10 static float delta_angle(float a, float b);
15 meshing_valid = false;
21 int ngears = (int)gears.size();
22 for(int i=0; i<ngears; i++) {
33 void Machine::add_gear(Gear *g)
35 if(gearidx.find(g) != gearidx.end()) {
36 return; // already have this gear
38 gearidx[g] = gears.size();
40 meshing_valid = false;
43 void Machine::add_motor(int gearidx, float speed_hz)
51 int Machine::get_gear_index(Gear *g) const
53 std::map<Gear*, int>::const_iterator it = gearidx.find(g);
54 if(it == gearidx.end()) {
60 void Machine::invalidate_meshing()
62 meshing_valid = false;
65 void Machine::calc_meshing()
67 int ngears = (int)gears.size();
70 meshing = new bool*[ngears];
71 meshing[0] = new bool[ngears * ngears];
73 for(int i=1; i<ngears; i++) {
74 meshing[i] = meshing[i - 1] + ngears;
79 visited = new bool[ngears];
82 // we're going to need the planar position of each gear on its plane, so let's cache it
83 Vec3 *ppos = (Vec3*)alloca(ngears * sizeof *ppos);
84 for(int i=0; i<ngears; i++) {
85 ppos[i] = gears[i]->get_position();
88 for(int i=0; i<ngears; i++) {
89 for(int j=i; j<ngears; j++) {
90 meshing[i][j] = meshing[j][i] = false;
92 if(i == j || gears[i]->get_super() == gears[j] || gears[j]->get_super() == gears[i]) {
93 // don't attempt meshing if it's the same gear, or they are attached to each other
97 if(1.0 - fabs(dot(gears[i]->axis, gears[j]->axis)) < 1e-5) {
98 // co-planar, just check Z range after inverse-transforming to the XY plane
99 if(fabs(ppos[i].z - ppos[j].z) > (gears[i]->thickness + gears[j]->thickness) / 2.0) {
102 // Z interval match, check distance
103 float dsq = length_sq(ppos[i].xy() - ppos[j].xy());
105 float outer_rad_sum = gears[i]->radius + gears[j]->radius;
106 float inner_rad_sum = outer_rad_sum - gears[i]->teeth_length - gears[j]->teeth_length;
108 if(dsq <= outer_rad_sum * outer_rad_sum && dsq >= inner_rad_sum * inner_rad_sum) {
109 //printf("connecting co-planar gears %d - %d\n", i, j);
110 meshing[i][j] = meshing[j][i] = true;
114 /* TODO: not co-planar
115 * - calc line of intersection between the two planes
116 * - find distance of each gear to that line
123 // fix the initial angles so that teeth mesh as best as possible
124 // should work in one pass as long as the gear train is not impossible
125 for(int i=0; i<ngears; i++) {
126 /*float rnd = gears[i]->angle + gears[i]->get_angular_pitch() / 2.0;
127 float snap = rnd - fmod(rnd, gears[i]->get_angular_pitch());
128 gears[i]->set_angle(snap);*/
129 gears[i]->set_angular_offset(0);
132 for(int i=0; i<ngears; i++) {
133 for(int j=i; j<ngears; j++) {
137 Vec2 dir = normalize(ppos[j].xy() - ppos[i].xy());
138 float rel_angle = atan2(dir.y, dir.x);
140 float frac_i = fmod((gears[i]->init_angle + rel_angle) / gears[i]->get_angular_pitch() + 100.0, 1.0);
141 float frac_j = fmod((gears[j]->init_angle - rel_angle) / gears[j]->get_angular_pitch() + 100.0, 1.0);
142 assert(frac_i >= 0.0 && frac_j >= 0.0);
143 float delta = frac_j - frac_i;
145 float correction = 0.5 - delta;
146 float prev_offs = gears[j]->get_angular_offset();
147 gears[j]->set_angular_offset(prev_offs + correction * gears[j]->get_angular_pitch());
153 printf("meshing graph\n");
154 for(int i=0; i<ngears; i++) {
156 for(int j=0; j<ngears; j++) {
157 printf("| %d ", meshing[i][j] ? 1 : 0);
164 void Machine::update_gear(int idx, float angle)
166 Gear *gear = gears[idx];
169 if(delta_angle(angle, gear->angle) > 0.25 / gear->nteeth) {
170 fprintf(stderr, "warning: trying to transmit different values to gear %s (%d)\n",
171 gear->name.c_str(), idx);
177 gear->set_angle(angle);
180 // propagate to meshing gears (depth-first)
181 int ngears = (int)gears.size();
182 for(int i=0; i<ngears; i++) {
183 if(!meshing[idx][i]) continue;
186 float ratio = -(float)gear->nteeth / (float)gears[i]->nteeth;
187 update_gear(i, angle * ratio);
190 // propagate to rigidly attached gears
191 if(gear->supergear) {
192 int supidx = gearidx[gear->supergear];
193 update_gear(supidx, angle);
196 int nsub = (int)gear->subgears.size();
197 for(int i=0; i<nsub; i++) {
198 int subidx = gearidx[gear->subgears[i]];
199 update_gear(subidx, angle);
203 void Machine::update(float dt)
205 int ngears = (int)gears.size();
209 meshing_valid = true;
212 memset(visited, 0, ngears * sizeof *visited);
213 for(size_t i=0; i<motors.size(); i++) {
214 int gidx = motors[i].drive;
215 if(gidx < 0) continue;
217 update_gear(gidx, gears[gidx]->angle + dt * motors[i].speed);
221 void Machine::draw() const
223 for(size_t i=0; i<gears.size(); i++) {
227 float dcol[] = {0.4, 0.4, 0.4, 1.0};
228 float scol[] = {0, 0, 0, 0};
229 glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, dcol);
230 glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, scol);
234 glVertex3f(-300, -100, 300);
235 glVertex3f(300, -100, 300);
236 glVertex3f(300, -100, -300);
237 glVertex3f(-300, -100, -300);
241 Gear *Machine::intersect_gear(const Ray &ray, HitPoint *hitp) const
245 nearest.dist = FLT_MAX;
247 for(size_t i=0; i<gears.size(); i++) {
248 Vec3 pos = gears[i]->get_global_position();
249 float rad = gears[i]->radius;
251 Plane plane = Plane(pos, gears[i]->axis);
254 if(plane.intersect(ray, &hit) && hit.dist < nearest.dist &&
255 length_sq(hit.pos - pos) <= rad * rad) {
261 if(hitp) *hitp = nearest;
265 static float delta_angle(float a, float b)
267 float api = fmod(a + M_PI, 2.0 * M_PI);
268 float bpi = fmod(b + M_PI, 2.0 * M_PI);
269 return std::min(fabs(a - b), fabs(api - bpi));