Explain This To Me

[friendlycyclone]

I am trying to understand code better, not just knowing what a function does because ,or what to do if you get this syntax error or that glitch but a fundamental understanding of what you’re asking of your program

I personally spend 90% of my time on this forum looking for the meaning of certain scripts so why not make a topic about it. so here I am, with a shiny new account, asking for your help with informing this growing community and inform aspiring coders on what they are asking of their computer and in turn teaching them when it is better for certain code or another.

it is in a snake game and i dont know for sure if i need to put the entire script in for it to be relivent but what i got form it it was something along the lines that when it hits a wall or eats itself it makes a new head and i just dont know

Select
        Case $newhead[0] < 0 Or $newhead[0] > 39 Or $newhead[1] < 0 Or $newhead[1] > 39
            If $snakelength > 0 Then
                MsgBox(0, "Your snake ate the wall.", "Your snake was "& ($snakelength + 1) & " units long")
            Else
                MsgBox(0, "Your snake ate the wall.", "You should play with your snake more.")
            EndIf
            _cleanup()
            
        Case $board[$newhead[0]][$newhead[1]]  ; OK to go there
            $newhead[2] = GUICtrlCreateLabel("", $newhead[0] * 10, $newhead[1] * 10, 10, 10)
            GUICtrlSetBkColor($newhead[2], 16777215)
            If $board[$newhead[0]][$newhead[1]] = 2 Then  ; Ate Food
                ; Move food
                Do
                    $a = Int(Random(0, 39))
                    $b = Int(Random(0, 39))
                Until $board[$a][$b] = 1  ; empty
                $board[$a][$b] = 2  ; food
                GUICtrlSetPos($food, $a * 10, $b * 10)
                $snakelength = $snakelength + 1
                ReDim $snake[$snakelength + 1][3]
            Else
                GUICtrlDelete($oldtail[2])
                $board[$oldtail[0]][$oldtail[1]] = 1
            EndIf
            $board[$newhead[0]][$newhead[1]] = 0
            For $i = $snakelength To 1 Step - 1 ; Array shift
                $snake[$i][0] = $snake[$i - 1][0]
                $snake[$i][1] = $snake[$i - 1][1]
                $snake[$i][2] = $snake[$i - 1][2]
            Next
            $snake[0][0] = $newhead[0]
            $snake[0][1] = $newhead[1]
            $snake[0][2] = $newhead[2]

p.s. sorry for the confusion first post's make me Skittish

Edited July 5, 2013 by friendlycyclone

[JohnOne]

I don't even know what you are asking here.

Please try to explain yourself more clearly.

[water]

What's this all about

[TheSaint]

In the goodness of time, this topic will be relocated to a more suitable part of the forum ... providing it of course has merit enough to remain and eventually make sense.

[Melba23]

friendlycyclone,

The previous posters have obviously never written a snake game - I understand perfectly what the code is trying to do!

Let me take a look at the code and I will see what I can do to better your "understanding" of what is happening (or perhaps not in this case).

M23

[JohnOne]

friendlycyclone,

The previous posters have obviously never written a snake game - I understand perfectly what the code is trying to do!

Let me take a look at the code and I will see what I can do to better your "understanding" of what is happening (or perhaps not in this case).

M23

There was no mention of snake game or indeed any code earlier 

I still must try to play with my snake more though.

[TheSaint]

Yep, the original version of the first post, was a little very confusing and sounded like it should probably end up in Chat ... though he did admit to clicking POST too soon. Who'd have thought it was about a Snake game.

Anyway, I never have liked snakes, so I'm with Indy on this one, and will leave you all to it.

[friendlycyclone]

here is the full snake game

expandcollapse popup

;left arrow                           25
;up arrow                             26
;right arrow                          27
;down arrow                           28
;space bar                            20
#include <GuiConstants.au3>
#include <Array.au3>
opt("GuiOnEventMode", 1)

MsgBox(0, "Directions", "Use the arrow keys to start the game, to guide the snake and unpause the game. Use the spacebar to pause the game.")

$gui = GUICreate("Snake", 400, 400)
GuiSetBkColor(0x000099) 
GUISetState()
GUISetOnEvent($gui_event_close, "_Exit")

Global $clientsize = WinGetClientSize($gui)
Global $speedder = 150
Global $food
Global $snakelength = 0
Dim $board[40][40]  ; tracks the board
Dim $snake[$snakelength + 1][3]  ; positions and parts of the snake
Dim $food_location[2]  ; not possible for multiple food locations?

DllOpen("user32.dll")
_start()
Global $dx = 1
Global $dy = 0
_sleep()
While 1
    Sleep($speedder)
    
    If _IsPressed(25) Then
        $dx = -1
        $dy = 0
    EndIf
    If _IsPressed(27) Then
        $dx = 1
        $dy = 0
    EndIf
    If _IsPressed(26) Then
        $dx = 0
        $dy = -1
    EndIf
    If _IsPressed(28) Then
        $dx = 0
        $dy = 1
    EndIf
    move()
    If _IsPressed(20) Then
        _sleep()
    EndIf
WEnd
Func _start()
    $snakelength = 0
    ReDim $snake[$snakelength + 1][3]
    Local $x, $y, $a, $b, $pos
    For $x = 0 To 39
        For $y = 0 To 39
            $board[$x][$y] = 1  ; empty
        Next
    Next
    $a = Int(Random(3, 36))
    $b = Int(Random(3, 36))
    $snake[0][2] = GUICtrlCreateLabel("", $a * 10, $b * 10, 10, 10)
    GUICtrlSetBkColor($snake[0][2], 16777215)
    $pos = ControlGetPos($gui, "", $snake[0][2])
    $snake[0][0] = Int($pos[0] / 10)
    $snake[0][1] = Int($pos[1] / 10)
    ;MsgBox (0, "Diagnostic", $snake[0][0] & ", " & $snake[0][1])
    $board[$a][$b] = 0  ; snake  simplifies the "can I go there?" logic
    
