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authorBryan Galdrikian <[email protected]>2018-05-31 11:36:08 -0700
committerBryan Galdrikian <[email protected]>2018-05-31 11:36:08 -0700
commit7115f60b91b5717d90f643fd692010905c7004db (patch)
treeeffd68c6978751c517d54c2f2bb5bb6e7dc93e18 /sdk/extensions/authoring/source/NvBlastExtAuthoringVSA.h
parentUpdating BlastTool zip (diff)
downloadblast-7115f60b91b5717d90f643fd692010905c7004db.tar.xz
blast-7115f60b91b5717d90f643fd692010905c7004db.zip
Blast 1.1.3. See docs/release_notes.txt.v1.1.3_rc1
Diffstat (limited to 'sdk/extensions/authoring/source/NvBlastExtAuthoringVSA.h')
-rwxr-xr-x[-rw-r--r--]sdk/extensions/authoring/source/NvBlastExtAuthoringVSA.h660
1 files changed, 330 insertions, 330 deletions
diff --git a/sdk/extensions/authoring/source/NvBlastExtAuthoringVSA.h b/sdk/extensions/authoring/source/NvBlastExtAuthoringVSA.h
index c59fa49..5d97f88 100644..100755
--- a/sdk/extensions/authoring/source/NvBlastExtAuthoringVSA.h
+++ b/sdk/extensions/authoring/source/NvBlastExtAuthoringVSA.h
@@ -1,330 +1,330 @@
-// This code contains NVIDIA Confidential Information and is disclosed to you
-// under a form of NVIDIA software license agreement provided separately to you.
-//
-// Notice
-// NVIDIA Corporation and its licensors retain all intellectual property and
-// proprietary rights in and to this software and related documentation and
-// any modifications thereto. Any use, reproduction, disclosure, or
-// distribution of this software and related documentation without an express
-// license agreement from NVIDIA Corporation is strictly prohibited.
-//
-// ALL NVIDIA DESIGN SPECIFICATIONS, CODE ARE PROVIDED "AS IS.". NVIDIA MAKES
-// NO WARRANTIES, EXPRESSED, IMPLIED, STATUTORY, OR OTHERWISE WITH RESPECT TO
-// THE MATERIALS, AND EXPRESSLY DISCLAIMS ALL IMPLIED WARRANTIES OF NONINFRINGEMENT,
-// MERCHANTABILITY, AND FITNESS FOR A PARTICULAR PURPOSE.
-//
-// Information and code furnished is believed to be accurate and reliable.
-// However, NVIDIA Corporation assumes no responsibility for the consequences of use of such
-// information or for any infringement of patents or other rights of third parties that may
-// result from its use. No license is granted by implication or otherwise under any patent
-// or patent rights of NVIDIA Corporation. Details are subject to change without notice.
-// This code supersedes and replaces all information previously supplied.
-// NVIDIA Corporation products are not authorized for use as critical
-// components in life support devices or systems without express written approval of
-// NVIDIA Corporation.
-//
-// Copyright (c) 2016-2018 NVIDIA Corporation. All rights reserved.
-
-
-#ifndef NVBLASTEXTAUTHORINGVSA_H
-#define NVBLASTEXTAUTHORINGVSA_H
-
-namespace Nv
-{
-namespace Blast
-{
-
-/*
- This code copied from APEX GSA
-*/
-
-namespace VSA
-{
-typedef float real;
-
-struct VS3D_Halfspace_Set
-{
- virtual real farthest_halfspace(real plane[4], const real point[4]) = 0;
-};
-
-
-// Simple types and operations for internal calculations
-struct Vec3 { real x, y, z; }; // 3-vector
-inline Vec3 vec3(real x, real y, real z) { Vec3 r; r.x = x; r.y = y; r.z = z; return r; } // vector builder
-inline Vec3 operator + (const Vec3& a, const Vec3& b) { return vec3(a.x + b.x, a.y + b.y, a.z + b.z); } // vector addition
-inline Vec3 operator * (real s, const Vec3& v) { return vec3(s*v.x, s*v.y, s*v.z); } // scalar multiplication
-inline real operator | (const Vec3& a, const Vec3& b) { return a.x*b.x + a.y*b.y + a.z*b.z; } // dot product
-inline Vec3 operator ^ (const Vec3& a, const Vec3& b) { return vec3(a.y*b.z - b.y*a.z, a.z*b.x - b.z*a.x, a.x*b.y - b.x*a.y); } // cross product
-
-struct Vec4 { Vec3 v; real w; }; // 4-vector split into 3-vector and scalar parts
-inline Vec4 vec4(const Vec3& v, real w) { Vec4 r; r.v = v; r.w = w; return r; } // vector builder
-inline real operator | (const Vec4& a, const Vec4& b) { return (a.v | b.v) + a.w*b.w; } // dot product
-
-// More accurate perpendicular
-inline Vec3 perp(const Vec3& a, const Vec3& b)
-{
- Vec3 c = a^b; // Cross-product gives perpendicular
-#if VS3D_HIGH_ACCURACY || REAL_DOUBLE
- const real c2 = c | c;
- if (c2 != 0) c = c + (1 / c2)*((a | c)*(c^b) + (b | c)*(a^c)); // Improvement to (a b)^T(c) = (0)
-#endif
- return c;
-}
-
-// Square
-inline real sq(real x) { return x*x; }
-
-// Returns index of the extremal element in a three-element set {e0, e1, e2} based upon comparisons c_ij. The extremal index m is such that c_mn is true, or e_m == e_n, for all n.
