float &vec2::operator[](int i)
{
if (i < VX || i > VY)
//VEC_ERROR("vec2 [] operator: illegal access; index = " << i << '\n')
VEC_ERROR("vec2 [] operator: illegal access" );
return n[i];
}
const vec4 &mat4::operator[](int i) const
{
if (i < VX || i > VW)
//VEC_ERROR("mat4 [] operator: illegal access; index = " << i << '\n')
VEC_ERROR("mat4 [] operator: illegal access" );
return v[i];
}
mat4 mat4::inverse(void) // Gauss-Jordan elimination with partial pivoting
{
mat4 a(*this), // As a evolves from original mat into identity
b(identity3D()); // b evolves from identity into inverse(a)
int i, j, i1;
// Loop over cols of a from left to right, eliminating above and below diag
for (j=0; j<4; j++) { // Find largest pivot in column j among rows j..3
i1 = j; // Row with largest pivot candidate
for (i=j+1; i<4; i++)
if (fabs(a.v[i].n[j]) > fabs(a.v[i1].n[j]))
i1 = i;
// Swap rows i1 and j in a and b to put pivot on diagonal
swap(a.v[i1], a.v[j]);
swap(b.v[i1], b.v[j]);
// Scale row j to have a unit diagonal
if (a.v[j].n[j]==0.)
VEC_ERROR("mat4::inverse: singular matrix; can't invert\n");
b.v[j] /= a.v[j].n[j];
a.v[j] /= a.v[j].n[j];
// Eliminate off-diagonal elems in col j of a, doing identical ops to b
for (i=0; i<4; i++)
if (i!=j) {
b.v[i] -= a.v[i].n[j]*b.v[j];
a.v[i] -= a.v[i].n[j]*a.v[j];
}
}
return b;
}
double& vec4::operator [] ( int i) {
if (i < VX || i > VW)
//VEC_ERROR("vec4 [] operator: illegal access; index = " << i << '\n')
VEC_ERROR("vec4 [] operator: illegal access" );
return n[i];
}
const float &vec3::operator[](int i) const
{
if (i < VX || i > VZ)
//VEC_ERROR("vec3 [] operator: illegal access; index = " << i << '\n')
VEC_ERROR("vec3 [] operator: illegal access" );
return n[i];
}
vec3 &mat3::operator[](int i)
{
if (i < VX || i > VZ)
//VEC_ERROR("mat3 [] operator: illegal access; index = " << i << '\n')
VEC_ERROR("mat3 [] operator: illegal access" );
return v[i];
}
