Pileus Git - grits/blob - src/grits-opengl.c

   1 /*
   2  * Copyright (C) 2009-2011 Andy Spencer <andy753421@gmail.com>
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   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, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 /**
  19  * SECTION:grits-opengl
  20  * @short_description: OpenGL based virtual globe
  21  *
  22  * #GritsOpenGL is the core rendering engine used by grits. Theoretically other
  23  * renderers could be writte, but they have not been. GritsOpenGL uses the ROAM
  24  * algorithm for updating surface mesh the planet. The only thing GritsOpenGL
  25  * can actually render on it's own is a wireframe of a sphere.
  26  *
  27  * GritsOpenGL requires (at least) OpenGL 2.0.
  28  */
  29
  30 #include <config.h>
  31 #include <math.h>
  32 #include <string.h>
  33 #include <gdk/gdkkeysyms.h>
  34 #include <gtk/gtk.h>
  35
  36 #include "grits-opengl.h"
  37 #include "grits-util.h"
  38 #include "gtkgl.h"
  39 #include "roam.h"
  40
  41 // #define ROAM_DEBUG
  42
  43 /* Tessellation, "finding intersecting triangles" */
  44 /* http://research.microsoft.com/pubs/70307/tr-2006-81.pdf */
  45 /* http://www.opengl.org/wiki/Alpha_Blending */
  46
  47 /* The unsorted/sroted GLists are blank head nodes,
  48  * This way us we can remove objects from the level just by fixing up links
  49  * I.e. we don't need to do a lookup to remove an object if we have its GList */
  50 struct RenderLevel {
  51         gint  num;
  52         GList unsorted;
  53         GList sorted;
  54 };
  55
  56 /***********
  57  * Helpers *
  58  ***********/
  59 static void _set_visuals(GritsOpenGL *opengl)
  60 {
  61         double lat, lon, elev, rx, ry, rz;
  62         grits_viewer_get_location(GRITS_VIEWER(opengl), &lat, &lon, &elev);
  63         grits_viewer_get_rotation(GRITS_VIEWER(opengl), &rx, &ry, &rz);
  64
  65         /* Set projection and clipping planes */
  66         glMatrixMode(GL_PROJECTION);
  67         glLoadIdentity();
  68
  69         double width  = GTK_WIDGET(opengl)->allocation.width;
  70         double height = GTK_WIDGET(opengl)->allocation.height;
  71         double ang    = atan((height/2)/FOV_DIST)*2;
  72         double atmos  = 100000;
  73         double near   = MAX(elev*0.75 - atmos, 50); // View 100km of atmosphere
  74         double far    = elev + 2*EARTH_R + atmos;   // on both sides of the earth
  75
  76         grits_viewer_get_location(GRITS_VIEWER(opengl), &lat, &lon, &elev);
  77         glViewport(0, 0, width, height);
  78         gluPerspective(rad2deg(ang), width/height, near, far);
  79
  80         /* Setup camera and lighting */
  81         glMatrixMode(GL_MODELVIEW);
  82         glLoadIdentity();
  83
  84         /* Camera 1 */
  85         glRotatef(rx, 1, 0, 0);
  86         glRotatef(rz, 0, 0, 1);
  87
  88         /* Lighting */
  89 #ifdef ROAM_DEBUG
  90         float light_ambient[]  = {0.7f, 0.7f, 0.7f, 1.0f};
  91         float light_diffuse[]  = {2.0f, 2.0f, 2.0f, 1.0f};
  92 #else
  93         float light_ambient[]  = {0.2f, 0.2f, 0.2f, 1.0f};
  94         float light_diffuse[]  = {0.8f, 0.8f, 0.8f, 1.0f};
  95 #endif
  96         float light_position[] = {-13*EARTH_R, 1*EARTH_R, 3*EARTH_R, 1.0f};
  97         glLightfv(GL_LIGHT0, GL_AMBIENT,  light_ambient);
  98         glLightfv(GL_LIGHT0, GL_DIFFUSE,  light_diffuse);
  99         glLightfv(GL_LIGHT0, GL_POSITION, light_position);
 100         glEnable(GL_LIGHT0);
 101         glEnable(GL_LIGHTING);
 102
 103         float material_ambient[]  = {1.0, 1.0, 1.0, 1.0};
 104         float material_diffuse[]  = {1.0, 1.0, 1.0, 1.0};
 105         float material_specular[] = {0.0, 0.0, 0.0, 1.0};
 106         float material_emission[] = {0.0, 0.0, 0.0, 1.0};
 107         glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT,  material_ambient);
 108         glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE,  material_diffuse);
 109         glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, material_specular);
 110         glMaterialfv(GL_FRONT_AND_BACK, GL_EMISSION, material_emission);
 111         glDisable(GL_TEXTURE_2D);
 112         glDisable(GL_COLOR_MATERIAL);
 113
 114         /* Camera 2 */
 115         glTranslatef(0, 0, -elev2rad(elev));
 116         glRotatef(lat, 1, 0, 0);
 117         glRotatef(-lon, 0, 1, 0);
 118
 119         glDisable(GL_ALPHA_TEST);
 120
 121         glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 122         glEnable(GL_BLEND);
 123
 124 #ifndef ROAM_DEBUG
 125         glCullFace(GL_BACK);
 126         glEnable(GL_CULL_FACE);
 127
 128         glClearDepth(1.0);
 129         glDepthFunc(GL_LEQUAL);
 130         glEnable(GL_DEPTH_TEST);
 131 #endif
 132
 133         glEnable(GL_LINE_SMOOTH);
 134
 135         glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
 136         //glShadeModel(GL_FLAT);
 137
 138         g_mutex_lock(&opengl->sphere_lock);
 139         roam_sphere_update_view(opengl->sphere);
 140         g_mutex_unlock(&opengl->sphere_lock);
 141 }
 142
 143 static GPtrArray *_objects_to_array(GritsOpenGL *opengl, gboolean ortho)
 144 {
 145         GPtrArray *array = g_ptr_array_new();
 146         for (GList *i = opengl->objects->head; i; i = i->next) {
 147                 struct RenderLevel *level = i->data;
 148                 if ((ortho == TRUE  && level->num <  GRITS_LEVEL_HUD) ||
 149                     (ortho == FALSE && level->num >= GRITS_LEVEL_HUD))
 150                         continue;
 151                 for (GList *j = level->unsorted.next; j; j = j->next)
 152                         g_ptr_array_add(array, j->data);
 153                 for (GList *j = level->sorted.next;   j; j = j->next)
 154                         g_ptr_array_add(array, j->data);
 155         }
 156         return array;
 157 }
 158
 159 /*************
 160  * Callbacks *
 161  *************/
 162 static gboolean on_configure(GritsOpenGL *opengl, GdkEventConfigure *event, gpointer _)
 163 {
 164         g_debug("GritsOpenGL: on_configure");
 165
 166         _set_visuals(opengl);
 167 #ifndef ROAM_DEBUG
 168         g_mutex_lock(&opengl->sphere_lock);
 169         roam_sphere_update_errors(opengl->sphere);
 170         g_mutex_unlock(&opengl->sphere_lock);
 171 #endif
 172
 173         return FALSE;
 174 }
 175
 176 static gint run_picking(GritsOpenGL *opengl, GdkEvent *event,
 177                 GPtrArray *objects, GritsObject **top)
 178 {
 179         /* Setup picking buffers */
 180         guint buffer[100][4] = {};
 181         glSelectBuffer(G_N_ELEMENTS(buffer), (guint*)buffer);
 182         if (!opengl->pickmode)
 183                 glRenderMode(GL_SELECT);
 184         glInitNames();
 185
 186         /* Render/pick objects */
 187         for (guint i = 0; i < objects->len; i++) {
 188                 glPushName(i);
 189                 GritsObject *object = objects->pdata[i];
 190                 object->state.picked = FALSE;
 191                 grits_object_pick(object, opengl);
 192                 glPopName();
 193         }
 194
 195         int hits = glRenderMode(GL_RENDER);
 196
 197         /* Process hits */
 198         for (int i = 0; i < hits; i++) {
 199                 //g_debug("\tHit: %d",     i);
 200                 //g_debug("\t\tcount: %d", buffer[i][0]);
 201                 //g_debug("\t\tz1:    %f", (float)buffer[i][1]/0x7fffffff);
 202                 //g_debug("\t\tz2:    %f", (float)buffer[i][2]/0x7fffffff);
 203                 //g_debug("\t\tname:  %p", (gpointer)buffer[i][3]);
 204                 guint        index  = buffer[i][3];
 205                 GritsObject *object = objects->pdata[index];
 206                 object->state.picked = TRUE;
 207                 *top = object;
 208         }
 209
 210         /* Notify objects of pointer movements */
 211         for (guint i = 0; i < objects->len; i++) {
 212                 GritsObject *object = objects->pdata[i];
 213                 grits_object_set_pointer(object, event, object->state.picked);
 214         }
 215
 216         return hits;
 217 }
 218
 219 static gboolean on_motion_notify(GritsOpenGL *opengl, GdkEventMotion *event, gpointer _)
 220 {
 221         gdouble height = GTK_WIDGET(opengl)->allocation.height;
 222         gdouble gl_x   = event->x;
 223         gdouble gl_y   = height - event->y;
 224         gdouble delta  = opengl->pickmode ? 200 : 2;
 225
 226         if (opengl->pickmode) {
 227                 gtk_gl_begin(GTK_WIDGET(opengl));
 228                 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 229         }
 230
 231         /* Save matricies */
 232         gdouble projection[16];
 233         gint    viewport[4]; // x=0,y=0,w,h
 234         glGetDoublev(GL_PROJECTION_MATRIX, projection);
 235         glGetIntegerv(GL_VIEWPORT, viewport);
 236         glMatrixMode(GL_MODELVIEW);  glPushMatrix();
 237         glMatrixMode(GL_PROJECTION); glPushMatrix();
 238
 239         g_mutex_lock(&opengl->objects_lock);
 240
 241         GritsObject *top = NULL;
 242         GPtrArray *ortho = _objects_to_array(opengl, TRUE);
 243         GPtrArray *world = _objects_to_array(opengl, FALSE);
 244
 245         /* Run perspective picking */
 246         glMatrixMode(GL_PROJECTION); glLoadIdentity();
 247         gluPickMatrix(gl_x, gl_y, delta, delta, viewport);
 248         glMultMatrixd(projection);
 249         gint world_hits = run_picking(opengl, (GdkEvent*)event, world, &top);
 250
 251         /* Run ortho picking */
 252         glMatrixMode(GL_PROJECTION); glLoadIdentity();
 253         gluPickMatrix(gl_x, gl_y, delta, delta, viewport);
 254         glMatrixMode(GL_MODELVIEW);  glLoadIdentity();
 255         glOrtho(0, viewport[2], viewport[3], 0, 1000, -1000);
 256         gint ortho_hits = run_picking(opengl, (GdkEvent*)event, ortho, &top);
 257
 258         /* Update cursor */
 259         static GdkCursor *cursor = NULL;
 260         static GdkWindow *window = NULL;
 261         if (!window || !cursor) {
 262                 cursor = gdk_cursor_new(GDK_FLEUR);
 263                 window = gtk_widget_get_window(GTK_WIDGET(opengl));
 264         }
 265         GdkCursor *topcursor = top && top->cursor ? top->cursor : cursor;
 266         gdk_window_set_cursor(window, topcursor);
 267
 268         g_debug("GritsOpenGL: on_motion_notify - hits=%d/%d,%d/%d ev=%.0lf,%.0lf",
 269                         world_hits, world->len, ortho_hits, ortho->len, gl_x, gl_y);
 270
 271         g_ptr_array_free(world, TRUE);
 272         g_ptr_array_free(ortho, TRUE);
 273
 274         g_mutex_unlock(&opengl->objects_lock);
 275
 276
 277         /* Test unproject */
 278         //gdouble lat, lon, elev;
 279         //grits_viewer_unproject(GRITS_VIEWER(opengl),
 280         //              gl_x, gl_y, -1, &lat, &lon, &elev);
 281
 282         /* Cleanup */
 283         glMatrixMode(GL_PROJECTION); glPopMatrix();
 284         glMatrixMode(GL_MODELVIEW);  glPopMatrix();
 285
 286         if (opengl->pickmode)
 287                 gtk_gl_end(GTK_WIDGET(opengl));
 288
 289         return FALSE;
 290 }
 291
 292 static void _draw_level(gpointer _level, gpointer _opengl)
 293 {
 294         GritsOpenGL *opengl = _opengl;
 295         struct RenderLevel *level = _level;
 296
 297         g_debug("GritsOpenGL: _draw_level - level=%-4d", level->num);
 298         int nsorted = 0, nunsorted = 0;
 299         GList *cur = NULL;
 300
 301         /* Configure individual levels */
 302         if (level->num < GRITS_LEVEL_WORLD) {
 303                 /* Disable depth for background levels */
 304                 glDepthMask(FALSE);
 305                 glDisable(GL_ALPHA_TEST);
 306         } else if (level->num < GRITS_LEVEL_OVERLAY) {
 307                 /* Enable depth and alpha for world levels */
 308                 glEnable(GL_ALPHA_TEST);
 309                 glAlphaFunc(GL_GREATER, 0.1);
 310         } else {
 311                 /* Disable depth for Overlay/HUD levels */
 312                 glDepthMask(FALSE);
 313         }
 314
 315         /* Start ortho */
 316         if (level->num >= GRITS_LEVEL_HUD) {
 317                 glMatrixMode(GL_PROJECTION); glPushMatrix(); glLoadIdentity();
 318                 glMatrixMode(GL_MODELVIEW);  glPushMatrix(); glLoadIdentity();
 319                 gint win_width  = GTK_WIDGET(opengl)->allocation.width;
 320                 gint win_height = GTK_WIDGET(opengl)->allocation.height;
 321                 glOrtho(0, win_width, win_height, 0, 1000, -1000);
 322         }
 323
 324         /* Draw unsorted objects without depth testing,
 325          * these are polygons, etc, rather than physical objects */
 326         glDisable(GL_DEPTH_TEST);
 327         for (cur = level->unsorted.next; cur; cur = cur->next, nunsorted++)
 328                 grits_object_draw(GRITS_OBJECT(cur->data), opengl);
 329
 330         /* Draw sorted objects using depth testing
 331          * These are things that are actually part of the world */
 332         glEnable(GL_DEPTH_TEST);
 333         for (cur = level->sorted.next; cur; cur = cur->next, nsorted++)
 334                 grits_object_draw(GRITS_OBJECT(cur->data), opengl);
 335
 336         /* End ortho */
 337         if (level->num >= GRITS_LEVEL_HUD) {
 338                 glMatrixMode(GL_PROJECTION); glPopMatrix();
 339                 glMatrixMode(GL_MODELVIEW);  glPopMatrix();
 340         }
 341
 342         /* Leave depth buffer write enabled */
 343         glDepthMask(TRUE);
 344
 345         /* TODO: Prune empty levels */
 346
 347         g_debug("GritsOpenGL: _draw_level - drew %d,%d objects",
 348                         nunsorted, nsorted);
 349 }
 350
 351 static gboolean on_expose(GritsOpenGL *opengl, GdkEventExpose *event, gpointer _)
 352 {
 353         g_debug("GritsOpenGL: on_expose - begin");
 354
 355         if (opengl->pickmode)
 356                 return on_motion_notify(opengl, (GdkEventMotion*)event, NULL);
 357
 358         gtk_gl_begin(GTK_WIDGET(opengl));
 359
 360         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 361
 362         _set_visuals(opengl);
 363 #ifdef ROAM_DEBUG
 364         glColor4f(1.0, 1.0, 1.0, 1.0);
 365         glLineWidth(2);
 366         glDisable(GL_TEXTURE_2D);
 367         glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
 368         roam_sphere_draw(opengl->sphere);
 369         (void)_draw_level;
 370         //roam_sphere_draw_normals(opengl->sphere);
 371 #else
 372         g_mutex_lock(&opengl->objects_lock);
 373         if (opengl->wireframe)
 374                 glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
 375         g_queue_foreach(opengl->objects, _draw_level, opengl);
 376         g_mutex_unlock(&opengl->objects_lock);
 377 #endif
 378
 379         gtk_gl_end(GTK_WIDGET(opengl));
 380
 381         g_debug("GritsOpenGL: on_expose - end\n");
 382         return FALSE;
 383 }
 384
 385 static gboolean on_key_press(GritsOpenGL *opengl, GdkEventKey *event, gpointer _)
 386 {
 387         g_debug("GritsOpenGL: on_key_press - key=%x, state=%x, plus=%x",
 388                         event->keyval, event->state, GDK_plus);
 389
 390         guint kv = event->keyval;
 391         /* Testing */
 392         if (kv == GDK_w) {
 393                 opengl->wireframe = !opengl->wireframe;
 394                 gtk_widget_queue_draw(GTK_WIDGET(opengl));
 395         }
 396         if (kv == GDK_p) {
 397                 opengl->pickmode = !opengl->pickmode;
 398                 gtk_widget_queue_draw(GTK_WIDGET(opengl));
 399         }
 400 #ifdef ROAM_DEBUG
 401         else if (kv == GDK_n) roam_sphere_split_one(opengl->sphere);
 402         else if (kv == GDK_p) roam_sphere_merge_one(opengl->sphere);
 403         else if (kv == GDK_r) roam_sphere_split_merge(opengl->sphere);
 404         else if (kv == GDK_u) roam_sphere_update_errors(opengl->sphere);
 405         gtk_widget_queue_draw(GTK_WIDGET(opengl));
 406 #endif
 407         return FALSE;
 408 }
 409
 410 static gboolean on_chained_event(GritsOpenGL *opengl, GdkEvent *event, gpointer _)
 411 {
 412         for (GList *i = opengl->objects->tail; i; i = i->prev) {
 413                 struct RenderLevel *level = i->data;
 414                 for (GList *j = level->unsorted.next; j; j = j->next)
 415                         if (grits_object_event(j->data, event))
 416                                 return TRUE;
 417                 for (GList *j = level->sorted.next;   j; j = j->next)
 418                         if (grits_object_event(j->data, event))
 419                                 return TRUE;
 420         }
 421         return FALSE;
 422 }
 423
 424 static gboolean _update_errors_cb(gpointer _opengl)
 425 {
 426         GritsOpenGL *opengl = _opengl;
 427         g_mutex_lock(&opengl->sphere_lock);
 428         roam_sphere_update_errors(opengl->sphere);
 429         g_mutex_unlock(&opengl->sphere_lock);
 430         opengl->ue_source = 0;
 431         return FALSE;
 432 }
 433 static void on_view_changed(GritsOpenGL *opengl,
 434                 gdouble _1, gdouble _2, gdouble _3)
 435 {
 436         g_debug("GritsOpenGL: on_view_changed");
 437         _set_visuals(opengl);
 438 #ifndef ROAM_DEBUG
 439         if (!opengl->ue_source)
 440                 opengl->ue_source = g_idle_add_full(G_PRIORITY_HIGH_IDLE+30,
 441                                 _update_errors_cb, opengl, NULL);
 442         //roam_sphere_update_errors(opengl->sphere);
 443 #else
 444         (void)_update_errors_cb;
 445 #endif
 446 }
 447
 448 static gboolean on_idle(GritsOpenGL *opengl)
 449 {
 450         //g_debug("GritsOpenGL: on_idle");
 451         g_mutex_lock(&opengl->sphere_lock);
 452         if (roam_sphere_split_merge(opengl->sphere))
 453                 gtk_widget_queue_draw(GTK_WIDGET(opengl));
 454         g_mutex_unlock(&opengl->sphere_lock);
 455         return TRUE;
 456 }
 457
 458 static void on_realize(GritsOpenGL *opengl, gpointer _)
 459 {
 460         g_debug("GritsOpenGL: on_realize");
 461         gtk_gl_begin(GTK_WIDGET(opengl));
 462
 463         /* Connect signals and idle functions now that opengl is fully initialized */
 464         gtk_widget_add_events(GTK_WIDGET(opengl), GDK_KEY_PRESS_MASK);
 465         g_signal_connect(opengl, "configure-event",  G_CALLBACK(on_configure),    NULL);
 466         g_signal_connect(opengl, "expose-event",     G_CALLBACK(on_expose),       NULL);
 467
 468         g_signal_connect(opengl, "key-press-event",  G_CALLBACK(on_key_press),    NULL);
 469
 470         g_signal_connect(opengl, "location-changed", G_CALLBACK(on_view_changed), NULL);
 471         g_signal_connect(opengl, "rotation-changed", G_CALLBACK(on_view_changed), NULL);
 472
 473         g_signal_connect(opengl, "motion-notify-event", G_CALLBACK(on_motion_notify), NULL);
 474         g_signal_connect_after(opengl, "key-press-event",      G_CALLBACK(on_chained_event), NULL);
 475         g_signal_connect_after(opengl, "key-release-event",    G_CALLBACK(on_chained_event), NULL);
 476         g_signal_connect_after(opengl, "button-press-event",   G_CALLBACK(on_chained_event), NULL);
 477         g_signal_connect_after(opengl, "button-release-event", G_CALLBACK(on_chained_event), NULL);
 478         g_signal_connect_after(opengl, "motion-notify-event",  G_CALLBACK(on_chained_event), NULL);
 479
 480 #ifndef ROAM_DEBUG
 481         opengl->sm_source[0] = g_timeout_add_full(G_PRIORITY_HIGH_IDLE+30, 33,  (GSourceFunc)on_idle, opengl, NULL);
 482         opengl->sm_source[1] = g_timeout_add_full(G_PRIORITY_HIGH_IDLE+10, 500, (GSourceFunc)on_idle, opengl, NULL);
 483 #else
 484         (void)on_idle;
 485         (void)_update_errors_cb;
 486 #endif
 487
 488         /* Re-queue resize incase configure was triggered before realize */
 489         gtk_widget_queue_resize(GTK_WIDGET(opengl));
 490 }
 491
 492 /*********************
 493  * GritsViewer methods *
 494  *********************/
 495 /**
 496  * grits_opengl_new:
 497  * @plugins: the plugins store to use
 498  * @prefs:   the preferences object to use
 499  *
 500  * Create a new OpenGL renderer.
 501  *
 502  * Returns: the new #GritsOpenGL
 503  */
 504 GritsViewer *grits_opengl_new(GritsPlugins *plugins, GritsPrefs *prefs)
 505 {
 506         g_debug("GritsOpenGL: new");
 507         GritsViewer *opengl = g_object_new(GRITS_TYPE_OPENGL, NULL);
 508         grits_viewer_setup(opengl, plugins, prefs);
 509         return opengl;
 510 }
 511
 512 static void grits_opengl_center_position(GritsViewer *_opengl, gdouble lat, gdouble lon, gdouble elev)
 513 {
 514         glRotatef(lon, 0, 1, 0);
 515         glRotatef(-lat, 1, 0, 0);
 516         glTranslatef(0, 0, elev2rad(elev));
 517 }
 518
 519 static void grits_opengl_project(GritsViewer *_opengl,
 520                 gdouble lat, gdouble lon, gdouble elev,
 521                 gdouble *px, gdouble *py, gdouble *pz)
 522 {
 523         GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
 524         gdouble x, y, z;
 525         lle2xyz(lat, lon, elev, &x, &y, &z);
 526         gluProject(x, y, z,
 527                 opengl->sphere->view->model,
 528                 opengl->sphere->view->proj,
 529                 opengl->sphere->view->view,
 530                 px, py, pz);
 531 }
 532
 533 static void grits_opengl_unproject(GritsViewer *_opengl,
 534                 gdouble px, gdouble py, gdouble pz,
 535                 gdouble *lat, gdouble *lon, gdouble *elev)
 536 {
 537         GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
 538         if (!opengl->sphere->view)
 539                 return;
 540         gdouble x, y, z;
 541         if (pz < 0) {
 542                 gfloat tmp = 0;
 543                 glReadPixels(px, py, 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &tmp);
 544                 pz = tmp;
 545         }
 546         gluUnProject(px, py, pz,
 547                 opengl->sphere->view->model,
 548                 opengl->sphere->view->proj,
 549                 opengl->sphere->view->view,
 550                 &x, &y, &z);
 551         xyz2lle(x, y, z, lat, lon, elev);
 552         //g_message("GritsOpenGL: unproject - "
 553         //              "%4.0lf,%4.0lf,(%5.3lf) -> "
 554         //              "%8.0lf,%8.0lf,%8.0lf -> "
 555         //              "%6.2lf,%7.2lf,%4.0lf",
 556         //      px, py, pz, x, y, z, *lat, *lon, *elev);
 557 }
 558
 559 static void grits_opengl_set_height_func(GritsViewer *_opengl, GritsBounds *bounds,
 560                 RoamHeightFunc height_func, gpointer user_data, gboolean update)
 561 {
 562         GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
 563         /* TODO: get points? */
 564         g_mutex_lock(&opengl->sphere_lock);
 565         GList *triangles = roam_sphere_get_intersect(opengl->sphere, TRUE,
 566                         bounds->n, bounds->s, bounds->e, bounds->w);
 567         for (GList *cur = triangles; cur; cur = cur->next) {
 568                 RoamTriangle *tri = cur->data;
 569                 RoamPoint *points[] = {tri->p.l, tri->p.m, tri->p.r, tri->split};
 570                 for (int i = 0; i < G_N_ELEMENTS(points); i++) {
 571                         if (bounds->n >= points[i]->lat && points[i]->lat >= bounds->s &&
 572                             bounds->e >= points[i]->lon && points[i]->lon >= bounds->w) {
 573                                 points[i]->height_func = height_func;
 574                                 points[i]->height_data = user_data;
 575                                 roam_point_update_height(points[i]);
 576                         }
 577                 }
 578         }
 579         g_list_free(triangles);
 580         g_mutex_unlock(&opengl->sphere_lock);
 581 }
 582
 583 static void _grits_opengl_clear_height_func_rec(RoamTriangle *root)
 584 {
 585         if (!root)
 586                 return;
 587         RoamPoint *points[] = {root->p.l, root->p.m, root->p.r, root->split};
 588         for (int i = 0; i < G_N_ELEMENTS(points); i++) {
 589                 points[i]->height_func = NULL;
 590                 points[i]->height_data = NULL;
 591                 roam_point_update_height(points[i]);
 592         }
 593         _grits_opengl_clear_height_func_rec(root->kids[0]);
 594         _grits_opengl_clear_height_func_rec(root->kids[1]);
 595 }
 596
 597 static void grits_opengl_clear_height_func(GritsViewer *_opengl)
 598 {
 599         GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
 600         for (int i = 0; i < G_N_ELEMENTS(opengl->sphere->roots); i++)
 601                 _grits_opengl_clear_height_func_rec(opengl->sphere->roots[i]);
 602 }
 603
 604 static gint _objects_find(gconstpointer a, gconstpointer b)
 605 {
 606         const struct RenderLevel *level = a;
 607         const gint *key = b;
 608         return level->num == *key ? 0 : 1;
 609 }
 610
 611 static gint _objects_sort(gconstpointer _a, gconstpointer _b, gpointer _)
 612 {
 613         const struct RenderLevel *a = _a;
 614         const struct RenderLevel *b = _b;
 615         return a->num < b->num ? -1 :
 616                a->num > b->num ?  1 : 0;
 617 }
 618
 619 static void _objects_free(gpointer value, gpointer _)
 620 {
 621         struct RenderLevel *level = value;
 622         if (level->sorted.next)
 623                 g_list_free(level->sorted.next);
 624         if (level->unsorted.next)
 625                 g_list_free(level->unsorted.next);
 626         g_free(level);
 627 }
 628
 629 static gpointer grits_opengl_add(GritsViewer *_opengl, GritsObject *object,
 630                 gint num, gboolean sort)
 631 {
 632         g_assert(GRITS_IS_OPENGL(_opengl));
 633         GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
 634         g_mutex_lock(&opengl->objects_lock);
 635         struct RenderLevel *level = NULL;
 636         GList *tmp = g_queue_find_custom(opengl->objects, &num, _objects_find);
 637         if (tmp) {
 638                 level = tmp->data;
 639         } else {
 640                 level = g_new0(struct RenderLevel, 1);
 641                 level->num = num;
 642                 g_queue_insert_sorted(opengl->objects, level, _objects_sort, NULL);
 643         }
 644         GList *list = sort ? &level->sorted : &level->unsorted;
 645         /* Put the link in the list */
 646         GList *link = g_new0(GList, 1);
 647         link->data = object;
 648         link->prev = list;
 649         link->next = list->next;
 650         if (list->next)
 651                 list->next->prev = link;
 652         list->next = link;
 653         g_mutex_unlock(&opengl->objects_lock);
 654         return link;
 655 }
 656
 657 static GritsObject *grits_opengl_remove(GritsViewer *_opengl, GritsObject *object)
 658 {
 659         g_assert(GRITS_IS_OPENGL(_opengl));
 660         GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
 661         GList *link = object->ref;
 662         g_mutex_lock(&opengl->objects_lock);
 663         /* Just unlink and free it, link->prev is assured */
 664         link->prev->next = link->next;
 665         if (link->next)
 666                 link->next->prev = link->prev;
 667         g_mutex_unlock(&opengl->objects_lock);
 668         object->ref    = NULL;
 669         object->viewer = NULL;
 670         g_free(link);
 671         g_object_unref(object);
 672         return object;
 673 }
 674
 675 /****************
 676  * GObject code *
 677  ****************/
 678 G_DEFINE_TYPE(GritsOpenGL, grits_opengl, GRITS_TYPE_VIEWER);
 679 static void grits_opengl_init(GritsOpenGL *opengl)
 680 {
 681         g_debug("GritsOpenGL: init");
 682         opengl->objects = g_queue_new();
 683         opengl->sphere  = roam_sphere_new(opengl);
 684         g_mutex_init(&opengl->objects_lock);
 685         g_mutex_init(&opengl->sphere_lock);
 686         gtk_gl_enable(GTK_WIDGET(opengl));
 687         gtk_widget_add_events(GTK_WIDGET(opengl), GDK_KEY_PRESS_MASK);
 688         g_signal_connect(opengl, "map", G_CALLBACK(on_realize), NULL);
 689 }
 690 static void grits_opengl_dispose(GObject *_opengl)
 691 {
 692         g_debug("GritsOpenGL: dispose");
 693         GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
 694         if (opengl->sm_source[0]) {
 695                 g_source_remove(opengl->sm_source[0]);
 696                 opengl->sm_source[0] = 0;
 697         }
 698         if (opengl->sm_source[1]) {
 699                 g_source_remove(opengl->sm_source[1]);
 700                 opengl->sm_source[1] = 0;
 701         }
 702         if (opengl->ue_source) {
 703                 g_source_remove(opengl->ue_source);
 704                 opengl->ue_source = 0;
 705         }
 706         G_OBJECT_CLASS(grits_opengl_parent_class)->dispose(_opengl);
 707 }
 708 static void grits_opengl_finalize(GObject *_opengl)
 709 {
 710         g_debug("GritsOpenGL: finalize");
 711         GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
 712         roam_sphere_free(opengl->sphere);
 713         g_queue_foreach(opengl->objects, _objects_free, NULL);
 714         g_queue_free(opengl->objects);
 715         g_mutex_clear(&opengl->objects_lock);
 716         g_mutex_clear(&opengl->sphere_lock);
 717         G_OBJECT_CLASS(grits_opengl_parent_class)->finalize(_opengl);
 718 }
 719 static void grits_opengl_class_init(GritsOpenGLClass *klass)
 720 {
 721         g_debug("GritsOpenGL: class_init");
 722         GObjectClass *gobject_class = G_OBJECT_CLASS(klass);
 723         gobject_class->finalize = grits_opengl_finalize;
 724         gobject_class->dispose = grits_opengl_dispose;
 725
 726         GritsViewerClass *viewer_class = GRITS_VIEWER_CLASS(klass);
 727         viewer_class->center_position   = grits_opengl_center_position;
 728         viewer_class->project           = grits_opengl_project;
 729         viewer_class->unproject         = grits_opengl_unproject;
 730         viewer_class->clear_height_func = grits_opengl_clear_height_func;
 731         viewer_class->set_height_func   = grits_opengl_set_height_func;
 732         viewer_class->add               = grits_opengl_add;
 733         viewer_class->remove            = grits_opengl_remove;
 734 }