-inline int ext_index(int c_10, int c_21, int c_20) { return c_10 << c_21 | (c_21&c_20) << 1; }
-
-// Returns index (0, 1, or 2) of minimum argument
-inline int index_of_min(real x0, real x1, real x2) { return ext_index((int)(x1 < x0), (int)(x2 < x1), (int)(x2 < x0)); }
-
-// Compare fractions with positive deominators. Returns a_num*sqrt(a_rden2) > b_num*sqrt(b_rden2)
-inline bool frac_gt(real a_num, real a_rden2, real b_num, real b_rden2)
-{
- const bool a_num_neg = a_num < 0;
- const bool b_num_neg = b_num < 0;
- return a_num_neg != b_num_neg ? b_num_neg : ((a_num*a_num*a_rden2 > b_num*b_num*b_rden2) != a_num_neg);
-}
-
-// Returns index (0, 1, or 2) of maximum fraction with positive deominators
-inline int index_of_max_frac(real x0_num, real x0_rden2, real x1_num, real x1_rden2, real x2_num, real x2_rden2)
-{
- return ext_index((int)frac_gt(x1_num, x1_rden2, x0_num, x0_rden2), (int)frac_gt(x2_num, x2_rden2, x1_num, x1_rden2), (int)frac_gt(x2_num, x2_rden2, x0_num, x0_rden2));
-}
-
-// Compare values given their signs and squares. Returns a > b. a2 and b2 may have any constant offset applied to them.
-inline bool sgn_sq_gt(real sgn_a, real a2, real sgn_b, real b2) { return sgn_a*sgn_b < 0 ? (sgn_b < 0) : ((a2 > b2) != (sgn_a < 0)); }
-
-// Returns index (0, 1, or 2) of maximum value given their signs and squares. sq_x0, sq_x1, and sq_x2 may have any constant offset applied to them.
-inline int index_of_max_sgn_sq(real sgn_x0, real sq_x0, real sgn_x1, real sq_x1, real sgn_x2, real sq_x2)
-{
- return ext_index((int)sgn_sq_gt(sgn_x1, sq_x1, sgn_x0, sq_x0), (int)sgn_sq_gt(sgn_x2, sq_x2, sgn_x1, sq_x1), (int)sgn_sq_gt(sgn_x2, sq_x2, sgn_x0, sq_x0));
-}
-
-// Project 2D (homogeneous) vector onto 2D half-space boundary
-inline void project2D(Vec3& r, const Vec3& plane, real delta, real recip_n2, real eps2)
-{
- r = r + (-delta*recip_n2)*vec3(plane.x, plane.y, 0);
- r = r + (-(r | plane)*recip_n2)*vec3(plane.x, plane.y, 0); // Second projection for increased accuracy
- if ((r | r) > eps2) return;
- r = (-plane.z*recip_n2)*vec3(plane.x, plane.y, 0);
- r.z = 1;
-}
-
-
-// Update function for vs3d_test
-static bool vs3d_update(Vec4& p, Vec4 S[4], int& plane_count, const Vec4& q, real eps2)
-{
- // h plane is the last plane
- const Vec4& h = S[plane_count - 1];
-
- // Handle plane_count == 1 specially (optimization; this could be commented out)
- if (plane_count == 1)
- {
- // Solution is objective projected onto h plane
- p = q;
- p.v = p.v + -(p | h)*h.v;
- if ((p | p) <= eps2) p = vec4(-h.w*h.v, 1); // If p == 0 then q is a direction vector, any point in h is a support point
- return true;
- }
-
- // Create basis in the h plane
- const int min_i = index_of_min(h.v.x*h.v.x, h.v.y*h.v.y, h.v.z*h.v.z);
- const Vec3 y = h.v^vec3((real)(min_i == 0), (real)(min_i == 1), (real)(min_i == 2));
- const Vec3 x = y^h.v;
-
- // Use reduced vector r instead of p
- Vec3 r = { x | q.v, y | q.v, q.w*(y | y) }; // (x|x) = (y|y) = square of plane basis scale
-
- // If r == 0 (within epsilon), then it is a direction vector, and we have a bounded solution
- if ((r | r) <= eps2) r.z = 1;
-
- // Create plane equations in the h plane. These will not be normalized in general.
