/*************************************************************************/ /* geometry.h */ /*************************************************************************/ /* This file is part of: */ /* GODOT ENGINE */ /* http://www.godotengine.org */ /*************************************************************************/ /* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */ /* */ /* 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 GEOMETRY_H #define GEOMETRY_H #include "vector3.h" #include "face3.h" #include "dvector.h" #include "math_2d.h" #include "vector.h" #include "print_string.h" #include "object.h" #include "triangulate.h" /** @author Juan Linietsky */ class Geometry { Geometry(); public: static float get_closest_points_between_segments( const Vector2& p1,const Vector2& q1, const Vector2& p2,const Vector2& q2, Vector2& c1, Vector2& c2) { Vector2 d1 = q1 - p1; // Direction vector of segment S1 Vector2 d2 = q2 - p2; // Direction vector of segment S2 Vector2 r = p1 - p2; float a = d1.dot(d1); // Squared length of segment S1, always nonnegative float e = d2.dot(d2); // Squared length of segment S2, always nonnegative float f = d2.dot(r); float s,t; // Check if either or both segments degenerate into points if (a <= CMP_EPSILON && e <= CMP_EPSILON) { // Both segments degenerate into points c1 = p1; c2 = p2; return Math::sqrt((c1 - c2).dot(c1 - c2)); } if (a <= CMP_EPSILON) { // First segment degenerates into a point s = 0.0f; t = f / e; // s = 0 => t = (b*s + f) / e = f / e t = CLAMP(t, 0.0f, 1.0f); } else { float c = d1.dot(r); if (e <= CMP_EPSILON) { // Second segment degenerates into a point t = 0.0f; s = CLAMP(-c / a, 0.0f, 1.0f); // t = 0 => s = (b*t - c) / a = -c / a } else { // The general nondegenerate case starts here float b = d1.dot(d2); float denom = a*e-b*b; // Always nonnegative // If segments not parallel, compute closest point on L1 to L2 and // clamp to segment S1. Else pick arbitrary s (here 0) if (denom != 0.0f) { s = CLAMP((b*f - c*e) / denom, 0.0f, 1.0f); } else s = 0.0f; // Compute point on L2 closest to S1(s) using // t = Dot((P1 + D1*s) - P2,D2) / Dot(D2,D2) = (b*s + f) / e t = (b*s + f) / e; //If t in [0,1] done. Else clamp t, recompute s for the new value // of t using s = Dot((P2 + D2*t) - P1,D1) / Dot(D1,D1)= (t*b - c) / a // and clamp s to [0, 1] if (t < 0.0f) { t = 0.0f; s = CLAMP(-c / a, 0.0f, 1.0f); } else if (t > 1.0f) { t = 1.0f; s = CLAMP((b - c) / a, 0.0f, 1.0f); } } } c1 = p1 + d1 * s; c2 = p2 + d2 * t; return Math::sqrt((c1 - c2).dot(c1 - c2)); } static void get_closest_points_between_segments(const Vector3& p1,const Vector3& p2,const Vector3& q1,const Vector3& q2,Vector3& c1, Vector3& c2) { //do the function 'd' as defined by pb. I think is is dot product of some sort #define d_of(m,n,o,p) ( (m.x - n.x) * (o.x - p.x) + (m.y - n.y) * (o.y - p.y) + (m.z - n.z) * (o.z - p.z) ) //caluclate the parpametric position on the 2 curves, mua and mub float mua = ( d_of(p1,q1,q2,q1) * d_of(q2,q1,p2,p1) - d_of(p1,q1,p2,p1) * d_of(q2,q1,q2,q1) ) / ( d_of(p2,p1,p2,p1) * d_of(q2,q1,q2,q1) - d_of(q2,q1,p2,p1) * d_of(q2,q1,p2,p1) ); float mub = ( d_of(p1,q1,q2,q1) + mua * d_of(q2,q1,p2,p1) ) / d_of(q2,q1,q2,q1); //clip the value between [0..1] constraining the solution to lie on the original curves if (mua < 0) mua = 0; if (mub < 0) mub = 0; if (mua > 1) mua = 1; if (mub > 1) mub = 1; c1 = p1.linear_interpolate(p2,mua); c2 = q1.linear_interpolate(q2,mub); } static float get_closest_distance_between_segments( const Vector3& p_from_a,const Vector3& p_to_a, const Vector3& p_from_b,const Vector3& p_to_b) { Vector3 u = p_to_a - p_from_a; Vector3 v = p_to_b - p_from_b; Vector3 w = p_from_a - p_to_a; real_t a = u.dot(u); // always >= 0 real_t b = u.dot(v); real_t c = v.dot(v); // always >= 0 real_t d = u.dot(w); real_t e = v.dot(w); real_t D = a*c - b*b; // always >= 0 real_t sc, sN, sD = D; // sc = sN / sD, default sD = D >= 0 real_t tc, tN, tD = D; // tc = tN / tD, default tD = D >= 0 // compute the line parameters of the two closest points if (D < CMP_EPSILON) { // the lines are almost parallel sN = 0.0; // force using point P0 on segment S1 sD = 1.0; // to prevent possible division by 0.0 later tN = e; tD = c; } else { // get the closest points on the infinite lines sN = (b*e - c*d); tN = (a*e - b*d); if (sN < 0.0) { // sc < 0 => the s=0 edge is visible sN = 0.0; tN = e; tD = c; } else if (sN > sD) { // sc > 1 => the s=1 edge is visible sN = sD; tN = e + b; tD = c; } } if (tN < 0.0) { // tc < 0 => the t=0 edge is visible tN = 0.0; // recompute sc for this edge if (-d < 0.0) sN = 0.0; else if (-d > a) sN = sD; else { sN = -d; sD = a; } } else if (tN > tD) { // tc > 1 => the t=1 edge is visible tN = tD; // recompute sc for this edge if ((-d + b) < 0.0) sN = 0; else if ((-d + b) > a) sN = sD; else { sN = (-d + b); sD = a; } } // finally do the division to get sc and tc sc = (Math::abs(sN) < CMP_EPSILON ? 0.0 : sN / sD); tc = (Math::abs(tN) < CMP_EPSILON ? 0.0 : tN / tD); // get the difference of the two closest points Vector3 dP = w + (sc * u) - (tc * v); // = S1(sc) - S2(tc) return dP.length(); // return the closest distance } static inline bool ray_intersects_triangle( const Vector3& p_from, const Vector3& p_dir, const Vector3& p_v0,const Vector3& p_v1,const Vector3& p_v2,Vector3* r_res=0) { Vector3 e1=p_v1-p_v0; Vector3 e2=p_v2-p_v0; Vector3 h = p_dir.cross(e2); real_t a =e1.dot(h); if (a>-CMP_EPSILON && a < CMP_EPSILON) // parallel test return false; real_t f=1.0/a; Vector3 s=p_from-p_v0; real_t u = f * s.dot(h); if ( u< 0.0 || u > 1.0) return false; Vector3 q=s.cross(e1); real_t v = f * p_dir.dot(q); if (v < 0.0 || u + v > 1.0) return false; // at this stage we can compute t to find out where // the intersection point is on the line real_t t = f * e2.dot(q); if (t > 0.00001) {// ray intersection if (r_res) *r_res=p_from+p_dir*t; return true; } else // this means that there is a line intersection // but not a ray intersection return false; } static inline bool segment_intersects_triangle( const Vector3& p_from, const Vector3& p_to, const Vector3& p_v0,const Vector3& p_v1,const Vector3& p_v2,Vector3* r_res=0) { Vector3 rel=p_to-p_from; Vector3 e1=p_v1-p_v0; Vector3 e2=p_v2-p_v0; Vector3 h = rel.cross(e2); real_t a =e1.dot(h); if (a>-CMP_EPSILON && a < CMP_EPSILON) // parallel test return false; real_t f=1.0/a; Vector3 s=p_from-p_v0; real_t u = f * s.dot(h); if ( u< 0.0 || u > 1.0) return false; Vector3 q=s.cross(e1); real_t v = f * rel.dot(q); if (v < 0.0 || u + v > 1.0) return false; // at this stage we can compute t to find out where // the intersection point is on the line real_t t = f * e2.dot(q); if (t > CMP_EPSILON && t<=1.0) {// ray intersection if (r_res) *r_res=p_from+rel*t; return true; } else // this means that there is a line intersection // but not a ray intersection return false; } static inline bool segment_intersects_sphere( const Vector3& p_from, const Vector3& p_to, const Vector3& p_sphere_pos,real_t p_sphere_radius,Vector3* r_res=0,Vector3 *r_norm=0) { Vector3 sphere_pos=p_sphere_pos-p_from; Vector3 rel=(p_to-p_from); float rel_l=rel.length(); if (rel_l=p_sphere_radius) return false; float inters_d2=p_sphere_radius*p_sphere_radius - ray_distance*ray_distance; float inters_d=sphere_d; if (inters_d2>=CMP_EPSILON) inters_d-=Math::sqrt(inters_d2); // check