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

   1 /*
   2  * Copyright (C) 2009-2010 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:gis-opengl
  20  * @short_description: OpenGL based virtual globe
  21  *
  22  * #GisOpenGL is the core rendering engine used by libgis. Theoretically other
  23  * renderers could be writte, but they have not been. GisOpenGL uses the ROAM
  24  * algorithm for updating surface mesh the planet. The only thing GisOpenGL can
  25  * actually render on it's own is a wireframe of a sphere.
  26  *
  27  * GisOpenGL relies on #GtkGlExt and 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 #include <gtk/gtkgl.h>
  36 #include <GL/gl.h>
  37 #include <GL/glu.h>
  38
  39 #include "gis-opengl.h"
  40 #include "gis-util.h"
  41 #include "roam.h"
  42
  43 // #define ROAM_DEBUG
  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 /***********
  50  * Helpers *
  51  ***********/
  52 static void _set_visuals(GisOpenGL *opengl)
  53 {
  54         glMatrixMode(GL_MODELVIEW);
  55         glLoadIdentity();
  56
  57         /* Camera 1 */
  58         double lat, lon, elev, rx, ry, rz;
  59         gis_viewer_get_location(GIS_VIEWER(opengl), &lat, &lon, &elev);
  60         gis_viewer_get_rotation(GIS_VIEWER(opengl), &rx, &ry, &rz);
  61         glRotatef(rx, 1, 0, 0);
  62         glRotatef(rz, 0, 0, 1);
  63
  64         /* Lighting */
  65 #ifdef ROAM_DEBUG
  66         float light_ambient[]  = {0.7f, 0.7f, 0.7f, 1.0f};
  67         float light_diffuse[]  = {2.0f, 2.0f, 2.0f, 1.0f};
  68 #else
  69         float light_ambient[]  = {0.2f, 0.2f, 0.2f, 1.0f};
  70         float light_diffuse[]  = {5.0f, 5.0f, 5.0f, 1.0f};
  71 #endif
  72         float light_position[] = {-13*EARTH_R, 1*EARTH_R, 3*EARTH_R, 1.0f};
  73         glLightfv(GL_LIGHT0, GL_AMBIENT,  light_ambient);
  74         glLightfv(GL_LIGHT0, GL_DIFFUSE,  light_diffuse);
  75         glLightfv(GL_LIGHT0, GL_POSITION, light_position);
  76         glEnable(GL_LIGHT0);
  77         glEnable(GL_LIGHTING);
  78
  79         float material_ambient[]  = {0.2, 0.2, 0.2, 1.0};
  80         float material_diffuse[]  = {0.8, 0.8, 0.8, 1.0};
  81         float material_specular[] = {0.1, 0.1, 0.1, 1.0};
  82         float material_emission[] = {0.0, 0.0, 0.0, 1.0};
  83         glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT,  material_ambient);
  84         glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE,  material_diffuse);
  85         glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, material_specular);
  86         glMaterialfv(GL_FRONT_AND_BACK, GL_EMISSION, material_emission);
  87         glDisable(GL_TEXTURE_2D);
  88         glDisable(GL_COLOR_MATERIAL);
  89
  90         /* Camera 2 */
  91         glTranslatef(0, 0, -elev2rad(elev));
  92         glRotatef(lat, 1, 0, 0);
  93         glRotatef(-lon, 0, 1, 0);
  94
  95         glDisable(GL_ALPHA_TEST);
  96
  97         glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
  98         glEnable(GL_BLEND);
  99
 100 #ifndef ROAM_DEBUG
 101         glCullFace(GL_BACK);
 102         glEnable(GL_CULL_FACE);
 103
 104         glClearDepth(1.0);
 105         glDepthFunc(GL_LEQUAL);
 106         glEnable(GL_DEPTH_TEST);
 107 #endif
 108
 109         glEnable(GL_LINE_SMOOTH);
 110
 111         glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
 112         //glShadeModel(GL_FLAT);
 113
 114         g_mutex_lock(opengl->sphere_lock);
 115         roam_sphere_update_view(opengl->sphere);
 116         g_mutex_unlock(opengl->sphere_lock);
 117 }
 118
 119
 120 /*************
 121  * Callbacks *
 122  *************/
 123 /* The unsorted/sroted GLists are blank head nodes,
 124  * This way us we can remove objects from the level just by fixing up links
 125  * I.e. we don't need to do a lookup to remove an object if we have its GList */
 126 struct RenderLevel {
 127         GList unsorted;
