void Movement::SetWindowSpeed(Vector2f desiredAppearedSpeed)
{
Vector2f totalSpeed = desiredAppearedSpeed;
if (totalSpeed.LengthSquared())
totalSpeed += spaceShooter->level.BaseVelocity();
if (totalSpeed.x != totalSpeed.x || totalSpeed.y != totalSpeed.y)
{
std::cout<<"\nCaught setting bad speeds!";
}
QueuePhysics(new PMSetEntity(shipEntity, PT_VELOCITY, totalSpeed));
}
bool Curve::recursiveIntersect(const Ray &ray, Float *tHit,
SurfaceInteraction *isect, const Point3f cp[4],
const Transform &rayToObject, Float u0, Float u1,
int depth) const {
// Try to cull curve segment versus ray
// Compute bounding box of curve segment, _curveBounds_
Bounds3f curveBounds =
Union(Bounds3f(cp[0], cp[1]), Bounds3f(cp[2], cp[3]));
Float maxWidth = std::max(Lerp(u0, common->width[0], common->width[1]),
Lerp(u1, common->width[0], common->width[1]));
curveBounds = Expand(curveBounds, 0.5 * maxWidth);
// Compute bounding box of ray, _rayBounds_
Float rayLength = ray.d.Length();
Float zMax = rayLength * ray.tMax;
Bounds3f rayBounds(Point3f(0, 0, 0), Point3f(0, 0, zMax));
if (Overlaps(curveBounds, rayBounds) == false) return false;
if (depth > 0) {
// Split curve segment into sub-segments and test for intersection
Float uMid = 0.5f * (u0 + u1);
Point3f cpSplit[7];
SubdivideBezier(cp, cpSplit);
return (recursiveIntersect(ray, tHit, isect, &cpSplit[0], rayToObject,
u0, uMid, depth - 1) ||
recursiveIntersect(ray, tHit, isect, &cpSplit[3], rayToObject,
uMid, u1, depth - 1));
} else {
// Intersect ray with curve segment
// Test ray against segment endpoint boundaries
// Test sample point against tangent perpendicular at curve start
Float edge =
(cp[1].y - cp[0].y) * -cp[0].y + cp[0].x * (cp[0].x - cp[1].x);
if (edge < 0) return false;
// Test sample point against tangent perpendicular at curve end
edge = (cp[2].y - cp[3].y) * -cp[3].y + cp[3].x * (cp[3].x - cp[2].x);
if (edge < 0) return false;
// Compute line $w$ that gives minimum distance to sample point
Vector2f segmentDirection = Point2f(cp[3]) - Point2f(cp[0]);
Float denom = segmentDirection.LengthSquared();
if (denom == 0) return false;
Float w = Dot(-Vector2f(cp[0]), segmentDirection) / denom;
// Compute $u$ coordinate of curve intersection point and _hitWidth_
Float u = Clamp(Lerp(w, u0, u1), u0, u1);
Float hitWidth = Lerp(u, common->width[0], common->width[1]);
Normal3f nHit;
if (common->type == CurveType::Ribbon) {
// Scale _hitWidth_ based on ribbon orientation
Float sin0 = std::sin((1 - u) * common->normalAngle) *
common->invSinNormalAngle;
Float sin1 =
std::sin(u * common->normalAngle) * common->invSinNormalAngle;
nHit = sin0 * common->n[0] + sin1 * common->n[1];
hitWidth *= AbsDot(nHit, ray.d) / rayLength;
}
// Test intersection point against curve width
Vector3f dpcdw;
Point3f pc = EvalBezier(cp, Clamp(w, 0, 1), &dpcdw);
Float ptCurveDist2 = pc.x * pc.x + pc.y * pc.y;
if (ptCurveDist2 > hitWidth * hitWidth * .25) return false;
if (pc.z < 0 || pc.z > zMax) return false;
// Compute $v$ coordinate of curve intersection point
Float ptCurveDist = std::sqrt(ptCurveDist2);
Float edgeFunc = dpcdw.x * -pc.y + pc.x * dpcdw.y;
Float v = (edgeFunc > 0) ? 0.5f + ptCurveDist / hitWidth
: 0.5f - ptCurveDist / hitWidth;
// Compute hit _t_ and partial derivatives for curve intersection
if (tHit != nullptr) {
// FIXME: this tHit isn't quite right for ribbons...
*tHit = pc.z / rayLength;
// Compute error bounds for curve intersection
Vector3f pError(2 * hitWidth, 2 * hitWidth, 2 * hitWidth);
// Compute $\dpdu$ and $\dpdv$ for curve intersection
Vector3f dpdu, dpdv;
EvalBezier(common->cpObj, u, &dpdu);
if (common->type == CurveType::Ribbon)
dpdv = Normalize(Cross(nHit, dpdu)) * hitWidth;
else {
// Compute curve $\dpdv$ for flat and cylinder curves
Vector3f dpduPlane = (Inverse(rayToObject))(dpdu);
Vector3f dpdvPlane =
Normalize(Vector3f(-dpduPlane.y, dpduPlane.x, 0)) *
hitWidth;
if (common->type == CurveType::Cylinder) {
// Rotate _dpdvPlane_ to give cylindrical appearance
Float theta = Lerp(v, -90., 90.);
Transform rot = Rotate(-theta, dpduPlane);
dpdvPlane = rot(dpdvPlane);
}
dpdv = rayToObject(dpdvPlane);
}
*isect = (*ObjectToWorld)(SurfaceInteraction(
ray(pc.z), pError, Point2f(u, v), -ray.d, dpdu, dpdv,
Normal3f(0, 0, 0), Normal3f(0, 0, 0), ray.time, this));
}
++nHits;
return true;
}
}
