; ==============================================================================
; EBLAN ENGINE - Global State and Data Structures
; ==============================================================================

.data
; Window and GDI
szClassName         db "EblanEngine3DWndClass",0
szWindowTitle       db "EBLAN ENGINE 3D - Retro Raycaster [Pure x86 Assembly]",0
hEngineWnd          dd 0
hEngineDC           dd 0
hEngineInstance     dd 0
isRunning           dd 1

; High Precision Timing
targetFrameTimeMs   dd 16           ; ~60 FPS (16.6 ms)
lastTickCount       dd 0
fpsCounter          dd 0
fpsTimer            dd 0
currentFps          dd 60
szFpsLabel          db "FPS: ",0

; Software Framebuffer & BITMAPINFO
ALIGN 4
bmiEngine           BITMAPINFOHEADER <sizeof BITMAPINFOHEADER, SCREEN_W, -SCREEN_H, 1, 32, 0, 0, 0, 0, 0, 0>
                    dd 0            ; palette dummy

rngSeed             dd 12345678h

; Player State
; Position in RAW world units (1 cell = 64 units; e.g. 160 = cell 2.5)
playerX             dd 160
playerY             dd 160
playerAngle         dd 0            ; 0..511 (0 = East, 128 = South, 256 = West, 384 = North)
playerMoveSpeed     dd 3            ; raw units per frame (walk)
playerRunSpeed      dd 6            ; raw units per frame (sprint)
playerTurnSpeed     dd 4            ; angle units per frame
playerRadius        dd 16           ; collision radius (raw units)

; Input State Flags
keyForward          db 0
keyBackward         db 0
keyStrafeLeft       db 0
keyStrafeRight      db 0
keyTurnLeft         db 0
keyTurnRight        db 0
keyAction           db 0
keyRun              db 0
keyShowMap          db 1            ; minimap toggle
keyScreenshot       db 0            ; F12 screenshot request

; Map palette (overridable by map.dat header)
mapCeilingColor     dd COLOR_CEILING
mapFloorColor       dd COLOR_FLOOR
szMapFilePath       db "assets\map.dat",0

; Texture pack (optional; falls back to procedural textures)
szTexPackPath       db "assets\textures\texturepack.bin",0
texPackLoaded       dd 0

; Sprite Manager
spriteCount         dd 0

; Engine HUD & Strings
strControls1        db "WASD: Move / Strafe | Shift: Run",0
strControls2        db "Arrows: Turn Camera",0
strControls3        db "E: Door | M: Minimap | F12: Shot | Esc: Exit",0
strEngineName       db "EBLAN ENGINE 3D (x86 MASM)",0
strDoorHint         db "[E] - Door",0

; Screenshot (F12): writes 32-bit top-down BMP of screenBuffer
szScreenshotPath    db "screenshot.bmp",0
ALIGN 4
screenshotHeader    db 'B','M'
                    dd (54 + FRAME_BUFFER_SIZE) ; bfSize
                    dd 0                        ; bfReserved
                    dd 54                       ; bfOffBits
                    dd 40                       ; BITMAPINFOHEADER.biSize
                    dd SCREEN_W                 ; biWidth
                    dd -SCREEN_H                ; biHeight (top-down)
                    dw 1                        ; biPlanes
                    dw 32                       ; biBitCount
                    dd 0                        ; biCompression = BI_RGB
                    dd FRAME_BUFFER_SIZE        ; biSizeImage
                    dd 0, 0, 0, 0

; ------------------------------------------------------------------------------
; Large buffers live in BSS (.data?) so they are NOT baked into the .exe
; ------------------------------------------------------------------------------
.data?
ALIGN 4
screenBuffer        db FRAME_BUFFER_SIZE dup(?)
ALIGN 4
depthBuffer         dd SCREEN_W dup(?)

; Fixed-point Math Lookup Tables (512 angles, 16.16 signed fixed point)
ALIGN 4
tableSin            dd ANGLE_512 dup(?)
tableCos            dd ANGLE_512 dup(?)

; Game Map Grid (32x32 = 1024 bytes)
gameMap             db MAP_SIZE dup(?)

; Texture Memory (16 slots of 128x128 32-bit BGRA = 1 MB)
ALIGN 4
textureBuffer       db MAX_TEXTURES * TEX_SIZE_BYTES dup(?)

ALIGN 4
spriteList          db MAX_SPRITES * (sizeof SpriteStruct) dup(?)
spriteOrder         dd MAX_SPRITES dup(?)   ; sprite indices sorted far-to-near