OVERLAY(3)

PACKAGE
overlay - Routines to manipulate 2-dimensional (image) overlay objects

PURPOSE
These routines provide a simple interface to the recursive, heirarchical data structure supported in Karma, to define 2-dimensional (image) overlay objects. In addition, all the mechanics for drawing onto world canvases (see the <-canvas-> package) is supplied automatically.

LIBRARY
karmagraphics

LINK WITH
-lkarmagraphics

FUNCTIONS

overlay_va_create_list
    Create a managed overlay object list.

overlay_destroy_list
    Destroy an overlay list.

overlay_prepare_for_slavery
    Allow an overlay list to be slaved.

overlay_specify_iarray_2d
    Extract specifications from an Intelligent Array.

overlay_specify_canvas
    Extract specification from a world canvas.

overlay_create_viewable
    Create a viewable overlay list.

overlay_set_active
    Set active state for a viewable overlay list controlled refresh.

overlay_set_all_inactive
    Clear active state all viewable overlay lists controlled refresh.

overlay_destroy_viewable
    Destroy a viewable overlay list.

overlay_redraw_on_canvas
    Redraw an overlay list onto a world canvas.

overlay_set_canvas_attributes
    Set the canvas attributes for overlay list display.

overlay_line
    Add a line to an overlay object list. See also <-overlay_lines->.

overlay_lines
    Add many lines to an overlay list.

overlay_text
    Add a text string to an overlay object list.

overlay_ellipse
    Add an ellipse to an overlay list. See also <-overlay_ellipses->

overlay_arc
    Add a rotated ellipse to an overlay list.

overlay_filled_polygon
    Add a filled polygon to an overlay object list.

overlay_vector
    Add a vector to an overlay list.

overlay_ellipses
    Add many ellipses to an overlay list.

overlay_segments
    Add many segments to an overlay list.

overlay_vectors
    Add many vectors to an overlay list.

overlay_remove_objects
    Remove objects from the end of an overlay object list.

overlay_remove_object
    Remove one object from an overlay object list.

overlay_move_object
    Move a object in an overlay object list.

overlay_get_num_coords
    Get the number of co-ordinates in an overlay object.

overlay_get_coords
    Get the co-ordinates for an overlay object.

overlay_have_token
    Test if an overay list has the token.

overlay_release_token
    Release the token to the master.

overlay_read_karma
    Read overlay instructions from a Karma file.

overlay_write_karma
    Write overlay instructions to a Karma file.

overlay_read_ascii
    Read overlay instructions from an ASCII file.

TABLE overlay_CANVAS_ATTRIBUTES
List of overlay attributes for KWorldCanvas objects
Name Get Type Set Type Meaning
OVERLAY_CANVAS_ATT_END End of varargs list
OVERLAY_CANVAS_ATT_CROP flag * flag Crop out-of-bounds objects

TABLE overlay_COORDINATE_TYPES
List of co-ordinate types
Name Meaning
OVERLAY_COORD_PIXEL Screen pixel co-ordinates
OVERLAY_COORD_RELATIVE Relative to a unit canvas (0,0) to (1,1)
OVERLAY_COORD_WORLD True world co-ordinates
OVERLAY_COORD_LAST Use last co-ordinate instead
OVERLAY_COORD_LINEAR Canvas linear co-ordinates

AUTHOR
Richard Gooch (rgooch@atnf.csiro.au)

AVAILABLITY
The Karma Distribution is available for anonymous ftp from: ftp://ftp.atnf.csiro.au/pub/software/karma/ ftp://wuarchive.wustl.edu/graphics/graphics/packages/karma/ ftp://ftp.pwr.wroc.pl/pub/karma/ The Karma Home Page is: http://www.atnf.csiro.au/karma/