git.maemo.org Git - navit-package/blob - navit/transform.c

   1 /**
   2  * Navit, a modular navigation system.
   3  * Copyright (C) 2005-2008 Navit Team
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * version 2 as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the
  16  * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  17  * Boston, MA  02110-1301, USA.
  18  */
  19
  20 #include <assert.h>
  21 #include <stdio.h>
  22 #include <math.h>
  23 #include <limits.h>
  24 #include <glib.h>
  25 #include <string.h>
  26 #include "config.h"
  27 #include "coord.h"
  28 #include "debug.h"
  29 #include "item.h"
  30 #include "map.h"
  31 #include "transform.h"
  32 #include "projection.h"
  33 #include "point.h"
  34
  35 #define POST_SHIFT 8
  36 /* #define ENABLE_ROLL */
  37
  38 struct transformation {
  39         int yaw;                /* Rotation angle */
  40         int pitch;
  41         int ddd;
  42         int m00,m01,m10,m11;    /* 2d transformation matrix */
  43         int xyscale;
  44         int m20,m21;            /* additional 3d parameters */
  45 #ifdef ENABLE_ROLL
  46         int roll;
  47         int m02,m12,m22;
  48         int hog;
  49         double im02,im12,im20,im21,im22;
  50 #endif
  51         double im00,im01,im10,im11;     /* inverse 2d transformation matrix */
  52         struct map_selection *map_sel;
  53         struct map_selection *screen_sel;
  54         struct point screen_center;
  55         int screen_dist;
  56         int offx,offy,offz;
  57         struct coord map_center;        /* Center of source rectangle */
  58         enum projection pro;
  59         double scale;           /* Scale factor */
  60         int scale_shift;
  61         int order;
  62 };
  63
  64 static void
  65 transform_setup_matrix(struct transformation *t)
  66 {
  67         double det;
  68         double fac;
  69         double yawc=cos(M_PI*t->yaw/180);
  70         double yaws=sin(M_PI*t->yaw/180);
  71         double pitchc=cos(-M_PI*t->pitch/180);
  72         double pitchs=sin(-M_PI*t->pitch/180);
  73 #ifdef ENABLE_ROLL
  74         double rollc=cos(M_PI*t->roll/180);
  75         double rolls=sin(M_PI*t->roll/180);
  76 #endif
  77
  78         int scale=t->scale;
  79         int order_dir=-1;
  80
  81         dbg(1,"yaw=%d pitch=%d center=0x%x,0x%x\n", t->yaw, t->pitch, t->map_center.x, t->map_center.y);
  82         t->scale_shift=0;
  83         t->order=14;
  84         if (t->scale >= 1) {
  85                 scale=t->scale;
  86         } else {
  87                 scale=1.0/t->scale;
  88                 order_dir=1;
  89         }
  90         while (scale > 1) {
  91                 if (order_dir < 0)
  92                         t->scale_shift++;
  93                 t->order+=order_dir;
  94                 scale >>= 1;
  95         }
  96         fac=(1 << POST_SHIFT) * (1 << t->scale_shift) / t->scale;
  97         dbg(1,"scale_shift=%d order=%d scale=%f fac=%f\n", t->scale_shift, t->order,t->scale,fac);
  98
  99 #ifdef ENABLE_ROLL
 100         t->m00=rollc*yawc*fac;
 101         t->m01=rollc*yaws*fac;
 102         t->m02=-rolls*fac;
 103         t->m10=(pitchs*rolls*yawc-pitchc*yaws)*(-fac);
 104         t->m11=(pitchs*rolls*yaws+pitchc*yawc)*(-fac);
 105         t->m12=pitchs*rollc*(-fac);
 106         t->m20=(pitchc*rolls*yawc+pitchs*yaws)*fac;
 107         t->m21=(pitchc*rolls*yaws-pitchs*yawc)*fac;
 108         t->m22=pitchc*rollc*fac;
 109 #else
 110         t->m00=yawc*fac;
 111         t->m01=yaws*fac;
 112         t->m10=(-pitchc*yaws)*(-fac);
 113         t->m11=pitchc*yawc*(-fac);
 114         t->m20=pitchs*yaws*fac;
 115         t->m21=(-pitchs*yawc)*fac;
 116 #endif
 117         t->offz=0;
 118         t->xyscale=1;
 119         t->ddd=0;
 120         t->offx=t->screen_center.x;
 121         t->offy=t->screen_center.y;
 122         if (t->pitch) {
 123                 t->ddd=1;
 124                 t->offz=t->screen_dist;
 125                 t->xyscale=t->offz;
 126         }
 127 #ifdef ENABLE_ROLL
 128         det=(double)t->m00*(double)t->m11*(double)t->m22+
 129             (double)t->m01*(double)t->m12*(double)t->m20+
 130             (double)t->m02*(double)t->m10*(double)t->m21-
 131             (double)t->m02*(double)t->m11*(double)t->m20-
 132             (double)t->m01*(double)t->m10*(double)t->m22-
 133             (double)t->m00*(double)t->m12*(double)t->m21;
 134
 135         t->im00=(t->m11*t->m22-t->m12*t->m21)/det;
 136         t->im01=(t->m02*t->m21-t->m01*t->m22)/det;
 137         t->im02=(t->m01*t->m12-t->m02*t->m11)/det;