    Do
        $a = Int(Random(0, 39))
        $b = Int(Random(0, 39))
    Until $board[$a][$b] = 1  ; empty
    $food = GUICtrlCreateLabel("", $a * 10, $b * 10, 10, 10)
    $pos2 = ControlGetPos($gui, "", $food)
    $food_location[0] = $pos2[0] / 10
    $food_location[1] = $pos2[1] / 10
    GUICtrlSetBkColor($food, 39219)
    $board[$a][$b] = 2  ; food
EndFunc   ;==>_start

Func move()
    
    Local $newhead[3]
    $newhead[0] = $snake[0][0] + $dx
    $newhead[1] = $snake[0][1] + $dy
    
    Local $oldtail[3]
    $oldtail[0] = $snake[$snakelength][0]
    $oldtail[1] = $snake[$snakelength][1]
    $oldtail[2] = $snake[$snakelength][2]
    
    Select
        Case $newhead[0] < 0 Or $newhead[0] > 39 Or $newhead[1] < 0 Or $newhead[1] > 39
            If $snakelength > 0 Then
                MsgBox(0, "Your snake ate the wall.", "Your snake was "& ($snakelength + 1) & " units long")
            Else
                MsgBox(0, "Your snake ate the wall.", "You should play with your snake more.")
            EndIf
            _cleanup()
            
        Case $board[$newhead[0]][$newhead[1]]  ; OK to go there
            $newhead[2] = GUICtrlCreateLabel("", $newhead[0] * 10, $newhead[1] * 10, 10, 10)
            GUICtrlSetBkColor($newhead[2], 16777215)
            If $board[$newhead[0]][$newhead[1]] = 2 Then  ; Ate Food
                ; Move food
                Do
                    $a = Int(Random(0, 39))
                    $b = Int(Random(0, 39))
                Until $board[$a][$b] = 1  ; empty
                $board[$a][$b] = 2  ; food
                GUICtrlSetPos($food, $a * 10, $b * 10)
                $snakelength = $snakelength + 1
                ReDim $snake[$snakelength + 1][3]
            Else
                GUICtrlDelete($oldtail[2])
                $board[$oldtail[0]][$oldtail[1]] = 1
            EndIf
            $board[$newhead[0]][$newhead[1]] = 0
            For $i = $snakelength To 1 Step - 1 ; Array shift
                $snake[$i][0] = $snake[$i - 1][0]
                $snake[$i][1] = $snake[$i - 1][1]
                $snake[$i][2] = $snake[$i - 1][2]
            Next
            $snake[0][0] = $newhead[0]
            $snake[0][1] = $newhead[1]
            $snake[0][2] = $newhead[2]
        Case Else
            ;eat self
            MsgBox(0, "Yor snake ate itself", "You snake was "& ($snakelength + 1) & " units long")
            _cleanup()
    EndSelect
EndFunc   ;==>move

Func _cleanup()
    For $x = 0 To 39
        For $y = 0 To 39
            $board[$x][$y] = 1  ; empty
        Next
    Next
    GUICtrlDelete($food)
    For $i = 0 To $snakelength
        GUICtrlDelete($snake[$i][2])
    Next
    _start()   ; This is going to choke after 300 something calls
    _sleep()
EndFunc   ;==>_cleanup

Func _Exit()
    DllClose("user32.dll")
    Exit
EndFunc   ;==>_Exit
Func _sleep()
    Do
        Do
            Sleep(100)
        Until _IsPressed(25) Or _IsPressed(26) Or _IsPressed(27) Or _IsPressed(28)
        If _IsPressed(25) Then
            $dx = -1
            $dy = 0
        EndIf
        If _IsPressed(27) Then
            $dx = 1
            $dy = 0
        EndIf
        If _IsPressed(26) Then
            $dx = 0
            $dy = -1
        EndIf
        If _IsPressed(28) Then
            $dx = 0
            $dy = 1
        EndIf
    Until _IsPressed(25) Or _IsPressed(26) Or _IsPressed(27) Or _IsPressed(28)
EndFunc   ;==>_sleep
Func _IsPressed($hexkey)
    Local $ar, $brv
    $hexkey = '0x' & $hexkey
    $ar = DllCall("user32", "int", "GetAsyncKeyState", "int", $hexkey)
    
    If $ar[0] <> 0 Then
        $brv = 1
    Else
        $brv = 0
    EndIf
    
    Return $brv
EndFunc   ;==>_IsPressed

its long though so ill put a copy as an atatchment for the sake of ease... as soon as i figure out how

[friendlycyclone]

again im really sorry about the confusion

[Melba23]

friendlycyclone,

No problem - but I have house guests this weekend so I may not have too much time to look at it for a while. Just do not hold your breath - or if you do, hope that someone else steps in!

M23

[friendlycyclone]

a bit off topic but i also would like to know if there were any simple ways to make an object that you can manipulate

in the snake program it seemed like it was changing the color of the board arays were the "snake" would be as aposed to having the snake move over the board.

so i would like to know two things.

 1) is it possible to have an objects that moves independantly of eachother

 2) how do you set the color of  a certain place in an array (or something along those lines)

p.s. im trying to make it look like legend of zelda  were it will change when i get to the edge of the screen

so if that is impossible well then poop