- int N = 0; // Plane count in h subspace
- Vec3 R[3]; // Planes in h subspace
- real recip_n2[3]; // Plane normal vector reciprocal lengths squared
- real delta[3]; // Signed distance of objective to the planes
- int index[3]; // Keep track of original plane indices
- for (int i = 0; i < plane_count - 1; ++i)
- {
- const Vec3& vi = S[i].v;
- const real cos_theta = h.v | vi;
- R[N] = vec3(x | vi, y | vi, S[i].w - h.w*cos_theta);
- index[N] = i;
- const real n2 = R[N].x*R[N].x + R[N].y*R[N].y;
- if (n2 >= eps2)
- {
- const real lin_norm = (real)1.5 - (real)0.5*n2; // 1st-order approximation to 1/sqrt(n2) expanded about n2 = 1
- R[N] = lin_norm*R[N]; // We don't need normalized plane equations, but rescaling (even with an approximate normalization) gives better numerical behavior
- recip_n2[N] = 1 / (R[N].x*R[N].x + R[N].y*R[N].y);
- delta[N] = r | R[N];
- ++N; // Keep this plane
- }
- else if (cos_theta < 0) return false; // Parallel cases are redundant and rejected, anti-parallel cases are 1D voids
- }
-
- // Now work with the N-sized R array of half-spaces in the h plane
- switch (N)
- {
- case 1: one_plane :
- if (delta[0] < 0) N = 0; // S[0] is redundant, eliminate it
- else project2D(r, R[0], delta[0], recip_n2[0], eps2);
- break;
- case 2: two_planes :
- if (delta[0] < 0 && delta[1] < 0) N = 0; // S[0] and S[1] are redundant, eliminate them
- else
- {
- const int max_d_index = (int)frac_gt(delta[1], recip_n2[1], delta[0], recip_n2[0]);
- project2D(r, R[max_d_index], delta[max_d_index], recip_n2[max_d_index], eps2);
- const int min_d_index = max_d_index ^ 1;
- const real new_delta_min = r | R[min_d_index];
- if (new_delta_min < 0)
- {
- index[0] = index[max_d_index];
- N = 1; // S[min_d_index] is redundant, eliminate it
- }
- else
- {
- // Set r to the intersection of R[0] and R[1] and keep both
- r = perp(R[0], R[1]);
- if (r.z*r.z*recip_n2[0] * recip_n2[1] < eps2)
- {
- if (R[0].x*R[1].x + R[0].y*R[1].y < 0) return false; // 2D void found
- goto one_plane;
- }
- r = (1 / r.z)*r; // We could just as well multiply r by sgn(r.z); we just need to ensure r.z > 0
- }
- }
- break;
- case 3:
- if (delta[0] < 0 && delta[1] < 0 && delta[2] < 0) N = 0; // S[0], S[1], and S[2] are redundant, eliminate them
- else
- {
- const Vec3 row_x = { R[0].x, R[1].x, R[2].x };
- const Vec3 row_y = { R[0].y, R[1].y, R[2].y };
- const Vec3 row_w = { R[0].z, R[1].z, R[2].z };
- const Vec3 cof_w = perp(row_x, row_y);
- const bool detR_pos = (row_w | cof_w) > 0;
- const int nrw_sgn0 = cof_w.x*cof_w.x*recip_n2[1] * recip_n2[2] < eps2 ? 0 : (((int)((cof_w.x > 0) == detR_pos) << 1) - 1);
- const int nrw_sgn1 = cof_w.y*cof_w.y*recip_n2[2] * recip_n2[0] < eps2 ? 0 : (((int)((cof_w.y > 0) == detR_pos) << 1) - 1);
- const int nrw_sgn2 = cof_w.z*cof_w.z*recip_n2[0] * recip_n2[1] < eps2 ? 0 : (((int)((cof_w.z > 0) == detR_pos) << 1) - 1);
-
- if ((nrw_sgn0 | nrw_sgn1 | nrw_sgn2) >= 0) return false; // 3D void found
-
- const int positive_width_count = ((nrw_sgn0 >> 1) & 1) + ((nrw_sgn1 >> 1) & 1) + ((nrw_sgn2 >> 1) & 1);
- if (positive_width_count == 1)
- {
- // A single positive width results from a redundant plane. Eliminate it and peform N = 2 calculation.
