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type problem (*solved*)
#1
Code:
Function distance (x1 as Integer, y1 as Integer, x2 as Integer, y2 as Integer) as Integer
Dim x as Integer
x=Abs(x1-x2)
Dim y as Integer
y=Abs(y1-y2)
Return x+y
End Function

Dim bresx(0 to 300) as UByte
Dim bresy(0 to 300) as UByte

Function line(X1 as Integer,Y1 as Integer,X2 as Integer,Y2 as Integer) as Integer
'Draws a line of individual pixels from X1,Y1 to X2,Y2 at any angle

Dim dist as Integer
dist=distance(X1,Y1,X2,Y2)
dim bresiter as Integer
For bresiter=0 To dist
bresx(bresiter)=0
bresy(bresiter)=0
Next

Dim steep as Byte
steep=Abs(Y2-Y1) > Abs(X2-X1)
PRINT AT 1,1 ; PAPER 1 ; INK 0 ; "steep "+STR(steep)
    
If steep =1 Then
Dim Temp as Integer
steep=X1
X1=Y1
Y1=Temp
Temp=X2
X2=Y2
Y2=Temp
End If
    Dim DeltaX as Integer
    DeltaX=Abs(X2-X1)
    Dim DeltaY as Integer
    DeltaY=Abs(Y2-Y1)
    Dim IError as Integer
    IError=0
    Dim DeltaError as Integer
    DeltaError=DeltaY
    Dim x as Integer
    x=X1        'Start at X1,Y1
    Dim y as Integer
    y=Y1        
    Dim XStep as Integer
    Dim YStep as Integer
    If X1<X2 Then
    XStep=1
    Else
    XStep=-1
    end if
    If Y1<Y2 Then
    YStep=1
    Else
    YStep=-1    'Direction
    end if
    'If Steep Then Plot(Y,X) Else Plot(X,Y)        'Draw
    Dim iter as Integer=1
    
    While x<>X2
    'Print x+" <x "+X2+"<x2"
    'Print "xstep "+XStep
    'x=truncate(x,1)
        x=x+XStep        'Move in X
    'Print x+" <x after adding xstep "+X2+"<x2"
        
        IError=IError+DeltaError        'Add to counter
        If (IError Shl 1)>DeltaX then        'Would it overflow?
        y=y+YStep        'Move in Y
        IError=IError-DeltaX        'Overflow/wrap the counter
        End if
    '    x=truncate(x,1)
    '    y=truncate(y,1)
    '        Print x+" <x after truncating xstep "+X2+"<x2"
    
    If steep then
        bresx(iter)=y
    '    Print bresx[iter]+"<bresx  iter>"+iter
        bresy(iter)=x
    '    Print bresy[iter]+"<bresy  iter>"+iter

    Else
        bresx(iter)=x
    '    Print bresx[iter]+"<bresx  iter>"+iter

        bresy(iter)=y
    '        Print bresy[iter]+"<bresy  iter>"+iter

    End If
        iter=iter+1
        
    If iter>dist then
    Print  "bresenham over distance "+dist
    Return dist
    End If
    '    If Steep Then Plot(Y,X) Else Plot(X,Y)        'Draw
    Wend
    Return dist
End Function

line(0,0,10,5)
for x=0 to 6
    Plot bresx(x),bresy(x)
next

When I try to compile it says cant convert to string on line 16 but there are no strings being referred to on that line

EDIT- the problem was on line 107 so the compiler was confused
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#2
Will try to debug ASAP.
NOTE: I'm alive. Just considering rewriting al ZX BASIC *from scratch* Confusedhock:
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#3
Confusedhock: Confusedhock:
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#4
Confusedhock: Confusedhock: Confusedhock:
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#5
Okay, not from scratch (the lexers modules and preprocessor, and assembler are ok), but almost.
It's a huge rewriting... :oops:
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#6
in python?
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#7
Yes: If it weren't in python it would be completely from scratch (even the lexer, asm and preprocessors). I guess I would choose C++ otherwise.
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#8
Yes, the bug was in line:
Code:
Print  "bresenham over distance "+dist
Variable dist is integer (use STR(dist) for that). It's incorrectly reporting line #15 (where Dist was declared!) instead of that line.
Will try to improve this...
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#9
britlion Wrote:Confusedhock: Confusedhock: Confusedhock:
I also asked about revamping the site into something more specific to ZX Basic, instead of my blog. :?:
(See Poll in the main forum)
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#10
boriel Wrote:Yes, the bug was in line:
Code:
Print  "bresenham over distance "+dist
Variable dist is integer (use STR(dist) for that). It's incorrectly reporting line #15 (where Dist was declared!) instead of that line.
Will try to improve this...
Sounds logical because dist could be DIMed as String, so the compiler is confused.
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#11
The error reporting line is now correct.
Can you check it? (download 1.2.8 s785 or newer)
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