417 lines
18 KiB
C++
417 lines
18 KiB
C++
// Copyright 2009-2021 Intel Corporation
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// SPDX-License-Identifier: Apache-2.0
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#pragma once
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#include "../common/ray.h"
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#include "curve_intersector_precalculations.h"
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#include "curve_intersector_sweep.h"
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#include "../subdiv/linear_bezier_patch.h"
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#define DBG(x)
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namespace embree
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{
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namespace isa
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{
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template<typename Ray, typename Epilog>
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struct TensorLinearCubicBezierSurfaceIntersector
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{
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const LinearSpace3fa& ray_space;
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Ray& ray;
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TensorLinearCubicBezierSurface3fa curve3d;
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TensorLinearCubicBezierSurface2fa curve2d;
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float eps;
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const Epilog& epilog;
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bool isHit;
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__forceinline TensorLinearCubicBezierSurfaceIntersector (const LinearSpace3fa& ray_space, Ray& ray, const TensorLinearCubicBezierSurface3fa& curve3d, const Epilog& epilog)
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: ray_space(ray_space), ray(ray), curve3d(curve3d), epilog(epilog), isHit(false)
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{
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const TensorLinearCubicBezierSurface3fa curve3dray = curve3d.xfm(ray_space,ray.org);
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curve2d = TensorLinearCubicBezierSurface2fa(CubicBezierCurve2fa(curve3dray.L),CubicBezierCurve2fa(curve3dray.R));
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const BBox2fa b2 = curve2d.bounds();
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eps = 8.0f*float(ulp)*reduce_max(max(abs(b2.lower),abs(b2.upper)));
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}
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__forceinline Interval1f solve_linear(const float u0, const float u1, const float& p0, const float& p1)
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{
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if (p1 == p0) {
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if (p0 == 0.0f) return Interval1f(u0,u1);
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else return Interval1f(empty);
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}
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const float t = -p0/(p1-p0);
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const float tt = lerp(u0,u1,t);
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return Interval1f(tt);
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}
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__forceinline void solve_linear(const float u0, const float u1, const Interval1f& p0, const Interval1f& p1, Interval1f& u)
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{
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if (sign(p0.lower) != sign(p0.upper)) u.extend(u0);
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if (sign(p0.lower) != sign(p1.lower)) u.extend(solve_linear(u0,u1,p0.lower,p1.lower));
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if (sign(p0.upper) != sign(p1.upper)) u.extend(solve_linear(u0,u1,p0.upper,p1.upper));
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if (sign(p1.lower) != sign(p1.upper)) u.extend(u1);
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}
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__forceinline Interval1f bezier_clipping(const CubicBezierCurve<Interval1f>& curve)
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{
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Interval1f u = empty;
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solve_linear(0.0f/3.0f,1.0f/3.0f,curve.v0,curve.v1,u);
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solve_linear(0.0f/3.0f,2.0f/3.0f,curve.v0,curve.v2,u);
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solve_linear(0.0f/3.0f,3.0f/3.0f,curve.v0,curve.v3,u);
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solve_linear(1.0f/3.0f,2.0f/3.0f,curve.v1,curve.v2,u);
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solve_linear(1.0f/3.0f,3.0f/3.0f,curve.v1,curve.v3,u);
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solve_linear(2.0f/3.0f,3.0f/3.0f,curve.v2,curve.v3,u);
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return intersect(u,Interval1f(0.0f,1.0f));
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}
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__forceinline Interval1f bezier_clipping(const LinearBezierCurve<Interval1f>& curve)
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{
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Interval1f v = empty;
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solve_linear(0.0f,1.0f,curve.v0,curve.v1,v);
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return intersect(v,Interval1f(0.0f,1.0f));
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}
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__forceinline void solve_bezier_clipping(BBox1f cu, BBox1f cv, const TensorLinearCubicBezierSurface2fa& curve2)
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{
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BBox2fa bounds = curve2.bounds();
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if (bounds.upper.x < 0.0f) return;
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if (bounds.upper.y < 0.0f) return;
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if (bounds.lower.x > 0.0f) return;
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if (bounds.lower.y > 0.0f) return;
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if (max(cu.size(),cv.size()) < 1E-4f)
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{
