/*************************************************************

                      Crispy.HeadsUp
                        VERSION 2

**************************************************************

An automated HUD library. Just define the HUD object under
/obj/crhud, give it a default screen_loc, and let the library
handle the rest. It's that simple!

Includes the optional ability to drag HUD objects around the
screen to customise the interface. This even optionally
supports pixel offsets!

This library has a standard prefix, crhud, which precedes all
vars and procs that it defines. This is done to avoid conflicts
with other libraries, and with any vars and procs you may have
defined.

Version 2 fixes some bugs caused by the changes to client.eye
that were made in BYOND versions 336, 338, 339 and 341.

See http://www.byond.com/people/Crispy for contact details.

INSTRUCTIONS:
    Include this library in your project by ticking the checkbox
    next to 'Crispy.HeadsUp' under the Lib entry on the left
    panel. (Tick the checkbox while your project is open, NOT
    this library!)

    Define each HUD object you need as a separate type under
    /obj/crhud. For each object, specify its screen_loc (where
    it appears on the screen; look it up in the DM reference for
    more information). If you want to use any of this library's
    advanced capabilities for that HUD object (such as dragging
    and pixel dragging), set the appropriate vars
    (see "User-modifiable vars" below).

KNOWN BUGS:
-   Pixel offset dragging is slightly buggy. It works fine,
    except for a slight cosmetic bug - namely, if you drag a
    HUD object a short distance (so that the centre of the new
    position is over a part of the object in its old position),
    that counts as a click on the HUD object rather than a drag
    of it.

-   If the player can see past the edge of the map,
    they will not be able to move HUD objects to some areas of
    their screen while they are near the edge. To work around
    this, set client.perspective to EDGE_PERSPECTIVE (which
    prevents the player from seeing past the edge of the map)
    or make sure that the player can never get close enough to
the edge of a map to see past it.

USER-MODIFABLE VARS:
    /obj/crhud/crhud_addatstart (default: true)
        If this is true (default), HeadsUp will automatically
        add this HUD object to the HUD of everyone who logs in.

    /obj/crhud/crhud_draggable (default: false)
        If this is true, players can drag this type of HUD object
        around on their screen to customize their HUD layout.

    /obj/crhud/crhud_dragpixel (default: false)
        If this is true, players can drag this type of HUD object
        to locations on the screen with pixel offsets. This var
        has no effect if crhud_draggable is false.

ATOMS:
    /obj/crhud
        Used for all HUD objects managed by HeadsUp.

CLIENT PROCS:
    crhud_add(hudtype)
        Adds a HUD object of the specified type to the client's
        HUD. hudtype can be any subtype of /atom/movable.

    crhud_remove(hudtype)
        Like crhud_add(), but removes all HUD objects of the
        specified type from the client's HUD. Does not remove
        subtypes of 'hudtype'.

*/

obj/crhud
    layer=200

    var/crhud_addatstart=0
    var/crhud_draggable=0
    var/crhud_dragpixel=0

    proc/crhud_add(client/C)
        if (istype(C)) C.screen+=src

    proc/crhud_remove(client/C)
        if (istype(C)) C.screen-=src

    MouseDrop(atom/over_object)
        .=..()
        if (!crhud_draggable || !usr.client) return
        if (!over_object || !istype(over_object)) return

        //Are we dragging it to another HUD object?
        if (over_object!=src && (over_object in usr.client.screen))
            //Can't drag to another HUD object
            return

        var{scrx;scry;viewx;viewy}

        if ((!over_object.loc || (over_object in usr.client.screen)) && istype(over_object,/atom/movable))
            ////// Dragged to HUD object
            var/atom/movable/O=over_object
            scrx=text2num(O.screen_loc)
            scry=text2num(copytext(screen_loc,findtext(screen_loc,",")+1))
        else
            ////// Dragged to object in the world
            ////Compare location of over_object to the location of client.virtual_eye
            var/atom/eyeloc=usr.client.virtual_eye
            if (!eyeloc) eyeloc=usr
            var/atom/objloc=locate(over_object.x,over_object.y,over_object.z)

            if (!objloc) return

            ////Get screen_loc
            scrx=objloc.x-eyeloc.x+1
            scry=objloc.y-eyeloc.y+1

            //Get size of client.view
            var/viewsize=usr.client.view
            if (isnum(viewsize))
                viewx=viewsize
                viewy=viewsize
            else
                //Extract viewx and viewy from text string
                viewx=round(text2num(viewsize)/2)
                viewy=round(text2num(copytext(viewsize,findtext(viewsize,"x")+1))/2)

        //Work out screen_loc position
        scrx+=viewx
        scry+=viewy
        if (crhud_dragpixel)
            screen_loc="[scrx]:[usr.crhud_mousepixelx-16],[scry]:[usr.crhud_mousepixely-16]"
        else
            screen_loc="[scrx],[scry]"

    New()
        //Set drag pointer
        if (crhud_draggable && !mouse_drag_pointer) mouse_drag_pointer=icon(icon,icon_state,dir)
        .=..()

client/New()
    //Add HUD objects
    for (var/X in typesof(/obj/crhud)-/obj/crhud)
        var/obj/crhud/O=new X()
        if (O.crhud_addatstart && O.screen_loc) O.crhud_add(src)
        else del O

    .=..()

client/proc/crhud_add(X)
    ////X is the type of hud object to add to this client's HUD

    //Get HUD object
    var/atom/movable/HudObj=new(X)

    //Add to HUD
    screen+=HudObj

client/proc/crhud_remove(X)
    ////X is the type of hud object to remove from this client's HUD
    for (var/obj/crhud/H in screen) if (H.type==X) screen-=H

//Keep track of the pixel offset of the user's mouse (for pixel dragging purposes)
atom/MouseUp(location,iconx,icony)
    ..()
    usr.crhud_mousepixelx=iconx
    usr.crhud_mousepixely=icony

mob/var
    crhud_mousepixelx=16
    crhud_mousepixely=16