_CopyImage crashing my program after a while, can somebody please help?

[madscijr]

I'm working on a basic tile-based game engine.

It mostly works, but it seems to crash after a certain number of iterations.

(The program window just closes when the sub PlotTextToScreenFast runs a 3rd time.)

I did a bunch of testing, writing log files, etc, and determined it is dying at the line:

Code: QB64: [Select]

1. swapcolor& = _CopyImage(handle&, 32)

where the value of handle& = -8191.

However I suspect the problem isn't just that line, because there are other times when it runs with that value and doesn't die.

I have attached the code and associated image files, if anyone wants to try running it.

Just search in the .bas file for the word "crash" where I have marked the lines leading up to the crash.

If you run it you will see a menu.
If you press 4 <ENTER> you will see some graphics and text.
Press <ENTER> again to exit back to the menu.

Repeat above 2 more times.
The 3rd time the program will just die.

Why is this happening?

I am definitely not a programming or QB64 expert, and I have been driving myself crazy trying to figure out what I'm doing wrong.

Any help would be much appreciated!

[FellippeHeitor]

Every time you call _CopyImage you generate an extra image in memory, as the name implies. Do you ever _FreeImage the unused handles? This sounds like a case of memory leaking.

[FellippeHeitor]

I'm replying solely based on your post above. I haven't checked your code.

[bplus]

7K lines, yikes!

[madscijr]

Every time you call _CopyImage you generate an extra image in memory, as the name implies. Do you ever _FreeImage the unused handles? This sounds like a case of memory leaking.

You know, that could be it!
It is clearing the main screen, tilesets, etc. with _FreeImage at the end, but I think that isn't happening in all the calls that repeat over & over in the main loop!
I'll check and let you know what happens.
Thanks for your reply!

[madscijr]

7K lines, yikes!

Yeah, I was not really sure where the problem exactly was, so I figured I'd post the whole thing. That's why I said search for the word "crash", lol. We will see if that _FREEIMAGE was the issue...

[madscijr]

I'm replying solely based on your post above. I haven't checked your code.

I did find a couple of places where there was not _FREEIMAGE and added it, however it is still crashing.

Here are just the 3 routines that seem to have the problem.

The function swapcolor& at the bottom is where the program actually dies.

Do you see any other commands in here other than _COPYIMAGE that might require _FREEIMAGE,
or anything else that looks like it could be causing the program to exit?

Code: QB64: [Select]