 138         t->im10=(t->m12*t->m20-t->m10*t->m22)/det;
 139         t->im11=(t->m00*t->m22-t->m02*t->m20)/det;
 140         t->im12=(t->m02*t->m10-t->m00*t->m12)/det;
 141         t->im20=(t->m10*t->m21-t->m11*t->m20)/det;
 142         t->im21=(t->m01*t->m20-t->m00*t->m21)/det;
 143         t->im22=(t->m00*t->m11-t->m01*t->m10)/det;
 144 #else
 145         det=((double)t->m00*(double)t->m11-(double)t->m01*(double)t->m10);
 146         t->im00=t->m11/det;
 147         t->im01=-t->m01/det;
 148         t->im10=-t->m10/det;
 149         t->im11=t->m00/det;
 150 #endif
 151 }
 152
 153 struct transformation *
 154 transform_new(void)
 155 {
 156         struct transformation *this_;
 157
 158         this_=g_new0(struct transformation, 1);
 159         this_->screen_dist=100;
 160 #if 0
 161         this_->pitch=20;
 162 #endif
 163 #if 0
 164         this_->roll=30;
 165         this_->hog=1000;
 166 #endif
 167         transform_setup_matrix(this_);
 168         return this_;
 169 }
 170
 171 struct transformation *
 172 transform_dup(struct transformation *t)
 173 {
 174         struct transformation *ret=g_new0(struct transformation, 1);
 175         *ret=*t;
 176         return ret;
 177 }
 178
 179 static const double gar2geo_units = 360.0/(1<<24);
 180 static const double geo2gar_units = 1/(360.0/(1<<24));
 181
 182 void
 183 transform_to_geo(enum projection pro, struct coord *c, struct coord_geo *g)
 184 {
 185         switch (pro) {
 186         case projection_mg:
 187                 g->lng=c->x/6371000.0/M_PI*180;
 188                 g->lat=atan(exp(c->y/6371000.0))/M_PI*360-90;
 189                 break;
 190         case projection_garmin:
 191                 g->lng=c->x*gar2geo_units;
 192                 g->lat=c->y*gar2geo_units;
 193                 break;
 194         default:
 195                 break;
 196         }
 197 }
 198
 199 void
 200 transform_from_geo(enum projection pro, struct coord_geo *g, struct coord *c)
 201 {
 202         switch (pro) {
 203         case projection_mg:
 204                 c->x=g->lng*6371000.0*M_PI/180;
 205                 c->y=log(tan(M_PI_4+g->lat*M_PI/360))*6371000.0;
 206                 break;
 207         case projection_garmin:
 208                 c->x=g->lng*geo2gar_units;
 209                 c->y=g->lat*geo2gar_units;
 210                 break;
 211         default:
 212                 break;
 213         }
 214 }
 215
 216 void
 217 transform_from_to(struct coord *cfrom, enum projection from, struct coord *cto, enum projection to)
 218 {
 219         struct coord_geo g;
 220         transform_to_geo(from, cfrom, &g);
 221         transform_from_geo(to, &g, cto);
 222 }
 223
 224 void
 225 transform_geo_to_cart(struct coord_geo *geo, double a, double b, struct coord_geo_cart *cart)
 226 {
 227         double n,ee=1-b*b/(a*a);
 228         n = a/sqrt(1-ee*sin(geo->lat)*sin(geo->lat));
 229         cart->x=n*cos(geo->lat)*cos(geo->lng);
 230         cart->y=n*cos(geo->lat)*sin(geo->lng);
 231         cart->z=n*(1-ee)*sin(geo->lat);
 232 }
 233
 234 void
 235 transform_cart_to_geo(struct coord_geo_cart *cart, double a, double b, struct coord_geo *geo)
 236 {
 237         double lat,lati,n,ee=1-b*b/(a*a), lng = atan(cart->y/cart->x);
 238
 239         lat = atan(cart->z / sqrt((cart->x * cart->x) + (cart->y * cart->y)));
 240         do
 241         {
 242                 lati = lat;
 243
 244                 n = a / sqrt(1-ee*sin(lat)*sin(lat));
 245                 lat = atan((cart->z + ee * n * sin(lat)) / sqrt(cart->x * cart->x + cart->y * cart->y));
 246         }
 247         while (fabs(lat - lati) >= 0.000000000000001);
 248
 249         geo->lng=lng/M_PI*180;
 250         geo->lat=lat/M_PI*180;
 251 }
 252
 253
 254 void
 255 transform_datum(struct coord_geo *from, enum map_datum from_datum, struct coord_geo *to, enum map_datum to_datum)
 256 {
 257 }
 258
 259 int
 260 transform(struct transformation *t, enum projection pro, struct coord *c, struct point *p, int count, int unique, int width, int *width_return)
 261 {
 262         struct coord c1;
 263         int xcn, ycn;
 264         struct coord_geo g;
 265         int xc, yc, zc=0, xco=0, yco=0, zco=0;
 266         int xm,ym,zct;
 267         int zlimit=1000;
 268         int visible, visibleo=-1;
 269         int i,j = 0;
 270         dbg(1,"count=%d\n", count);
 271         for (i=0; i < count; i++) {
 272                 if (pro == t->pro) {
 273                         xc=c[i].x;
 274                         yc=c[i].y;
 275                 } else {
 276                         transform_to_geo(pro, &c[i], &g);
