; ==============================================================================
; EBLAN ENGINE - Constants and Definitions
; ==============================================================================

; Screen & Render Dimensions
SCREEN_W            equ 320
SCREEN_H            equ 240
SCREEN_HALF_W       equ 160
SCREEN_HALF_H       equ 120
SCREEN_PITCH        equ 1280            ; 320 * 4 bytes (BGRA)
FRAME_BUFFER_SIZE   equ 307200          ; 320 * 240 * 4 bytes

WINDOW_W            equ 1280
WINDOW_H            equ 960

; Fixed Point Math (16.16)
FIXED_SHIFT         equ 16
FIXED_ONE           equ 65536
FIXED_HALF          equ 32768

; Angles & Field of View
ANGLE_512           equ 512
ANGLE_MASK          equ 511
ANGLE_360           equ 512
ANGLE_180           equ 256
ANGLE_90            equ 128
ANGLE_45            equ 64
FOV_ANGLES          equ 96              ; ~67.5 degrees FOV
FOV_HALF            equ 48

; Map Dimensions & Units
MAP_W               equ 32
MAP_H               equ 32
MAP_SIZE            equ 1024
CELL_SIZE           equ 64              ; 64x64 units per cell
CELL_SHIFT          equ 6               ; 2^6 = 64

; Projection Constants
PROJ_DIST           equ 239             ; (SCREEN_W / 2) / tan(FOV / 2), FOV = 67.5 deg

; Texture Sizes (128x128 pixels, 4 bytes BGRA = 65536 bytes per texture)
TEX_W               equ 128
TEX_H               equ 128
TEX_SHIFT           equ 7               ; 2^7 = 128
TEX_MASK            equ 127
TEX_SIZE_BYTES      equ 65536
MAX_TEXTURES        equ 16

; Virtual Keys
VK_KEY_W            equ 57h
VK_KEY_A            equ 41h
VK_KEY_S            equ 53h
VK_KEY_D            equ 44h
VK_KEY_E            equ 45h
VK_KEY_Q            equ 51h
VK_KEY_M            equ 4Dh
VK_KEY_SPACE        equ 20h
VK_KEY_SHIFT        equ 10h
VK_KEY_ESCAPE       equ 1Bh
VK_KEY_LEFT         equ 25h
VK_KEY_UP           equ 26h
VK_KEY_RIGHT        equ 27h
VK_KEY_DOWN         equ 28h
VK_KEY_F12          equ 7Bh
VK_KEY_C            equ 43h
VK_KEY_TAB          equ 9

; Colors (32-bit 00RRGGBBh; in memory a DIB stores bytes B,G,R,0 little-endian)
COLOR_BLACK         equ 00000000h
COLOR_WHITE         equ 00FFFFFFh
COLOR_RED           equ 00FF0000h
COLOR_GREEN         equ 0000FF00h
COLOR_BLUE          equ 000000FFh
COLOR_YELLOW        equ 00FFFF00h
COLOR_CYAN          equ 0000FFFFh
COLOR_MAGENTA       equ 00FF00FFh
COLOR_GRAY          equ 00808080h
COLOR_DARK_GRAY     equ 00303030h
COLOR_FLOOR         equ 00222222h
COLOR_CEILING       equ 00383838h
COLOR_CHROMA_KEY    equ 00FF00FFh       ; transparent sprite texel (magenta)

; Wall Cell Types (value = texture slot index)
CELL_EMPTY          equ 0
CELL_BRICK          equ 1
CELL_WOOD           equ 2
CELL_STONE          equ 3
CELL_METAL          equ 4
CELL_DOOR           equ 5
CELL_DOOR_OPEN      equ 6
CELL_PILLAR         equ 7
CELL_GLASS          equ 8
CELL_MARBLE         equ 9
CELL_PORTAL         equ 10      ; Sector transition portal
CELL_COUNT          equ 11

; Sector Transition Portals
MAX_TRANSITIONS     equ 16
MAX_PATH_BYTES      equ 260
MAP_FORMAT_VERSION  equ 4

LevelTransition STRUCT          ; sizeof = 42 bytes (packed)
    triggerCellX    db 0        ; 1 byte
    triggerCellY    db 0        ; 1 byte
    targetMap       db 32 dup(0); 32 bytes ASCII
    targetSpawnX    dw 0        ; 2 bytes
    targetSpawnY    dw 0        ; 2 bytes
    targetAngle     dw 0        ; 2 bytes
    fadeEffect      db 0        ; 1 byte (0=instant, 1=fade to black)
    reserved        db 0        ; 1 byte padding
LevelTransition ENDS

; Sprite Types & Struct
MAX_SPRITES         equ 32

SpriteStruct STRUCT
    x           dd 0    ; raw world units (1 cell = 64 units)
    y           dd 0    ; raw world units
    textureId   dd 0    ; texture slot 1..15 (0 = solid marker color)
    scale       dd 0    ; fixed-point 16.16 (65536 = 1.0)
    dist        dd 0    ; runtime: squared distance to player (for sorting)
    flags       dd 0
SpriteStruct ENDS

; Texture Pack (assets/textures/texturepack.bin):
;   dd magic 'EBTX', dw version (1), dw slotCount, then slotCount * 65536 bytes
TEXPACK_MAGIC       equ 58544245h       ; 'EBTX'

; File I/O Constants
GENERIC_READ        equ 80000000h
GENERIC_WRITE       equ 40000000h
FILE_SHARE_READ     equ 1
OPEN_EXISTING       equ 3
CREATE_ALWAYS       equ 2
FILE_ATTRIBUTE_NORMAL equ 80h
INVALID_HANDLE_VALUE equ -1
MAP_MAGIC           equ 4E4C4245h       ; 'EBLN'

MapHeader STRUCT          ; sizeof = 38 bytes (packed)
    magic           dd 0    ; 'EBLN'
    version         dw 0    ; 1 = fixed coords, 2/3 = transitions, 4 = cutscenes
    mapWidth        dw 0    ; 32
    mapHeight       dw 0    ; 32
    playerStartX    dw 0    ; cell X
    playerStartY    dw 0    ; cell Y
    playerStartAngle dw 0   ; 0..511
    spriteCount     dw 0    ; number of sprites
    ceilingColor    dd 0    ; 00RRGGBBh
    floorColor      dd 0    ; 00RRGGBBh
    transitionCount dw 0    ; number of transitions in file
    cutsceneCount   dw 0
    cutsceneStringCount dw 0
    cutsceneFlags   dw 0
    reserved        db 4 dup(0)
MapHeader ENDS

MAX_CUTSCENE_EVENTS  equ 128
MAX_CUTSCENE_STRINGS equ 32
CUTSCENE_STRING_BYTES equ 96
CUTSCENE_MAX_DURATION equ 3600
CUTSCENE_AUTOPLAY equ 1
OP_END equ 0
OP_WAIT equ 1
OP_MOVE_CAM_TO equ 2
OP_PAN_CAM_TO equ 3
OP_SHOW_SUBTITLE equ 4
OP_HIDE_SUBTITLE equ 5
OP_PLAY_SOUND equ 6
OP_FADE_SCREEN equ 7
OP_CHANGE_SUBLEVEL equ 8
CutsceneEvent STRUCT
    tickTimestamp dw 0
    opCode db 0
    param8 db 0
    paramA dd 0
    paramB dd 0
    dataId dd 0
CutsceneEvent ENDS