1. ' /////////////////////////////////////////////////////////////////////////////
2. ' Draw entire array on screen in the specified fonts/colors for each character.
3.  
4. ' Like PlotTextToScreen but faster because it uses precalculated coordinates
5. ' to find the tile on the tile sheet, and the destination on the screen.
6.  
7. ' Receives:
8. ' imgScreen& = handle to screen to draw tile on
9. ' arrImage() = array of image handles pointing to 16x16 tile sheets of 16x16 pixel tiles colored black (256 tiles)
10. ' arrTileSheetMap() = array of TileSheetMapType which holds precalculated positions of tiles on tilesheet
11. ' arrTileMap() = array of TileMapType which holds precalculated positions where tiles go on screen
12. ' tileWidthPx% = width of tiles in pixels
13. ' tileHeightPx% = height of tiles in pixels
14. ' TextInfo = TextInfoType which stores info about the text to plot (# columns, # rows. among other things not used here)
15. ' arrText(80, 80) = 2D array of PlotTextType which stores character code, forecolor, backcolor, bitmap font's tileset image handle; indexed by arrText(column #, index in arrLineOrder)
16. ' arrLineOrder(80) AS INTEGER = array storing the row position of lines of text in arrText (done this way to speed up scrolling text)
17.  
18. Sub PlotTextToScreenFast(imgScreen&, arrImage() AS Long, arrTileSheetMap() AS TileSheetMapType, arrTileMap() AS TileMapType, tileWidthPx%, tileHeightPx%, TextInfo AS TextInfoType, arrText() AS PlotTextType, arrLineOrder() AS INTEGER)
19.     Dim dx%
20.     Dim dy%
21.     Dim TileNum%
22.     Dim TileColor&
23.     DIM BackColor&
24.     DIM iRowPos%
25.    
26.     IF TextInfo.numCols > UBound(arrText, 1) THEN
27.         TextInfo.numCols = UBound(arrText, 1)
28.     END IF
29.     IF TextInfo.numRows > UBound(arrText, 2) THEN
30.         TextInfo.numRows = UBound(arrText, 2)
31.     END IF
32.    
33.     For dy% = 1 To TextInfo.numRows
34.         iRowPos% = arrLineOrder(dy%)
35.         For dx% = 1 To TextInfo.numCols
36.             TileNum% = arrText(dx%, dy%).charCode
37.             TileColor& = arrText(dx%, dy%).foreColor
38.             BackColor& = arrText(dx%, dy%).backColor
39.            
40.             IF arrText(dx%, dy%).fontNumber > 0 AND arrText(dx%, dy%).fontNumber < 11 THEN
41. 'THIS IS WHERE THE PROGRAM CRASHES:
42.                 DrawColorTileFast imgScreen&, arrImage(arrText(dx%, dy%).fontNumber), arrTileSheetMap(), arrTileMap(), tileWidthPx%, tileHeightPx%, TileNum%, TileColor&, BackColor&, dx%, iRowPos%
43.             ELSE
44. 'THIS IS WHERE THE PROGRAM CRASHES:
45.                 DrawColorTileFast imgScreen&, arrImage(1), arrTileSheetMap(), arrTileMap(), tileWidthPx%, tileHeightPx%, TileNum%, TileColor&, BackColor&, dx%, iRowPos%
46.             END IF
47.            
48.         Next dx%
49.     Next dy%
50.    
51.     _Dest imgScreen&
52.    
53. End Sub ' PlotTextToScreenFast
54.  
55. ' /////////////////////////////////////////////////////////////////////////////
56. ' Like DrawColorTile but faster because it uses precalculated coordinates
57. ' to find the tile on the tile sheet, and the destination on the screen.
58.  
59. ' Receives:
60. ' imgScreen& = handle to screen to draw tile on
61. ' imgTiles& = handle to 16x16 tile sheet of 16x16 pixel tiles colored black (256 tiles)
62. ' arrTileSheetMap() = array of TileSheetMapType which holds precalculated positions of tiles on tilesheet
63. ' arrTileMap() = array of TileMapType which holds precalculated positions where tiles go on screen
64. ' tileWidthPx% = width of tiles in pixels
65. ' tileHeightPx% = height of tiles in pixels
66. ' TileNum% = ordinal number of tile on tile sheet to draw (0-255)
67. ' TileColor& = color to use for tile
68. ' BackColor& = color to use for background
69. ' dx% = column # to draw tile at (where each column is 16 pixels wide)
70. ' dy% = row # to draw tile at (where each row is 16 pixels high)
71.  
72. ' *** QUESTION
73. ' *** IF THE SUB RECEIVES IMAGE HANDLE PARAMETERS imgScreen&, imgTiles&
74. ' *** ARE THESE BY REFERENCE?
75. ' *** IF NOT, DO THESE LOCAL COPIES HAVE TO BE RELEASED WITH _FREEIMAGE ?
76.  
77. Sub DrawColorTileFast (imgScreen&, imgTiles&, arrTileSheetMap() AS TileSheetMapType, arrTileMap() AS TileMapType, tileWidthPx%, tileHeightPx%, TileNum%, TileColor&, BackColor&, dx%, dy%)
78.     DIM ColorSprite&
79.     DIM UniversalSprite&
80.    
81.     ' IS THERE A BACKGROUND COLOR?
82.     IF BackColor& <> cEmpty& THEN
83.         ColorSprite& = _NewImage(tileWidthPx%, tileHeightPx%, 32)
84.         _Dest ColorSprite&
85.         CLS, BackColor&
86.        
87.         ' COPY THE TEMPORARY TILE TO THE SCREEN imgScreen&
88.         _SOURCE ColorSprite&
89.         _Dest imgScreen&
90.        
91.         _PutImage (arrTileMap(dx%, dy%).xPos, arrTileMap(dx%, dy%).yPos), ColorSprite&, imgScreen&, (0, 0)-(tileWidthPx% - 1, tileHeightPx% - 1) ' portion of source to the top-left corner of the destination page
92.     END IF
93.  
94.     ' CREATE A TEMPORARY TILE TO COLOR
95.     UniversalSprite& = _NewImage(tileWidthPx%, tileHeightPx%, 32)
96.    
97.     ' COPY THE TILE TO THE TEMPORARY ONE
98.     _SOURCE imgTiles&
99.     _Dest UniversalSprite&
100.     _PutImage (0, 0), imgTiles&, UniversalSprite&, (arrTileSheetMap(TileNum%).xStart, arrTileSheetMap(TileNum%).yStart)-(arrTileSheetMap(TileNum%).xEnd, arrTileSheetMap(TileNum%).yEnd)
101.    
102.     ' COLOR IN THE TEMPORARY TILE
103.     ' REPLACING BLACK (THE SOURCE COLOR) WITH THE TILE COLOR
104. 'THIS IS WHERE THE PROGRAM CRASHES:
105.     ColorSprite& = swapcolor&(UniversalSprite&, cBlack&, TileColor&)
106.    
107.     ' COPY THE TEMPORARY TILE TO THE SCREEN imgScreen&
108.     _SOURCE ColorSprite&
109.     _Dest imgScreen&
110.     _PutImage (arrTileMap(dx%, dy%).xPos, arrTileMap(dx%, dy%).yPos), ColorSprite&, imgScreen&, (0, 0)-(tileWidthPx% - 1, tileHeightPx% - 1) ' portion of source to the top-left corner of the destination page
111.    
112.     ' ADDED PER FellipeHeitor
113.     _FREEIMAGE ColorSprite&
114.     _FREEIMAGE UniversalSprite&
115.    
116. End Sub ' DrawColorTileFast
117.  
118. ' /////////////////////////////////////////////////////////////////////////////
119. ' Image color swap?
120. ' https://www.qb64.org/forum/index.php?topic=2312.0
121.  
122. ' Receives:
123. ' handle& = image handle to swap colors in
124. ' oldcolor~& = old color to be replaced
125. ' newcolor~& = new color
126.  
127. ' Return value = image handle to copy of image with the new colors
128.  
129. Function swapcolor& (handle&, oldcolor~&, newcolor~&)
130.     Dim m As _MEM
131.     DIM a&
132.     'Dim c As _Unsigned Long
133.     DIM c~&
134.    
135. 'THIS IS WHERE THE PROGRAM CRASHES:
136.     swapcolor& = _CopyImage(handle&, 32)
137.    
138.     m = _MemImage(swapcolor&)
139.    
140.     Do Until a& = m.SIZE - 4
141.         a& = a& + 4
142.        
143.         c~& = _MemGet(m, m.OFFSET + a&, _Unsigned Long)
144.        
145.         If c~& = oldcolor~& Then
146.             _MemPut m, m.OFFSET + a&, newcolor~&
147.         End If
148.     Loop
149.    
150.     _MemFree m
151.    
152. End Function ' swapcolor&
153.  

