DentedEvaluate (Dented *inst, LWTextureAccess *ta)
{
/* Local stuff */
double size, result;
double magnitude = 0;
int i;
/* Position Stuff */
double PP[3], PS[3];
// Lets work in texture space
Vec3Assign(PP, ta->tPos[0], ta->tPos[1], ta->tPos[2]);
size = inst->frq[0];
for (i = 0; i < inst->oct[0]; i++) {
Vec3MultC(PS, PP, size);
magnitude += Abs(noisey(PS, inst->fnoise)) / size;
size *= 2;
}
result = pow(magnitude, inst->pwr[0]);
/* Use value to determine new shading values. */
result *= inst->scl[0];
return result;
}
HeteroTerrainEvaluate (HeteroTerrain *inst, LWTextureAccess *ta)
{
double turb;
double PP[3];
// Lets work in texture space
Vec3Assign(PP, ta->tPos[0], ta->tPos[1], ta->tPos[2]);
// Use the fBm function to get some fractal turbulence
turb = heteroterrain(PP, inst->inc[0], inst->lac[0], inst->oct[0],
inst->off[0], inst->fnoise);
return turb;
}
CoriolisEvaluate (Coriolis *inst, LWTextureAccess *ta)
{
/* Local stuff */
double rsq, angle, value, sine, cosine, turb;
/* Position Stuff */
double Pt[3], PtN[3], PP[3];
// Lets work in shader space
if (ta->axis == 0) {
Vec3Assign(Pt, ta->tPos[2], -ta->tPos[1], ta->tPos[0]);
} else if (ta->axis == 1) {
Vec3Assign(Pt, ta->tPos[0], -ta->tPos[2], ta->tPos[1]);
} else {
Vec3Assign(Pt, ta->tPos[0], -ta->tPos[1], ta->tPos[2]);
}
Vec3Copy(PtN, Pt);
normalize3(PtN);
rsq = xcomp(PtN) * xcomp(PtN) + ycomp(PtN) * ycomp(PtN);
angle = inst->tws[0] * rsq;
sine = sin( angle );
cosine = cos( angle );
PP[0] = Pt[0]*cosine - Pt[1]*sine;
PP[1] = Pt[0]*sine + Pt[1]*cosine;
PP[2] = Pt[2];
turb = fBm(PP, inst->inc[0], inst->lac[0], inst->oct[0], inst->fnoise);
value = Abs(inst->off[0] + inst->scl[0] * turb);
value = clamp(value, 0, 1);
return value;
}
