/*
**  $VER: screens.e V0.8B
**
**  Screen Definitions.
**
**  (C) Copyright 1996-1997 DreamWorld Productions.
**      All Rights Reserved
*/

OPT MODULE
OPT EXPORT
OPT PREPROCESS

MODULE 'gms/dpkernel','graphics/blitter','system/register'

/****************************************************************************
** Screen object. 
*/

CONST SCRVERSION  = 1,
      TAGS_SCREEN = $FFFB0000 OR ID_SCREEN

OBJECT screen
    head[1]      :ARRAY OF head
    memptr1      :LONG          -> Ptr to screen 1
    memptr2      :LONG          -> Ptr to screen 2 (double buffer)
    memptr3      :LONG          -> Ptr to screen 3 (triple buffer)
    screenlink   :LONG          -> Ptr to a linked screen
    palette      :LONG          -> Ptr to the screen palette
    rasterlist   :LONG          -> Ptr to a rasterlist
    amtcolours   :LONG          -> The amount of colours in the palette.
    scrwidth     :INT           -> The width of the visible screen
    scrheight    :INT           -> The height of the visible screen
    picwidth     :INT           -> The width of the picture in pixels.
    picbytewidth :INT           -> The width of the picture in bytes.
    picheight    :INT           -> The height of the entire screen
    planes       :INT           -> The amount of planes in da screen
    scrxoffset   :INT           -> Hardware co-ordinate for TOS
    scryoffset   :INT           -> Hardware co-ordinate for LOS
    picxoffset   :INT           -> Offset of the horizontal axis
    picyoffset   :INT           -> Offset of the vertical axis
    attrib       :LONG          -> Special Attributes are?
    scrmode      :INT           -> What screen mode is it?
    scrtype      :INT           -> Interleaved/Planar/Chunky?
    task         :LONG          -> R: Task that owns this screen.
    planesize    :LONG          -> R: Size of a plane (bytewidth*height).
    bitmap       :PTR TO bitmap
ENDOBJECT

CONST BUFFER1 = 8,
      BUFFER2 = 12,
      BUFFER3 = 16

-> SCREEN ATTRIBUTES (attrib) 

CONST DBLBUFFER = $00000001,  -> For double buffering 
      TPLBUFFER = $00000002,  -> Triple buffering!! 
      PLAYFIELD = $00000004,  -> Set if it's part of a playfield 
      HSCROLL   = $00000008,  -> Gotta set this to do scrolling 
      VSCROLL   = $00000010,  -> For vertical scrolling 
      SPRITES   = $00000020,  -> Set this if you want sprites 
      SBUFFER   = $00000040,  -> Creates a scroll buff for up to 100 screens.
      CENTRE    = $00000080,  -> Centres the screens (sets XOffset/YOffset).
      BLKBDR    = $00000100,  -> Gives a blackborder on AGA machines 
      NOSCRBDR  = $00000200   -> For putting sprites in the border 

-> SCREEN TYPES (type) 

CONST INTERLEAVED = 1,        -> These are actual numbers, not bits.
      ILBM        = 1,
      PLANAR      = 2, 
      CHUNKY8     = 3,
      CHUNKY16    = 4,
      TRUECOLOUR  = 5

-> SCREEN MODES (mode) 

CONST HIRES   = $0001,     -> High resolution 
      SHIRES  = $0002,     -> Super-High resolution 
      LACED   = $0004,     -> Interlaced 
      LORES   = $0008,     -> Low resolution (default) 
      EXTRAHB = $0010,     -> Extra HalfBrite
      SLACED  = $0020,     -> Super-Laced resolution.
      HAM     = $0040      -> For HAM mode 

#define WAITLINE(a)         Shl(00,16) OR (a),0
#define COLOUR(a,b)         Shl(02,16),(a),(b),0
#define NEWPALETTE(a,b,c)   Shl(04,16),(a),(b),(c),0
#define COLOURLIST(a,b,c,d) Shl(06,16) OR (a),Shl(b,16) OR (c),(d),0
#define SPRITE(a)           Shl(08,16) OR (a),0
#define SCROLL(a,b,c)       Shl(10,16) OR (a),Shl(b,16) OR (c),0
#define FSCROLL(a,b,c,d)    Shl(12,16) OR (a),Shl(b,16) OR (c),Shl(d,16),0
#define FLOOD               Shl(14,16),0
#define REPOINT(a)          Shl(16,16),(a),0
#define MIRROR              Shl(18,16),0
#define RASTEND             $ffffffff

/* Screen tags */

CONST GSA_MEMPTR1      = TAPTR OR 12,
      GSA_MEMPTR2      = TAPTR OR 16,
      GSA_MEMPTR3      = TAPTR OR 20,
      GSA_SCREENLINK   = TAPTR OR 24,
      GSA_PALETTE      = TAPTR OR 28,
      GSA_RASTERLIST   = TAPTR OR 32,
      GSA_AMTCOLOURS   = TLONG OR 36,
      GSA_SCRWIDTH     = TWORD OR 40,
      GSA_SCRHEIGHT    = TWORD OR 42,
      GSA_PICWIDTH     = TWORD OR 44,
      GSA_PICBYTEWIDTH = TWORD OR 46,
      GSA_PICHEIGHT    = TWORD OR 48,
      GSA_PLANES       = TWORD OR 50,
      GSA_SCRXOFFSET   = TWORD OR 52,
      GSA_SCRYOFFSET   = TWORD OR 54,
      GSA_PICXOFFSET   = TWORD OR 56,
      GSA_PICYOFFSET   = TWORD OR 58,
      GSA_SCRATTRIB    = TLONG OR 60,
      GSA_SCRMODE      = TWORD OR 64,
      GSA_SCRTYPE      = TWORD OR 66