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const float u = cu.center();
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const float v = cv.center();
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TensorLinearCubicBezierSurface1f curve_z = curve3d.xfm(ray_space.row2(),ray.org);
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const float t = curve_z.eval(u,v);
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if (ray.tnear() <= t && t <= ray.tfar) {
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const Vec3fa Ng = cross(curve3d.eval_du(u,v),curve3d.eval_dv(u,v));
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BezierCurveHit hit(t,u,v,Ng);
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isHit |= epilog(hit);
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}
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return;
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}
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const Vec2fa dv = curve2.axis_v();
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const TensorLinearCubicBezierSurface1f curve1v = curve2.xfm(dv);
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LinearBezierCurve<Interval1f> curve0v = curve1v.reduce_u();
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if (!curve0v.hasRoot()) return;
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const Interval1f v = bezier_clipping(curve0v);
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if (isEmpty(v)) return;
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TensorLinearCubicBezierSurface2fa curve2a = curve2.clip_v(v);
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cv = BBox1f(lerp(cv.lower,cv.upper,v.lower),lerp(cv.lower,cv.upper,v.upper));
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const Vec2fa du = curve2.axis_u();
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const TensorLinearCubicBezierSurface1f curve1u = curve2a.xfm(du);
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CubicBezierCurve<Interval1f> curve0u = curve1u.reduce_v();
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int roots = curve0u.maxRoots();
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if (roots == 0) return;
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if (roots == 1)
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{
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const Interval1f u = bezier_clipping(curve0u);
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if (isEmpty(u)) return;
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TensorLinearCubicBezierSurface2fa curve2b = curve2a.clip_u(u);
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cu = BBox1f(lerp(cu.lower,cu.upper,u.lower),lerp(cu.lower,cu.upper,u.upper));
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solve_bezier_clipping(cu,cv,curve2b);
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return;
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}
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TensorLinearCubicBezierSurface2fa curve2l, curve2r;
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curve2a.split_u(curve2l,curve2r);
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solve_bezier_clipping(BBox1f(cu.lower,cu.center()),cv,curve2l);
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solve_bezier_clipping(BBox1f(cu.center(),cu.upper),cv,curve2r);
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}
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__forceinline bool solve_bezier_clipping()
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{
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solve_bezier_clipping(BBox1f(0.0f,1.0f),BBox1f(0.0f,1.0f),curve2d);
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return isHit;
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}
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__forceinline void solve_newton_raphson(BBox1f cu, BBox1f cv)
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{
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Vec2fa uv(cu.center(),cv.center());
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const Vec2fa dfdu = curve2d.eval_du(uv.x,uv.y);
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const Vec2fa dfdv = curve2d.eval_dv(uv.x,uv.y);
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const LinearSpace2fa rcp_J = rcp(LinearSpace2fa(dfdu,dfdv));
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solve_newton_raphson_loop(cu,cv,uv,dfdu,dfdv,rcp_J);
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}
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__forceinline void solve_newton_raphson_loop(BBox1f cu, BBox1f cv, const Vec2fa& uv_in, const Vec2fa& dfdu, const Vec2fa& dfdv, const LinearSpace2fa& rcp_J)
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{
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Vec2fa uv = uv_in;
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for (size_t i=0; i<200; i++)
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{
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const Vec2fa f = curve2d.eval(uv.x,uv.y);
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const Vec2fa duv = rcp_J*f;
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uv -= duv;
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if (max(abs(f.x),abs(f.y)) < eps)
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{
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const float u = uv.x;
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const float v = uv.y;
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if (!(u >= 0.0f && u <= 1.0f)) return; // rejects NaNs
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if (!(v >= 0.0f && v <= 1.0f)) return; // rejects NaNs
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const TensorLinearCubicBezierSurface1f curve_z = curve3d.xfm(ray_space.row2(),ray.org);
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const float t = curve_z.eval(u,v);
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if (!(ray.tnear() <= t && t <= ray.tfar)) return; // rejects NaNs
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const Vec3fa Ng = cross(curve3d.eval_du(u,v),curve3d.eval_dv(u,v));
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BezierCurveHit hit(t,u,v,Ng);
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isHit |= epilog(hit);
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return;
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}
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}
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}
