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authorgit perforce import user <a@b>2016-10-25 12:29:14 -0600
committerSheikh Dawood Abdul Ajees <Sheikh Dawood Abdul Ajees>2016-10-25 18:56:37 -0500
commit3dfe2108cfab31ba3ee5527e217d0d8e99a51162 (patch)
treefa6485c169e50d7415a651bf838f5bcd0fd3bfbd /APEX_1.4/shared/internal/include/authoring/ApexGSA.h
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PhysX 3.4.0 Update @ 21294896 APEX 1.4.0 Update @ 21275617 [CL 21300167]
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+/*
+ * Copyright (c) 2008-2015, NVIDIA CORPORATION. All rights reserved.
+ *
+ * NVIDIA CORPORATION and its licensors retain all intellectual property
+ * and proprietary rights in and to this software, 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.
+ */
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+
+#ifndef APEX_GSA_H
+#define APEX_GSA_H
+
+
+#include "ApexCSGMath.h"
+
+#ifndef WITHOUT_APEX_AUTHORING
+
+namespace ApexCSG
+{
+namespace GSA
+{
+
+// Utility vector format translation
+inline physx::PxVec3 toPxVec3(const Vec4Real& p)
+{
+ return physx::PxVec3(static_cast<float>(p[0]), static_cast<float>(p[1]), static_cast<float>(p[2]));
+}
+
+
+/*** Compact implementation of the void simplex algorithm for D = 3 ***/
+
+typedef physx::PxF32 real;
+
+/*
+ The implementation of farthest_halfspace should return the half-space "most below" the given point. The point
+ is represented by a vector in projective coordinates, and its last element (point[3]) will not necessarily equal 1.
+ However, point[3] will be non-negative. The plane returned is the boundary of the half-space found, and is also
+ represented as a vector in projective coordinates (the coefficients of the plane equation). The plane vector
+ returned should have the greatest dot product with the input point.
+
+ plane = the returned half-space boundary
+ point = the input point
+ returns the dot product of point and plane
+*/
+struct VS3D_Halfspace_Set
+{
+ virtual real farthest_halfspace(real plane[4], const real point[4]) = 0;
+};
+
+
+#define VS3D_HIGH_ACCURACY 1
+#define VS3D_UNNORMALIZED_PLANE_HANDLING 0 // 0 = planes must be normalized, 1 = planes must be near-normalized, 2 = planes may be arbitrary
+#define REAL_DOUBLE 0
+
+
+#if VS3D_UNNORMALIZED_PLANE_HANDLING == 1
+// Returns approximation to 1/sqrt(x)
+inline real vs3d_recip_sqrt(real x)
+{
+ real y = (real)1.5 - (real)0.5*x;
+#if REAL_DOUBLE
+ y *= (real)1.5 - (real)0.5*x*y*y; // Perform another iteration for doubles, to handle the case where float-normalized normals are converted to double-precision
+#endif
+ return y;
+}
+#elif VS3D_UNNORMALIZED_PLANE_HANDLING == 2
+#include <cmath>
+inline real vs3d_recip_sqrt(real x) { return 1/sqrt(x); }
+#elif VS3D_UNNORMALIZED_PLANE_HANDLING != 0
+#error Unrecognized value given for VS3D_UNNORMALIZED_PLANE_HANDLING. Please set to 0, 1, or 2.
+#endif
+
+
+// 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 = NULL)
+{
+ // 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;
+
+ PX_ASSERT(result >= 0);
+
+ return result;
+}
+
+
+/*
+ Utility class derived from GSA::ConvexShape, to handle common implementations
+
+ PlaneIterator must have:
+ 1) a constructor which takes an object of type IteratorInitValues (either by value or refrence) in its constructor,
+ 2) a valid() method which returns a bool (true iff the plane() function can return a valid plane, see below),
+ 3) an inc() method to advance to the next plane, and
+ 4) a plane() method which returns a plane of type ApexCSG::Plane, either by value or reference (the plane will be copied).
+*/
+template<class PlaneIterator, class IteratorInitValues>
+class StaticConvexPolyhedron : public VS3D_Halfspace_Set
+{
+public:
+ virtual GSA::real farthest_halfspace(GSA::real plane[4], const GSA::real point[4])
+ {
+ plane[0] = plane[1] = plane[2] = 0.0f;
+ plane[3] = 1.0f;
+ Real greatest_s = -MAX_REAL;
+
+ for (PlaneIterator it(m_initValues); it.valid(); it.inc())
+ {
+ const Plane test = it.plane();
+ const Real s = point[0]*test[0] + point[1]*test[1] + point[2]*test[2] + point[3]*test[3];
+ if (s > greatest_s)
+ {
+ greatest_s = s;
+ for (int i = 0; i < 4; ++i)
+ {
+ plane[i] = (GSA::real)test[i];
+ }
+ }
+ }
+
+ // Return results
+ return (GSA::real)greatest_s;
+ }
+
+protected:
+ IteratorInitValues m_initValues;
+};
+
+}; // namespace GSA
+}; // namespace ApexCSG
+
+#endif // #ifndef WITHOUT_APEX_AUTHORING
+
+#endif // #ifndef APEX_GSA_H