 128         GList sorted;
 129 };
 130
 131 static gboolean on_configure(GisOpenGL *opengl, GdkEventConfigure *event, gpointer _)
 132 {
 133         g_debug("GisOpenGL: on_configure");
 134
 135         double width  = GTK_WIDGET(opengl)->allocation.width;
 136         double height = GTK_WIDGET(opengl)->allocation.height;
 137
 138         /* Setup OpenGL Window */
 139         glViewport(0, 0, width, height);
 140         glMatrixMode(GL_PROJECTION);
 141         glLoadIdentity();
 142         double ang = atan(height/FOV_DIST);
 143         gluPerspective(rad2deg(ang)*2, width/height, 1000, 10*EARTH_R);
 144
 145 #ifndef ROAM_DEBUG
 146         g_mutex_lock(opengl->sphere_lock);
 147         roam_sphere_update_errors(opengl->sphere);
 148         g_mutex_unlock(opengl->sphere_lock);
 149 #endif
 150
 151         return FALSE;
 152 }
 153
 154 static void on_realize(GisOpenGL *opengl, gpointer _)
 155 {
 156         g_debug("GisOpenGL: on_realize");
 157
 158         GdkGLContext   *glcontext  = gtk_widget_get_gl_context(GTK_WIDGET(opengl));
 159         GdkGLDrawable  *gldrawable = gtk_widget_get_gl_drawable(GTK_WIDGET(opengl));
 160         if (!gdk_gl_drawable_gl_begin(gldrawable, glcontext))
 161                 g_assert_not_reached();
 162
 163         _set_visuals(opengl);
 164         on_configure(opengl, NULL, NULL);
 165 }
 166
 167 static gboolean _draw_level(gpointer key, gpointer value, gpointer user_data)
 168 {
 169         g_debug("GisOpenGL: _draw_level - level=%-4d", (int)key);
 170         GisOpenGL *opengl = user_data;
 171         struct RenderLevel *level = value;
 172         int nsorted = 0, nunsorted = 0;
 173         GList *cur = NULL;
 174
 175         /* Draw opaque objects without sorting */
 176         glDepthMask(TRUE);
 177         glClear(GL_DEPTH_BUFFER_BIT);
 178         for (cur = level->unsorted.next; cur; cur = cur->next, nunsorted++)
 179                 gis_object_draw( GIS_OBJECT(cur->data), opengl);
 180
 181         /* Freeze depth buffer and draw transparent objects sorted */
 182         /* TODO: sorting */
 183         //glDepthMask(FALSE);
 184         glAlphaFunc(GL_GREATER, 0.1);
 185         for (cur = level->sorted.next; cur; cur = cur->next, nsorted++)
 186                 gis_object_draw(GIS_OBJECT(cur->data), opengl);
 187
 188         /* TODO: Prune empty levels */
 189
 190         g_debug("GisOpenGL: _draw_level - drew %d,%d objects",
 191                         nunsorted, nsorted);
 192         return FALSE;
 193 }
 194
 195 static gboolean on_expose(GisOpenGL *opengl, GdkEventExpose *event, gpointer _)
 196 {
 197         g_debug("GisOpenGL: on_expose - begin");
 198
 199         glClear(GL_COLOR_BUFFER_BIT);
 200
 201         _set_visuals(opengl);
 202 #ifdef ROAM_DEBUG
 203         glColor4f(1.0, 1.0, 1.0, 1.0);
 204         glLineWidth(2);
 205         glDisable(GL_TEXTURE_2D);
 206         glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
 207         roam_sphere_draw(opengl->sphere);
 208         (void)_draw_level;
 209         //roam_sphere_draw_normals(opengl->sphere);
 210 #else
 211         g_mutex_lock(opengl->objects_lock);
 212         g_tree_foreach(opengl->objects, _draw_level, opengl);
 213         if (opengl->wireframe) {
 214                 glClear(GL_DEPTH_BUFFER_BIT);
 215                 glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
 216                 roam_sphere_draw(opengl->sphere);
 217         }
 218         g_mutex_unlock(opengl->objects_lock);
 219 #endif
 220
 221         GdkGLDrawable *gldrawable = gtk_widget_get_gl_drawable(GTK_WIDGET(opengl));
 222         gdk_gl_drawable_swap_buffers(gldrawable);
 223
 224         g_debug("GisOpenGL: on_expose - end\n");
 225         return FALSE;
 226 }
 227
 228 static gboolean on_key_press(GisOpenGL *opengl, GdkEventKey *event, gpointer _)
 229 {
 230         g_debug("GisOpenGL: on_key_press - key=%x, state=%x, plus=%x",
