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asimage.3x

NAME

asimage - internal structures and methods used for image manipulation in libAfterImage libAfterImage/asimage.h

NAMEasimage

defines main structures and function for image manipulation.

DESCRIPTION

 libAfterImage provides powerful functionality to load, store
 and transform images. It allows for smaller memory utilization by
 utilizing run-length encoding of the image data. There could be
 different levels of compression selected, allowing to choose best
 speed/memory ratio.
 

SEE ALSO

 Structures :
          ASImage
          ASImageManager
          ASImageBevel
          ASImageDecoder
          ASImageOutput
          ASImageLayer
          ASGradient
 
 Functions :
          asimage_init(), asimage_start(), create_asimage(),
          clone_asimage(), destroy_asimage()
 
   ImageManager Reference counting and managing :
          create_image_manager(), destroy_image_manager(),
          store_asimage(), fetch_asimage(), query_asimage(),
          dup_asimage(), release_asimage(),
          release_asimage_by_name(), forget_asimage(),
          safe_asimage_destroy()
 
   Gradients helper functions :
          flip_gradient(), destroy_asgradient()
 
   Layers helper functions :
          init_image_layers(), create_image_layers(),
          destroy_image_layers()
 
   Encoding :
          asimage_add_line(),    asimage_add_line_mono(),
          asimage_print_line(), get_asimage_chanmask(),
          move_asimage_channel(), copy_asimage_channel(),
          copy_asimage_lines()
 
   Decoding
          start_image_decoding(), stop_image_decoding(),
          asimage_decode_line (), set_decoder_shift(),
          set_decoder_back_color()
 
   Output :
          start_image_output(), set_image_output_back_color(),
          toggle_image_output_direction(), stop_image_output()
 
 Other libAfterImage modules :
          ascmap.h asfont.h asimage.h asvisual.h blender.h export.h
          import.h transform.h ximage.h
 

AUTHOR

 Sasha Vasko <sasha at aftercode dot net>
 

libAfterImage/ASAltImFormats

NAMEASAltImFormats

identifies what output format should be used for storing the transformation result. Also identifies what data is currently stored in alt member of ASImage structure.

SOURCE

 typedef enum {
     ASA_ASImage = 0,
     ASA_XImage,
     ASA_MaskXImage,
     /* temporary XImages to be allocated from static pool of memory :*/
     ASA_ScratchXImage,  
     ASA_ScratchMaskXImage,
     
     ASA_ScratchXImageAndAlpha,
 
     ASA_ARGB32,
     ASA_Vector,       /* This cannot be used for transformation's result
                        * format */
     ASA_Formats
 }ASAltImFormats;
 

libAfterImage/ASImage

NAMEASImage

is the main structure to hold image data.

DESCRIPTION

 Images are stored internally split into ARGB channels, each split
 into scanline. Actuall data is stored using ASStorage container. Inside
 ASImage data structure we only store IDs pointing to data in ASStorage
 ASStorage implements reference counting, data compression, 
 automatic memory defragmentation and other nice things.
 

SEE ALSO

  asimage_init()
  asimage_start()
  create_asimage()
  destroy_asimage()
 

SOURCE

 struct ASImageAlternative;
 struct ASImageManager;
 
 /* magic number identifying ASFont data structure */
 #define MAGIC_ASIMAGE            0xA3A314AE
 
 typedef struct ASImage
 {
 
   unsigned long magic ;
 
   unsigned int width, height;       /* size of the image in pixels */
 
   /* arrays of storage ids of stored scanlines of particular channel: */
   ASStorageID *alpha,
               *red,
               *green,
               *blue;
   
   ASStorageID *channels[IC_NUM_CHANNELS]; 
                                     /* merely a shortcut so we can
                                      * somewhat simplify code in loops */
 