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__forceinline bool clip_v(BBox1f& cu, BBox1f& cv)
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{
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const Vec2fa dv = curve2d.eval_dv(cu.lower,cv.lower);
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const TensorLinearCubicBezierSurface1f curve1v = curve2d.xfm(dv).clip(cu,cv);
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LinearBezierCurve<Interval1f> curve0v = curve1v.reduce_u();
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if (!curve0v.hasRoot()) return false;
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Interval1f v = bezier_clipping(curve0v);
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if (isEmpty(v)) return false;
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v = intersect(v + Interval1f(-0.1f,+0.1f),Interval1f(0.0f,1.0f));
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cv = BBox1f(lerp(cv.lower,cv.upper,v.lower),lerp(cv.lower,cv.upper,v.upper));
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return true;
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}
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__forceinline bool solve_krawczyk(bool very_small, BBox1f& cu, BBox1f& cv)
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{
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/* perform bezier clipping in v-direction to get tight v-bounds */
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TensorLinearCubicBezierSurface2fa curve2 = curve2d.clip(cu,cv);
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const Vec2fa dv = curve2.axis_v();
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const TensorLinearCubicBezierSurface1f curve1v = curve2.xfm(dv);
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LinearBezierCurve<Interval1f> curve0v = curve1v.reduce_u();
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if (unlikely(!curve0v.hasRoot())) return true;
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Interval1f v = bezier_clipping(curve0v);
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if (unlikely(isEmpty(v))) return true;
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v = intersect(v + Interval1f(-0.1f,+0.1f),Interval1f(0.0f,1.0f));
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curve2 = curve2.clip_v(v);
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cv = BBox1f(lerp(cv.lower,cv.upper,v.lower),lerp(cv.lower,cv.upper,v.upper));
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/* perform one newton raphson iteration */
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Vec2fa c(cu.center(),cv.center());
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Vec2fa f,dfdu,dfdv; curve2d.eval(c.x,c.y,f,dfdu,dfdv);
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const LinearSpace2fa rcp_J = rcp(LinearSpace2fa(dfdu,dfdv));
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const Vec2fa c1 = c - rcp_J*f;
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/* calculate bounds of derivatives */
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const BBox2fa bounds_du = (1.0f/cu.size())*curve2.derivative_u().bounds();
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const BBox2fa bounds_dv = (1.0f/cv.size())*curve2.derivative_v().bounds();
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/* calculate krawczyk test */
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LinearSpace2<Vec2<Interval1f>> I(Interval1f(1.0f), Interval1f(0.0f),
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Interval1f(0.0f), Interval1f(1.0f));
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LinearSpace2<Vec2<Interval1f>> G(Interval1f(bounds_du.lower.x,bounds_du.upper.x), Interval1f(bounds_dv.lower.x,bounds_dv.upper.x),
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Interval1f(bounds_du.lower.y,bounds_du.upper.y), Interval1f(bounds_dv.lower.y,bounds_dv.upper.y));
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const LinearSpace2<Vec2f> rcp_J2(rcp_J);
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const LinearSpace2<Vec2<Interval1f>> rcp_Ji(rcp_J2);
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const Vec2<Interval1f> x(cu,cv);
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const Vec2<Interval1f> K = Vec2<Interval1f>(Vec2f(c1)) + (I - rcp_Ji*G)*(x-Vec2<Interval1f>(Vec2f(c)));
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/* test if there is no solution */
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const Vec2<Interval1f> KK = intersect(K,x);
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if (unlikely(isEmpty(KK.x) || isEmpty(KK.y))) return true;
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/* exit if convergence cannot get proven, but terminate if we are very small */
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if (unlikely(!subset(K,x) && !very_small)) return false;
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/* solve using newton raphson iteration of convergence is guaranteed */
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solve_newton_raphson_loop(cu,cv,c1,dfdu,dfdv,rcp_J);
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return true;
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}
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__forceinline void solve_newton_raphson_no_recursion(BBox1f cu, BBox1f cv)
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{
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if (!clip_v(cu,cv)) return;
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return solve_newton_raphson(cu,cv);
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}
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__forceinline void solve_newton_raphson_recursion(BBox1f cu, BBox1f cv)
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{
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unsigned int sptr = 0;
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const unsigned int stack_size = 4;
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unsigned int mask_stack[stack_size];
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BBox1f cu_stack[stack_size];
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BBox1f cv_stack[stack_size];
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goto entry;
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/* terminate if stack is empty */
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while (sptr)
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{
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/* pop from stack */