[NOVARSEG]

without looking at the code

Say a variable is counting and then suddenly becomes  negative?

[FellippeHeitor]

When you call Function swapcolor&, it returns a handle that's the newly created image you used _CopyImage for. The variables you eventually use to do variable& = swapcolor&(etc) need freeing too.

[madscijr]

When you call Function swapcolor&, it returns a handle that's the newly created image you used _CopyImage for. The variables you eventually use to do variable& = swapcolor&(etc) need freeing too.

Yes, it is doing that. The value retrieved from the function in line 105:

Code: QB64: [Select]

1.     ColorSprite& = swapcolor&(UniversalSprite&, cBlack&, TileColor&)

is freed in line 113:

Code: QB64: [Select]

1.     _FREEIMAGE ColorSprite&

Is it possible that swapcolor& is causing a memory leak just by being a function?
Would it be better to instead make it a sub and return the value in a parameter?

[NOVARSEG]

Do Until a& = m.SIZE - 4
        a& = a& + 4
               
        c~& = _MemGet(m, m.OFFSET + a&, _Unsigned Long)
               
        If c~& = oldcolor~& Then
            _MemPut m, m.OFFSET + a&, newcolor~&
        End If
    Loop

It looks like you are memgetting 4 bytes at a time.  Is a& large enough to hold the  count?

There should be a a& = 0 after the loop or before it?

and is

 DIM a&
    'Dim c As _Unsigned Long
    DIM c~&

a valid way of DIMming?

[FellippeHeitor]

Try this:

Code: QB64: [Select]

1. IF ColorSprite& < -1 THEN _FreeImage ColorSprite&
2. ColorSprite& = swapcolor&(UniversalSprite&, cBlack&, TileColor&)

[FellippeHeitor]

Also, monitor your program as it runs in Task Manager to see if memory usage is constantly increasing until it crashes, if the above doesn't cut it.

[NOVARSEG]

Do Until a& = m.SIZE - 4
        a& = a& + 4
               
        c~& = _MemGet(m, m.OFFSET + a&, _Unsigned Long)
               
        If c~& = oldcolor~& Then
            _MemPut m, m.OFFSET + a&, newcolor~&
        End If
    Loop

 

a& = a& + 4
               
 c~& = _MemGet(m, m.OFFSET + a&, _Unsigned Long)

the count has gotta  be after 
             

c~& = _MemGet(m, m.OFFSET + a&, _Unsigned Long)

a& = a& + 4

because the first memget is at byte zero

[madscijr]

Try this:

Code: QB64: [Select]

1. IF ColorSprite& < -1 THEN _FreeImage ColorSprite&
2. ColorSprite& = swapcolor&(UniversalSprite&, cBlack&, TileColor&)

I added this but on its own prog was still crashing, but see next reply to NOVARSEG.