Method pnInit

Libraries/unrar/rs.cpp:39–60

Create the generator polynomial g(x). g(x)=(x-a)(x-a^2)(x-a^3)..(x-a^N)

// Create the generator polynomial g(x).
// g(x)=(x-a)(x-a^2)(x-a^3)..(x-a^N)
void RSCoder::pnInit()
{
  int p2[MAXPAR+1]; // Currently calculated part of g(x).

  Clean(p2,ParSize);
  p2[0]=1; // Set p2 polynomial to 1.

  for (int I=1;I<=ParSize;I++)
  {
    int p1[MAXPAR+1]; // We use p1 as current (x+a^i) expression.
    Clean(p1,ParSize);
    p1[0]=gfExp[I];
    p1[1]=1; // Set p1 polynomial to x+a^i.

    // Multiply the already calucated part of g(x) to next (x+a^i).
    pnMult(p1,p2,GXPol);

    // p2=g(x).
    for (int J=0;J<ParSize;J++)
      p2[J]=GXPol[J];
  }
}


// Multiply polynomial 'p1' to 'p2' and store the result in 'r'.