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{
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sptr--;
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size_t mask = mask_stack[sptr];
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cu = cu_stack[sptr];
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cv = cv_stack[sptr];
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const size_t i = bscf(mask);
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mask_stack[sptr] = mask;
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if (mask) sptr++; // there are still items on the stack
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/* process next element recurse into each hit curve segment */
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const float u0 = float(i+0)*(1.0f/(VSIZEX-1));
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const float u1 = float(i+1)*(1.0f/(VSIZEX-1));
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const BBox1f cui(lerp(cu.lower,cu.upper,u0),lerp(cu.lower,cu.upper,u1));
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cu = cui;
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}
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#if 0
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solve_newton_raphson_no_recursion(cu,cv);
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continue;
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#else
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/* we assume convergence for small u ranges and verify using krawczyk */
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if (cu.size() < 1.0f/6.0f) {
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const bool very_small = cu.size() < 0.001f || sptr >= stack_size;
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if (solve_krawczyk(very_small,cu,cv)) {
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continue;
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}
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}
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#endif
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entry:
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/* split the curve into VSIZEX-1 segments in u-direction */
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vboolx valid = true;
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TensorLinearCubicBezierSurface<Vec2vfx> subcurves = curve2d.clip_v(cv).vsplit_u(valid,cu);
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/* slabs test in u-direction */
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Vec2vfx ndv = cross(subcurves.axis_v());
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BBox<vfloatx> boundsv = subcurves.vxfm(ndv).bounds();
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valid &= boundsv.lower <= eps;
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valid &= boundsv.upper >= -eps;
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if (none(valid)) continue;
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/* slabs test in v-direction */
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Vec2vfx ndu = cross(subcurves.axis_u());
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BBox<vfloatx> boundsu = subcurves.vxfm(ndu).bounds();
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valid &= boundsu.lower <= eps;
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valid &= boundsu.upper >= -eps;
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if (none(valid)) continue;
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/* push valid segments to stack */
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assert(sptr < stack_size);
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mask_stack [sptr] = movemask(valid);
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cu_stack [sptr] = cu;
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cv_stack [sptr] = cv;
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sptr++;
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}
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}
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__forceinline bool solve_newton_raphson_main()
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{
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BBox1f vu(0.0f,1.0f);
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BBox1f vv(0.0f,1.0f);
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solve_newton_raphson_recursion(vu,vv);
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return isHit;
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}
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};
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template<template<typename Ty> class SourceCurve>
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struct OrientedCurve1Intersector1
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{
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//template<typename Ty> using Curve = SourceCurve<Ty>;
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typedef SourceCurve<Vec3ff> SourceCurve3ff;
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typedef SourceCurve<Vec3fa> SourceCurve3fa;
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__forceinline OrientedCurve1Intersector1() {}
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__forceinline OrientedCurve1Intersector1(const Ray& ray, const void* ptr) {}
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template<typename Epilog>
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__noinline bool intersect(const CurvePrecalculations1& pre, Ray& ray,
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IntersectContext* context,
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const CurveGeometry* geom, const unsigned int primID,
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const Vec3ff& v0i, const Vec3ff& v1i, const Vec3ff& v2i, const Vec3ff& v3i,
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const Vec3fa& n0i, const Vec3fa& n1i, const Vec3fa& n2i, const Vec3fa& n3i,
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const Epilog& epilog) const
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{
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STAT3(normal.trav_prims,1,1,1);
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SourceCurve3ff ccurve(v0i,v1i,v2i,v3i);
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SourceCurve3fa ncurve(n0i,n1i,n2i,n3i);
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ccurve = enlargeRadiusToMinWidth(context,geom,ray.org,ccurve);