   ARGB32 back_color ;               /* background color of the image, so
                                      * we could discard everything that
                                      * matches it, and then restore it
                                      * back. */
 
   struct ASImageAlternative
   {  /* alternative forms of ASImage storage : */
     XImage *ximage ;                /* pointer to XImage created as the
                                      * result of transformations whenever
                                      * we request it to output into
                                      * XImage ( see to_xim parameter ) */
     XImage *mask_ximage ;           /* XImage of depth 1 that could be
                                      * used to store mask of the image */
     ARGB32 *argb32 ;                /* array of widthxheight ARGB32
                                      * values */
     double *vector ;                /* scientific data that should be used
                                      * in conjunction with
                                      * ASScientificPalette to produce
                                      * actuall ARGB data */
   }alt;
 
   struct ASImageManager *imageman;  /* if not null - then image could be
                                      * referenced by some other code */
   int                    ref_count ;/* this will tell us what us how many
                                      * times */
 
     
   char                  *name ;     /* readonly copy of image name 
                                      * this name is a hash value used to 
                                      * store image in the image-man's hash,
                                      * and gets freed automagically on image 
                                      * removal from hash */
 
 #define ASIM_DATA_NOT_USEFUL    (0x01<<0)
 #define ASIM_VECTOR_TOP2BOTTOM  (0x01<<1)
 #define ASIM_XIMAGE_8BIT_MASK   (0x01<<2)
 #define ASIM_NO_COMPRESSION     (0x01<<3) /* Do not use compression to 
                                            * save some computation time
                                            */
 #define ASIM_ALPHA_IS_BITMAP    (0x01<<4) 
 #define ASIM_RGB_IS_BITMAP      (0x01<<5) 
 #define ASIM_XIMAGE_NOT_USEFUL  (0x01<<6)
 #define ASIM_NAME_IS_FILENAME   (0x01<<7)
 
   ASFlagType             flags ;    /* combination of the above flags */
   
 } ASImage;
 

libAfterImage/ASImageManager

NAMEASImageManager

structure to be used to maintain list of loaded images for given set of search paths and gamma. Images are named and reference counted.

SOURCE

 typedef struct ASImageManager
 {
     ASHashTable  *image_hash ;
     /* misc stuff that may come handy : */
     char         *search_path[MAX_SEARCH_PATHS+1];
     double        gamma ;
 }ASImageManager;
 

libAfterImage/LIMITS

NAMEMAX_IMPORT_IMAGE_SIZE

effectively limits size of the allowed images to be loaded from files. That is needed to be able to filter out corrupt files. MAX_BEVEL_OUTLINE Limit on bevel outline to be drawn around the image. MAX_SEARCH_PATHS Number of search paths to be used while loading images from files.

 #define MAX_IMPORT_IMAGE_SIZE   8000
 #define MAX_BEVEL_OUTLINE       100
 #define MAX_SEARCH_PATHS        8      /* prudently limiting ourselfs */
 

libAfterImage/ASVectorPalette

NAMEASVectorPalette

contains palette allowing us to map double values in vector image data into actuall ARGB values.

SOURCE

 typedef struct ASVectorPalette
 {
     unsigned int npoints ;
     double *points ;
     CARD16 *channels[IC_NUM_CHANNELS] ;   /* ARGB data for key points. */
     ARGB32  default_color;
 }ASVectorPalette;
 

libAfterImage/asimage/ASImageLayer

NAMEASImageLayer

specifies parameters of the image superimposition.

DESCRIPTION

 libAfterImage allows for simultaneous superimposition (overlaying) of
 arbitrary number of images. To facilitate this ASImageLayer structure
 has been created in order to specify parameters of each image
 participating in overlaying operation. Images need not to be exact
 same size. For each image its position on destination is specified
 via dst_x and dst_y data members. Each image maybe tiled and clipped
 to fit into rectangle specified by clip_x, clip_y, clip_width,
 clip_height ( in image coordinates - not destination ). If image is
 missing, then area specified by dst_x, dst_y, clip_width, clip_height
 will be filled with solid_color.
 Entire image will be tinted using tint parameter prior to overlaying.
 Bevel specified by bevel member will be drawn over image prior to
 overlaying. Specific overlay method has to be specified.
 merge_scanlines method is pointer to a function,
 that accepts 2 ASScanlines as arguments and performs overlaying of
 first one with the second one.
 There are 15 different merge_scanline methods implemented in
 libAfterImage, including alpha-blending, tinting, averaging,
 HSV and HSL colorspace operations, etc.
 