- const int pos_width_index = ((nrw_sgn1 >> 1) & 1) | (nrw_sgn2 & 2); // Calculates which index corresponds to the positive-width side
- R[pos_width_index] = R[2];
- recip_n2[pos_width_index] = recip_n2[2];
- delta[pos_width_index] = delta[2];
- index[pos_width_index] = index[2];
- N = 2;
- goto two_planes;
- }
-
- // Find the max dot product of r and R[i]/|R_normal[i]|. For numerical accuracy when the angle between r and the i^{th} plane normal is small, we take some care below:
- const int max_d_index = r.z != 0
- ? index_of_max_frac(delta[0], recip_n2[0], delta[1], recip_n2[1], delta[2], recip_n2[2]) // displacement term resolves small-angle ambiguity, just use dot product
- : index_of_max_sgn_sq(delta[0], -sq(r.x*R[0].y - r.y*R[0].x)*recip_n2[0], delta[1], -sq(r.x*R[1].y - r.y*R[1].x)*recip_n2[1], delta[2], -sq(r.x*R[2].y - r.y*R[2].x)*recip_n2[2]); // No displacement term. Use wedge product to find the sine of the angle.
-
- // Project r onto max-d plane
- project2D(r, R[max_d_index], delta[max_d_index], recip_n2[max_d_index], eps2);
- N = 1; // Unless we use a vertex in the loop below
- const int index_max = index[max_d_index];
-
- // The number of finite widths should be >= 2. If not, it should be 0, but in any case it implies three parallel lines in the plane, which we should not have here.
- // If we do have three parallel lines (# of finite widths < 2), we've picked the line corresponding to the half-plane farthest from r, which is correct.
- const int finite_width_count = (nrw_sgn0 & 1) + (nrw_sgn1 & 1) + (nrw_sgn2 & 1);
- if (finite_width_count >= 2)
- {
- const int i_remaining[2] = { (1 << max_d_index) & 3, (3 >> max_d_index) ^ 1 }; // = {(max_d_index+1)%3, (max_d_index+2)%3}
- const int i_select = (int)frac_gt(delta[i_remaining[1]], recip_n2[i_remaining[1]], delta[i_remaining[0]], recip_n2[i_remaining[0]]); // Select the greater of the remaining dot products
- for (int i = 0; i < 2; ++i)
- {
- const int j = i_remaining[i_select^i]; // i = 0 => the next-greatest, i = 1 => the least
- if ((r | R[j]) >= 0)
- {
- r = perp(R[max_d_index], R[j]);
- r = (1 / r.z)*r; // We could just as well multiply r by sgn(r.z); we just need to ensure r.z > 0
- index[1] = index[j];
- N = 2;
- break;
- }
- }
- }
-
- index[0] = index_max;
- }
- break;
- }
-
- // Transform r back to 3D space
- p = vec4(r.x*x + r.y*y + (-r.z*h.w)*h.v, r.z);
-
- // Pack S array with kept planes
- if (N < 2 || index[1] != 0) { for (int i = 0; i < N; ++i) S[i] = S[index[i]]; } // Safe to copy columns in order
- else { const Vec4 temp = S[0]; S[0] = S[index[0]]; S[1] = temp; } // Otherwise use temp storage to avoid overwrite
- S[N] = h;
- plane_count = N + 1;
-
- return true;
-}
-
-
-// Performs the VS algorithm for D = 3
-inline int vs3d_test(VS3D_Halfspace_Set& halfspace_set, real* q = nullptr)
-{
- // Objective = q if it is not NULL, otherwise it is the origin represented in homogeneous coordinates
- const Vec4 objective = q ? (q[3] != 0 ? vec4((1 / q[3])*vec3(q[0], q[1], q[2]), 1) : *(Vec4*)q) : vec4(vec3(0, 0, 0), 1);
-
- // Tolerance for 3D void simplex algorithm
- const real eps_f = (real)1 / (sizeof(real) == 4 ? (1L << 23) : (1LL << 52)); // Floating-point epsilon
-#if VS3D_HIGH_ACCURACY || REAL_DOUBLE
- const real eps = 8 * eps_f;
-#else
- const real eps = 80 * eps_f;
-#endif
- const real eps2 = eps*eps; // Using epsilon squared
-
- // Maximum allowed iterations of main loop. If exceeded, error code is returned
- const int max_iteration_count = 50;
-
- // State
- Vec4 S[4]; // Up to 4 planes
- int plane_count = 0; // Number of valid planes
- Vec4 p = objective; // Test point, initialized to objective
-
- // Default result, changed to valid result if found in loop below
- int result = -1;
-
- // Iterate until a stopping condition is met or the maximum number of iterations is reached
- for (int i = 0; result < 0 && i < max_iteration_count; ++i)
- {
- Vec4& plane = S[plane_count++];
- real delta = halfspace_set.farthest_halfspace(&plane.v.x, &p.v.x);
-#if VS3D_UNNORMALIZED_PLANE_HANDLING != 0
- const real recip_norm = vs3d_recip_sqrt(plane.v | plane.v);
- plane = vec4(recip_norm*plane.v, recip_norm*plane.w);
- delta *= recip_norm;
-#endif
- if (delta <= 0 || delta*delta <= eps2*(p | p)) result = 1; // Intersection found
- else if (!vs3d_update(p, S, plane_count, objective, eps2)) result = 0; // Void simplex found
- }
-
- // If q is given, fill it with the solution (normalize p.w if it is not zero)
- if (q) *(Vec4*)q = (p.w != 0) ? vec4((1 / p.w)*p.v, 1) : p;
-
- return result;
-}
-
-} // namespace VSA
-
-} // namespace Blast
-} // namespace Nv
-
-
-#endif // ifndef NVBLASTEXTAUTHORINGVSA_H
+// This code contains NVIDIA Confidential Information and is disclosed to you
+// under a form of NVIDIA software license agreement provided separately to you.