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TensorLinearCubicBezierSurface3fa curve = TensorLinearCubicBezierSurface3fa::fromCenterAndNormalCurve(ccurve,ncurve);
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//return TensorLinearCubicBezierSurfaceIntersector<Ray,Epilog>(pre.ray_space,ray,curve,epilog).solve_bezier_clipping();
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return TensorLinearCubicBezierSurfaceIntersector<Ray,Epilog>(pre.ray_space,ray,curve,epilog).solve_newton_raphson_main();
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}
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template<typename Epilog>
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__noinline bool intersect(const CurvePrecalculations1& pre, Ray& ray,
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IntersectContext* context,
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const CurveGeometry* geom, const unsigned int primID,
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const TensorLinearCubicBezierSurface3fa& curve, const Epilog& epilog) const
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{
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STAT3(normal.trav_prims,1,1,1);
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//return TensorLinearCubicBezierSurfaceIntersector<Ray,Epilog>(pre.ray_space,ray,curve,epilog).solve_bezier_clipping();
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return TensorLinearCubicBezierSurfaceIntersector<Ray,Epilog>(pre.ray_space,ray,curve,epilog).solve_newton_raphson_main();
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}
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};
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template<template<typename Ty> class SourceCurve, int K>
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struct OrientedCurve1IntersectorK
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{
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//template<typename Ty> using Curve = SourceCurve<Ty>;
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typedef SourceCurve<Vec3ff> SourceCurve3ff;
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typedef SourceCurve<Vec3fa> SourceCurve3fa;
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struct Ray1
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{
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__forceinline Ray1(RayK<K>& ray, size_t k)
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: org(ray.org.x[k],ray.org.y[k],ray.org.z[k]), dir(ray.dir.x[k],ray.dir.y[k],ray.dir.z[k]), _tnear(ray.tnear()[k]), tfar(ray.tfar[k]) {}
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Vec3fa org;
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Vec3fa dir;
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float _tnear;
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float& tfar;
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__forceinline float& tnear() { return _tnear; }
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//__forceinline float& tfar() { return _tfar; }
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__forceinline const float& tnear() const { return _tnear; }
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//__forceinline const float& tfar() const { return _tfar; }
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};
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template<typename Epilog>
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__forceinline bool intersect(const CurvePrecalculationsK<K>& pre, RayK<K>& vray, size_t k,
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IntersectContext* context,
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const CurveGeometry* geom, const unsigned int primID,
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const Vec3ff& v0i, const Vec3ff& v1i, const Vec3ff& v2i, const Vec3ff& v3i,
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const Vec3fa& n0i, const Vec3fa& n1i, const Vec3fa& n2i, const Vec3fa& n3i,
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const Epilog& epilog)
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{
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STAT3(normal.trav_prims,1,1,1);
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Ray1 ray(vray,k);
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SourceCurve3ff ccurve(v0i,v1i,v2i,v3i);
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SourceCurve3fa ncurve(n0i,n1i,n2i,n3i);
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ccurve = enlargeRadiusToMinWidth(context,geom,ray.org,ccurve);
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TensorLinearCubicBezierSurface3fa curve = TensorLinearCubicBezierSurface3fa::fromCenterAndNormalCurve(ccurve,ncurve);
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//return TensorLinearCubicBezierSurfaceIntersector<Ray1,Epilog>(pre.ray_space[k],ray,curve,epilog).solve_bezier_clipping();
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return TensorLinearCubicBezierSurfaceIntersector<Ray1,Epilog>(pre.ray_space[k],ray,curve,epilog).solve_newton_raphson_main();
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}
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template<typename Epilog>
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__forceinline bool intersect(const CurvePrecalculationsK<K>& pre, RayK<K>& vray, size_t k,
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IntersectContext* context,
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const CurveGeometry* geom, const unsigned int primID,
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const TensorLinearCubicBezierSurface3fa& curve,
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const Epilog& epilog)
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{
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STAT3(normal.trav_prims,1,1,1);
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Ray1 ray(vray,k);
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//return TensorLinearCubicBezierSurfaceIntersector<Ray1,Epilog>(pre.ray_space[k],ray,curve,epilog).solve_bezier_clipping();
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return TensorLinearCubicBezierSurfaceIntersector<Ray1,Epilog>(pre.ray_space[k],ray,curve,epilog).solve_newton_raphson_main();
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}
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};
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}
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}
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