[bb] Saving/Loading Types by BlackJumper [ 1+ years ago ]

[BlitzBot]

Title : Saving/Loading Types
Author : BlackJumper
Posted : 1+ years ago

Description : This was created in response to a request about saving and reloading a game. Someone demonstrated a custom save routine + corresponding loader.

To me this seemed like too much work, when the Str$() function will format all fields in a type for printing, thus saving half the work. The challenge then becomes the writing of a parser for the text values of your type.

The example below shows the reading of a couple of ints and a string. There is a code snippet (add's Parser Function) elsewhere in the Archives that could help with parsing other values such as floats...

<a href="codearcsb4d9.html?code=161" target="_blank">http://www.blitzbasic.com/codearcs/codearcs.php?code=161[/url]

Code :

Code: BlitzBasic

1. [code]
2. ;------------------------------------------------------------------
3. ;----   demo of saving and reloading game data using Str$()    ----
4. ;----             Blackjumper  - Jan 2005                      ----
5. ;------------------------------------------------------------------
6.  
7. Type test
8.         Field x
9.         Field y
10.         Field name$
11. End Type
12.  
13. For count = 1 To 4
14.         n.test = New test
15.         nx = Rand(10)
16.         ny = Rand(10)+100
17.         n
18. ame$ = Chr(Rand(26)+65) +Chr(Rand(26)+65) +Chr(Rand(26)+65)
19. Next
20.  
21.  
22. fileout = WriteFile("C:storedgame.txt")
23. For n.test = Each test
24.         Print Str$(n)
25.         WriteString (fileout, Str$(n))
26. Next
27. CloseFile( fileout )
28.  
29. Print "game data written to file... press any key to continue"
30. Print
31. WaitKey
32.  
33. Print "deleting all instances of type 'test'..."
34. For n.test = Each test
35.         Delete n
36. Next
37. Print "printing all type information...
38. Print "________________________________"
39. For n = Each test
40.         Print Str$(n)
41. Next
42. Print "--------------------------------"
43. WaitKey
44. Print
45.  
46.  
47. Print "... now reading from disk..."
48. filein = ReadFile("C:storedgame.txt")
49. While Not Eof(filein)
50. Read1$ = ReadString$( filein )
51. RestoreTestInfo(Read1$)
52. Wend
53.  
54. Print "printing all reloaded type information...
55. Print "------------------------"
56. For n.test = Each test
57.         Print Str$(n)
58. Next
59. Print "------------------------"
60.  
61. WaitKey
62. End
63.  
64. Function RestoreTestInfo( SavedString$ )
65.         Print "Read from file --> " + SavedString$
66.         SavedString$ = Mid$( SavedString$, 2, Len(SavedString$)-2) ; remove end square brackets
67.        
68.         firstcomma = Instr(SavedString$, ",")
69.         firstvalue% = Left$(SavedString$, firstcomma-1)   ; convert first value (up to comma) to an int
70.        
71.         SavedString$ = Mid$( SavedString$, firstcomma+1, Len(SavedString$)-firstcomma+1)  ; eat up to 1st comma
72.  
73.         firstcomma = Instr(SavedString$, ",")
74.         secondvalue% = Left$(SavedString$, firstcomma-1)  ; convert up to new first comma to another int
75.        
76.         SavedString$ = Mid$( SavedString$, firstcomma+1, Len(SavedString$)-firstcomma+1)  ; eat up to new 1st comma
77.         ThirdString$ = Mid$( SavedString$, 2, Len(SavedString$)-2)                        ; remove quotes from string
78.  
79.         reloaded.test = New test                        ; make a new type
80.         reloadedx = firstvalue%                 ; and assign the
81.         reloadedy = secondvalue%                        ; reloaded values
82.         reloaded
83. ame$ = ThirdString$             ; to the fields
84.        
85. End Function
86.  
87.  

[/code]

Comments :


Xerra(Posted 1+ years ago)

 I found this very useful for ripping out the code to get 3 bits of data from one line in the function by reading up to commas and reworking the string.Thanks for that.


BlackJumper(Posted 1+ years ago)

 Someone (Sefery) was asking for an example of how to load and save object position by using the F6 and F7 keys. <a href="../Community/posts7e11-2.html?topic=59739" target="_blank">http://www.blitzbasic.com/Community/posts.php?topic=59739[/url]I modified their code as follows to achieve this...