NOTES

 ASImageLayer s could be organized into chains using next pointers.
 Since there could be a need to rearrange layers and maybe bypass some
 layers - we need to provide for flexibility, while at the same time
 allowing for simplicity of arrays. As the result next pointers could
 be used to link together continuous arrays of layer, like so :
 array1: [layer1(next==NULL)][layer2(next!=NULL)]
          ____________________________|
          V
 array2: [layer3(next==NULL)][layer4(next==NULL)][layer5(next!=NULL)]
          ________________________________________________|
          V
 array3: [layer6(next==NULL)][layer7(next==layer7)]
                                ^______|
 
 While iterating through such a list we check for two conditions -
 exceeding count of layers and layer pointing to self. When any of
 that is met - we stopping iteration.
 

SEE ALSO

 merge_layers()
 blender.h
 

SOURCE

 typedef struct ASImageLayer
 {
     ASImage *im;
     ARGB32   solid_color ;              /* If im == NULL, then fill
                                          * the area with this color. */
 
     int dst_x, dst_y;                   /* placement in overall
                                          * composition */
 
     /* clip area could be partially outside of the image -
      * image gets tiled in it */
     int clip_x, clip_y;
     unsigned int clip_width, clip_height;
 
     ARGB32 tint ;                       /* if 0 - no tint */
     struct ASImageBevel *bevel ;        /* border to wrap layer with
                                          * (for buttons, etc.)*/
 
     /* if image is clipped then we need to specify offsets of bevel as
      * related to clipped rectangle. Normally it should be :
      * 0, 0, im->width, im->height. And if width/height left 0 - it will
      * default to this values. Note that clipped image MUST be entirely
      * inside the bevel rectangle. !!!*/
     int bevel_x, bevel_y;
     unsigned int bevel_width, bevel_height;
 
     int merge_mode ;                        /* reserved for future use */
     merge_scanlines_func merge_scanlines ;  /* overlay method */
     struct ASImageLayer *next;              /* optional pointer to next
                                              * layer. If it points to
                                              * itself - then end of the
                                              * chain.*/
     void *data;                             /* hook to hung data on */
 }ASImageLayer;
 

libAfterImage/asimage/GRADIENT_TYPE_flags

FUNCTION

 Combination of this flags defines the way gradient is rendered.
 

NAMEGRADIENT_TYPE_DIAG

when set it will cause gradient's direction to be rotated by 45 degrees GRADIENT_TYPE_ORIENTATION will cause gradient direction to be rotated by 90 degrees. When combined with GRADIENT_TYPE_DIAG - rotates gradient direction by 135 degrees.

SOURCE

 #define GRADIENT_TYPE_DIAG          (0x01<<0)
 #define GRADIENT_TYPE_ORIENTATION   (0x01<<1)
 #define GRADIENT_TYPE_MASK          (GRADIENT_TYPE_ORIENTATION| \
                                      GRADIENT_TYPE_DIAG)
 

libAfterImage/asimage/GRADIENT_TYPE

FUNCTION

 This are named combinations of above flags to define type of gradient.
 

NAMEGRADIENT_Left2Right

normal left-to-right gradient. GRADIENT_TopLeft2BottomRight diagonal top-left to bottom-right. GRADIENT_Top2Bottom vertical top to bottom gradient. GRADIENT_BottomLeft2TopRight diagonal bottom-left to top-right.

SOURCE

 #define GRADIENT_Left2Right             0
 #define GRADIENT_TopLeft2BottomRight    GRADIENT_TYPE_DIAG
 #define GRADIENT_Top2Bottom             GRADIENT_TYPE_ORIENTATION
 #define GRADIENT_BottomLeft2TopRight    (GRADIENT_TYPE_DIAG| \
                                          GRADIENT_TYPE_ORIENTATION)
 

libAfterImage/ASGradient

NAMEASGradient

describes how gradient is to be drawn.

DESCRIPTION

 libAfterImage includes functionality to draw multipoint gradients in
 4 different directions left->right, top->bottom and diagonal
 lefttop->rightbottom and bottomleft->topright. Each gradient described
 by type, number of colors (or anchor points), ARGB values for each
 color and offsets of each point from the beginning of gradient in
 fractions of entire length. There should be at least 2 anchor points.
 very first point should have offset of 0. and last point should have
 offset of 1. Gradients are drawn in ARGB colorspace, so it is possible
 to have semitransparent gradients.
 

