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# ASImage

internal structures and methods used for image manipulation in libAfterImage

libAfterImage/asimage.h

- NAME

  asimage

  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

- NAME

  ASAltImFormats

  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

- NAME

  ASImage

  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

- NAME

  ASImageManager

  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

- NAME

  MAX_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

- NAME

  ASVectorPalette

  contains pallette 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

- NAME

  ASImageLayer

  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 throught 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.

- NAME

  GRADIENT_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.

- NAME

  GRADIENT_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

- NAME

  ASGradient

  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.

- NAME

  FLIP_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()

- NAME

  flip_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.

- NAME

  TINT_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.

- NAME

  ASIM_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()

- NAME

  asimage_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()

- NAME

  flush_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()

- NAME

  asimage_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()

- NAME

  create_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()

- NAME

  clone_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()

- NAME

  destroy_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()

- NAME

  asimage_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()

- NAME

  set_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()

- NAME

  vectorize_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()

- NAME

  create_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()

- NAME

  destroy_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. Usefull 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()

- NAME

  store_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()

- NAME

  relocate_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()

- NAME

  fetch_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()

- NAME

  dup_asimage()

  increment reference count of stored ASImage.

- SYNOPSIS

      ASImage *dup_asimage( ASImage* im );

- INPUTS

  im
    - pointer to already referenced image.

libAfterImage/asimage/release_asimage()

- NAME

  release_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()

- NAME

  forget_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()

- NAME

  safe_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()

- NAME

  print_asimage_manager()

  prints list of images referenced in given ASImageManager structure.

libAfterImage/asimage/destroy_asgradient()

- NAME

  destroy_asgradient()

  - destroy ASGradient structure, deallocating all associated memory

libAfterImage/asimage/init_image_layers()

- NAME

  init_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()

- NAME

  create_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()

- NAME

  destroy_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()

- NAME

  asimage_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()

- NAME

  asimage_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()

- NAME

  get_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()

- NAME

  move_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()

- NAME

  copy_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()

- NAME

  copy_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()

- NAME

  asimage_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()

- NAME

  get_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
      (usualy alpha) into a list of rectangles, ecompasing regions
      with values above the threshold. This is usefull to generate shape
      of the window to be used with X Shape extention.

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AfterStep version 2.2.8