 231                         event->keyval, event->state, GDK_plus);
 232
 233         guint kv = event->keyval;
 234         /* Testing */
 235         if (kv == GDK_w) {
 236                 opengl->wireframe = !opengl->wireframe;
 237                 gtk_widget_queue_draw(GTK_WIDGET(opengl));
 238         }
 239 #ifdef ROAM_DEBUG
 240         else if (kv == GDK_n) roam_sphere_split_one(opengl->sphere);
 241         else if (kv == GDK_p) roam_sphere_merge_one(opengl->sphere);
 242         else if (kv == GDK_r) roam_sphere_split_merge(opengl->sphere);
 243         else if (kv == GDK_u) roam_sphere_update_errors(opengl->sphere);
 244         gtk_widget_queue_draw(GTK_WIDGET(opengl));
 245 #endif
 246         return FALSE;
 247 }
 248
 249 static gboolean _update_errors_cb(gpointer _opengl)
 250 {
 251         GisOpenGL *opengl = _opengl;
 252         g_mutex_lock(opengl->sphere_lock);
 253         roam_sphere_update_errors(opengl->sphere);
 254         g_mutex_unlock(opengl->sphere_lock);
 255         opengl->ue_source = 0;
 256         return FALSE;
 257 }
 258 static void on_view_changed(GisOpenGL *opengl,
 259                 gdouble _1, gdouble _2, gdouble _3)
 260 {
 261         g_debug("GisOpenGL: on_view_changed");
 262         _set_visuals(opengl);
 263 #ifndef ROAM_DEBUG
 264         if (!opengl->ue_source)
 265                 opengl->ue_source = g_idle_add_full(G_PRIORITY_HIGH_IDLE+30,
 266                                 _update_errors_cb, opengl, NULL);
 267         //roam_sphere_update_errors(opengl->sphere);
 268 #else
 269         (void)_update_errors_cb;
 270 #endif
 271 }
 272
 273 static gboolean on_idle(GisOpenGL *opengl)
 274 {
 275         //g_debug("GisOpenGL: on_idle");
 276         g_mutex_lock(opengl->sphere_lock);
 277         if (roam_sphere_split_merge(opengl->sphere))
 278                 gtk_widget_queue_draw(GTK_WIDGET(opengl));
 279         g_mutex_unlock(opengl->sphere_lock);
 280         return TRUE;
 281 }
 282
 283
 284 /*********************
 285  * GisViewer methods *
 286  *********************/
 287 /**
 288  * gis_opengl_new:
 289  * @plugins: the plugins store to use
 290  * @prefs:   the preferences object to use
 291  *
 292  * Create a new OpenGL renderer.
 293  *
 294  * Returns: the new #GisOpenGL
 295  */
 296 GisViewer *gis_opengl_new(GisPlugins *plugins, GisPrefs *prefs)
 297 {
 298         g_debug("GisOpenGL: new");
 299         GisViewer *opengl = g_object_new(GIS_TYPE_OPENGL, NULL);
 300         gis_viewer_setup(opengl, plugins, prefs);
 301         return opengl;
 302 }
 303
 304 static void gis_opengl_center_position(GisViewer *_opengl, gdouble lat, gdouble lon, gdouble elev)
 305 {
 306         glRotatef(lon, 0, 1, 0);
 307         glRotatef(-lat, 1, 0, 0);
 308         glTranslatef(0, 0, elev2rad(elev));
 309 }
 310
 311 static void gis_opengl_project(GisViewer *_opengl,
 312                 gdouble lat, gdouble lon, gdouble elev,
 313                 gdouble *px, gdouble *py, gdouble *pz)
 314 {
 315         GisOpenGL *opengl = GIS_OPENGL(_opengl);
 316         gdouble x, y, z;
 317         lle2xyz(lat, lon, elev, &x, &y, &z);
 318         gluProject(x, y, z,
 319                 opengl->sphere->view->model,
 320                 opengl->sphere->view->proj,
 321                 opengl->sphere->view->view,
 322                 px, py, pz);
 323 }
 324
 325 static void gis_opengl_set_height_func(GisViewer *_opengl, GisBounds *bounds,
 326                 RoamHeightFunc height_func, gpointer user_data, gboolean update)
 327 {
 328         GisOpenGL *opengl = GIS_OPENGL(_opengl);
 329         /* TODO: get points? */
 330         g_mutex_lock(opengl->sphere_lock);
 331         GList *triangles = roam_sphere_get_intersect(opengl->sphere, TRUE,
 332                         bounds->n, bounds->s, bounds->e, bounds->w);
 333         for (GList *cur = triangles; cur; cur = cur->next) {