+//
+// Notice
+// NVIDIA Corporation and its licensors retain all intellectual property and
+// proprietary rights in and to this software and related documentation and
+// any modifications thereto. Any use, reproduction, disclosure, or
+// distribution of this software and related documentation without an express
+// license agreement from NVIDIA Corporation is strictly prohibited.
+//
+// ALL NVIDIA DESIGN SPECIFICATIONS, CODE ARE PROVIDED "AS IS.". NVIDIA MAKES
+// NO WARRANTIES, EXPRESSED, IMPLIED, STATUTORY, OR OTHERWISE WITH RESPECT TO
+// THE MATERIALS, AND EXPRESSLY DISCLAIMS ALL IMPLIED WARRANTIES OF NONINFRINGEMENT,
+// MERCHANTABILITY, AND FITNESS FOR A PARTICULAR PURPOSE.
+//
+// Information and code furnished is believed to be accurate and reliable.
+// However, NVIDIA Corporation assumes no responsibility for the consequences of use of such
+// information or for any infringement of patents or other rights of third parties that may
+// result from its use. No license is granted by implication or otherwise under any patent
+// or patent rights of NVIDIA Corporation. Details are subject to change without notice.
+// This code supersedes and replaces all information previously supplied.
+// NVIDIA Corporation products are not authorized for use as critical
+// components in life support devices or systems without express written approval of
+// NVIDIA Corporation.
+//
+// Copyright (c) 2016-2018 NVIDIA Corporation. All rights reserved.
+
+
+#ifndef NVBLASTEXTAUTHORINGVSA_H
+#define NVBLASTEXTAUTHORINGVSA_H
+
+namespace Nv
+{
+namespace Blast
+{
+
+/*
+ This code copied from APEX GSA
+*/
+
+namespace VSA
+{
+typedef float real;
+
+struct VS3D_Halfspace_Set
+{
+ virtual real farthest_halfspace(real plane[4], const real point[4]) = 0;
+};
+
+
+// Simple types and operations for internal calculations
+struct Vec3 { real x, y, z; }; // 3-vector
+inline Vec3 vec3(real x, real y, real z) { Vec3 r; r.x = x; r.y = y; r.z = z; return r; } // vector builder
+inline Vec3 operator + (const Vec3& a, const Vec3& b) { return vec3(a.x + b.x, a.y + b.y, a.z + b.z); } // vector addition
+inline Vec3 operator * (real s, const Vec3& v) { return vec3(s*v.x, s*v.y, s*v.z); } // scalar multiplication
+inline real operator | (const Vec3& a, const Vec3& b) { return a.x*b.x + a.y*b.y + a.z*b.z; } // dot product
+inline Vec3 operator ^ (const Vec3& a, const Vec3& b) { return vec3(a.y*b.z - b.y*a.z, a.z*b.x - b.z*a.x, a.x*b.y - b.x*a.y); } // cross product
+
+struct Vec4 { Vec3 v; real w; }; // 4-vector split into 3-vector and scalar parts
+inline Vec4 vec4(const Vec3& v, real w) { Vec4 r; r.v = v; r.w = w; return r; } // vector builder
+inline real operator | (const Vec4& a, const Vec4& b) { return (a.v | b.v) + a.w*b.w; } // dot product
+
+// More accurate perpendicular
+inline Vec3 perp(const Vec3& a, const Vec3& b)
+{
+ Vec3 c = a^b; // Cross-product gives perpendicular
+#if VS3D_HIGH_ACCURACY || REAL_DOUBLE
+ const real c2 = c | c;
+ if (c2 != 0) c = c + (1 / c2)*((a | c)*(c^b) + (b | c)*(a^c)); // Improvement to (a b)^T(c) = (0)
+#endif
+ return c;
+}
+
+// Square
+inline real sq(real x) { return x*x; }
+
+// Returns index of the extremal element in a three-element set {e0, e1, e2} based upon comparisons c_ij. The extremal index m is such that c_mn is true, or e_m == e_n, for all n.
