bool quakelib::Element<nverts>::overlaps(const Element<nverts> &block) const {
bool normal_a_sep, normal_b_sep;
std::vector<Vec<3> > normals;
unsigned int i, j;
normals.push_back(block.normal());
normals.push_back(normal());
normal_a_sep = check_separation(normals[0], block);
normal_b_sep = check_separation(normals[1], block);
if (normal_a_sep || normal_b_sep) {
//there is no intersection
return false;
} else {
//there could be an intersection
//test if they are co-planar
Vec<3> cross = normal().cross(block.normal());
std::vector<Vec<3> > edges_a;
std::vector<Vec<3> > edges_b;
std::vector<Vec<3> > sep_vecs;
edges_a.push_back(block._vert[1] - block._vert[0]);
edges_a.push_back(block._vert[2] - block._vert[1]);
edges_a.push_back(block._vert[3] - block._vert[2]);
edges_a.push_back(block._vert[0] - block._vert[3]);
edges_b.push_back(_vert[1] - _vert[0]);
edges_b.push_back(_vert[2] - _vert[1]);
edges_b.push_back(_vert[3] - _vert[2]);
edges_b.push_back(_vert[0] - _vert[3]);
if (cross.mag() > 0) {
//they are not co-planar
for (i=0;i<edges_a.size();i++) {
for (j=0;j<edges_b.size();j++) {
sep_vecs.push_back(edges_a[i].cross(edges_b[j]).unit_vector());
}
}
} else {
//they are coplanar. the case where they could be parallel is tested with the normal separations.
//this is now the 2d case.
for (i=0;i<edges_a.size();i++) {
sep_vecs.push_back(normals[0].cross(edges_a[i]).unit_vector());
}
for (i=0;i<edges_b.size();i++) {
sep_vecs.push_back(normals[0].cross(edges_b[i]).unit_vector());
}
}
for (i=0; i < sep_vecs.size(); i++) {
// if any of the results are seperated the elements don't intersect
if (check_separation(sep_vecs[0], block)) {
return false;
}
}
return true;
}
}
Quat TangentSpace::expMap(const Vec &p)
{
float theta = p.mag();
//float theta = Quat::spherical_distance(centre, p);
float convFactor = 0.0;
if(fabs(theta) < 0.00001)
convFactor = 0.0;
else
convFactor = sin(theta)/theta;
Quat p1;
//Quat p2;
p1[0] = cos (theta);
p1[1] = p[0]*convFactor;
p1[2] = p[1]*convFactor;
p1[3] = p[2]*convFactor;
p1 = p1*centre;
//p2[0] = p1[0] + coordAxes[0][0];
//p2[1] = p1[1] + coordAxes[0][1];
//p2[2] = p1[2] + coordAxes[0][2];
//p2[3] = p1[3] + coordAxes[0][3];
//p2[0] = p1[0]*coordAxes[0][0] + p1[1]*coordAxes[1][0];
//p2[0] += p1[2]*coordAxes[2][0] + p1[3]*coordAxes[3][0];
//p2[1] = p1[0]*coordAxes[0][1] + p1[1]*coordAxes[1][1];
//p2[1] += p1[2]*coordAxes[2][1] + p1[3]*coordAxes[3][1];
//p2[2] = p1[0]*coordAxes[0][2] + p1[1]*coordAxes[1][2];
//p2[2] += p1[2]*coordAxes[2][2] + p1[3]*coordAxes[3][2];
//p2[3] = p1[0]*coordAxes[0][3] + p1[1]*coordAxes[1][3];
//p2[3] += p1[2]*coordAxes[2][3] + p1[3]*coordAxes[3][3];
return p1;
}
/** Phong lighting model
** @param pt intersection point
** @param n normal of pt
** @param light pointer to the light source
** @param obj pointer to the object
** @param ray ray
** @return color calculated from local shading using phong model
**/
Vec phongModel(Vec pt, Vec n, Light* light, Shape* obj, Ray ray) {
float t;
Vec v = ray.getOrig() - pt; v = v.normalize(); // vector to viewer
Vec l = light->pos - pt;
float dis = l.mag(); // distance to light source
l = l.normalize(); // vector to light source
Vec ir = n * (2 * n.dot(l)) - l; ir = ir.normalize(); // vector of ideal reflector
Vec intensity = light->intensity; // light intensity
Ray shadowRay(pt, l, 0, 9999, ShadowRay); // shadow ray to the light source
float f = light->attenFac(dis); // attentuation factor
Pigment p = obj->getPigment();
Vec obj_color; // object color
float scalar; int tmp;
if (p.type == SOLID) {
obj_color = p.c1;
} else if (p.type == CHECKER) {
scalar = p.width;
tmp = (int)(pt.x/scalar) + (int)(pt.y/scalar) + (int)(pt.z/scalar);
if (tmp % 2 == 0) obj_color = p.c1;
else obj_color = p.c2;
} else if (p.type == TEXTURE) {
if (obj->getType() == sphere)
obj_color = sphereMapping(pt, n, p);
}
// get the surface parameters
SurFinish appearance = obj->getSurFin();
float Ka = appearance.ambient; // ambient coefficient
float Kd = appearance.diffuse; // diffuse coefficient
float Ks = appearance.specular; // specular coefficient
float shininess = appearance.shininess;
// for each object in the scene, see if is blocks the light
if (light->type != ambient) {
for (ShapeIter its = scene.shapes.begin(); its != scene.shapes.end(); its++) {
if ((*its) == obj) continue;
if ((*its)->getType() == sphere) {
Sphere *shape = dynamic_cast<Sphere*>(*its);
if (shape->intersect(shadowRay, t) && t < dis)
return black;
} else if((*its)->getType() == polyhedron){
Polyhedron *shape = dynamic_cast<Polyhedron*>(*its);
if (shape->intersect(shadowRay, t) && t < dis) {
return black;
}
} else if((*its)->getType() == triangleMesh){
TriangleMesh *shape = dynamic_cast<TriangleMesh*>(*its);
if (shape->intersect(shadowRay, t) && shadowRay.calcDest(t).mag() < dis)
return black;
}
}
}
Vec diffuse(0.0, 0.0, 0.0);
Vec specular(0.0, 0.0, 0.0);
// if the light is casted from front
if (n.dot(l) > 0) {
diffuse = intensity * (Kd * n.dot(l) * f);
specular = white * (Ks * pow(v.dot(ir),shininess) * f);
// update light color
intensity.x = (light->type != ambient) ? diffuse.x * obj_color.x + specular.x : obj_color.x * Ka;
intensity.y = (light->type != ambient) ? diffuse.y * obj_color.y + specular.y : obj_color.y * Ka;
intensity.z = (light->type != ambient) ? diffuse.z * obj_color.z + specular.z : obj_color.z * Ka;
} // if the light is casted from behind
else {
intensity.x = (light->type != ambient) ? black.x : obj_color.x * Ka;
intensity.y = (light->type != ambient) ? black.y : obj_color.y * Ka;
intensity.z = (light->type != ambient) ? black.z : obj_color.z * Ka;
}
return intensity;
}