 334                 RoamTriangle *tri = cur->data;
 335                 RoamPoint *points[] = {tri->p.l, tri->p.m, tri->p.r, tri->split};
 336                 for (int i = 0; i < G_N_ELEMENTS(points); i++) {
 337                         if (bounds->n >= points[i]->lat && points[i]->lat >= bounds->s &&
 338                             bounds->e >= points[i]->lon && points[i]->lon >= bounds->w) {
 339                                 points[i]->height_func = height_func;
 340                                 points[i]->height_data = user_data;
 341                                 roam_point_update_height(points[i]);
 342                         }
 343                 }
 344         }
 345         g_list_free(triangles);
 346         g_mutex_unlock(opengl->sphere_lock);
 347 }
 348
 349 static void _gis_opengl_clear_height_func_rec(RoamTriangle *root)
 350 {
 351         if (!root)
 352                 return;
 353         RoamPoint *points[] = {root->p.l, root->p.m, root->p.r, root->split};
 354         for (int i = 0; i < G_N_ELEMENTS(points); i++) {
 355                 points[i]->height_func = NULL;
 356                 points[i]->height_data = NULL;
 357                 roam_point_update_height(points[i]);
 358         }
 359         _gis_opengl_clear_height_func_rec(root->kids[0]);
 360         _gis_opengl_clear_height_func_rec(root->kids[1]);
 361 }
 362
 363 static void gis_opengl_clear_height_func(GisViewer *_opengl)
 364 {
 365         GisOpenGL *opengl = GIS_OPENGL(_opengl);
 366         for (int i = 0; i < G_N_ELEMENTS(opengl->sphere->roots); i++)
 367                 _gis_opengl_clear_height_func_rec(opengl->sphere->roots[i]);
 368 }
 369
 370 static gpointer gis_opengl_add(GisViewer *_opengl, GisObject *object,
 371                 gint key, gboolean sort)
 372 {
 373         g_assert(GIS_IS_OPENGL(_opengl));
 374         GisOpenGL *opengl = GIS_OPENGL(_opengl);
 375         g_mutex_lock(opengl->objects_lock);
 376         struct RenderLevel *level = g_tree_lookup(opengl->objects, (gpointer)key);
 377         if (!level) {
 378                 level = g_new0(struct RenderLevel, 1);
 379                 g_tree_insert(opengl->objects, (gpointer)key, level);
 380         }
 381         GList *list = sort ? &level->sorted : &level->unsorted;
 382         /* Put the link in the list */
 383         GList *link = g_new0(GList, 1);
 384         link->data = object;
 385         link->prev = list;
 386         link->next = list->next;
 387         if (list->next)
 388                 list->next->prev = link;
 389         list->next = link;
 390         g_mutex_unlock(opengl->objects_lock);
 391         return link;
 392 }
 393
 394 static GisObject *gis_opengl_remove(GisViewer *_opengl, gpointer _link)
 395 {
 396         g_assert(GIS_IS_OPENGL(_opengl));
 397         GisOpenGL *opengl = GIS_OPENGL(_opengl);
 398         g_mutex_lock(opengl->objects_lock);
 399         GList *link = _link;
 400         GisObject *object = link->data;
 401         /* Just unlink and free it, link->prev is assured */
 402         link->prev->next = link->next;
 403         if (link->next)
 404                 link->next->prev = link->prev;
 405         g_free(link);
 406         g_object_unref(object);
 407         g_mutex_unlock(opengl->objects_lock);
 408         return object;
 409 }
 410
 411 /****************
 412  * GObject code *
 413  ****************/
 414 static int _objects_cmp(gconstpointer _a, gconstpointer _b, gpointer _)
 415 {
 416         gint a = (int)_a, b = (int)_b;
 417         return a < b ? -1 :
 418                a > b ?  1 : 0;
 419 }
 420 static void _objects_free(gpointer value)
 421 {
 422         struct RenderLevel *level = value;
 423         if (level->sorted.next)
 424                 g_list_free(level->sorted.next);
 425         if (level->unsorted.next)
 426                 g_list_free(level->unsorted.next);
 427         g_free(level);
 428 }
 429