+inline int ext_index(int c_10, int c_21, int c_20) { return c_10 << c_21 | (c_21&c_20) << 1; }
+
+// Returns index (0, 1, or 2) of minimum argument
+inline int index_of_min(real x0, real x1, real x2) { return ext_index((int)(x1 < x0), (int)(x2 < x1), (int)(x2 < x0)); }
+
+// Compare fractions with positive deominators. Returns a_num*sqrt(a_rden2) > b_num*sqrt(b_rden2)
+inline bool frac_gt(real a_num, real a_rden2, real b_num, real b_rden2)
+{
+ const bool a_num_neg = a_num < 0;
+ const bool b_num_neg = b_num < 0;
+ return a_num_neg != b_num_neg ? b_num_neg : ((a_num*a_num*a_rden2 > b_num*b_num*b_rden2) != a_num_neg);
+}
+
+// Returns index (0, 1, or 2) of maximum fraction with positive deominators
+inline int index_of_max_frac(real x0_num, real x0_rden2, real x1_num, real x1_rden2, real x2_num, real x2_rden2)
+{
+ return ext_index((int)frac_gt(x1_num, x1_rden2, x0_num, x0_rden2), (int)frac_gt(x2_num, x2_rden2, x1_num, x1_rden2), (int)frac_gt(x2_num, x2_rden2, x0_num, x0_rden2));
+}
+
+// Compare values given their signs and squares. Returns a > b. a2 and b2 may have any constant offset applied to them.
+inline bool sgn_sq_gt(real sgn_a, real a2, real sgn_b, real b2) { return sgn_a*sgn_b < 0 ? (sgn_b < 0) : ((a2 > b2) != (sgn_a < 0)); }
+
+// Returns index (0, 1, or 2) of maximum value given their signs and squares. sq_x0, sq_x1, and sq_x2 may have any constant offset applied to them.
+inline int index_of_max_sgn_sq(real sgn_x0, real sq_x0, real sgn_x1, real sq_x1, real sgn_x2, real sq_x2)
+{
+ return ext_index((int)sgn_sq_gt(sgn_x1, sq_x1, sgn_x0, sq_x0), (int)sgn_sq_gt(sgn_x2, sq_x2, sgn_x1, sq_x1), (int)sgn_sq_gt(sgn_x2, sq_x2, sgn_x0, sq_x0));
+}
+
+// Project 2D (homogeneous) vector onto 2D half-space boundary
+inline void project2D(Vec3& r, const Vec3& plane, real delta, real recip_n2, real eps2)
+{
+ r = r + (-delta*recip_n2)*vec3(plane.x, plane.y, 0);
+ r = r + (-(r | plane)*recip_n2)*vec3(plane.x, plane.y, 0); // Second projection for increased accuracy
+ if ((r | r) > eps2) return;
+ r = (-plane.z*recip_n2)*vec3(plane.x, plane.y, 0);
+ r.z = 1;
+}
+
+
+// Update function for vs3d_test
+static bool vs3d_update(Vec4& p, Vec4 S[4], int& plane_count, const Vec4& q, real eps2)
+{
+ // h plane is the last plane
+ const Vec4& h = S[plane_count - 1];
+
+ // Handle plane_count == 1 specially (optimization; this could be commented out)
+ if (plane_count == 1)
+ {
+ // Solution is objective projected onto h plane
+ p = q;
+ p.v = p.v + -(p | h)*h.v;
+ if ((p | p) <= eps2) p = vec4(-h.w*h.v, 1); // If p == 0 then q is a direction vector, any point in h is a support point
+ return true;
+ }
+
+ // Create basis in the h plane
+ const int min_i = index_of_min(h.v.x*h.v.x, h.v.y*h.v.y, h.v.z*h.v.z);
+ const Vec3 y = h.v^vec3((real)(min_i == 0), (real)(min_i == 1), (real)(min_i == 2));
+ const Vec3 x = y^h.v;
+
+ // Use reduced vector r instead of p
+ Vec3 r = { x | q.v, y | q.v, q.w*(y | y) }; // (x|x) = (y|y) = square of plane basis scale
+
+ // If r == 0 (within epsilon), then it is a direction vector, and we have a bounded solution
+ if ((r | r) <= eps2) r.z = 1;
+
+ // Create plane equations in the h plane. These will not be normalized in general.
