void PointLightInteractionHandler::setLightPosFromScreenCoords(const vec2& normalizedScreenCoord) {
vec2 deviceCoord(2.f * (normalizedScreenCoord - 0.5f));
// Flip vertical axis since mouse event y position starts at top of screen
deviceCoord.y *= -1.f;
// Use half distance between look from and look to positions as scene radius.
float sceneRadius = 0.5f * glm::length(camera_->getLookTo() - camera_->getLookFrom());
vec3 rayOrigin = camera_->getWorldPosFromNormalizedDeviceCoords(vec3(deviceCoord, 0.f));
vec3 rayDir = glm::normalize(
camera_->getWorldPosFromNormalizedDeviceCoords(vec3(deviceCoord, 1.f)) - rayOrigin);
float t0 = 0, t1 = std::numeric_limits<float>::max();
float lightRadius = glm::length(lightPosition_->get());
if (raySphereIntersection(vec3(0.f), sceneRadius, rayOrigin, rayDir, &t0, &t1)) {
lightPosition_->set(glm::normalize(rayOrigin + t1 * rayDir) * lightRadius);
} else {
// Project it to the rim of the sphere
t0 = 0;
t1 = std::numeric_limits<float>::max();
if (rayPlaneIntersection(camera_->getLookTo(),
glm::normalize(camera_->getLookTo() - camera_->getLookFrom()),
rayOrigin, rayDir, &t0, &t1)) {
// Project it to the edge of the sphere
lightPosition_->set(glm::normalize(rayOrigin + t1 * rayDir) * lightRadius);
}
}
// Ensure that up vector is same as camera afterwards
setLookUp(camera_->getLookUp());
}
/* @param t distance */
static intersection ray_hit_object(const point3 e, const point3 d,
double t0, double t1,
const rectangular_node rectangulars,
rectangular_node *hit_rectangular,
const sphere_node spheres,
sphere_node *hit_sphere)
{
/* set these to not hit */
*hit_rectangular = NULL;
*hit_sphere = NULL;
point3 biased_e;
multiply_vector(d, t0, biased_e);
add_vector(biased_e, e, biased_e);
double nearest = t1;
intersection result, tmpresult;
for (rectangular_node rec = rectangulars; rec; rec = rec->next) {
if (rayRectangularIntersection(biased_e, d, &(rec->element),
&tmpresult, &t1) && (t1 < nearest)) {
/* hit is closest so far */
*hit_rectangular = rec;
nearest = t1;
result = tmpresult;
}
}
/* check the spheres */
for (sphere_node sphere = spheres; sphere; sphere = sphere->next) {
if (raySphereIntersection(biased_e, d, &(sphere->element),
&tmpresult, &t1) && (t1 < nearest)) {
*hit_sphere = sphere;
*hit_rectangular = NULL;
nearest = t1;
result = tmpresult;
}
}
return result;
}
//Ray-Object intersection--------------------------------------------------------------------------
float rayObjectIntersection(Ray ray, SPHERE sphere, POLY4 poly, Point3dPtr n, Point3dPtr interp, float * kd)
{
float t1, t2; // The two distances;
float *kd1, *kd2;
Point3dPtr n1, n2, interp1, interp2;
n1 = (Point3dPtr)malloc(sizeof(Point3d));
n2 = (Point3dPtr)malloc(sizeof(Point3d));
interp1 = (Point3dPtr)malloc(sizeof(Point3d));
interp2 = (Point3dPtr)malloc(sizeof(Point3d));
kd1 = (float*)malloc(sizeof(*kd1));
kd2 = (float*)malloc(sizeof(*kd2));
t1 = raySphereIntersection(ray, sphere, n1, interp1, kd1);
t2 = rayPolygonIntersection(ray, poly, n2, interp2, kd2);
if (t1 == 0.0 && t2 == 0.0)
return 0.0;
else if (t2 == 0)
{
//the normal = n1;
n->x = n1->x;
n->y = n1->y;
n->z = n1->z;
//the intersection point = interp1;
interp->x = interp1->x;
interp->y = interp1->y;
interp->z = interp1->z;
*kd = *kd1;
return t1;
}
else if (t1 == 0.0)
{
//the normal = n2;
n->x = n2->x;
n->y = n2->y;
n->z = n2->z;
//the intersection point = interp2;
interp->x = interp2->x;
interp->y = interp2->y;
interp->z = interp2->z;
*kd = *kd2;
return t2;
}
else if (t1 < t2)
{
//the normal = n1;
n->x = n1->x;
n->y = n1->y;
n->z = n1->z;
//the intersection point = interp1;
interp->x = interp1->x;
interp->y = interp1->y;
interp->z = interp1->z;
*kd = *kd1;
return t1;
}
else
{
//the normal = n2;
n->x = n2->x;
n->y = n2->y;
n->z = n2->z;
//the intersection point = interp2;
interp->x = interp2->x;
interp->y = interp2->y;
interp->z = interp2->z;
*kd = *kd2;
return t2;
}
free(n1);
free(n2);
free(interp1);
free(interp2);
free(kd1);
free(kd2);
}