SEE ALSO

 make_gradient()
 

SOURCE

 typedef struct ASGradient
 {
     int         type;     /* see GRADIENT_TYPE above */
     
     int         npoints;  /* number of anchor points */
     ARGB32     *color;    /* ARGB color values for each anchor point*/
     double     *offset;   /* offset of each point from the beginning in
                            * fractions of entire length */
 }ASGradient;
 

libAfterImage/asimage/flip

FUNCTION

 This are flags that define rotation angle.
 

NAMEFLIP_VERTICAL

defines rotation of 90 degrees counterclockwise. FLIP_UPSIDEDOWN defines rotation of 180 degrees counterclockwise. combined they define rotation of 270 degrees counterclockwise.

SOURCE

 #define FLIP_VERTICAL       (0x01<<0)
 #define FLIP_UPSIDEDOWN     (0x01<<1)
 #define FLIP_MASK           (FLIP_UPSIDEDOWN|FLIP_VERTICAL)
 

libAfterImage/asimage/flip_gradient()

NAMEflip_gradient()

- rotates gradient in 90 degree increments.

SYNOPSIS

 ASGradient *flip_gradient( ASGradient *orig, int flip );
 

INPUTS

orig

- pointer to original ASGradient structure to be rotated.

flip

- value defining desired rotation.

RETURN VALUE

 Same as original gradient if flip is 0. New gradient structure in any
 other case.
 

DESCRIPTION

 Rotates ( flips ) gradient data in 90 degree increments. When needed
 order of points is reversed.
 

libAfterImage/asimage/tint

FUNCTION

 We use 32 bit ARGB values to define how tinting should be done.
 The formula for tinting particular channel data goes like that:
 tinted_data = (image_data * tint)/128
 So if tint channel value is greater then 127 - same channel will be
 brighter in destination image; if it is lower then 127 - same channel
 will be darker in destination image. Tint channel value of 127
 ( or 0x7F hex ) does not change anything.
 Alpha channel is tinted as well, allowing for creation of
 semitransparent images. Calculations are performed in 24.8 format -
 with 8 bit precision. Result is saturated to avoid overflow, and
 precision is carried over to next pixel ( error diffusion ), when con
 verting 24.8 to 8 bit format.
 

NAMETINT_NONE

special value that disables tinting TINT_LEAVE_SAME also disables tinting.

SOURCE

 #define TINT_NONE           0
 #define TINT_LEAVE_SAME     (0x7F7F7F7F)
 #define TINT_HALF_DARKER    (0x3F3F3F3F)
 #define TINT_HALF_BRIGHTER  (0xCFCFCFCF)
 #define TINT_RED            (0x7F7F0000)
 #define TINT_GREEN          (0x7F007F00)
 #define TINT_BLUE           (0x7F00007F)
 

libAfterImage/asimage/compression

FUNCTION

 Defines the level of compression to attempt on ASImage scanlines.
 

NAMEASIM_COMPRESSION_NONE

defined as 0 - disables compression. ASIM_COMPRESSION_FULL defined as 100 - highest compression level. Anything in between 0 and 100 will cause only part of the scanline to be compressed. This is obsolete. Now all images are compressed if possible. libAfterImage/asimage/asimage_init()

NAMEasimage_init()

frees datamembers of the supplied ASImage structure, and initializes it to all 0.

SYNOPSIS

 void asimage_init (ASImage * im, Bool free_resources);
 

INPUTS

im

- pointer to valid ASImage structure

free_resources

- if True will make function attempt to free all non-NULL pointers. libAfterImage/asimage/flush_asimage_cache()

NAMEflush_asimage_cache()

destroys XImage and mask XImage kept from previous conversions to/from X Pixmap.

SYNOPSIS

 void flush_asimage_cache (ASImage * im );
 

INPUTS

im

- pointer to valid ASImage structure libAfterImage/asimage/asimage_start()

NAMEasimage_start()

Allocates memory needed to store scanline of the image of supplied size. Assigns all the data members valid values. Makes sure that ASImage structure is ready to store image data.

SYNOPSIS

 void asimage_start (ASImage * im, unsigned int width,
                                   unsigned int height,
                                   unsigned int compression);
 

INPUTS

im

- pointer to valid ASImage structure

width

- width of the image

height

- height of the image

compression

- level of compression to perform on image data. compression has to be in range of 0-100 with 100 signifying highest level of compression.