+ int N = 0; // Plane count in h subspace
+ Vec3 R[3]; // Planes in h subspace
+ real recip_n2[3]; // Plane normal vector reciprocal lengths squared
+ real delta[3]; // Signed distance of objective to the planes
+ int index[3]; // Keep track of original plane indices
+ for (int i = 0; i < plane_count - 1; ++i)
+ {
+ const Vec3& vi = S[i].v;
+ const real cos_theta = h.v | vi;
+ R[N] = vec3(x | vi, y | vi, S[i].w - h.w*cos_theta);
+ index[N] = i;
+ const real n2 = R[N].x*R[N].x + R[N].y*R[N].y;
+ if (n2 >= eps2)
+ {
+ const real lin_norm = (real)1.5 - (real)0.5*n2; // 1st-order approximation to 1/sqrt(n2) expanded about n2 = 1
+ R[N] = lin_norm*R[N]; // We don't need normalized plane equations, but rescaling (even with an approximate normalization) gives better numerical behavior
+ recip_n2[N] = 1 / (R[N].x*R[N].x + R[N].y*R[N].y);
+ delta[N] = r | R[N];
+ ++N; // Keep this plane
+ }
+ else if (cos_theta < 0) return false; // Parallel cases are redundant and rejected, anti-parallel cases are 1D voids
+ }
+
+ // Now work with the N-sized R array of half-spaces in the h plane
+ switch (N)
+ {
+ case 1: one_plane :
+ if (delta[0] < 0) N = 0; // S[0] is redundant, eliminate it
+ else project2D(r, R[0], delta[0], recip_n2[0], eps2);
+ break;
+ case 2: two_planes :
+ if (delta[0] < 0 && delta[1] < 0) N = 0; // S[0] and S[1] are redundant, eliminate them
+ else
+ {
+ const int max_d_index = (int)frac_gt(delta[1], recip_n2[1], delta[0], recip_n2[0]);
+ project2D(r, R[max_d_index], delta[max_d_index], recip_n2[max_d_index], eps2);
+ const int min_d_index = max_d_index ^ 1;
+ const real new_delta_min = r | R[min_d_index];
+ if (new_delta_min < 0)
+ {
+ index[0] = index[max_d_index];
+ N = 1; // S[min_d_index] is redundant, eliminate it
+ }
+ else
+ {
+ // Set r to the intersection of R[0] and R[1] and keep both
+ r = perp(R[0], R[1]);
+ if (r.z*r.z*recip_n2[0] * recip_n2[1] < eps2)
+ {
+ if (R[0].x*R[1].x + R[0].y*R[1].y < 0) return false; // 2D void found
+ goto one_plane;
+ }
+ r = (1 / r.z)*r; // We could just as well multiply r by sgn(r.z); we just need to ensure r.z > 0
+ }
+ }
+ break;
+ case 3:
+ if (delta[0] < 0 && delta[1] < 0 && delta[2] < 0) N = 0; // S[0], S[1], and S[2] are redundant, eliminate them
+ else
+ {
+ const Vec3 row_x = { R[0].x, R[1].x, R[2].x };
+ const Vec3 row_y = { R[0].y, R[1].y, R[2].y };
+ const Vec3 row_w = { R[0].z, R[1].z, R[2].z };
+ const Vec3 cof_w = perp(row_x, row_y);
+ const bool detR_pos = (row_w | cof_w) > 0;
+ const int nrw_sgn0 = cof_w.x*cof_w.x*recip_n2[1] * recip_n2[2] < eps2 ? 0 : (((int)((cof_w.x > 0) == detR_pos) << 1) - 1);
+ const int nrw_sgn1 = cof_w.y*cof_w.y*recip_n2[2] * recip_n2[0] < eps2 ? 0 : (((int)((cof_w.y > 0) == detR_pos) << 1) - 1);
+ const int nrw_sgn2 = cof_w.z*cof_w.z*recip_n2[0] * recip_n2[1] < eps2 ? 0 : (((int)((cof_w.z > 0) == detR_pos) << 1) - 1);
+
+ if ((nrw_sgn0 | nrw_sgn1 | nrw_sgn2) >= 0) return false; // 3D void found
+
+ const int positive_width_count = ((nrw_sgn0 >> 1) & 1) + ((nrw_sgn1 >> 1) & 1) + ((nrw_sgn2 >> 1) & 1);
+ if (positive_width_count == 1)
+ {
+ // A single positive width results from a redundant plane. Eliminate it and peform N = 2 calculation.
+ const int pos_width_index = ((nrw_sgn1 >> 1) & 1) | (nrw_sgn2 & 2); // Calculates which index corresponds to the positive-width side
+ R[pos_width_index] = R[2];
+ recip_n2[pos_width_index] = recip_n2[2];
+ delta[pos_width_index] = delta[2];
+ index[pos_width_index] = index[2];
+ N = 2;
+ goto two_planes;
+ }
+
+ // Find the max dot product of r and R[i]/|R_normal[i]|. For numerical accuracy when the angle between r and the i^{th} plane normal is small, we take some care below:
+ const int max_d_index = r.z != 0
+ ? index_of_max_frac(delta[0], recip_n2[0], delta[1], recip_n2[1], delta[2], recip_n2[2]) // displacement term resolves small-angle ambiguity, just use dot product
+ : index_of_max_sgn_sq(delta[0], -sq(r.x*R[0].y - r.y*R[0].x)*recip_n2[0], delta[1], -sq(r.x*R[1].y - r.y*R[1].x)*recip_n2[1], delta[2], -sq(r.x*R[2].y - r.y*R[2].x)*recip_n2[2]); // No displacement term. Use wedge product to find the sine of the angle.