 277                         transform_from_geo(t->pro, &g, &c1);
 278                         xc=c1.x;
 279                         yc=c1.y;
 280                 }
 281                 xm=xc;
 282                 ym=yc;
 283 //              dbg(2,"0x%x, 0x%x - 0x%x,0x%x contains 0x%x,0x%x\n", t->r.lu.x, t->r.lu.y, t->r.rl.x, t->r.rl.y, c->x, c->y);
 284 //              ret=coord_rect_contains(&t->r, c);
 285                 xc-=t->map_center.x;
 286                 yc-=t->map_center.y;
 287                 xc >>= t->scale_shift;
 288                 yc >>= t->scale_shift;
 289 #ifdef ENABLE_ROLL
 290                 xcn=xc*t->m00+yc*t->m01+t->hog*t->m02;
 291                 ycn=xc*t->m10+yc*t->m11+t->hog*t->m12;
 292 #else
 293                 xcn=xc*t->m00+yc*t->m01;
 294                 ycn=xc*t->m10+yc*t->m11;
 295 #endif
 296
 297                 if (t->ddd) {
 298 #ifdef ENABLE_ROLL
 299                         zc=(xc*t->m20+yc*t->m21+t->hog*t->m22);
 300 #else
 301                         zc=(xc*t->m20+yc*t->m21);
 302 #endif
 303                         zct=zc;
 304                         zc+=t->offz << POST_SHIFT;
 305                         dbg(1,"zc=%d\n", zc);
 306                         dbg(1,"zc(%d)=xc(%d)*m20(%d)+yc(%d)*m21(%d)\n", (xc*t->m20+yc*t->m21), xc, t->m20, yc, t->m21);
 307                         /* visibility */
 308                         visible=(zc < zlimit ? 0:1);
 309                         dbg(1,"visible=%d old %d\n", visible, visibleo);
 310                         if (visible != visibleo && visibleo != -1) {
 311                                 dbg(1,"clipping (%d,%d,%d)-(%d,%d,%d) (%d,%d,%d)\n", xcn, ycn, zc, xco, yco, zco, xco-xcn, yco-ycn, zco-zc);
 312                                 if (zco != zc) {
 313                                         xcn=xcn+(long long)(xco-xcn)*(zlimit-zc)/(zco-zc);
 314                                         ycn=ycn+(long long)(yco-ycn)*(zlimit-zc)/(zco-zc);
 315                                 }
 316                                 dbg(1,"result (%d,%d,%d) * %d / %d\n", xcn,ycn,zc,zlimit-zc,zco-zc);
 317                                 zc=zlimit;
 318                                 xco=xcn;
 319                                 yco=ycn;
 320                                 zco=zc;
 321                                 if (visible)
 322                                         i--;
 323                                 visibleo=visible;
 324                         } else {
 325                                 xco=xcn;
 326                                 yco=ycn;
 327                                 zco=zc;
 328                                 visibleo=visible;
 329                                 if (! visible)
 330                                         continue;
 331                         }
 332                         dbg(1,"zc=%d\n", zc);
 333                         dbg(1,"xcn %d ycn %d\n", xcn, ycn);
 334                         dbg(1,"%d,%d %d\n",xc,yc,zc);
 335 #if 0
 336                         dbg(0,"%d/%d=%d %d/%d=%d\n",xcn,xc,xcn/xc,ycn,yc,ycn/yc);
 337 #endif
 338 #if 1
 339                         xc=(long long)xcn*t->xyscale/zc;
 340                         yc=(long long)ycn*t->xyscale/zc;
 341 #else
 342                         xc=xcn/(1000+zc);
 343                         yc=ycn/(1000+zc);
 344 #endif
 345                         dbg(1,"%d,%d %d\n",xc,yc,zc);
 346                 } else {
 347                         xc=xcn;
 348                         yc=ycn;
 349                         xc>>=POST_SHIFT;
 350                         yc>>=POST_SHIFT;
 351                 }
 352                 xc+=t->offx;
 353                 yc+=t->offy;
 354                 dbg(1,"xc=%d yc=%d\n", xc, yc);
 355                 if (j == 0 || !unique || p[j-1].x != xc || p[j-1].y != yc) {
 356                         p[j].x=xc;
 357                         p[j].y=yc;
 358                         if (width_return) {
 359                                 if (t->ddd)
 360                                         width_return[j]=width*(t->offz << POST_SHIFT)/zc;
 361                                 else
 362                                         width_return[j]=width;
 363                         }
 364                         j++;
 365                 }
 366         }
 367         return j;
 368 }
 369
 370 void
 371 transform_reverse(struct transformation *t, struct point *p, struct coord *c)
 372 {
 373         double zc,xc,yc,xcn,ycn,q;
 374         double offz=t->offz << POST_SHIFT;
 375         xc=p->x - t->offx;
 376         yc=p->y - t->offy;
 377         if (t->ddd) {
 378                 xc/=t->xyscale;