NOTES

 In order to resize ASImage structure after asimage_start() has been
 called, asimage_init() must be invoked to free all the memory, and
 then asimage_start() has to be called with new dimensions.
 

libAfterImage/asimage/create_asimage()

NAMEcreate_asimage()

Performs memory allocation for the new ASImage structure, as well as initialization of allocated structure based on supplied parameters.

SYNOPSIS

 ASImage *create_asimage( unsigned int width,
                          unsigned int height,
                          unsigned int compression);
 

INPUTS

width

- desired image width

height

- desired image height

compression

- compression level in new ASImage( see asimage_start() for more ).

RETURN VALUE

 Pointer to newly allocated and initialized ASImage structure on
 Success. NULL in case of any kind of error - that should never happen.
 

libAfterImage/asimage/clone_asimage()

NAMEclone_asimage()

SYNOPSIS

 ASImage *clone_asimage(ASImage *src, ASFlagType filter );
 

INPUTS

src

- original ASImage.

filter

- bitmask of channels to be copied from one image to another.

RETURN VALUE

 New ASImage, as a copy of original image.
 

DESCRIPTION

 Creates exact clone of the original ASImage, with same compression,
 back_color and rest of the attributes. Only ASImage data will be
 carried over. Any attached alternative forms of images (XImages, etc.)
 will not be copied. Any channel with unset bit in filter will not be
 copied. Image name, ASImageManager and ref_count will not be copied -
 use store_asimage() afterwards and make sure you use different name,
 to avoid clashes with original image.
 

libAfterImage/asimage/destroy_asimage()

NAMEdestroy_asimage()

frees all the memory allocated for specified ASImage.

SYNOPSIS

 void destroy_asimage( ASImage **im );
 

INPUTS

im

- pointer to valid ASImage structure.

NOTES

 If there was XImage attached to it - it will be deallocated as well.
 

EXAMPLE

 asview.c: ASView.5
 

libAfterImage/asimage/asimage_replace()

NAMEasimage_replace()

will replace ASImage's data using data from another ASImage

SYNOPSIS

 Bool asimage_replace (ASImage *im, ASImage *from);
 

INPUTS

im

- pointer to valid ASImage structure.

from

- pointer to ASImage from which to take the data.

NOTES

 this function updates image without reallocating structure itself, which 
 means that all pointers to it will still be valid. If that function 
 succeeds - [from] ASImage will become unusable and should be deallocated 
 using free() call.
 

libAfterImage/asimage/set_asimage_vector()

NAMEset_asimage_vector()

This function replaces contents of the vector member of ASImage structure with new double precision data.

SYNOPSIS

 set_asimage_vector( ASImage *im, register double *vector );
 

INPUTS

im

- pointer to valid ASImage structure.

vector

- scientific data to attach to the image.

NOTES

 Data must have size of width*height ahere width and height are size of 
 the ASImage.
 

libAfterImage/asimage/vectorize_asimage()

NAMEvectorize_asimage()

This function replaces contents of the vector member of ASImage structure with new double precision data, generated from native ARGB32 image contents. Color palette is generated by indexing color values using max_colors, dither and opaque_threshold parameters.

SYNOPSIS

 ASVectorPalette* vectorize_asimage( ASImage *im, 
                                     unsigned int max_colors, 
                                     unsigned int dither,  
                                     int opaque_threshold );
 

INPUTS

im

- pointer to valid ASImage structure.

max_colors

- maximum size of the colormap.

dither

- number of bits to strip off the color data ( 0...7 )

opaque_threshold

- alpha channel threshold at which pixel should be treated as opaque

RETURN VALUE

 pointer to the ASVectorPalette structure that could be used for 
 reverse conversion from double values to ARGB32. 
 

NOTES

 alt.vector member of the supplied ASImage will be replaced and will 
 contain WIDTHxHEIGHT double values representing generated scientific 
 data.
 

libAfterImage/asimage/create_image_manager()

NAMEcreate_image_manager()

create ASImage management and reference counting object.