 430 G_DEFINE_TYPE(GisOpenGL, gis_opengl, GIS_TYPE_VIEWER);
 431 static void gis_opengl_init(GisOpenGL *opengl)
 432 {
 433         g_debug("GisOpenGL: init");
 434         /* OpenGL setup */
 435         GdkGLConfig *glconfig = gdk_gl_config_new_by_mode(
 436                         GDK_GL_MODE_RGBA   | GDK_GL_MODE_DEPTH |
 437                         GDK_GL_MODE_DOUBLE | GDK_GL_MODE_ALPHA);
 438         if (!glconfig)
 439                 g_error("Failed to create glconfig");
 440         if (!gtk_widget_set_gl_capability(GTK_WIDGET(opengl),
 441                                 glconfig, NULL, TRUE, GDK_GL_RGBA_TYPE))
 442                 g_error("GL lacks required capabilities");
 443         g_object_unref(glconfig);
 444
 445         opengl->objects = g_tree_new_full(_objects_cmp, NULL, NULL, _objects_free);
 446         opengl->objects_lock = g_mutex_new();
 447         opengl->sphere = roam_sphere_new(opengl);
 448         opengl->sphere_lock = g_mutex_new();
 449
 450 #ifndef ROAM_DEBUG
 451         opengl->sm_source[0] = g_timeout_add_full(G_PRIORITY_HIGH_IDLE+30, 33,  (GSourceFunc)on_idle, opengl, NULL);
 452         opengl->sm_source[1] = g_timeout_add_full(G_PRIORITY_HIGH_IDLE+10, 500, (GSourceFunc)on_idle, opengl, NULL);
 453 #else
 454         (void)on_idle;
 455         (void)_update_errors_cb;
 456 #endif
 457
 458         gtk_widget_add_events(GTK_WIDGET(opengl), GDK_KEY_PRESS_MASK);
 459         g_signal_connect(opengl, "realize",          G_CALLBACK(on_realize),      NULL);
 460         g_signal_connect(opengl, "configure-event",  G_CALLBACK(on_configure),    NULL);
 461         g_signal_connect(opengl, "expose-event",     G_CALLBACK(on_expose),       NULL);
 462
 463         g_signal_connect(opengl, "key-press-event",  G_CALLBACK(on_key_press),    NULL);
 464
 465         g_signal_connect(opengl, "location-changed", G_CALLBACK(on_view_changed), NULL);
 466         g_signal_connect(opengl, "rotation-changed", G_CALLBACK(on_view_changed), NULL);
 467 }
 468 static void gis_opengl_dispose(GObject *_opengl)
 469 {
 470         g_debug("GisOpenGL: dispose");
 471         GisOpenGL *opengl = GIS_OPENGL(_opengl);
 472         if (opengl->sm_source[0]) {
 473                 g_source_remove(opengl->sm_source[0]);
 474                 opengl->sm_source[0] = 0;
 475         }
 476         if (opengl->sm_source[1]) {
 477                 g_source_remove(opengl->sm_source[1]);
 478                 opengl->sm_source[1] = 0;
 479         }
 480         if (opengl->ue_source) {
 481                 g_source_remove(opengl->ue_source);
 482                 opengl->ue_source = 0;
 483         }
 484         G_OBJECT_CLASS(gis_opengl_parent_class)->dispose(_opengl);
 485 }
 486 static void gis_opengl_finalize(GObject *_opengl)
 487 {
 488         g_debug("GisOpenGL: finalize");
 489         GisOpenGL *opengl = GIS_OPENGL(_opengl);
 490         roam_sphere_free(opengl->sphere);
 491         g_tree_destroy(opengl->objects);
 492         g_mutex_free(opengl->objects_lock);
 493         g_mutex_free(opengl->sphere_lock);
 494         G_OBJECT_CLASS(gis_opengl_parent_class)->finalize(_opengl);
 495 }
 496 static void gis_opengl_class_init(GisOpenGLClass *klass)
 497 {
 498         g_debug("GisOpenGL: class_init");
 499         GObjectClass *gobject_class = G_OBJECT_CLASS(klass);
 500         gobject_class->finalize = gis_opengl_finalize;
 501         gobject_class->dispose = gis_opengl_dispose;
 502
 503         GisViewerClass *viewer_class = GIS_VIEWER_CLASS(klass);
 504         viewer_class->center_position   = gis_opengl_center_position;
 505         viewer_class->project           = gis_opengl_project;
 506         viewer_class->clear_height_func = gis_opengl_clear_height_func;
 507         viewer_class->set_height_func   = gis_opengl_set_height_func;
 508         viewer_class->add               = gis_opengl_add;
 509         viewer_class->remove            = gis_opengl_remove;
 510 }