup hooks for XImage deallocation to
       be handled by custom function.

3rd Berkeley Distribution                      AfterStep v.2.2.12                                   asvisual(3x)

       asview.c: ASView.2
       libAfterImage/visual2visual_prop()

       Ids of the channels. These are basically synonyms to related ARGB32 channel numbers

       asv    - pointer to the valid ASVisual structure.

       width, height - size of the XImage to create.

       depth  - depth of the XImage to create. If 0 asv->true_depth will be used.

asvisual - abstraction layer on top of X Visuals, focusing on color handling libAfterImage/asvisual.h

       - main color datatype

       - This function can be used to evaluate closeness of two colors.

       - an abstraction layer on top of X Server Visual.

       - convenient structure to hold pair of colors.

       - red channel IC_GREEN - green channel IC_BLUE - blue channel IC_ALPHA - alpha channel IC_NUM_CHANNELS  -
       number of supported channels

       query_screen_visual()

       pointer to newly created XImage on success. NULL on failure.

       Structures:
               ColorPair
               ASVisual

       Functions :
         ASVisual initialization :
               query_screen_visual(), setup_truecolor_visual(),
               setup_pseudo_visual(), setup_as_colormap(),create_asvisual(),
               destroy_asvisual()

         ASVisual encoding/decoding :
               visual2visual_prop(), visual_prop2visual()

         ASVisual convenience functions :
               create_visual_window(), create_visual_pixmap(),
               create_visual_ximage()

       Other libAfterImage modules :
                ascmap.h asfont.h asimage.h asvisual.h blender.h export.h
                import.h transform.h ximage.h

           typedef struct ASVisual {
               Display      *dpy;

               /* This envvar will be used to determine what X Visual
                * (in hex) to use. If unset then best possible will
                * be selected automagically : */ #define ASVISUAL_ID_ENVVAR "AFTERIMAGE_VISUAL_ID"

               XVisualInfo   visual_info;
               /* this things are calculated based on Visual : */
               unsigned long rshift, gshift, bshift;
               unsigned long rbits,  gbits,  bbits;
               unsigned long true_depth;   /* could be 15 when X reports 16 */
               Bool          BGR_mode;
               Bool          msb_first;
               /* we must have colormap so that we can safely create windows
                * with different visuals even if we are in TrueColor mode : */
               Colormap      colormap;
               Bool          own_colormap; /* tells us to free colormap when we
                                            * done */
               unsigned long black_pixel, white_pixel;
               /* for PseudoColor mode we need some more stuff : */
               enum {
                   ACM_None = 0,
                   ACM_3BPP,
                   ACM_6BPP,
                   ACM_12BPP
               } as_colormap_type ;    /* there can only be 64 or 4096 entries
                                        * so far ( 6 or 12 bpp) */
               unsigned long *as_colormap; /* array of preallocated colors for
                                            * PseudoColor mode */
               union                       /* reverse color lookup tables : */
               {
                   ARGB32              *xref;
                   struct ASHashTable  *hash;
               }as_colormap_reverse ;

               /* different useful callbacks : */
               CARD32 (*color2pixel_func)    ( struct ASVisual *asv,
                                               CARD32 encoded_color,
                                               unsigned long *pixel);
               void   (*pixel2color_func)    ( struct ASVisual *asv,
                                               unsigned long pixel,
                                               CARD32 *red, CARD32 *green,
                                               CARD32 *blue);
               void   (*ximage2scanline_func)( struct ASVisual *asv,
                                               XImage *xim,
                                               struct ASScanline *sl, int y,
                                               unsigned char *xim_data );
               void   (*scanline2ximage_func)( struct ASVisual *asv,
                                               XImage *xim,
                                               struct ASScanline *sl, int y,
                                               unsigned char *xim_data );

           #define  ASGLX_Unavailable            0   #define   ASGLX_Available               (0x01<<0)   #define
           ASGLX_DoubleBuffer            (0x01<<1)   #define   ASGLX_RGBA                    (0x01<<2)   #define
           ASGLX_UseForImageTx         (0x01<<3)
               ASFlagType glx_support ;    /* one of the above flags */

               void *glx_scratch_gc_indirect ; /* (GLXContext) */
               void *glx_scratch_gc_direct ;   /* (GLXContext) */

               Window scratch_window;

           #ifndef X_DISPLAY_MISSING #define ARGB2PIXEL(asv,argb,pixel)         \
               (asv)->color2pixel_func((asv),(argb),(pixel)) #define GET_SCANLINE(asv,xim,sl,y,xim_data) \
               (asv)->ximage2scanline_func((asv),(xim),(sl),(y),(xim_data))                              #define
           PUT_SCANLINE(asv,xim,sl,y,xim_data) \
               (asv)->scanline2ximage_func((asv),(xim),(sl),(y),(xim_data))             #else            #define
           ARGB2PIXEL(asv,argb,pixel)         \
               do{ break; }while(0) #define GET_SCANLINE(asv,xim,sl,y,xim_data) \
               do{ break; }while(0) #define PUT_SCANLINE(asv,xim,sl,y,xim_data) \
               do{ break; }while(0) #endif }ASVisual;

       libAfterImage/query_screen_visual()

       XImage* create_visual_ximage( ASVisual *asv,
                                     unsigned int width, unsigned int height,
                                     unsigned int depth );