 379                 yc/=t->xyscale;
 380                 double f00=xc*t->im00*t->m20;
 381                 double f01=yc*t->im01*t->m20;
 382                 double f10=xc*t->im10*t->m21;
 383                 double f11=yc*t->im11*t->m21;
 384 #ifdef ENABLE_ROLL
 385                 q=(1-f00-f01-t->im02*t->m20-f10-f11-t->im12*t->m21);
 386                 if (q < 0)
 387                         q=0.15;
 388                 zc=(offz*((f00+f01+f10+f11))+t->hog*t->m22)/q;
 389 #else
 390                 q=(1-f00-f01-f10-f11);
 391                 if (q < 0)
 392                         q=0.15;
 393                 zc=offz*(f00+f01+f10+f11)/q;
 394 #endif
 395                 xcn=xc*(zc+offz);
 396                 ycn=yc*(zc+offz);
 397 #ifdef ENABLE_ROLL
 398                 xc=xcn*t->im00+ycn*t->im01+zc*t->im02;
 399                 yc=xcn*t->im10+ycn*t->im11+zc*t->im12;
 400 #else
 401                 xc=xcn*t->im00+ycn*t->im01;
 402                 yc=xcn*t->im10+ycn*t->im11;
 403 #endif
 404
 405         } else {
 406                 xcn=xc;
 407                 ycn=yc;
 408                 xc=(xcn*t->im00+ycn*t->im01)*(1 << POST_SHIFT);
 409                 yc=(xcn*t->im10+ycn*t->im11)*(1 << POST_SHIFT);
 410         }
 411         c->x=xc*(1 << t->scale_shift)+t->map_center.x;
 412         c->y=yc*(1 << t->scale_shift)+t->map_center.y;
 413 }
 414
 415 enum projection
 416 transform_get_projection(struct transformation *this_)
 417 {
 418         return this_->pro;
 419 }
 420
 421 void
 422 transform_set_projection(struct transformation *this_, enum projection pro)
 423 {
 424         this_->pro=pro;
 425 }
 426
 427 static int
 428 min4(int v1,int v2, int v3, int v4)
 429 {
 430         int res=v1;
 431         if (v2 < res)
 432                 res=v2;
 433         if (v3 < res)
 434                 res=v3;
 435         if (v4 < res)
 436                 res=v4;
 437         return res;
 438 }
 439
 440 static int
 441 max4(int v1,int v2, int v3, int v4)
 442 {
 443         int res=v1;
 444         if (v2 > res)
 445                 res=v2;
 446         if (v3 > res)
 447                 res=v3;
 448         if (v4 > res)
 449                 res=v4;
 450         return res;
 451 }
 452
 453 struct map_selection *
 454 transform_get_selection(struct transformation *this_, enum projection pro, int order)
 455 {
 456
 457         struct map_selection *ret,*curri,*curro;
 458         struct coord_geo g;
 459
 460         ret=map_selection_dup(this_->map_sel);
 461         curri=this_->map_sel;
 462         curro=ret;
 463         while (curri) {
 464                 if (this_->pro != pro) {
 465                         transform_to_geo(this_->pro, &curri->u.c_rect.lu, &g);
 466                         transform_from_geo(pro, &g, &curro->u.c_rect.lu);
 467                         dbg(1,"%f,%f", g.lat, g.lng);
 468                         transform_to_geo(this_->pro, &curri->u.c_rect.rl, &g);
 469                         transform_from_geo(pro, &g, &curro->u.c_rect.rl);
 470                         dbg(1,": - %f,%f\n", g.lat, g.lng);
 471                 }
 472                 dbg(1,"transform rect for %d is %d,%d - %d,%d\n", pro, curro->u.c_rect.lu.x, curro->u.c_rect.lu.y, curro->u.c_rect.rl.x, curro->u.c_rect.rl.y);
 473                 curro->order+=order;
 474                 curro->range=item_range_all;
 475                 curri=curri->next;
 476                 curro=curro->next;
 477         }
 478         return ret;
 479 }
 480
 481 struct coord *
 482 transform_center(struct transformation *this_)
 483 {
 484         return &this_->map_center;
 485 }
 486
 487 struct coord *
 488 transform_get_center(struct transformation *this_)
 489 {
 490         return &this_->map_center;
 491 }
 492
 493 void
 494 transform_set_center(struct transformation *this_, struct coord *c)
 495 {
 496         this_->map_center=*c;
 497 }
 498
 499
 500 void
 501 transform_set_yaw(struct transformation *t,int yaw)
 502 {
 503         t->yaw=yaw;
 504         transform_setup_matrix(t);
 505 }
 506
 507 int
 508 transform_get_yaw(struct transformation *this_)
 509 {
 510         return this_->yaw;
 511 }
 512
 513 void
 514 transform_set_pitch(struct transformation *this_,int pitch)
 515 {
 516         this_->pitch=pitch;
 517         transform_setup_matrix(this_);
 518 }
 519 int
 520 transform_get_pitch(struct transformation *this_)
 521 {
 522         return this_->pitch;
 523 }
 524
 525 #ifdef ENABLE_ROLL
 526 void
 527 transform_set_roll(struct transformation *this_,int roll)
 528 {
 529         this_->roll=roll;
 530         transform_setup_matrix(this_);