in segment if (inters_d<0 || inters_d>rel_l) return false; Vector3 result=p_from+normal*inters_d;; if (r_res) *r_res=result; if (r_norm) *r_norm=(result-p_sphere_pos).normalized(); return true; } static inline bool segment_intersects_cylinder( const Vector3& p_from, const Vector3& p_to, float p_height,float p_radius,Vector3* r_res=0,Vector3 *r_norm=0) { Vector3 rel=(p_to-p_from); float rel_l=rel.length(); if (rel_l=p_radius) return false; // too far away // convert to 2D float w2=p_radius*p_radius-dist*dist; if (w2 box_end || seg_to < box_begin) return false; real_t length=seg_to-seg_from; cmin = (seg_from < box_begin)?((box_begin - seg_from)/length):0; cmax = (seg_to > box_end)?((box_end - seg_from)/length):1; } else { if (seg_to > box_end || seg_from < box_begin) return false; real_t length=seg_to-seg_from; cmin = (seg_from > box_end)?(box_end - seg_from)/length:0; cmax = (seg_to < box_begin)?(box_begin - seg_from)/length:1; } if (cmin > min) { min = cmin; axis=i; } if (cmax < max) max = cmax; if (max < min) return false; } // convert to 3D again Vector3 result = p_from + (rel*min); Vector3 res_normal = result; if (axis==0) { res_normal.z=0; } else { res_normal.x=0; res_normal.y=0; } res_normal.normalize(); if (r_res) *r_res=result; if (r_norm) *r_norm=res_normal; return true; } static bool segment_intersects_convex(const Vector3& p_from, const Vector3& p_to,const Plane* p_planes, int p_plane_count,Vector3 *p_res, Vector3 *p_norm) { real_t min=-1e20,max=1e20; Vector3 rel=p_to-p_from; real_t rel_l=rel.length(); if (rel_l0) { //backwards facing plane if (distmin) { min=dist; min_index=i; } } } if (max<=min || min<0 || min>rel_l || min_index==-1) // exit conditions return false; // no intersection if (p_res) *p_res=p_from+dir*min; if (p_norm) *p_norm=p_planes[min_index].normal; return true; } static Vector3 get_closest_point_to_segment(const Vector3& p_point, const Vector3 *p_segment) { Vector3 p=p_point-p_segment[0]; Vector3 n=p_segment[1]-p_segment[0]; float l =n.length(); if (l<1e-10) return p_segment[0]; // both points are the same, just give any n/=l; float d=n.dot(p); if (d<=0.0) return p_segment[0]; // before first point else if (d>=l) return p_segment[1]; // after first point else return p_segment[0]+n*d; // inside } static Vector3 get_closest_point_to_segment_uncapped(const Vector3& p_point, const Vector3 *p_segment) { Vector3 p=p_point-p_segment[0]; Vector3 n=p_segment[1]-p_segment[0]; float l =n.length(); if (l<1e-10) return p_segment[0]; // both points are the same, just give any n/=l; float d=n.dot(p); return p_segment[0]+n*d; // inside } static Vector2 get_closest_point_to_segment_2d(const Vector2& p_point, const Vector2 *p_segment) { Vector2 p=p_point-p_segment[0]; Vector2 n=p_segment[1]-p_segment[0]; float l =n.length(); if (l<1e-10) return p_segment[0]; // both points are the same, just give any n/=l; float d=n.dot(p); if (d<=0.0) return p_segment[0]; // before first point else if (d>=l) return p_segment[1]; // after first point else return p_segment[0]+n*d; // inside } static Vector2 get_closest_point_to_segment_uncapped_2d(const Vector2& p_point, const Vector2 *p_segment) { Vector2 p=p_point-p_segment[0]; Vector2 n=p_segment[1]-p_segment[0]; float l =n.length(); if (l<1e-10) return p_segment[0]; // both points are the same, just give any n/=l; float d=n.dot(p); return p_segment[0]+n*d; // inside } static bool segment_intersects_segment_2d(const Vector2& p_from_a,const Vector2& p_to_a,const Vector2& p_from_b,const Vector2& p_to_b,Vector2* r_result) { Vector2 B = p_to_a-p_from_a; Vector2 C = p_from_b-p_from_a; Vector2 D = p_to_b-p_from_a; real_t ABlen = B.dot(B); if (ABlen<=0) return false; Vector2 Bn = B/ABlen; C = Vector2( C.x*Bn.x + C.y*Bn.y, C.y*Bn.x - C.x*Bn.y ); D = Vector2( D.x*Bn.x + D.y*Bn.y, D.y*Bn.x - D.x*Bn.y ); if ((C.y<0 && D.y<0) || (C.y>=0 && D.y>=0)) return false; float ABpos=D.x+(C.x-D.x)*D.y/(D.y-C.y); // Fail if segment C-D crosses line A-B outside of segment A-B. if (ABpos<0 || ABpos>1.0) return false; // (4) Apply the discovered position to line A-B in the original coordinate system. if (r_result) *r_result=p_from_a+B*ABpos; return true; } static inline bool point_in_projected_triangle(const Vector3& p_point,const Vector3& p_v1,const Vector3& p_v2,const Vector3& p_v3) { Vector3 face_n = (p_v1-p_v3).cross(p_v1-p_v2); Vector3 n1 = (p_point-p_v3).cross(p_point-p_v2); if (face_n.dot(n1)<0) return false; Vector3 n2 = (p_v1-p_v3).cross(p_v1-p_point); if (face_n.dot(n2)<0) return false; Vector3 n3 = (p_v1-p_point).cross(p_v1-p_v2); if (face_n.dot(n3)<0) return false; return true; } static inline bool triangle_sphere_intersection_test(const Vector3 *p_triangle,const Vector3& p_normal,const Vector3& p_sphere_pos, real_t p_sphere_radius,Vector3& r_triangle_contact,Vector3& r_sphere_contact) { float d=p_normal.dot(p_sphere_pos)-p_normal.dot(p_triangle[0]); if (d > p_sphere_radius || d < -p_sphere_radius) // not touching the plane of the face, return return false; Vector3 contact=p_sphere_pos - (p_normal*d); /** 2nd) TEST INSIDE TRIANGLE **/ if (Geometry::point_in_projected_triangle(contact,p_triangle[0],p_triangle[1],p_triangle[2])) { r_triangle_contact=contact; r_sphere_contact=p_sphere_pos-p_normal*p_sphere_radius; //printf("solved inside triangle\n"); return true; } /** 3rd TEST INSIDE EDGE CYLINDERS **/ const Vector3 verts[4]={p_triangle[0],p_triangle[1],p_triangle[2],p_triangle[0]}; // for() friendly for (int i=0;i<3;i++) { // check edge cylinder Vector3 n1=verts[i]-verts[i+1]; Vector3 n2=p_sphere_pos-verts[i+1]; ///@TODO i could discard by range here to make the algorithm quicker? dunno.. // check point within cylinder radius Vector3 axis =n1.cross(n2).cross(n1); axis.normalize(); // ugh float ad=axis.dot(n2); if (ABS(ad)>p_sphere_radius) { // no chance with this edge, too far away continue; } // check point within edge capsule cylinder /** 4th TEST INSIDE EDGE POINTS **/ float sphere_at = n1.dot(n2); if (sphere_at>=0 && sphere_at= 0 && res1 <= 1) ? res1 : -1; } static Vector triangulate_polygon(const Vector& p_polygon) { Vector triangles; if (!Triangulate::triangulate(p_polygon,triangles)) return Vector(); //fail return triangles; } static Vector< Vector > (*_decompose_func)(const Vector& p_polygon); static Vector< Vector > decompose_polygon(const Vector& p_polygon) { if (_decompose_func) return _decompose_func(p_polygon); return Vector< Vector >(); } static DVector< DVector< Face3 > > separate_objects( DVector< Face3 > p_array ); static DVector< Face3 > wrap_geometry( DVector< Face3 > p_array, float *p_error=NULL ); ///< create a "wrap" that encloses the given geometry struct MeshData { struct Face { Plane plane; Vector indices; }; Vector faces; struct Edge { int a,b; }; Vector edges; Vector< Vector3 > vertices; void optimize_vertices(); }; static MeshData build_convex_mesh(const DVector &p_planes); static DVector build_sphere_planes(float p_radius, int p_lats, int p_lons, Vector3::Axis p_axis=Vector3::AXIS_Z); static DVector build_box_planes(const Vector3& p_extents); static DVector build_cylinder_planes(float p_radius, float p_height, int p_sides, Vector3::Axis p_axis=Vector3::AXIS_Z); static DVector build_capsule_planes(float p_radius, float p_height, int p_sides, int p_lats, Vector3::Axis p_axis=Vector3::AXIS_Z); }; #endif