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+--- Thread: Pointer Bug? (/thread-6195.html)
Pointer Bug? - lkd85 - 02-22-2005
The following indexing code crashes (can't read memory error):
Code:
Type Vert
x As Single
y As Single
z As Single
End Type
Type Tri
verts(2) As Vert
End Type
Type Object
numoftris As Integer
tris As Tri Ptr
End Type
Dim obj As Object
With obj
.numoftris = 7
.tris = Allocate(.numoftris * Len(Tri))
For i = 0 To .numoftris
For v = 0 To 2
.tris[i].verts(v).x = Rnd * 23
.tris[i].verts(v).y = Rnd * 75
.tris[i].verts(v).z = Rnd * 51
Next v
Next i
End With
Print obj.numoftris, obj.tris[0].verts(0).y '<- Error here
SleepBut doesn't with a minor change to print the values as they're being set:
Code:
Type Vert
x As Single
y As Single
z As Single
End Type
Type Tri
verts(2) As Vert
End Type
Type Object
numoftris As Integer
tris As Tri Ptr
End Type
Dim obj As Object
With obj
.numoftris = 7
.tris = Allocate(.numoftris * Len(Tri))
For i = 0 To .numoftris
For v = 0 To 2
.tris[i].verts(v).x = Rnd * 23
.tris[i].verts(v).y = Rnd * 75
.tris[i].verts(v).z = Rnd * 51
Print .tris[i].verts(v).x '<- Change
Next v
Next i
End With
Print obj.numoftris, obj.tris[0].verts(0).y '<- Reads fine with print in loop
SleepWhat's wrong? :o
Pointer Bug? - steven_basic - 02-22-2005
I don't get an error on either one.
WinXP Pro SP2
Pointer Bug? - v3cz0r - 02-22-2005
Yeah, there was a bug with 0.11 when calculating the len of types that have array fields (reported by Dr_D), it was fixed 2 weeks ago, the patch will be on the next release.
That code worked fine with version 0.12.
Btw, it should be: for i = 0 To .numoftris-1
Pointer Bug? - lkd85 - 02-22-2005
Got it. Thanks.
Pointer Bug? - lkd85 - 02-23-2005
One more thing, there also seems to be another bug in assigning variables to pointer indexes. This time the compiler crashes.:
Code:
Type Vert
x As Single
y As Single
z As Single
End Type
Type Tri
verts(2) As Vert
End Type
Type Object
numoftris As Integer
tris As Tri Ptr
End Type
Dim obj As Object
With obj
.numoftris = 7
.tris = Allocate(.numoftris * Len(Tri))
For i = 0 To .numoftris - 1
For v = 0 To 2
.tris[i].verts(v).x = Rnd * 23
.tris[i].verts(v).y = Rnd * 75
.tris[i].verts(v).z = Rnd * 51
Next v
Next i
End With
newfile = FreeFile
Open "data.obj" For Binary As #newfile
Put #newfile,,obj.numoftris
For i = 0 To obj.numoftris - 1
Put #newfile,,obj.tris[i].verts()
Next i
Close #newfile
Deallocate(obj.tris)
Dim newobj As Object, temptri As Tri
readfile = FreeFile
Open "data.obj" For Binary As #readfile
Get #readfile,,newobj.numoftris
Print newobj.numoftris
newobj.tris = Allocate(newobj.numoftris * Len(Tri))
For i = 0 To newobj.numoftris - 1
Get #readfile,,newobj.tris[i].verts() '<- Crashes here, compiles when commented out.
Print "X: ", newobj.tris[i].verts(0), "Y: ", newobj.tris[i].verts(1), "Z: ", newobj.tris[i].verts(2)
Next i
Close #readfile
SleepEven using a temp variable to read in a triangle (temptri), assigning it to the pointer index fails.
Pointer Bug? - v3cz0r - 02-23-2005
Problem is at Print "X: ", newobj.tris[i].verts(0), "Y: ", newobj.tris[i].verts(1), "Z: ", newobj.tris
TYPE's can't be printed, but PRINT and WRITE are not checking for that, new check added..
Pointer Bug? - lkd85 - 02-23-2005
LOL, are you serious? :oops: I really, really need to proofread my code more, Thanks.
The test works now:
Code:
With newobj
Get #readfile,,.numoftris
Print "Number of triangles: "; .numoftris
.tris = Allocate(.numoftris * Len(Tri))
For i = 0 To .numoftris - 1
Get #readfile,,.tris[i].verts()
Color i + 10
Print "Triangle: ";i
Print "X: "; .tris[i].verts(0).x; " Y: "; .tris[i].verts(0).y; " Z: "; .tris[i].verts(0).z
Print "X: "; .tris[i].verts(1).x; " Y: "; .tris[i].verts(1).y; " Z: "; .tris[i].verts(1).z
Print "X: "; .tris[i].verts(2).x; " Y: "; .tris[i].verts(2).y; " Z: "; .tris[i].verts(2).z
Next i
Close #readfile
End With