;*********************;
; Program Fun to Draw ;
;*********************;

pile    SEGMENT stack
pile    ENDS

data    SEGMENT public
    mode    DB  0
    autoRun DB  0
    delay   DW  0
    color1  DB  0
    exCol1  DB  0
    dirX1   DW  0
    dirY1   DW  0
data    ENDS

;*****************************************************************************;
;** FEW TESTS // and failed :( don't know why I can't add more variable without
;** getting some strange effects like freezing when I quite
; datap1    SEGMENT public
    ; posX1 DW  0
    ; posY1     DW  0
; datap1    ENDS
; datap2    SEGMENT public
    ; color2    DB  0
    ; exCol2  DB    0
    ; dirX2 DW  0
    ; dirY2 DW  0
    ; posX2 DW  0
    ; posY2     DW  0
; datap2    ENDS
; dataAll   group   data, datap1
;*****************************************************************************;

code    SEGMENT public
assume  cs:code,ds:data,es:code,ss:pile
; assume    ds:datap1
; assume    ds:datap2

; graphic mode
MOV AL, 13h
MOV AH, 0
INT 10h

MOV CX, 50
MOV DX, 50
; MOV posX1, 30
; MOV posY1, 30
MOV dirX1, 1
MOV dirY1, 0
MOV exCol1, 0
MOV autoRun, 1
MOV mode, 1
MOV color1, 64

; MOV   dirX2, 0
; MOV   dirY2, 0
; MOV   exCol2, 0
; MOV color2, 14
; MOV posX2, 180
; MOV   posY2, 100

JMP mainLoop

; *** Sub PutPxl ***
PutPxl:
    MOV AH, 0Ch
    ; MOV CX, posX1
    ; MOV DX, posY1
    MOV AL, color1
    INT 10h
    ; MOV CX, posX2
    ; MOV DX, posY2
    ; MOV AL, color2
    ; INT 10h
    RET

; *** Sub ReadPxl ***
fReadPxl:
    MOV AH, 0Dh
    INT 10h
    CMP dirX1, 0
    JNE withExColor
    CMP dirY1, 0
    JE withOutExColor
    withExColor:
    MOV exCol1, AL
    withOutExColor:
    RET

fCheckCollision:
    MOV BX, 0
    CMP CX, 10 ;CMP posX1, 10
    JNG yes_collision
    CMP DX, 10 ;CMP posY1, 10
    JNG yes_collision
    CMP CX, 309 ;CMP posX1, 309
    JG yes_collision
    CMP DX, 189 ;CMP posY1, 189
    JG yes_collision
    CMP exCol1, 0
    JE no_collision
    CMP exCol1, 52
    JE no_collision
    yes_collision:
    MOV BX, 1
    no_collision:
    RET

fInitGrid:
    MOV AH, 0Ch
    MOV AL, 52 ;148
    MOV CX, 10
    MOV DX, 10
    INT 10h
    lineH:
        INC CX
        INT 10h
        CMP CX, 310
        JNE lineH
        ADD DX, 10
        MOV CX, 9
        CMP DX, 200
        JNE lineH

    MOV DX, 9
    MOV CX, 10
    lineV:
        INC DX
        INT 10h
        CMP DX, 190
        JNE lineV
        ADD CX, 10
        MOV DX, 9
        CMP CX, 320
        JNE lineV

    MOV CX, 100
    MOV DX, 95
    MOV AL, 15
    RET

fCleanScreen:
    MOV AH, 0Ch
    MOV AL, 0
    MOV CX, 0
    MOV DX, 0
    loopScreenReset:
        int 10h
        INC CX
        CMP CX, 320
        jne loopScreenReset
        MOV CX, 0
        INC DX
        CMP DX, 200
        jne loopScreenReset
        MOV CX, 32
        MOV DX, 32
        MOV AL, 15
    RET

updateData proc
    CMP mode, 1
    JE rainbow
    CMP mode, 2
    JE cursor
    CMP mode, 3
    JE erase
    CMP mode, 4
    JE noClear
    erase:
        MOV exCol1, 0
    cursor:
        MOV AL, exCol1
        MOV AH, 0Ch
        INT 10h
        JMP noClear
    rainbow:
        CMP color1, 54
        JNG upColor
        MOV color1, 31
        upColor:
            INC color1
    noClear:
        ; MOV CX, posX1
        ADD CX, dirX1
        ; MOV posX1, CX
        ; MOV DX, posY1
        ADD DX, dirY1
        ; MOV posY1, DX
        CALL fReadPxl
        CALL PutPxl
        CMP autoRun, 1
        JE yes_autoRun
        MOV dirX1, 0
        MOV dirY1, 0
        yes_autoRun:

    RET
updateData endp

mainLoop:
    CALL handleKeyBoard
    CALL updateData
    CALL fCheckCollision
    CMP BX, 1
    JE collision

    MOV delay, 32768
    loopDelay:
        DEC delay
        JNZ loopDelay

    JMP mainLoop

NLeft:
    CMP dirX1, 0        ; test to avoid way back
    JNE mainLoop
    MOV dirX1, -1
    MOV dirY1, 0
    JMP mainLoop
NRight:
    CMP dirX1, 0        ; idem
    JNE mainLoop
    MOV dirX1, 1
    MOV dirY1, 0
    JMP mainLoop
NUp:
    CMP dirY1, 0        ; ...
    JNE mainLoop
    MOV dirX1, 0
    MOV dirY1, -1
    JMP mainLoop
NDown:
    CMP dirY1, 0
    JNE mainLoop
    MOV dirX1, 0
    MOV dirY1, 1
    JMP mainLoop

putPixel:
    JMP mainLoop

collision:
    CMP mode, 4
    JE cleanScreen

handleKeyBoard proc
    MOV AH, 01h     ; just to check if a key is pressed
    INT 16h
    JZ notPressed

    MOV AH, 00h     ; get the key
    INT 16h
    pressed:
        CMP AH, 4Bh     ; narrow left
        JE NLeft
        CMP AH, 4Dh     ; narrow right
        JE NRight
        CMP AH, 48h     ; narrow up
        JE NUp
        CMP AH, 50h     ; narrow down
        JE NDown
        CMP AL, "a"
        JE toggleAutoRun
        CMP AL, "r"
        JE rainbowMode
        CMP AL, "c"
        JE cursorMode
        CMP AL, "g"
        JE initGrid
        CMP AL, "s"
        JE cleanScreen
        CMP AL, "e"
        JE eraseMode
        CMP AL, "t"
        JE traceMode
        CMP AL, "q"
        JE endProgram
    notPressed:
    RET
handleKeyBoard endp

toggleAutoRun:
    CMP autoRun, 0
    JE switch
    MOV autoRun, 0
    JMP putPixel
    switch:
        MOV autoRun, 1
    JMP putPixel

cleanScreen:
    CALL fCleanScreen
    JMP putPixel

rainbowMode:
    MOV mode, 1
    JMP putPixel

cursorMode:
    MOV mode, 2
    JMP putPixel

initGrid:
    CALL fCleanScreen
    CALL fInitGrid
    MOV dirX1, 1
    MOV dirY1, 0
    MOV color1, 14
    MOV autoRun, 1
    JMP traceMode

eraseMode:
    MOV color1, 15
    MOV mode, 3
    JMP PutPxl

traceMode:
    MOV mode, 4
    JMP PutPxl

; *** EXIT ***
endProgram:
    mov AX, 3       ; return to console mode (to avoid typing "cls" command)
    int 10h
    mov AH, 4Ch     ; end of DOS program
    mov AL, 00h
    int 21h

code    ENDS
END