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# GUIMath

class `GUIMath`
  Syntax:
    `obj = new GUIMath()`
  Description:
    Contains functions which calculate common relationships between graphics objects.

`GUIMath.``d2line`()
  Syntax:
    `d = math.d2line(xpoint, ypoint, xline0, yline0, xline1, yline1)`
  Description:
    Return distance between the point (xpoint,ypoint) and the (infinitely long) line defined by the 0 and 1 points.

`GUIMath.``d2line_seg`()
  Syntax:
    `d = math.d2line_seg(xpoint, ypoint, xline0, yline0, xline1, yline1)`
  Description:
    Return distance between the point (xpoint,ypoint) and the line segment line defined by the 0 and 1 points.

`GUIMath.``inside`()
  Syntax:
    `boolean = math.inside(xpoint, ypoint, left, bottom, right, top)`
  Description:
    return 1 if the point is inside the box, 0 otherwise

`GUIMath.``feround`()
  Syntax:

    `mode = math.feround()`

    `lastmode = math.feround(mode)`

  Description:

    Set the floating point rounding mode. Mode 1, 2, 3, 4 refers to FE_DOWNWARD, FE_TONEAREST, FE_TOWARDZERO, FE_UPWARD respectively. The default, and most accurate, mode is FE_TONEAREST. The mode is changed only if the argument is 1-4. If there is no support for this function the return value is 0.

    This function is useful to determine if a simulation depends unduly on double precision round-off error.

  Example:

  >     objref gm
  >     gm = new GUIMath()
  >     {printf("default rounding mode %d\n", gm.feround())}

  >     proc test_round() {local i, old, x  localobj gm
  >             gm = new GUIMath()
  >             old = gm.feround($1)
  >             x = 0
  >             for i=1, 1000000 x += 0.1
  >             printf("rounding mode %d x=%25.17lf\n", $1, x)
  >             gm.feround(old)
  >     }

  >     for i=1, 4 test_round(i)

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