Avalon: Data at EB43

EB43: Data buffer - for each room object, creature, scenery item


This 16 byte working buffer handles each room item data set, stored at 7C00. Bytes are copied back and forth between store and buffer.
EB43	DEFB $00	Type of graphic to draw - checked & dealt with at routine at C89F: 1 = Back wall bricks/scenery, door frames, and wall-floor connector graphics. Also servant and flashing eye cursor 2 = Door 3 = Creature 4 = Interactable objects (e.g. key, chest, scroll) 5 = Missile fired by creature/warlock 6 = Corner-wall section (left) 7 = Corner-wall section (right) 8 = Missile fired by Maroc 14 = Tunnel item - boundary wall, spider or bat 15 = Viewport position for tunnel rooms 32 = Viewport position for standard rooms
EB44	DEFW $0000	Multiple use: Tunnel number offset (32) stored at C627 Address pointer to data sets at 6790 (plus offset) stored in routine at C38E Address pointer to data set for a room object (736F) in the current room (checked at DE7F) Pointer to warlock & creature data sets at 6C7C and 6CB4 For missiles, address pointer to missile table at 6CDC
EB46	DEFB $00	Multiple uses: 0 = Back wall door 1 = Right wall door 2 = Left wall door Connecting door set number (from 6790) Tunnel boundary wall type, 1 (right) or 2 (left) - D702 Tunnel number 0-31 (room number minus 224) stored at C62B. Data set number for object in room interactable objects table at 736F Creature type setup in routine at CD96 - warlock & creature data at 6C7C: 1-7 = Warlock 8 = Guardian of Chaos 9 = Goblin warrior 10 = Goblin missile thrower 11 = Wraith 12 = Demon 4 = Spider (creature generation in tunnel at D758) 8 = Bat (creature generation in tunnel at D758)
EB47	DEFB $00	Overflow/precision byte used when calculating the item's horizontal room position ('true' position is the next - high - byte which follows this one) Acts as a fraction/overflow value for large/small values when this item's horizontal room position is calculated at C841 Second byte of foreground scenery set (at 7F01) stored here in routine at D511
EB48	DEFB $00	Graphic horizontal position within current room, in half character (4-pixel) steps
EB49	DEFB $00	Overflow/precision byte used when calculating the item's vertical room position ('true' position is the next - high - byte which follows this one)
EB4A	DEFB $00	Graphic vertical position within current room, in pixels, from top of room playing area
EB4B	DEFB $00	64 - item in standard room 254 - spider/bat in tunnel room at D758 255 - other item in tunnel room (C5E7)
EB4C	DEFB $00	Item's horizontal movement speed For room scenery items, calculated at E8EE using the reverse (NEG) of Maroc's horizontal movement speed (EB04) > 128 (negative) = left, < 128 (positive) = right
EB4D	DEFB $00	Item's vertical movement speed For room scenery items, calculated at E8EE using the reverse (NEG) of Maroc's vertical movement speed (EB05) > 128 (negative) = up, < 128 (positive) = down
EB4E	DEFB $00	Item properties byte: ALL - Bit 0 (1) set indicates if any part of graphic is visible on-screen (1 = visible, 0 = not visible) ITEMS - Bit 1 (2) set indicates an item is hidden (e.g. inside a chest) ALL - Bit 2 (4) set if this item needs erasing on-screen, before being re-drawn (e.g. item has changed frame/moved) ITEMS - Bit 3 (8) indicates (when set) that an item is flying/falling - e.g. an item thrown/dropped by the servant (see CB5B) ITEMS - Bit 4 (16) set = item currently carried by servant ITEMS - Bit 6 (64) = item is portable DOORS - Bit 3 (8) set (1) if door is open, reset (0) if closed DOORS - Bit 5 (32) set when a door opening/closing is triggered DOORS - Bit 6 (64) set if door is now opening/closing DOORS - Bit 7 (128) set - Maroc has just gone through a doorway MISSILES - Bits 5-8 - length of missile's existence on-screen before disappearing CREATURES - Bit 5 (32) - creature is disintegrating, will need removing post-animation WARLOCKS - Bit 6 (64) trigger warlock disappearance post-materialization animation (CE89) - successful object trade WARLOCKS - Bit 7 (128) trigger warlock's appearance, post-materialization animation
EB4F	DEFB $00	Pre-graphics data byte (see Graphic properties): Bits 0-3 - graphics frame Bit 5 is set - graphic is 'flippable' Bit 6 is set = graphic has a left/right facing direction (e.g. mouse, goblins) Bit 7 is set = graphic is animated
EB50	DEFB $00	Graphic address frame offset (>1 for mirrored graphics frames) Used at E0C2 to calculate the graphics address pointer offset for the graphic in the table at 97C3 Offset address = [(n-1)*2] - e.g. a byte value of 1 = no offset, byte value of 4 = offset of 6 bytes, or 3 x 2-byte pointer addresses Bit 3 (8) - used for creatures with left/right facing graphics, to indicate if they are facing right (set) or left (not set) - see E35B
EB51	DEFW $0000	Graphic address pointer (in table at 97C3), including any offset for the correct graphic frame