+
+ // Project r onto max-d plane
+ project2D(r, R[max_d_index], delta[max_d_index], recip_n2[max_d_index], eps2);
+ N = 1; // Unless we use a vertex in the loop below
+ const int index_max = index[max_d_index];
+
+ // The number of finite widths should be >= 2. If not, it should be 0, but in any case it implies three parallel lines in the plane, which we should not have here.
+ // If we do have three parallel lines (# of finite widths < 2), we've picked the line corresponding to the half-plane farthest from r, which is correct.
+ const int finite_width_count = (nrw_sgn0 & 1) + (nrw_sgn1 & 1) + (nrw_sgn2 & 1);
+ if (finite_width_count >= 2)
+ {
+ const int i_remaining[2] = { (1 << max_d_index) & 3, (3 >> max_d_index) ^ 1 }; // = {(max_d_index+1)%3, (max_d_index+2)%3}
+ const int i_select = (int)frac_gt(delta[i_remaining[1]], recip_n2[i_remaining[1]], delta[i_remaining[0]], recip_n2[i_remaining[0]]); // Select the greater of the remaining dot products
+ for (int i = 0; i < 2; ++i)
+ {
+ const int j = i_remaining[i_select^i]; // i = 0 => the next-greatest, i = 1 => the least
+ if ((r | R[j]) >= 0)
+ {
+ r = perp(R[max_d_index], R[j]);
+ r = (1 / r.z)*r; // We could just as well multiply r by sgn(r.z); we just need to ensure r.z > 0
+ index[1] = index[j];
+ N = 2;
+ break;
+ }
+ }
+ }
+
+ index[0] = index_max;
+ }
+ break;
+ }
+
+ // Transform r back to 3D space
+ p = vec4(r.x*x + r.y*y + (-r.z*h.w)*h.v, r.z);
+
+ // Pack S array with kept planes
+ if (N < 2 || index[1] != 0) { for (int i = 0; i < N; ++i) S[i] = S[index[i]]; } // Safe to copy columns in order
+ else { const Vec4 temp = S[0]; S[0] = S[index[0]]; S[1] = temp; } // Otherwise use temp storage to avoid overwrite
+ S[N] = h;
+ plane_count = N + 1;
+
+ return true;
+}
+
+
+// Performs the VS algorithm for D = 3
+inline int vs3d_test(VS3D_Halfspace_Set& halfspace_set, real* q = nullptr)
+{
+ // Objective = q if it is not NULL, otherwise it is the origin represented in homogeneous coordinates
+ const Vec4 objective = q ? (q[3] != 0 ? vec4((1 / q[3])*vec3(q[0], q[1], q[2]), 1) : *(Vec4*)q) : vec4(vec3(0, 0, 0), 1);
+
+ // Tolerance for 3D void simplex algorithm
+ const real eps_f = (real)1 / (sizeof(real) == 4 ? (1L << 23) : (1LL << 52)); // Floating-point epsilon
+#if VS3D_HIGH_ACCURACY || REAL_DOUBLE
+ const real eps = 8 * eps_f;
+#else
+ const real eps = 80 * eps_f;
+#endif
+ const real eps2 = eps*eps; // Using epsilon squared
+
+ // Maximum allowed iterations of main loop. If exceeded, error code is returned
+ const int max_iteration_count = 50;
+
+ // State
+ Vec4 S[4]; // Up to 4 planes
+ int plane_count = 0; // Number of valid planes
+ Vec4 p = objective; // Test point, initialized to objective
+
+ // Default result, changed to valid result if found in loop below
+ int result = -1;
+
+ // Iterate until a stopping condition is met or the maximum number of iterations is reached
+ for (int i = 0; result < 0 && i < max_iteration_count; ++i)
+ {
+ Vec4& plane = S[plane_count++];
+ real delta = halfspace_set.farthest_halfspace(&plane.v.x, &p.v.x);
+#if VS3D_UNNORMALIZED_PLANE_HANDLING != 0
+ const real recip_norm = vs3d_recip_sqrt(plane.v | plane.v);
+ plane = vec4(recip_norm*plane.v, recip_norm*plane.w);
+ delta *= recip_norm;
+#endif
+ if (delta <= 0 || delta*delta <= eps2*(p | p)) result = 1; // Intersection found
+ else if (!vs3d_update(p, S, plane_count, objective, eps2)) result = 0; // Void simplex found
+ }
+
+ // If q is given, fill it with the solution (normalize p.w if it is not zero)
+ if (q) *(Vec4*)q = (p.w != 0) ? vec4((1 / p.w)*p.v, 1) : p;
+
+ return result;
+}
+
+} // namespace VSA
+
+} // namespace Blast
+} // namespace Nv
+
+
+#endif // ifndef NVBLASTEXTAUTHORINGVSA_H