 531 }
 532
 533 int
 534 transform_get_roll(struct transformation *this_)
 535 {
 536         return this_->roll;
 537 }
 538 #endif
 539
 540 void
 541 transform_set_distance(struct transformation *this_,int distance)
 542 {
 543         this_->screen_dist=distance;
 544         transform_setup_matrix(this_);
 545 }
 546
 547 int
 548 transform_get_distance(struct transformation *this_)
 549 {
 550         return this_->screen_dist;
 551 }
 552
 553 void
 554 transform_set_screen_selection(struct transformation *t, struct map_selection *sel)
 555 {
 556         map_selection_destroy(t->screen_sel);
 557         t->screen_sel=map_selection_dup(sel);
 558         if (sel) {
 559                 t->screen_center.x=(sel->u.p_rect.rl.x-sel->u.p_rect.lu.x)/2;
 560                 t->screen_center.y=(sel->u.p_rect.rl.y-sel->u.p_rect.lu.y)/2;
 561                 transform_setup_matrix(t);
 562         }
 563 }
 564
 565 void
 566 transform_set_screen_center(struct transformation *t, struct point *p)
 567 {
 568         t->screen_center=*p;
 569 }
 570
 571 #if 0
 572 void
 573 transform_set_size(struct transformation *t, int width, int height)
 574 {
 575         t->width=width;
 576         t->height=height;
 577 }
 578 #endif
 579
 580 void
 581 transform_get_size(struct transformation *t, int *width, int *height)
 582 {
 583         struct point_rect *r;
 584         if (t->screen_sel) {
 585                 r=&t->screen_sel->u.p_rect;
 586                 *width=r->rl.x-r->lu.x;
 587                 *height=r->rl.y-r->lu.y;
 588         }
 589 }
 590
 591 void
 592 transform_setup(struct transformation *t, struct pcoord *c, int scale, int yaw)
 593 {
 594         t->pro=c->pro;
 595         t->map_center.x=c->x;
 596         t->map_center.y=c->y;
 597         t->scale=scale/16.0;
 598         transform_set_yaw(t, yaw);
 599 }
 600
 601 #if 0
 602
 603 void
 604 transform_setup_source_rect_limit(struct transformation *t, struct coord *center, int limit)
 605 {
 606         t->center=*center;
 607         t->scale=1;
 608         t->angle=0;
 609         t->r.lu.x=center->x-limit;
 610         t->r.rl.x=center->x+limit;
 611         t->r.rl.y=center->y-limit;
 612         t->r.lu.y=center->y+limit;
 613 }
 614 #endif
 615
 616 void
 617 transform_setup_source_rect(struct transformation *t)
 618 {
 619         int i;
 620         struct coord screen[4];
 621         struct point screen_pnt[4];
 622         struct point_rect *pr;
 623         struct map_selection *ms,*msm,*next,**msm_last;
 624         ms=t->map_sel;
 625         while (ms) {
 626                 next=ms->next;
 627                 g_free(ms);
 628                 ms=next;
 629         }
 630         t->map_sel=NULL;
 631         msm_last=&t->map_sel;
 632         ms=t->screen_sel;
 633         while (ms) {
 634                 msm=g_new0(struct map_selection, 1);
 635                 *msm=*ms;
 636                 pr=&ms->u.p_rect;
 637                 screen_pnt[0].x=pr->lu.x;
 638                 screen_pnt[0].y=pr->lu.y;
 639                 screen_pnt[1].x=pr->rl.x;
 640                 screen_pnt[1].y=pr->lu.y;
 641                 screen_pnt[2].x=pr->lu.x;
 642                 screen_pnt[2].y=pr->rl.y;
 643                 screen_pnt[3].x=pr->rl.x;
 644                 screen_pnt[3].y=pr->rl.y;
 645                 for (i = 0 ; i < 4 ; i++) {
 646                         transform_reverse(t, &screen_pnt[i], &screen[i]);
 647                         dbg(1,"map(%d) %d,%d=0x%x,0x%x\n", i,screen_pnt[i].x, screen_pnt[i].y, screen[i].x, screen[i].y);
 648                 }
 649                 msm->u.c_rect.lu.x=min4(screen[0].x,screen[1].x,screen[2].x,screen[3].x);
 650                 msm->u.c_rect.rl.x=max4(screen[0].x,screen[1].x,screen[2].x,screen[3].x);
 651                 msm->u.c_rect.rl.y=min4(screen[0].y,screen[1].y,screen[2].y,screen[3].y);
 652                 msm->u.c_rect.lu.y=max4(screen[0].y,screen[1].y,screen[2].y,screen[3].y);
 653                 dbg(1,"%dx%d\n", msm->u.c_rect.rl.x-msm->u.c_rect.lu.x,
 654                                  msm->u.c_rect.lu.y-msm->u.c_rect.rl.y);
 655                 *msm_last=msm;
 656                 msm_last=&msm->next;
 657                 ms=ms->next;
 658         }
 659 }
 660
 661 long
 662 transform_get_scale(struct transformation *t)
 663 {
 664         return (int)(t->scale*16);
 665 }
 666
 667 void
 668 transform_set_scale(struct transformation *t, long scale)
 669 {
 670         t->scale=scale/16.0;
 671         transform_setup_matrix(t);
 672 }
 673
 674
 675 int
 676 transform_get_order(struct transformation *t)
