Hi,

in case you are interested, I managed to statically define the error bounds used by the Shewchuk predicates using standard C defines, so that it is no longer necessary to compute the machine epsilon in the way exactinit() does. It's not a big deal, but allows people to directly use the exact version of the predicates without having to call exactinit at the beginning of the program. The initialization is as follows:

#include <float.h>
#define SHEWCHUK_EPSILON DBL_EPSILON/2;

const REAL resulterrbound = ( 3.0 + 8.0 * SHEWCHUK_EPSILON) * SHEWCHUK_EPSILON;
const REAL ccwerrboundA = ( 3.0 + 16.0 * SHEWCHUK_EPSILON) * SHEWCHUK_EPSILON;
const REAL ccwerrboundB = ( 2.0 + 12.0 * SHEWCHUK_EPSILON) * SHEWCHUK_EPSILON;
const REAL ccwerrboundC = ( 9.0 + 64.0 * SHEWCHUK_EPSILON) * SHEWCHUK_EPSILON * SHEWCHUK_EPSILON;

const REAL o3derrboundA = ( 7.0 + 56.0 * SHEWCHUK_EPSILON) * SHEWCHUK_EPSILON;
const REAL o3derrboundB = ( 3.0 + 28.0 * SHEWCHUK_EPSILON) * SHEWCHUK_EPSILON;
const REAL o3derrboundC = (26.0 + 288.0 * SHEWCHUK_EPSILON) * SHEWCHUK_EPSILON * SHEWCHUK_EPSILON;

const REAL iccerrboundA = (10.0 + 96.0 * SHEWCHUK_EPSILON) * SHEWCHUK_EPSILON;
const REAL iccerrboundB = ( 4.0 + 48.0 * SHEWCHUK_EPSILON) * SHEWCHUK_EPSILON;
const REAL iccerrboundC = (44.0 + 576.0 * SHEWCHUK_EPSILON) * SHEWCHUK_EPSILON * SHEWCHUK_EPSILON;

const REAL isperrboundA = (16.0 + 224.0 * SHEWCHUK_EPSILON) * SHEWCHUK_EPSILON;
const REAL isperrboundB = ( 5.0 + 72.0 * SHEWCHUK_EPSILON) * SHEWCHUK_EPSILON;
const REAL isperrboundC = (71.0 + 1408.0 * SHEWCHUK_EPSILON) * SHEWCHUK_EPSILON * SHEWCHUK_EPSILON;

const REAL splitter = (1 << (DBL_MANT_DIG/2+1)) + 1.0;

Here is the full C file containing the (modified) Shewchuk predicates

cheers,
cino