SYNOPSIS

 ASImageManager *create_image_manager( ASImageManager *reusable_memory,
                                       double gamma, ... );
 

INPUTS

reusable_memory

- optional pointer to a block of memory to be used to store ASImageManager object.

double

gamma - value of gamma correction to be used while loading images from files.

...

- NULL terminated list of up to 8 PATH strings to list locations at which images could be found.

DESCRIPTION

 Creates ASImageManager object in memory and initializes it with
 requested gamma value and PATH list. This Object will contain a hash
 table referencing all the loaded images. When such object is used while
 loading images from the file - gamma and PATH values will be used, so
 that all the loaded and referenced images will have same parameters.
 File name will be used as the image name, and if same file is attempted
 to be loaded again - instead reference will be incremented, and
 previously loaded image will be retyrned. All the images stored in
 ASImageManager's table will contain a back pointer to it, and they must
 be deallocated only by calling release_asimage(). destroy_asimage() will
 refuse to deallocate such an image.
 

libAfterImage/asimage/destroy_image_manager()

NAMEdestroy_image_manager()

destroy management obejct.

SYNOPSIS

 void destroy_image_manager( struct ASImageManager *imman, 
                                Bool reusable );
 

INPUTS

imman

- pointer to ASImageManager object to be deallocated

reusable

- if True, then memory that holds object itself will not be deallocated. Useful when object is created on stack.

DESCRIPTION

 Destroys all the referenced images, PATH values and if reusable is False,
 also deallocates object's memory.
 

libAfterImage/asimage/store_asimage()

NAMEstore_asimage()

add ASImage to the reference.

SYNOPSIS

 Bool store_asimage( ASImageManager* imageman, ASImage *im, 
                        const char *name );
 

INPUTS

imageman

- pointer to valid ASImageManager object.

im

- pointer to the image to be stored.

name

- unique name of the image.

DESCRIPTION

 Adds specifyed image to the ASImageManager's list of referenced images.
 Stored ASImage could be deallocated only by release_asimage(), or when
 ASImageManager object itself is destroyed.
 

libAfterImage/asimage/relocate_asimage()

NAMErelocate_asimage()

relocate ASImage into a different image manager.

SYNOPSIS

 void     relocate_asimage( ASImageManager* to_imageman, ASImage *im );
 

INPUTS

to_imageman

- pointer to valid ASImageManager object.

im

- pointer to the image to be stored.

DESCRIPTION

 Moves image from one ASImageManager's list of referenced images into 
 another ASImageManager. Reference count will be kept the same.
 

libAfterImage/asimage/fetch_asimage()

NAMEfetch_asimage()

query_asimage()

SYNOPSIS

 ASImage *fetch_asimage( ASImageManager* imageman, const char *name );
 ASImage *query_asimage( ASImageManager* imageman, const char *name );
 

INPUTS

imageman

- pointer to valid ASImageManager object.

name

- unique name of the image.

DESCRIPTION

 Looks for image with the name in ASImageManager's list and if found,
 returns pointer to it. Note that query_asimage() does not increment 
 reference count, while fetch_asimage() does. Therefore if fetch_asimage()
 is used - release_asimage() should be called , when image is no longer 
 in use.
 

libAfterImage/asimage/dup_asimage()

NAMEdup_asimage()

increment reference count of stored ASImage.

SYNOPSIS

 ASImage *dup_asimage( ASImage* im );
 

INPUTS

im

- pointer to already referenced image. libAfterImage/asimage/release_asimage()

NAMErelease_asimage()

decrement reference count for given ASImage. release_asimage_by_name() decrement reference count for ASImage identifyed by its name.

SYNOPSIS

 int release_asimage( ASImage *im );
 int release_asimage_by_name( ASImageManager *imman, char *name );
 

INPUTS

im

- pointer to already referenced image.

imageman

- pointer to valid ASImageManager object.

name

- unique name of the image.

DESCRIPTION

 Decrements reference count on the ASImage object and destroys it if
 reference count is below zero.
 

libAfterImage/asimage/forget_asimage()

NAMEforget_asimage()

remove ASImage from ASImageManager's hash by pointer. forget_asimage_name() remove ASImage from ASImageManager's hash by its name.