 677 {
 678         return t->order;
 679 }
 680
 681
 682
 683 #define TWOPI (M_PI*2)
 684 #define GC2RAD(c) ((c) * TWOPI/(1<<24))
 685 #define minf(a,b) ((a) < (b) ? (a) : (b))
 686
 687 static double
 688 transform_distance_garmin(struct coord *c1, struct coord *c2)
 689 {
 690 #ifdef USE_HALVESINE
 691         static const int earth_radius = 6371*1000; //m change accordingly
 692 // static const int earth_radius  = 3960; //miles
 693
 694 //Point 1 cords
 695         float lat1  = GC2RAD(c1->y);
 696         float long1 = GC2RAD(c1->x);
 697
 698 //Point 2 cords
 699         float lat2  = GC2RAD(c2->y);
 700         float long2 = GC2RAD(c2->x);
 701
 702 //Haversine Formula
 703         float dlong = long2-long1;
 704         float dlat  = lat2-lat1;
 705
 706         float sinlat  = sinf(dlat/2);
 707         float sinlong = sinf(dlong/2);
 708
 709         float a=(sinlat*sinlat)+cosf(lat1)*cosf(lat2)*(sinlong*sinlong);
 710         float c=2*asinf(minf(1,sqrt(a)));
 711 #ifdef AVOID_FLOAT
 712         return round(earth_radius*c);
 713 #else
 714         return earth_radius*c;
 715 #endif
 716 #else
 717 #define GMETER 2.3887499999999999
 718         double dx,dy;
 719         dx=c1->x-c2->x;
 720         dy=c1->y-c2->y;
 721         return sqrt(dx*dx+dy*dy)*GMETER;
 722 #undef GMETER
 723 #endif
 724 }
 725
 726 double
 727 transform_scale(int y)
 728 {
 729         struct coord c;
 730         struct coord_geo g;
 731         c.x=0;
 732         c.y=y;
 733         transform_to_geo(projection_mg, &c, &g);
 734         return 1/cos(g.lat/180*M_PI);
 735 }
 736
 737 #ifdef AVOID_FLOAT
 738 static int
 739 tab_sqrt[]={14142,13379,12806,12364,12018,11741,11517,11333,11180,11051,10943,10850,10770,10701,10640,10587,10540,10499,10462,10429,10400,10373,10349,10327,10307,10289,10273,10257,10243,10231,10219,10208};
 740 #endif
 741
 742 double
 743 transform_distance(enum projection pro, struct coord *c1, struct coord *c2)
 744 {
 745         if (pro == projection_mg) {
 746 #ifndef AVOID_FLOAT
 747         double dx,dy,scale=transform_scale((c1->y+c2->y)/2);
 748         dx=c1->x-c2->x;
 749         dy=c1->y-c2->y;
 750         return sqrt(dx*dx+dy*dy)/scale;
 751 #else
 752         int dx,dy,f,scale=15539;
 753         dx=c1->x-c2->x;
 754         dy=c1->y-c2->y;
 755         if (dx < 0)
 756                 dx=-dx;
 757         if (dy < 0)
 758                 dy=-dy;
 759         while (dx > 20000 || dy > 20000) {
 760                 dx/=10;
 761                 dy/=10;
 762                 scale/=10;
 763         }
 764         if (! dy)
 765                 return dx*10000/scale;
 766         if (! dx)
 767                 return dy*10000/scale;
 768         if (dx > dy) {
 769                 f=dx*8/dy-8;
 770                 if (f >= 32)
 771                         return dx*10000/scale;
 772                 return dx*tab_sqrt[f]/scale;
 773         } else {
 774                 f=dy*8/dx-8;
 775                 if (f >= 32)
 776                         return dy*10000/scale;
 777                 return dy*tab_sqrt[f]/scale;
 778         }
 779 #endif
 780         } else if (pro == projection_garmin) {
 781                 return transform_distance_garmin(c1, c2);
 782         } else {
 783                 dbg(0,"Unknown projection: %d\n", pro);
 784                 return 0;
 785         }
 786 }
 787
 788 double
 789 transform_polyline_length(enum projection pro, struct coord *c, int count)
 790 {
 791         double ret=0;
 792         int i;
 793
 794         for (i = 0 ; i < count-1 ; i++)
 795                 ret+=transform_distance(pro, &c[i], &c[i+1]);
 796         return ret;
 797 }
 798
 799 int
 800 transform_distance_sq(struct coord *c1, struct coord *c2)
 801 {
 802         int dx=c1->x-c2->x;
 803         int dy=c1->y-c2->y;
 804
 805         if (dx > 32767 || dy > 32767 || dx < -32767 || dy < -32767)
 806                 return INT_MAX;
 807         else
 808                 return dx*dx+dy*dy;
 809 }
 810
 811 int
 812 transform_distance_sq_pc(struct pcoord *c1, struct pcoord *c2)
 813 {
 814         struct coord p1,p2;
 815         p1.x = c1->x; p1.y = c1->y;
 816         p2.x = c2->x; p2.y = c2->y;
 817         return transform_distance_sq(&p1, &p2);
 818 }
 819
 820 int
 821 transform_distance_line_sq(struct coord *l0, struct coord *l1, struct coord *ref, struct coord *lpnt)
 822 {
 823         int vx,vy,wx,wy;
 824         int c1,c2;
 825         int climit=1000000;
 826         struct coord l;
 827
 828         vx=l1->x-l0->x;
 829         vy=l1->y-l0->y;
 830         wx=ref->x-l0->x;
 831         wy=ref->y-l0->y;
