3 This file is part of R²C²
4 Copyright © 2010 Mikkosoft Productions, Mikko Rasa
5 Distributed under the GPL
10 #include <msp/gl/technique.h>
11 #include "catalogue.h"
12 #include "tracktype.h"
19 bool compare_z(const R2C2::Point &p1, const R2C2::Point &p2)
24 template<typename Iter>
25 Iter graham_scan(Iter begin, Iter end)
27 // http://en.wikipedia.org/wiki/Graham_scan
29 // Find point with lowest X coordinate
30 R2C2::Point lowest = *begin;
31 for(Iter i=begin; i!=end; ++i)
32 if(i->x<lowest.x || (i->x==lowest.x && i->y>lowest.y))
35 // Compute tangents and sort points
36 for(Iter i=begin; i!=end; ++i)
37 i->z = (i->x==lowest.x ? 1e5/(i->y-lowest.y-1) : (i->y-lowest.y)/(i->x-lowest.x));
38 sort(begin, end, compare_z);
40 for(Iter k=begin, i=k++, j=k++;; )
42 // Compute winding by cross product
43 float turn = (j->x-i->x)*(k->y-j->y) - (k->x-j->x)*(j->y-i->y);
47 // Right turn - throw the middle point away
48 // Special case for collinear vertices in the beginning
56 // Left turn - store the middle point and advance
62 // Cycle back to beginning and terminate after checking the last point
74 TrackType3D::TrackType3D(Catalogue3D &cat3d, const TrackType &tt):
76 mesh((GL::NORMAL3, GL::TEXCOORD2, GL::VERTEX3))
78 const Catalogue &cat = cat3d.get_catalogue();
79 const vector<TrackPart> &parts = tt.get_parts();
81 const Profile &ballast_profile = cat.get_ballast_profile();
82 const Point &ballast_min = ballast_profile.get_min_coords();
83 const Point &ballast_max = ballast_profile.get_max_coords();
84 float ballast_h = ballast_max.y-ballast_min.y;
86 const Profile &rail_profile = cat.get_rail_profile();
87 const Point &rail_min = rail_profile.get_min_coords();
88 const Point &rail_max = rail_profile.get_max_coords();
89 float rail_h = rail_max.y-rail_min.y;
91 float gauge = cat.get_gauge();
95 GL::MeshBuilder bld(mesh);
96 bld.texcoord(0.25, 0.5);
97 for(vector<TrackPart>::const_iterator i=parts.begin(); i!=parts.end(); ++i)
98 build_part(*i, ballast_profile, Point(0, -ballast_min.y), bld, index);
100 bld.texcoord(0.75, 0.5);
101 float y = ballast_h-rail_min.y;
102 for(vector<TrackPart>::const_iterator i=parts.begin(); i!=parts.end(); ++i)
103 build_part(*i, rail_profile, Point(-gauge/2-rail_max.x, y), bld, index);
104 for(vector<TrackPart>::const_iterator i=parts.begin(); i!=parts.end(); ++i)
105 build_part(*i, rail_profile, Point(gauge/2-rail_min.x, y), bld, index);
108 mesh.set_winding(&GL::WindingTest::counterclockwise());
109 object.set_mesh(&mesh);
110 object.set_technique(catalogue.get<GL::Technique>(cat.get_track_technique()));
112 unsigned paths = tt.get_paths();
113 for(unsigned i=0; paths; ++i, paths>>=1)
118 m = new GL::Mesh(GL::VERTEX3);
119 GL::MeshBuilder bld(*m);
121 for(vector<TrackPart>::const_iterator j=parts.begin(); j!=parts.end(); ++j)
123 build_part(*j, cat.get_path_profile(), Point(0, ballast_h+1.5*rail_h), bld, index);
125 path_meshes.push_back(m);
128 min_z = max_z = border.front().z;
129 for(vector<Point>::iterator i=border.begin(); i!=border.end(); ++i)
131 min_z = min(min_z, i->z);
132 max_z = max(max_z, i->z);
134 border.erase(graham_scan(border.begin(), border.end()), border.end());
137 TrackType3D::~TrackType3D()
139 for(vector<GL::Mesh *>::iterator i=path_meshes.begin(); i!=path_meshes.end(); ++i)
143 void TrackType3D::get_bounds(float angle, Point &minp, Point &maxp) const
145 float c = cos(-angle);
146 float s = sin(-angle);
148 minp = maxp = Point();
152 for(vector<Point>::const_iterator i=border.begin(); i!=border.end(); ++i)
154 float x = c*i->x-s*i->y;
155 float y = s*i->x+c*i->y;
157 minp.x = min(minp.x, x);
158 minp.y = min(minp.y, y);
159 maxp.x = max(maxp.x, x);
160 maxp.y = max(maxp.y, y);
164 const GL::Mesh &TrackType3D::get_path_mesh(unsigned p) const
166 if(p>=path_meshes.size() || !path_meshes[p])
167 throw InvalidParameterValue("Invalid path");
168 return *path_meshes[p];
171 void TrackType3D::build_part(const TrackPart &part, const Profile &profile, const Point &offset, GL::MeshBuilder &bld, unsigned &base_index)
173 float plen = part.get_length();
174 unsigned nsegs = (part.is_curved() ? static_cast<unsigned>(plen*32)+1 : 1);
176 unsigned n_points = profile.get_n_points();
177 for(unsigned i=0; i<=nsegs; ++i)
179 TrackPoint basep = part.get_point(i*plen/nsegs);
180 float c = cos(basep.dir);
181 float s = sin(basep.dir);
184 for(unsigned j=0; j<n_points; ++j)
186 // TODO: smoothing - only duplicate vertex if the angle is large enough
188 p = profile.get_point(j);
189 p.z = basep.pos.z+p.y+offset.y;
190 p.y = basep.pos.y-c*(p.x+offset.x);
191 p.x = basep.pos.x+s*(p.x+offset.x);
193 bld.vertex(p.x, p.y, p.z);
197 Point n = profile.get_edge_normal(j);
198 bld.normal(s*n.x, -c*n.x, n.y);
199 bld.vertex(p.x, p.y, p.z);
206 for(unsigned i=0; i+1<n_points; ++i)
208 bld.begin(GL::TRIANGLE_STRIP);
209 for(unsigned j=0; j<=nsegs; ++j)
211 unsigned k = (j*(n_points-1)+i)*2;
212 bld.element(base_index+k+1);
213 bld.element(base_index+k);
218 base_index += (nsegs+1)*(n_points-1)*2;