Code: [Select]

AppTitle "My little box"

Graphics3D 800,600,32,2

SetBuffer BackBuffer()
Global message$ = "move the boxes... '[' and ']' to change box"
Type test
Field x
Field y
Field z
Field name$
Field shape
End Type

For count = 1 To 4
n.test = New test
nx = Rand(10)
ny = Rand(10)
nz = Rand(10)+10
n
ame$ = Chr(Rand(26)+65) +Chr(Rand(26)+65) +Chr(Rand(26)+65)
nshape = CreateCube()
EntityColor nshape, count*50, 0,0
Next

camera=CreateCamera()

light=CreateLight()

RotateEntity light,0,0,90

Global reload.test
Global control.test = Last test
maxshape = controlshape
control.test = First test
minshape = controlshape


Repeat

If KeyDown(200)=True Then controly = controly + 1
If KeyDown(203)=True Then controlx = controlx - 1
If KeyDown(205)=True Then controlx = controlx + 1
If KeyDown(208)=True Then controly = controly - 1

If (KeyHit(26)=True And controlshape <> minshape) Then control = Before control
If (KeyHit(27)=True And controlshape <> maxshape) Then control = After control

For update.test = Each test
    PositionEntity updateshape, updatex, updatey, updatez
Next

If KeyHit(64) Then save
If KeyHit(65) Then load

UpdateWorld
RenderWorld

Text 20, 20, message$
Flip

Until KeyHit(1)
End

;+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Function save()

fileout = WriteFile("Shay1.SM")
For n.test = Each test
Print Str$(n)
WriteString (fileout, Str$(n))
; WriteFloat (fileout,cube)
; WriteFloat (fileout,EntityX)
; WriteFloat (fileout,EntityY)
; WriteFloat (fileout,EntityZ)
Next
CloseFile( fileout )
Cls
message$ = "game data written to file..."
FlushKeys

End Function
;+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Function load()
Cls
For destroy.test = Each test
    FreeEntity destroyshape
    Delete destroy
Next

filein = ReadFile("Shay1.SM")
While Not Eof(filein)
      Read1$ = ReadString$( filein )
      ;Read1$ = ReadFloat( filein )
      If Read1$<>"" Then
        reload.test = RestoreTestInfo(Read1$)
      EndIf
Wend
DebugLog "finished with loaded file"
FlushKeys
control = First test
End Function
;+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Function RestoreTestInfo.test( SavedString$ )
message$ =  "Read from file --> " + SavedString$ + "    ...     "
DebugLog message$     ; typical type looks like ... [-3,-4,14,"LQT",18898368]
SavedString$ = Mid$( SavedString$, 2, Len(SavedString$)-2) ; remove end square brackets

firstcomma = Instr(SavedString$, ",")
xvalue% = Left$(SavedString$, firstcomma-1)   ; convert first value (up to comma) to an int

SavedString$ = Mid$( SavedString$, firstcomma+1, Len(SavedString$)-firstcomma+1)  ; eat up to 1st comma

firstcomma = Instr(SavedString$, ",")
yvalue% = Left$(SavedString$, firstcomma-1)  ; convert up to new first comma to another int
SavedString$ = Mid$( SavedString$, firstcomma+1, Len(SavedString$)-firstcomma+1)  ; eat up to new 1st comma


firstcomma = Instr(SavedString$, ",")
zvalue% = Left$(SavedString$, firstcomma-1)  ; convert up to new first comma to another int


SavedString$ = Mid$( SavedString$, firstcomma+1, Len(SavedString$)-firstcomma+1)  ; eat up to new 1st comma
ThirdString$ = Mid$( SavedString$, 2, Len(SavedString$))     ; remove first quote from string

firstcomma = Instr(SavedString$, ",")
ThirdString$ = Mid$(SavedString$, 2, firstcomma-3)

message$ = message$ + "x: " + xvalue + "   y: " + yvalue + "   z: " + zvalue + "     name: " + ThirdString$
DebugLog message$

reloaded.test = New test ; make a new type
reloadedx = xvalue%    ; and assign the
reloadedy = yvalue%     ; reloaded values
reloadedz = zvalue%
reloaded
ame$ = ThirdString$ ; to the fields
reloadedshape = CreateCube()

Return (reloaded)

End Function
;+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++