 832
 833         c1=vx*wx+vy*wy;
 834         if ( c1 <= 0 ) {
 835                 if (lpnt)
 836                         *lpnt=*l0;
 837                 return transform_distance_sq(l0, ref);
 838         }
 839         c2=vx*vx+vy*vy;
 840         if ( c2 <= c1 ) {
 841                 if (lpnt)
 842                         *lpnt=*l1;
 843                 return transform_distance_sq(l1, ref);
 844         }
 845         while (c1 > climit || c2 > climit) {
 846                 c1/=256;
 847                 c2/=256;
 848         }
 849         l.x=l0->x+vx*c1/c2;
 850         l.y=l0->y+vy*c1/c2;
 851         if (lpnt)
 852                 *lpnt=l;
 853         return transform_distance_sq(&l, ref);
 854 }
 855
 856 int
 857 transform_distance_polyline_sq(struct coord *c, int count, struct coord *ref, struct coord *lpnt, int *pos)
 858 {
 859         int i,dist,distn;
 860         struct coord lp;
 861         if (count < 2)
 862                 return INT_MAX;
 863         if (pos)
 864                 *pos=0;
 865         dist=transform_distance_line_sq(&c[0], &c[1], ref, lpnt);
 866         for (i=2 ; i < count ; i++) {
 867                 distn=transform_distance_line_sq(&c[i-1], &c[i], ref, &lp);
 868                 if (distn < dist) {
 869                         dist=distn;
 870                         if (lpnt)
 871                                 *lpnt=lp;
 872                         if (pos)
 873                                 *pos=i-1;
 874                 }
 875         }
 876         return dist;
 877 }
 878
 879
 880 void
 881 transform_print_deg(double deg)
 882 {
 883         printf("%2.0f:%2.0f:%2.4f", floor(deg), fmod(deg*60,60), fmod(deg*3600,60));
 884 }
 885
 886 #ifdef AVOID_FLOAT
 887 static int tab_atan[]={0,262,524,787,1051,1317,1584,1853,2126,2401,2679,2962,3249,3541,3839,4142,4452,4770,5095,5430,5774,6128,6494,6873,7265,7673,8098,8541,9004,9490,10000,10538};
 888
 889 static int
 890 atan2_int_lookup(int val)
 891 {
 892         int len=sizeof(tab_atan)/sizeof(int);
 893         int i=len/2;
 894         int p=i-1;
 895         for (;;) {
 896                 i>>=1;
 897                 if (val < tab_atan[p])
 898                         p-=i;
 899                 else
 900                         if (val < tab_atan[p+1])
 901                                 return p+(p>>1);
 902                         else
 903                                 p+=i;
 904         }
 905 }
 906
 907 static int
 908 atan2_int(int dx, int dy)
 909 {
 910         int f,mul=1,add=0,ret;
 911         if (! dx) {
 912                 return dy < 0 ? 180 : 0;
 913         }
 914         if (! dy) {
 915                 return dx < 0 ? -90 : 90;
 916         }
 917         if (dx < 0) {
 918                 dx=-dx;
 919                 mul=-1;
 920         }
 921         if (dy < 0) {
 922                 dy=-dy;
 923                 add=180*mul;
 924                 mul*=-1;
 925         }
 926         while (dx > 20000 || dy > 20000) {
 927                 dx/=10;
 928                 dy/=10;
 929         }
 930         if (dx > dy) {
 931                 ret=90-atan2_int_lookup(dy*10000/dx);
 932         } else {
 933                 ret=atan2_int_lookup(dx*10000/dy);
 934         }
 935         return ret*mul+add;
 936 }
 937 #endif
 938
 939 int
 940 transform_get_angle_delta(struct coord *c1, struct coord *c2, int dir)
 941 {
 942         int dx=c2->x-c1->x;
 943         int dy=c2->y-c1->y;
 944 #ifndef AVOID_FLOAT
 945         double angle;
 946         angle=atan2(dx,dy);
 947         angle*=180/M_PI;
 948 #else
 949         int angle;
 950         angle=atan2_int(dx,dy);
 951 #endif
 952         if (dir == -1)
 953                 angle=angle-180;
 954         if (angle < 0)
 955                 angle+=360;
 956         return angle;
 957 }
 958
 959 int
 960 transform_within_border(struct transformation *this_, struct point *p, int border)
 961 {
 962         struct map_selection *ms=this_->screen_sel;
 963         while (ms) {
 964                 struct point_rect *r=&ms->u.p_rect;
 965                 if (p->x >= r->lu.x+border && p->x <= r->rl.x-border &&
 966                     p->y >= r->lu.y+border && p->y <= r->rl.y-border)
 967                         return 1;
 968                 ms=ms->next;
 969         }
 970         return 0;
 971 }
 972
 973 int
 974 transform_within_dist_point(struct coord *ref, struct coord *c, int dist)
 975 {
 976         if (c->x-dist > ref->x)
 977                 return 0;
 978         if (c->x+dist < ref->x)
 979                 return 0;
 980         if (c->y-dist > ref->y)
 981                 return 0;
 982         if (c->y+dist < ref->y)
 983                 return 0;
 984         if ((c->x-ref->x)*(c->x-ref->x) + (c->y-ref->y)*(c->y-ref->y) <= dist*dist)
 985                 return 1;
 986         return 0;
 987 }
 988
 989 int
 990 transform_within_dist_line(struct coord *ref, struct coord *c0, struct coord *c1, int dist)
 991 {
 992         int vx,vy,wx,wy;
 993         int n1,n2;
 994         struct coord lc;
 995
 996         if (c0->x < c1->x) {
 997                 if (c0->x-dist > ref->x)
 998                         return 0;
 999                 if (c1->x+dist < ref->x)
1000                         return 0;
1001         } else {
1002                 if (c1->x-dist > ref->x)
1003                         return 0;
1004                 if (c0->x+dist < ref->x)
1005                         return 0;
1006         }
1007         if (c0->y < c1->y) {
1008                 if (c0->y-dist > ref->y)
1009                         return 0;
1010                 if (c1->y+dist < ref->y)
1011                         return 0;
1012         } else {
1013                 if (c1->y-dist > ref->y)
1014                         return 0;
1015                 if (c0->y+dist < ref->y)
1016                         return 0;
1017         }
1018         vx=c1->x-c0->x;
1019         vy=c1->y-c0->y;
1020         wx=ref->x-c0->x;
1021         wy=ref->y-c0->y;
1022
1023         n1=vx*wx+vy*wy;
1024         if ( n1 <= 0 )
1025                 return transform_within_dist_point(ref, c0, dist);
1026         n2=vx*vx+vy*vy;
1027         if ( n2 <= n1 )
1028                 return transform_within_dist_point(ref, c1, dist);
1029
1030         lc.x=c0->x+vx*n1/n2;
1031         lc.y=c0->y+vy*n1/n2;
1032         return transform_within_dist_point(ref, &lc, dist);
1033 }
1034
1035 int
1036 transform_within_dist_polyline(struct coord *ref, struct coord *c, int count, int close, int dist)
1037 {
1038         int i;
1039         for (i = 0 ; i < count-1 ; i++) {
1040                 if (transform_within_dist_line(ref,c+i,c+i+1,dist)) {
1041                         return 1;
1042                 }
1043         }
1044         if (close)
1045                 return (transform_within_dist_line(ref,c,c+count-1,dist));
1046         return 0;
1047 }
1048
1049 int
1050 transform_within_dist_polygon(struct coord *ref, struct coord *c, int count, int dist)
1051 {
1052         int i, j, ci = 0;
1053         for (i = 0, j = count-1; i < count; j = i++) {
1054                 if ((((c[i].y <= ref->y) && ( ref->y < c[j].y )) ||
1055                 ((c[j].y <= ref->y) && ( ref->y < c[i].y))) &&
1056                 (ref->x < (c[j].x - c[i].x) * (ref->y - c[i].y) / (c[j].y - c[i].y) + c[i].x))
1057                         ci = !ci;
1058         }
1059         if (! ci) {
1060                 if (dist)
1061                         return transform_within_dist_polyline(ref, c, count, dist, 1);
1062                 else
1063                         return 0;
1064         }
1065         return 1;
1066 }
1067
1068 int
1069 transform_within_dist_item(struct coord *ref, enum item_type type, struct coord *c, int count, int dist)
1070 {
1071         if (type < type_line)
1072                 return transform_within_dist_point(ref, c, dist);
1073         if (type < type_area)
1074                 return transform_within_dist_polyline(ref, c, count, 0, dist);
1075         return transform_within_dist_polygon(ref, c, count, dist);
1076 }
1077
1078 void
1079 transform_destroy(struct transformation *t)
1080 {
1081         g_free(t);
1082 }
1083
1084
1085 /*
1086 Note: there are many mathematically equivalent ways to express these formulas. As usual, not all of them are computationally equivalent.
1087
1088 L = latitude in radians (positive north)
1089 Lo = longitude in radians (positive east)
1090 E = easting (meters)
1091 N = northing (meters)
1092
1093 For the sphere
1094
1095 E = r Lo
1096 N = r ln [ tan (pi/4 + L/2) ]
1097
1098 where
1099
1100 r = radius of the sphere (meters)
1101 ln() is the natural logarithm
1102
1103 For the ellipsoid
1104
1105 E = a Lo
1106 N = a * ln ( tan (pi/4 + L/2) * ( (1 - e * sin (L)) / (1 + e * sin (L))) ** (e/2)  )
1107
1108
1109                                                e
1110                                                -
1111                    pi     L     1 - e sin(L)   2
1112     =  a ln( tan( ---- + ---) (--------------)   )
1113                    4      2     1 + e sin(L)
1114
1115
1116 where
1117
1118 a = the length of the semi-major axis of the ellipsoid (meters)
1119 e = the first eccentricity of the ellipsoid
1120
1121
1122 */
1123
1124