SYNOPSIS

 void     forget_asimage( ASImage *im );
 void  forget_asimage_name( ASImageManager *imman, const char *name );
 

INPUTS

im

pointer to already referenced image.

imageman

pointer to valid ASImageManager object.

name

unique name of the image. libAfterImage/safe_asimage_destroy()

NAMEsafe_asimage_destroy()

either release or destroy asimage, checking if it is attached to ASImageManager.

SYNOPSIS

 int      safe_asimage_destroy( ASImage *im );
 

INPUTS

im

pointer to and ASImage structure. libAfterImage/print_asimage_manager()

NAMEprint_asimage_manager()

prints list of images referenced in given ASImageManager structure. libAfterImage/asimage/destroy_asgradient()

NAMEdestroy_asgradient()

- destroy ASGradient structure, deallocating all associated memory libAfterImage/asimage/init_image_layers()

NAMEinit_image_layers()

- initialize set of ASImageLayer structures.

SYNOPSIS

 void init_image_layers( register ASImageLayer *l, int count );
 

INPUTS

l

- pointer to valid ASImageLayer structure.

count

- number of elements to initialize.

DESCRIPTION

 Initializes array on ASImageLayer structures to sensible defaults.
 Basically - all zeros and merge_scanlines == alphablend_scanlines.
 

libAfterImage/asimage/create_image_layers()

NAMEcreate_image_layers()

- allocate and initialize set of ASImageLayer's.

SYNOPSIS

 ASImageLayer *create_image_layers( int count );
 

INPUTS

count

- number of ASImageLayer structures in allocated array.

RETURN VALUE

 Pointer to newly allocated and initialized array of ASImageLayer
 structures on Success. NULL in case of any kind of error - that
 should never happen.
 

DESCRIPTION

 Performs memory allocation for the new array of ASImageLayer
 structures, as well as initialization of allocated structure to
 sensible defaults - merge_func will be set to alphablend_scanlines.
 

libAfterImage/asimage/destroy_image_layers()

NAMEdestroy_image_layers()

- destroy set of ASImageLayer structures.

SYNOPSIS

 void destroy_image_layers( register ASImageLayer *l,
                            int count,
                            Bool reusable );
 

INPUTS

l

- pointer to pointer to valid array of ASImageLayer structures.

count

- number of structures in array.

reusable

- if True - then array itself will not be deallocates - which is usable when it was allocated on stack.

DESCRIPTION

 frees all the memory allocated for specified array of ASImageLayer s.
 If there was ASImage and/or ASImageBevel attached to it - it will be
 deallocated as well.
 

libAfterImage/asimage/asimage_add_line()

NAMEasimage_add_line()

SYNOPSIS

 size_t asimage_add_line ( ASImage * im, ColorPart color,
                           CARD32 * data, unsigned int y);
 

INPUTS

im

- pointer to valid ASImage structure

color

- color channel's number

data

- raw channel data of 32 bits per pixel - only lowest 8 bits gets encoded.

y

- image row starting with 0

RETURN VALUE

 asimage_add_line() return size of the encoded channel scanline in
 bytes. On failure it will return 0.
 

DESCRIPTION

 Encodes raw data of the single channel into ASImage channel scanline.
 based on compression level selected for this ASImage all or part of
 the scanline will be RLE encoded.
 

libAfterImage/asimage/asimage_add_line_mono()

NAMEasimage_add_line_mono()

SYNOPSIS

 size_t asimage_add_line_mono ( ASImage * im, ColorPart color,
                                CARD8 value, unsigned int y);
 

INPUTS

im

- pointer to valid ASImage structure

color

- color channel's number

value

- value for the channel

y

- image row starting with 0

RETURN VALUE

 asimage_add_line_mono() return size of the encoded channel scanline
 in bytes. On failure it will return 0.
 

DESCRIPTION

 encodes ASImage channel scanline to have same color components
 value in every pixel. Useful for vertical gradients for example.
 

libAfterImage/asimage/get_asimage_chanmask()

NAMEget_asimage_chanmask()

SYNOPSIS

 ASFlagType get_asimage_chanmask( ASImage *im);
 

INPUTS

im

- valid ASImage object.

