Fixed Point LIbrary

[kevin]

PlayBASIC Code: [Select]

Constant PI=205887
Constant PI_OVER_2=PI/2


rem Test plot ----------------------------------------------------
pi# = 3.14159265359
for x = 0 to 360
  rad# = x * pi# / 180
  fpRad = float2FP(rad#)
  mysin# = FP2Float(fp_Sin(fpRad))
  mycos# = FP2Float(fp_Cos(fpRad))
  dotc x,(mysin# * 100) + 200,rgb(255,0,0)
  dotc x,(mycos# * 100) + 200,rgb(0,0,255)
next x
sync
waitkey
end
rem Test plot end -------------------------------------------------


Psub Float2FP(value#)
  result = value# * 65536
endPsub result

Psub fp2Float(value)
  result# = value / 65536.0
endPSUB result#

psub fp_Add(Value1, Value2)
   result=Value1+Value2
endpsub result


psub fp_Sub(Value1, Value2)
   result=Value1-Value2
endpsub result



Psub fp_Mul(Value1, Value2)
  if abs(value1) > abs(value2)
      result = value1 / 256 * value2 / 256
  else
      result = value2 / 256  * value1 / 256
  endif
endPsub result

Psub fp_Div(Value1, Value2)
  result = (value1 * 256) / (Value2 / 256)
endPsub result

Psub fp_Sqrt(Value)
  result = (Value + 65536) / 2
  for i = 0 to 7
      result = (result + fp_Div(Value,result)) / 2
  next i
endPsub result

Psub fp_Sin(Value)
  rem Ported from the Java IAppli Fixed Point Math Library
  rem http://www.ai.mit.edu/people/hqm/imode/fplib

  SK1 = 498
  SK2 = 10882
  sign = 1
  if (Value > PI_Over_2) and (value <= PI) then Value = PI - Value
  if (Value > PI) and (Value <= (PI + PI_Over_2))
      Value = Value - PI
      sign = -1
  endif
  if (Value > (PI + PI_Over_2))
      Value = (PI * 2) - Value
      sign = -1
  endif

  sqr = fp_Mul(Value,Value)
  result = SK1
  result = fp_MUL(result,sqr)
  result = result - SK2
  result = fp_Mul(result,sqr)
  result = result + 65536
  result = fp_Mul(result, value)
  result = sign * result
endpsub result

Psub fp_Cos(Value)
  rem Ported from the Java IAppli Fixed Point Math Library
  rem http://www.ai.mit.edu/people/hqm/imode/fplib

  CK1 = 2328
  CK2 = 32551
  sign = 1
  if (Value > PI_Over_2) and (Value <= PI)
      value = PI - value
      sign = -1
  else
      if (Value > PI_Over_2) and (Value <= (PI + PI_Over_2))
        value = value - PI
        sign = -1
      endif
  endif
  if Value > (PI + PI_Over_2) then value = (PI*2)-value

  sqr = fp_Mul(Value,Value)
  result = CK1
  result = fp_MUL(result,sqr)
  result = result - CK2
  result = fp_Mul(result,sqr)
  result = result + 65536
  result = result * sign
endPsub result

[empty]

Well, you're quick... ;)

[kevin]

I guess, not a lot to port though :).. I mean it's not like their similar at all .. erm..   :rolleyes: