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 #define OVERLAY_SLICE 0.01
  44
  45 /* Tessellation, "finding intersecting triangles" */
  46 /* http://research.microsoft.com/pubs/70307/tr-2006-81.pdf */
  47 /* http://www.opengl.org/wiki/Alpha_Blending */
  48
  49 /* The unsorted/sroted GLists are blank head nodes,
  50  * This way us we can remove objects from the level just by fixing up links
  51  * I.e. we don't need to do a lookup to remove an object if we have its GList */
  52 struct RenderLevel {
  53         gint  num;
  54         GList unsorted;
  55         GList sorted;
  56 };
  57
  58 /***********
  59  * Helpers *
  60  ***********/
  61 static void _set_projection(GritsOpenGL *opengl)
  62 {
  63         double lat, lon, elev, rx, ry, rz;
  64         grits_viewer_get_location(GRITS_VIEWER(opengl), &lat, &lon, &elev);
  65         grits_viewer_get_rotation(GRITS_VIEWER(opengl), &rx, &ry, &rz);
  66
  67         /* Set projection and clipping planes */
  68         glMatrixMode(GL_PROJECTION);
  69         glLoadIdentity();
  70
  71         GtkAllocation alloc;
  72         gtk_widget_get_allocation(GTK_WIDGET(opengl), &alloc);
  73         double width  = alloc.width;
  74         double height = alloc.height;
  75         double ang    = atan((height/2)/FOV_DIST)*2;
  76         double atmos  = 100000;
  77         double near   = MAX(elev*0.75 - atmos, 50); // View 100km of atmosphere
  78         double far    = elev + 2*EARTH_R + atmos;   // on both sides of the earth
  79
  80         glViewport(0, 0, width, height);
  81         gluPerspective(rad2deg(ang), width/height, near, far);
  82
  83         /* Setup camera and lighting */
  84         glMatrixMode(GL_MODELVIEW);
  85         glLoadIdentity();
  86
  87         /* Camera 1 */
  88         glRotatef(rx, 1, 0, 0);
  89         glRotatef(rz, 0, 0, 1);
  90
  91         /* Lighting */
  92         float light_position[] = {-13*EARTH_R, 1*EARTH_R, 3*EARTH_R, 1.0f};
  93         glLightfv(GL_LIGHT0, GL_POSITION, light_position);
  94
  95         /* Camera 2 */
  96         glTranslatef(0, 0, -elev2rad(elev));
  97         glRotatef(lat, 1, 0, 0);
  98         glRotatef(-lon, 0, 1, 0);
  99
 100         /* Update roam view */
 101         g_mutex_lock(&opengl->sphere_lock);
 102         roam_sphere_update_view(opengl->sphere);
 103         g_mutex_unlock(&opengl->sphere_lock);
 104 }
 105
 106 static void _set_settings(GritsOpenGL *opengl)
 107 {
 108         glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 109         glEnable(GL_BLEND);
 110         glDisable(GL_ALPHA_TEST);
 111
 112         glEnable(GL_LIGHT0);
 113         glEnable(GL_LIGHTING);
 114
 115         glEnable(GL_LINE_SMOOTH);
 116
 117         glDisable(GL_TEXTURE_2D);
 118         glDisable(GL_COLOR_MATERIAL);
 119
 120         if (opengl->wireframe)
 121                 glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
 122         else
 123                 glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
 124
 125         /* Lighting */
 126 #ifdef ROAM_DEBUG
 127         float light_ambient[]  = {0.7f, 0.7f, 0.7f, 1.0f};
 128         float light_diffuse[]  = {2.0f, 2.0f, 2.0f, 1.0f};
 129 #else
 130         float light_ambient[]  = {0.2f, 0.2f, 0.2f, 1.0f};
 131         float light_diffuse[]  = {0.8f, 0.8f, 0.8f, 1.0f};
 132 #endif
 133         glLightfv(GL_LIGHT0, GL_AMBIENT,  light_ambient);
 134         glLightfv(GL_LIGHT0, GL_DIFFUSE,  light_diffuse);
 135
 136         /* Materials */
 137         float material_ambient[]  = {1.0, 1.0, 1.0, 1.0};
 138         float material_diffuse[]  = {1.0, 1.0, 1.0, 1.0};
 139         float material_specular[] = {0.0, 0.0, 0.0, 1.0};
 140         float material_emission[] = {0.0, 0.0, 0.0, 1.0};
 141         glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT,  material_ambient);
 142         glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE,  material_diffuse);
 143         glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, material_specular);
 144         glMaterialfv(GL_FRONT_AND_BACK, GL_EMISSION, material_emission);
 145
 146 #ifdef ROAM_DEBUG
 147         glColor4f(1.0, 1.0, 1.0, 1.0);
 148         glLineWidth(2);
 149 #else
 150         glCullFace(GL_BACK);
 151         glEnable(GL_CULL_FACE);
 152
 153         glClearDepth(1.0);
 154         glDepthFunc(GL_LEQUAL);
 155         glEnable(GL_DEPTH_TEST);
 156 #endif
 157 }
 158
 159 static GPtrArray *_objects_to_array(GritsOpenGL *opengl, gboolean ortho)
 160 {
 161         GPtrArray *array = g_ptr_array_new();
 162         for (GList *i = opengl->objects->head; i; i = i->next) {
 163                 struct RenderLevel *level = i->data;
 164                 if ((ortho == TRUE  && level->num <  GRITS_LEVEL_HUD) ||
 165                     (ortho == FALSE && level->num >= GRITS_LEVEL_HUD))
 166                         continue;
 167                 for (GList *j = level->unsorted.next; j; j = j->next)
 168                         g_ptr_array_add(array, j->data);
 169                 for (GList *j = level->sorted.next;   j; j = j->next)
 170                         g_ptr_array_add(array, j->data);
 171         }
 172         return array;
 173 }
 174
 175 /*************
 176  * Callbacks *
 177  *************/
 178
 179 static gint run_picking(GritsOpenGL *opengl, GdkEvent *event,
 180                 GPtrArray *objects, GritsObject **top)
 181 {
 182         /* Setup picking buffers */
 183         guint buffer[100][4] = {};
 184         glSelectBuffer(G_N_ELEMENTS(buffer), (guint*)buffer);
 185         if (!opengl->pickmode)
 186                 glRenderMode(GL_SELECT);
 187         glInitNames();
 188
 189         /* Render/pick objects */
 190         for (guint i = 0; i < objects->len; i++) {
 191                 glPushName(i);
 192                 GritsObject *object = objects->pdata[i];
 193                 object->state.picked = FALSE;
 194                 grits_object_pick(object, opengl);
 195                 glPopName();
 196         }
 197
 198         int hits = glRenderMode(GL_RENDER);
 199
 200         /* Process hits */
 201         for (int i = 0; i < hits; i++) {
 202                 //g_debug("\tHit: %d",     i);
 203                 //g_debug("\t\tcount: %d", buffer[i][0]);
 204                 //g_debug("\t\tz1:    %f", (float)buffer[i][1]/0x7fffffff);
 205                 //g_debug("\t\tz2:    %f", (float)buffer[i][2]/0x7fffffff);
 206                 //g_debug("\t\tname:  %p", (gpointer)buffer[i][3]);
 207                 guint        index  = buffer[i][3];
 208                 GritsObject *object = objects->pdata[index];
 209                 object->state.picked = TRUE;
 210                 *top = object;
 211         }
 212
 213         /* Notify objects of pointer movements */
 214         for (guint i = 0; i < objects->len; i++) {
 215                 GritsObject *object = objects->pdata[i];
 216                 grits_object_set_pointer(object, event, object->state.picked);
 217         }
 218
 219         return hits;
 220 }
 221
 222 static gboolean run_mouse_move(GritsOpenGL *opengl, GdkEventMotion *event)
 223 {
 224         GtkAllocation alloc;
 225         gtk_widget_get_allocation(GTK_WIDGET(opengl), &alloc);
 226
 227         gdouble gl_x   = event->x;
 228         gdouble gl_y   = alloc.height - event->y;
 229         gdouble delta  = opengl->pickmode ? 200 : 2;
 230
 231         if (opengl->pickmode) {
 232                 gtk_gl_begin(GTK_WIDGET(opengl));
 233                 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 234         }
 235
 236         /* Save matricies */
 237         gdouble projection[16];
 238         gint    viewport[4]; // x=0,y=0,w,h
 239         glGetDoublev(GL_PROJECTION_MATRIX, projection);
 240         glGetIntegerv(GL_VIEWPORT, viewport);
 241         glMatrixMode(GL_MODELVIEW);  glPushMatrix();
 242         glMatrixMode(GL_PROJECTION); glPushMatrix();
 243
 244         g_mutex_lock(&opengl->objects_lock);
 245
 246         GritsObject *top = NULL;
 247         GPtrArray *ortho = _objects_to_array(opengl, TRUE);
 248         GPtrArray *world = _objects_to_array(opengl, FALSE);
 249
 250         /* Run perspective picking */
 251         glMatrixMode(GL_PROJECTION); glLoadIdentity();
 252         gluPickMatrix(gl_x, gl_y, delta, delta, viewport);
 253         glMultMatrixd(projection);
 254         gint world_hits = run_picking(opengl, (GdkEvent*)event, world, &top);
 255
 256         /* Run ortho picking */
 257         glMatrixMode(GL_PROJECTION); glLoadIdentity();
 258         gluPickMatrix(gl_x, gl_y, delta, delta, viewport);
 259         glMatrixMode(GL_MODELVIEW);  glLoadIdentity();
 260         glOrtho(0, viewport[2], viewport[3], 0, 1000, -1000);
 261         gint ortho_hits = run_picking(opengl, (GdkEvent*)event, ortho, &top);
 262
 263         /* Update cursor */
 264         static GdkCursor *cursor = NULL;
 265         static GdkWindow *window = NULL;
 266         if (!window || !cursor) {
 267                 cursor = gdk_cursor_new(GDK_FLEUR);
 268                 window = gtk_widget_get_window(GTK_WIDGET(opengl));
 269         }
 270         GdkCursor *topcursor = top && top->cursor ? top->cursor : cursor;
 271         gdk_window_set_cursor(window, topcursor);
 272
 273         g_debug("GritsOpenGL: run_mouse_move - hits=%d/%d,%d/%d ev=%.0lf,%.0lf",
 274                         world_hits, world->len, ortho_hits, ortho->len, gl_x, gl_y);
 275
 276         g_ptr_array_free(world, TRUE);
 277         g_ptr_array_free(ortho, TRUE);
 278
 279         g_mutex_unlock(&opengl->objects_lock);
 280
 281         /* Test unproject */
 282         //gdouble lat, lon, elev;
 283         //grits_viewer_unproject(GRITS_VIEWER(opengl),
 284         //              gl_x, gl_y, -1, &lat, &lon, &elev);
 285
 286         /* Cleanup */
 287         glMatrixMode(GL_PROJECTION); glPopMatrix();
 288         glMatrixMode(GL_MODELVIEW);  glPopMatrix();
 289
 290         if (opengl->pickmode)
 291                 gtk_gl_end(GTK_WIDGET(opengl));
 292
 293         return FALSE;
 294 }
 295
 296 static gboolean on_motion_notify(GritsOpenGL *opengl, GdkEventMotion *event, gpointer _)
 297 {
 298         opengl->mouse_queue = *event;
 299         grits_viewer_queue_draw(GRITS_VIEWER(opengl));
 300         return FALSE;
 301 }
 302
 303 static void _draw_level(gpointer _level, gpointer _opengl)
 304 {
 305         GritsOpenGL *opengl = _opengl;
 306         struct RenderLevel *level = _level;
 307
 308         g_debug("GritsOpenGL: _draw_level - level=%-4d", level->num);
 309         int nsorted = 0, nunsorted = 0;
 310         GList *cur = NULL;
 311
 312         /* Configure individual levels */
 313         if (level->num < GRITS_LEVEL_WORLD) {
 314                 /* Disable depth for background levels */
 315                 glDepthMask(FALSE);
 316                 glDisable(GL_ALPHA_TEST);
 317         } else if (level->num < GRITS_LEVEL_OVERLAY) {
 318                 /* Enable depth and alpha for world levels */
 319                 glEnable(GL_ALPHA_TEST);
 320                 glAlphaFunc(GL_GREATER, 0.1);
 321                 glDepthRange(OVERLAY_SLICE, 1);
 322         } else {
 323                 /* Draw overlay in front of world */
 324                 glDepthRange(0, OVERLAY_SLICE);
 325         }
 326
 327         /* Start ortho */
 328         if (level->num >= GRITS_LEVEL_HUD) {
 329                 GtkAllocation alloc;
 330                 gtk_widget_get_allocation(GTK_WIDGET(opengl), &alloc);
 331                 glMatrixMode(GL_PROJECTION); glPushMatrix(); glLoadIdentity();
 332                 glMatrixMode(GL_MODELVIEW);  glPushMatrix(); glLoadIdentity();
 333                 glOrtho(0, alloc.width, alloc.height, 0, 1000, -1000);
 334         }
 335
 336         /* Draw unsorted objects without depth testing,
 337          * these are polygons, etc, rather than physical objects */
 338         glDisable(GL_DEPTH_TEST);
 339         for (cur = level->unsorted.next; cur; cur = cur->next, nunsorted++)
 340                 grits_object_draw(GRITS_OBJECT(cur->data), opengl);
 341
 342         /* Draw sorted objects using depth testing
 343          * These are things that are actually part of the world */
 344         glEnable(GL_DEPTH_TEST);
 345         for (cur = level->sorted.next; cur; cur = cur->next, nsorted++)
 346                 grits_object_draw(GRITS_OBJECT(cur->data), opengl);
 347
 348         /* End ortho */
 349         if (level->num >= GRITS_LEVEL_HUD) {
 350                 glMatrixMode(GL_PROJECTION); glPopMatrix();
 351                 glMatrixMode(GL_MODELVIEW);  glPopMatrix();
 352         }
 353
 354         /* Leave depth buffer write enabled */
 355         glDepthMask(TRUE);
 356
 357         /* TODO: Prune empty levels */
 358
 359         g_debug("GritsOpenGL: _draw_level - drew %d,%d objects",
 360                         nunsorted, nsorted);
 361 }
 362
 363 static gboolean on_expose(GritsOpenGL *opengl, gpointer data, gpointer _)
 364 {
 365         g_debug("GritsOpenGL: on_expose - begin");
 366
 367         if (opengl->pickmode)
 368                 return run_mouse_move(opengl, &(GdkEventMotion){});
 369
 370         if (opengl->mouse_queue.type != GDK_NOTHING) {
 371                 run_mouse_move(opengl, &opengl->mouse_queue);
 372                 opengl->mouse_queue.type = GDK_NOTHING;
 373         }
 374
 375         gtk_gl_begin(GTK_WIDGET(opengl));
 376
 377         _set_settings(opengl);
 378         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 379
 380 #ifndef ROAM_DEBUG
 381         g_mutex_lock(&opengl->sphere_lock);
 382         roam_sphere_update_errors(opengl->sphere);
 383         roam_sphere_split_merge(opengl->sphere);
 384         g_mutex_unlock(&opengl->sphere_lock);
 385 #endif
 386
 387 #ifdef ROAM_DEBUG
 388         roam_sphere_draw(opengl->sphere);
 389         roam_sphere_draw_normals(opengl->sphere);
 390         (void)_draw_level;
 391 #else
 392         g_mutex_lock(&opengl->objects_lock);
 393         g_queue_foreach(opengl->objects, _draw_level, opengl);
 394         g_mutex_unlock(&opengl->objects_lock);
 395 #endif
 396
 397         gtk_gl_end(GTK_WIDGET(opengl));
 398
 399         g_debug("GritsOpenGL: on_expose - end\n");
 400         return FALSE;
 401 }
 402
 403 static gboolean on_key_press(GritsOpenGL *opengl, GdkEventKey *event, gpointer _)
 404 {
 405         g_debug("GritsOpenGL: on_key_press - key=%x, state=%x, plus=%x",
 406                         event->keyval, event->state, GDK_KEY_plus);
 407
 408         guint kv = event->keyval;
 409         /* Testing */
 410         if (kv == GDK_KEY_w) {
 411                 opengl->wireframe = !opengl->wireframe;
 412                 grits_viewer_queue_draw(GRITS_VIEWER(opengl));
 413         }
 414         if (kv == GDK_KEY_p) {
 415                 opengl->pickmode = !opengl->pickmode;
 416                 grits_viewer_queue_draw(GRITS_VIEWER(opengl));
 417         }
 418 #ifdef ROAM_DEBUG
 419         else if (kv == GDK_KEY_n) roam_sphere_split_one(opengl->sphere);
 420         else if (kv == GDK_KEY_p) roam_sphere_merge_one(opengl->sphere);
 421         else if (kv == GDK_KEY_r) roam_sphere_split_merge(opengl->sphere);
 422         else if (kv == GDK_KEY_u) roam_sphere_update_errors(opengl->sphere);
 423         grits_viewer_queue_draw(GRITS_VIEWER(opengl));
 424 #endif
 425         return FALSE;
 426 }
 427
 428 static gboolean on_chained_event(GritsOpenGL *opengl, GdkEvent *event, gpointer _)
 429 {
 430         for (GList *i = opengl->objects->tail; i; i = i->prev) {
 431                 struct RenderLevel *level = i->data;
 432                 for (GList *j = level->unsorted.next; j; j = j->next)
 433                         if (grits_object_event(j->data, event))
 434                                 return TRUE;
 435                 for (GList *j = level->sorted.next;   j; j = j->next)
 436                         if (grits_object_event(j->data, event))
 437                                 return TRUE;
 438         }
 439         return FALSE;
 440 }
 441
 442 static void on_realize(GritsOpenGL *opengl, gpointer _)
 443 {
 444         g_debug("GritsOpenGL: on_realize");
 445         gtk_gl_begin(GTK_WIDGET(opengl));
 446
 447         /* Connect signals and idle functions now that opengl is fully initialized */
 448         gtk_widget_add_events(GTK_WIDGET(opengl), GDK_KEY_PRESS_MASK);
 449         g_signal_connect(opengl, "configure-event",  G_CALLBACK(_set_projection), NULL);
 450 #if GTK_CHECK_VERSION(3,0,0)
 451         g_signal_connect(opengl, "draw",             G_CALLBACK(on_expose),       NULL);
 452 #else
 453         g_signal_connect(opengl, "expose-event",     G_CALLBACK(on_expose),       NULL);
 454 #endif
 455
 456         g_signal_connect(opengl, "key-press-event",  G_CALLBACK(on_key_press),    NULL);
 457
 458         g_signal_connect(opengl, "location-changed", G_CALLBACK(_set_projection), NULL);
 459         g_signal_connect(opengl, "rotation-changed", G_CALLBACK(_set_projection), NULL);
 460
 461         g_signal_connect(opengl, "motion-notify-event", G_CALLBACK(on_motion_notify), NULL);
 462         g_signal_connect_after(opengl, "key-press-event",      G_CALLBACK(on_chained_event), NULL);
 463         g_signal_connect_after(opengl, "key-release-event",    G_CALLBACK(on_chained_event), NULL);
 464         g_signal_connect_after(opengl, "button-press-event",   G_CALLBACK(on_chained_event), NULL);
 465         g_signal_connect_after(opengl, "button-release-event", G_CALLBACK(on_chained_event), NULL);
 466         g_signal_connect_after(opengl, "motion-notify-event",  G_CALLBACK(on_chained_event), NULL);
 467
 468         /* Re-queue resize incase configure was triggered before realize */
 469         gtk_widget_queue_resize(GTK_WIDGET(opengl));
 470 }
 471
 472 /*********************
 473  * GritsViewer methods *
 474  *********************/
 475 /**
 476  * grits_opengl_new:
 477  * @plugins: the plugins store to use
 478  * @prefs:   the preferences object to use
 479  *
 480  * Create a new OpenGL renderer.
 481  *
 482  * Returns: the new #GritsOpenGL
 483  */
 484 GritsViewer *grits_opengl_new(GritsPlugins *plugins, GritsPrefs *prefs)
 485 {
 486         g_debug("GritsOpenGL: new");
 487         GritsViewer *opengl = g_object_new(GRITS_TYPE_OPENGL, NULL);
 488         grits_viewer_setup(opengl, plugins, prefs);
 489         return opengl;
 490 }
 491
 492 static void grits_opengl_center_position(GritsViewer *_opengl, gdouble lat, gdouble lon, gdouble elev)
 493 {
 494         glRotatef(lon, 0, 1, 0);
 495         glRotatef(-lat, 1, 0, 0);
 496         glTranslatef(0, 0, elev2rad(elev));
 497 }
 498
 499 static void grits_opengl_project(GritsViewer *_opengl,
 500                 gdouble lat, gdouble lon, gdouble elev,
 501                 gdouble *px, gdouble *py, gdouble *pz)
 502 {
 503         GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
 504         gdouble x, y, z;
 505         lle2xyz(lat, lon, elev, &x, &y, &z);
 506         gluProject(x, y, z,
 507                 opengl->sphere->view->model,
 508                 opengl->sphere->view->proj,
 509                 opengl->sphere->view->view,
 510                 px, py, pz);
 511 }
 512
 513 static void grits_opengl_unproject(GritsViewer *_opengl,
 514                 gdouble px, gdouble py, gdouble pz,
 515                 gdouble *lat, gdouble *lon, gdouble *elev)
 516 {
 517         GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
 518         if (!opengl->sphere->view)
 519                 return;
 520         gdouble x, y, z;
 521         if (pz < 0) {
 522                 gfloat tmp = 0;
 523                 glReadPixels(px, py, 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &tmp);
 524                 pz = tmp;
 525         }
 526         pz = (pz-OVERLAY_SLICE) * (1.0/(1-OVERLAY_SLICE));
 527         gluUnProject(px, py, pz,
 528                 opengl->sphere->view->model,
 529                 opengl->sphere->view->proj,
 530                 opengl->sphere->view->view,
 531                 &x, &y, &z);
 532         xyz2lle(x, y, z, lat, lon, elev);
 533         //g_message("GritsOpenGL: unproject - "
 534         //              "%4.0lf,%4.0lf,(%5.3lf) -> "
 535         //              "%8.0lf,%8.0lf,%8.0lf -> "
 536         //              "%6.2lf,%7.2lf,%4.0lf",
 537         //      px, py, pz, x, y, z, *lat, *lon, *elev);
 538 }
 539
 540 static void grits_opengl_set_height_func(GritsViewer *_opengl, GritsBounds *bounds,
 541                 RoamHeightFunc height_func, gpointer user_data, gboolean update)
 542 {
 543         GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
 544         /* TODO: get points? */
 545         g_mutex_lock(&opengl->sphere_lock);
 546         GList *triangles = roam_sphere_get_intersect(opengl->sphere, TRUE,
 547                         bounds->n, bounds->s, bounds->e, bounds->w);
 548         for (GList *cur = triangles; cur; cur = cur->next) {
 549                 RoamTriangle *tri = cur->data;
 550                 RoamPoint *points[] = {tri->p.l, tri->p.m, tri->p.r, tri->split};
 551                 for (int i = 0; i < G_N_ELEMENTS(points); i++) {
 552                         if (bounds->n >= points[i]->lat && points[i]->lat >= bounds->s &&
 553                             bounds->e >= points[i]->lon && points[i]->lon >= bounds->w) {
 554                                 points[i]->height_func = height_func;
 555                                 points[i]->height_data = user_data;
 556                                 roam_point_update_height(points[i]);
 557                         }
 558                 }
 559         }
 560         g_list_free(triangles);
 561         g_mutex_unlock(&opengl->sphere_lock);
 562 }
 563
 564 static void _grits_opengl_clear_height_func_rec(RoamTriangle *root)
 565 {
 566         if (!root)
 567                 return;
 568         RoamPoint *points[] = {root->p.l, root->p.m, root->p.r, root->split};
 569         for (int i = 0; i < G_N_ELEMENTS(points); i++) {
 570                 points[i]->height_func = NULL;
 571                 points[i]->height_data = NULL;
 572                 roam_point_update_height(points[i]);
 573         }
 574         _grits_opengl_clear_height_func_rec(root->kids[0]);
 575         _grits_opengl_clear_height_func_rec(root->kids[1]);
 576 }
 577
 578 static void grits_opengl_clear_height_func(GritsViewer *_opengl)
 579 {
 580         GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
 581         for (int i = 0; i < G_N_ELEMENTS(opengl->sphere->roots); i++)
 582                 _grits_opengl_clear_height_func_rec(opengl->sphere->roots[i]);
 583 }
 584
 585 static gint _objects_find(gconstpointer a, gconstpointer b)
 586 {
 587         const struct RenderLevel *level = a;
 588         const gint *key = b;
 589         return level->num == *key ? 0 : 1;
 590 }
 591
 592 static gint _objects_sort(gconstpointer _a, gconstpointer _b, gpointer _)
 593 {
 594         const struct RenderLevel *a = _a;
 595         const struct RenderLevel *b = _b;
 596         return a->num < b->num ? -1 :
 597                a->num > b->num ?  1 : 0;
 598 }
 599
 600 static void _objects_free(gpointer value, gpointer _)
 601 {
 602         struct RenderLevel *level = value;
 603         if (level->sorted.next)
 604                 g_list_free_full(level->sorted.next, g_object_unref);
 605         if (level->unsorted.next)
 606                 g_list_free_full(level->unsorted.next, g_object_unref);
 607         g_free(level);
 608 }
 609
 610 static void grits_opengl_add(GritsViewer *_opengl, GritsObject *object,
 611                 gint num, gboolean sort)
 612 {
 613         g_assert(GRITS_IS_OPENGL(_opengl));
 614         GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
 615         g_mutex_lock(&opengl->objects_lock);
 616         struct RenderLevel *level = NULL;
 617         GList *tmp = g_queue_find_custom(opengl->objects, &num, _objects_find);
 618         if (tmp) {
 619                 level = tmp->data;
 620         } else {
 621                 level = g_new0(struct RenderLevel, 1);
 622                 level->num = num;
 623                 g_queue_insert_sorted(opengl->objects, level, _objects_sort, NULL);
 624         }
 625         GList *list = sort ? &level->sorted : &level->unsorted;
 626         /* Put the link in the list */
 627         GList *link = g_new0(GList, 1);
 628         link->data = object;
 629         link->prev = list;
 630         link->next = list->next;
 631         if (list->next)
 632                 list->next->prev = link;
 633         list->next = link;
 634         object->ref = link;
 635         g_object_ref(object);
 636         g_mutex_unlock(&opengl->objects_lock);
 637 }
 638
 639 void grits_opengl_remove(GritsViewer *_opengl, GritsObject *object)
 640 {
 641         g_assert(GRITS_IS_OPENGL(_opengl));
 642         GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
 643         if (!object->ref)
 644                 return;
 645         g_mutex_lock(&opengl->objects_lock);
 646         GList *link = object->ref;
 647         /* Just unlink and free it, link->prev is assured */
 648         link->prev->next = link->next;
 649         if (link->next)
 650                 link->next->prev = link->prev;
 651         g_free(link);
 652         object->ref = NULL;
 653         g_object_unref(object);
 654         g_mutex_unlock(&opengl->objects_lock);
 655 }
 656
 657 /****************
 658  * GObject code *
 659  ****************/
 660 G_DEFINE_TYPE(GritsOpenGL, grits_opengl, GRITS_TYPE_VIEWER);
 661 static void grits_opengl_init(GritsOpenGL *opengl)
 662 {
 663         g_debug("GritsOpenGL: init");
 664         opengl->objects = g_queue_new();
 665         opengl->sphere  = roam_sphere_new(opengl);
 666         g_mutex_init(&opengl->objects_lock);
 667         g_mutex_init(&opengl->sphere_lock);
 668         gtk_gl_enable(GTK_WIDGET(opengl));
 669         gtk_widget_add_events(GTK_WIDGET(opengl), GDK_KEY_PRESS_MASK);
 670         g_signal_connect(opengl, "map", G_CALLBACK(on_realize), NULL);
 671 }
 672 static void grits_opengl_dispose(GObject *_opengl)
 673 {
 674         g_debug("GritsOpenGL: dispose");
 675         GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
 676         if (opengl->objects) {
 677                 GQueue *objects = opengl->objects;;
 678                 opengl->objects = NULL;
 679                 g_mutex_lock(&opengl->objects_lock);
 680                 g_queue_foreach(objects, _objects_free, NULL);
 681                 g_queue_free(objects);
 682                 g_mutex_unlock(&opengl->objects_lock);
 683         }
 684         G_OBJECT_CLASS(grits_opengl_parent_class)->dispose(_opengl);
 685 }
 686 static void grits_opengl_finalize(GObject *_opengl)
 687 {
 688         g_debug("GritsOpenGL: finalize");
 689         GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
 690         roam_sphere_free(opengl->sphere);
 691         g_mutex_clear(&opengl->objects_lock);
 692         g_mutex_clear(&opengl->sphere_lock);
 693         gtk_gl_disable(GTK_WIDGET(opengl));
 694         G_OBJECT_CLASS(grits_opengl_parent_class)->finalize(_opengl);
 695 }
 696 static void grits_opengl_class_init(GritsOpenGLClass *klass)
 697 {
 698         g_debug("GritsOpenGL: class_init");
 699         GObjectClass *gobject_class = G_OBJECT_CLASS(klass);
 700         gobject_class->finalize = grits_opengl_finalize;
 701         gobject_class->dispose = grits_opengl_dispose;
 702
 703         GritsViewerClass *viewer_class = GRITS_VIEWER_CLASS(klass);
 704         viewer_class->center_position   = grits_opengl_center_position;
 705         viewer_class->project           = grits_opengl_project;
 706         viewer_class->unproject         = grits_opengl_unproject;
 707         viewer_class->clear_height_func = grits_opengl_clear_height_func;
 708         viewer_class->set_height_func   = grits_opengl_set_height_func;
 709         viewer_class->add               = grits_opengl_add;
 710         viewer_class->remove            = grits_opengl_remove;
 711 }