DESCRIPTION

 goes throu all the scanlines of the ASImage and toggles bits 
 representing those components that have at least some data.
 

libAfterImage/asimage/move_asimage_channel()

NAMEmove_asimage_channel()

SYNOPSIS

 void move_asimage_channel( ASImage *dst, int channel_dst,
                            ASImage *src, int channel_src );
 

INPUTS

dst

- ASImage which will have its channel substituted;

channel_dst

- what channel to move data to;

src

- ASImage which will donate its channel to dst;

channel_src

- what source image channel to move data from.

DESCRIPTION

 MOves channel data from one ASImage to another, while discarding
 what was already in destination's channel.
 

NOTES

 Source image (donor) will loose its channel data, as it will be
 moved to destination ASImage. Also there is a condition that both
 images must be of the same width - otherwise function returns
 without doing anything. If height is different - the minimum of
 two will be used.
 

libAfterImage/asimage/copy_asimage_channel()

NAMEcopy_asimage_channel()

SYNOPSIS

 void copy_asimage_channel( ASImage *dst, int channel_dst,
                            ASImage *src, int channel_src );
 

INPUTS

dst

- ASImage which will have its channel substituted;

channel_dst

- what channel to copy data to;

src

- ASImage which will donate its channel to dst;

channel_src

- what source image channel to copy data from.

DESCRIPTION

 Same as move_asimage_channel() but makes copy of channel's data
 instead of simply moving it from one image to another.
 

libAfterImage/asimage/copy_asimage_lines()

NAMEcopy_asimage_lines()

SYNOPSIS

 void copy_asimage_lines( ASImage *dst, unsigned int offset_dst,
                          ASImage *src, unsigned int offset_src,
                          unsigned int nlines, ASFlagType filter );
 

INPUTS

dst

- ASImage which will have its channel substituted;

offset_dst

- scanline in destination image to copy to;

src

- ASImage which will donate its channel to dst;

offset_src

- scanline in source image to copy data from;

nlines

- number of scanlines to be copied;

filter

- specifies what channels should be copied.

DESCRIPTION

 Makes copy of scanline data for continuos set of scanlines, affecting
 only those channels marked in filter.
 NOTE
 Images must be of the same width.
 

libAfterImage/asimage/verbosity

FUNCTION

 This are flags that define what should be printed by
 asimage_print_line():
     VRB_LINE_SUMMARY    - print only summary for each scanline
     VRB_LINE_CONTENT    - print summary and data for each scanline
     VRB_CTRL_EXPLAIN    - print summary, data and control codes for each
                           scanline
 

SOURCE

 #define VRB_LINE_SUMMARY    (0x01<<0)
 #define VRB_LINE_CONTENT    (0x01<<1)
 #define VRB_CTRL_EXPLAIN    (0x01<<2)
 #define VRB_EVERYTHING      (VRB_LINE_SUMMARY|VRB_CTRL_EXPLAIN| \
                              VRB_LINE_CONTENT)
 

libAfterImage/asimage/asimage_print_line()

NAMEasimage_print_line()

SYNOPSIS

     unsigned int asimage_print_line ( ASImage * im, ColorPart color,
                                       unsigned int y,
                                       unsigned long verbosity);
 

INPUTS

im

- pointer to valid ASImage structure

color

- color channel's number

y

- image row starting with 0

verbosity

- verbosity level - any combination of flags is allowed

RETURN VALUE

 amount of memory used by this particular channel of specified
 scanline.
 

DESCRIPTION

 asimage_print_line() prints data stored in specified image scanline
 channel. That may include simple summary of how much memory is used,
 actual visible data, and/or RLE control codes. That helps to see
 how effectively data is encoded.
 
 Useful mostly for debugging purposes.
 

libAfterImage/asimage/get_asimage_channel_rects()

NAMEget_asimage_channel_rects()

- translate image into a list of rectangles.

SYNOPSIS

 XRectangle* 
     get_asimage_channel_rects( ASImage *src, int channel, 
                                unsigned int threshold, 
                                unsigned int *rects_count_ret ); 
 

INPUTS

src

- ASImage which will donate its channel to dst;

channel

- what source image channel to copy data from;

threshold

- threshold to compare channel values against;

rects_count_ret

- returns count of generated rectangles.

DESCRIPTION

 This function will translate contents of selected channel 
 (usually alpha) into a list of rectangles, ecompasing regions 
 with values above the threshold. This is useful to generate shape
 of the window to be used with X Shape extension.