Abnormal program termination

[chris857]

I was wondering if anyone else gets this error. With a few programs, after ending the program I get an error saying "Abnormal program termination". Here is the program that most recently causes this:

dim final$ = "FX"
dim temp$
dim i,j
for j = 1 to 11
   temp$ = final$
   final$ = ""
   for i = 1 to len(temp$)
       if mid$(temp$,i,1) = "X" then
           final$ = final$ + "X+YF"
       elseif mid$(temp$,i,1) = "Y" then
           final$ = final$ + "FX-Y"
       else
           final$ = final$ + mid$(temp$,i,1)
       endif
   next
next
dim x = 0
dim y = 0
dim direction = 0
glTranslatef(0,0,-100)
glBegin(GL_LINE_STRIP)
'glBegin(GL_LINES)
   glVertex2f(0,0)
   for i = 1 to len(final$)
       if mid$(final$,i,1) = "F" then
           if direction % 4 = 0 then
               direction = 0
               x = x + 1
           elseif direction % 4 = 1 then
               y = y + 1
           elseif direction % 4 = 2 then
               x = x - 1
           elseif direction % 4 = 3 then
               y = y - 1
           endif
       elseif mid$(final$,i,1) = "+" then
           direction = direction + 1
       elseif mid$(final$,i,1) = "-" then
           direction = direction - 1
       endif
       glVertex2f(x,y)
   next
glEnd()
SwapBuffers()
but only if the first for-loop runs for more than ten times. Does anyone know what causes this?

[DJLinux]

you use to mutch vertices for one GL_LINE_STRIP
if you render it split it in more pieces

Joshy

[DJLinux]

Here are an example of
how you can split the drawing
in pieces of 32 coords per line strip

Joshy

sub IncColors(&r,&g,&b)
  r=r+1
  g=r/2
  b=g/3
  glColor3UB(r,g,b) 
end sub

dim final$ = "FX"
dim temp$,char$
dim i,i1,j,flag,d
dim r,g,b
for j = 1 to 12
  temp$ = final$
  final$ = ""
  for i = 1 to len(temp$)
    ' use mid$() only once
    char$=mid$(temp$,i,1)
    if char$ = "X" then
      final$ = final$ + "X+YF"
    elseif char$ = "Y" then
      final$ = final$ + "FX-Y"
    else
      final$ = final$ + char$
    endif
  next
next

dim x = 0
dim y = 0
dim direction = 0

glTranslatef(0,0,-100)

j=len(final$)-1  

glColor3UB(r,g,b)
for i=0 to j      
  i1=i+1
  ' begin of a new line strip strip ?
  if (i % 32)=0 then
    flag=1
    glBegin(GL_LINE_STRIP)  
    ' fist time it's 0,0
    ' or the last x,y 
    glVertex2f(x,y) 
  end if
  ' use mid$() only once
  char$=mid$(final$,i1,1)
  if  char$ = "F" then
    ' use mod operator only once
    d=direction % 4
    if d = 0 then 
      x = x + 1
    elseif d = 1 then
      y = y + 1
    elseif d = 2 then
      x = x - 1
    elseif d = 3 then
      y = y - 1
    endif
  elseif char$ = "+" then
    IncColors(r,g,b)
    direction = direction + 1
  elseif char$ = "-" then
    IncColors(r,g,b)
    direction = direction - 1
  endif
  glVertex2f(x,y)  

  ' end of current line strip ?
  if (i1 % 32)=0 then
    flag=0
    glEnd()
    ' optional show whats going on
    SwapBuffers()
  end if
next     

' close any open line strip
' of course your coords must not be a multiply of 32 
if flag<>0 then
  glEnd()
end if

' show it
SwapBuffers()
end

[DJLinux]

i see you create "dragon curve"

en.wikipedia.org/wiki/Lindenmayer_systems#Example_7:_Dragon_curve

Joshy

[chris857]

What is the limit on vertices in this case? Is it 4096?

[DJLinux]

Nov 14, 2010 20:45:20 GMT -5 chris857 said:

What is the limit on vertices in this case? Is it 4096?

I don't know but you can read the specs on opengl.org

by the way the strings will crash on recursion too :-(

function L_System$(in$,replace$,n)
  dim result$,char$,i
  printr n
  n=n-1
  for i = 1 to len(in$)
    char$=mid$(in$,i,1)
    if char$="F" then
      result$=result$+replace$
    else
      result$=result$+char$
    end if
  next
  if n>0 then
    result$=L_System$(result$,replace$,n)
  end if
  return result$
end function           

dim start$,rule$,result$

start$  = "F--F--F--"
rule$   = "F+F--F+F"
result$ = L_System$(Start$,Rule$,5)

printr result$

[Adam]

I have also noticed that this will happen with heavy network usage, everytime i press esc on say my file server for instance, basic4gl crashes