2 * Copyright (C) 2009-2011 Andy Spencer <andy753421@gmail.com>
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.
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.
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/>.
19 * SECTION:grits-opengl
20 * @short_description: OpenGL based virtual globe
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.
27 * GritsOpenGL requires (at least) OpenGL 2.0.
33 #include <gdk/gdkkeysyms.h>
36 #include "grits-opengl.h"
37 #include "grits-util.h"
43 /* Tessellation, "finding intersecting triangles" */
44 /* http://research.microsoft.com/pubs/70307/tr-2006-81.pdf */
45 /* http://www.opengl.org/wiki/Alpha_Blending */
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 */
58 static void _set_visuals(GritsOpenGL *opengl)
60 double lat, lon, elev, rx, ry, rz;
61 grits_viewer_get_location(GRITS_VIEWER(opengl), &lat, &lon, &elev);
62 grits_viewer_get_rotation(GRITS_VIEWER(opengl), &rx, &ry, &rz);
64 /* Set projection and clipping planes */
65 glMatrixMode(GL_PROJECTION);
68 double width = GTK_WIDGET(opengl)->allocation.width;
69 double height = GTK_WIDGET(opengl)->allocation.height;
70 double ang = atan((height/2)/FOV_DIST)*2;
71 double atmos = 100000;
72 double near = MAX(elev*0.75 - atmos, 50); // View 100km of atmosphere
73 double far = elev + 2*EARTH_R + atmos; // on both sides of the earth
75 grits_viewer_get_location(GRITS_VIEWER(opengl), &lat, &lon, &elev);
76 glViewport(0, 0, width, height);
77 gluPerspective(rad2deg(ang), width/height, near, far);
79 /* Setup camera and lighting */
80 glMatrixMode(GL_MODELVIEW);
84 glRotatef(rx, 1, 0, 0);
85 glRotatef(rz, 0, 0, 1);
89 float light_ambient[] = {0.7f, 0.7f, 0.7f, 1.0f};
90 float light_diffuse[] = {2.0f, 2.0f, 2.0f, 1.0f};
92 float light_ambient[] = {0.2f, 0.2f, 0.2f, 1.0f};
93 float light_diffuse[] = {0.8f, 0.8f, 0.8f, 1.0f};
95 float light_position[] = {-13*EARTH_R, 1*EARTH_R, 3*EARTH_R, 1.0f};
96 glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
97 glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
98 glLightfv(GL_LIGHT0, GL_POSITION, light_position);
100 glEnable(GL_LIGHTING);
102 float material_ambient[] = {1.0, 1.0, 1.0, 1.0};
103 float material_diffuse[] = {1.0, 1.0, 1.0, 1.0};
104 float material_specular[] = {0.0, 0.0, 0.0, 1.0};
105 float material_emission[] = {0.0, 0.0, 0.0, 1.0};
106 glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, material_ambient);
107 glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, material_diffuse);
108 glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, material_specular);
109 glMaterialfv(GL_FRONT_AND_BACK, GL_EMISSION, material_emission);
110 glDisable(GL_TEXTURE_2D);
111 glDisable(GL_COLOR_MATERIAL);
114 glTranslatef(0, 0, -elev2rad(elev));
115 glRotatef(lat, 1, 0, 0);
116 glRotatef(-lon, 0, 1, 0);
118 glDisable(GL_ALPHA_TEST);
120 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
125 glEnable(GL_CULL_FACE);
128 glDepthFunc(GL_LEQUAL);
129 glEnable(GL_DEPTH_TEST);
132 glEnable(GL_LINE_SMOOTH);
134 glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
135 //glShadeModel(GL_FLAT);
137 g_mutex_lock(opengl->sphere_lock);
138 roam_sphere_update_view(opengl->sphere);
139 g_mutex_unlock(opengl->sphere_lock);
142 static gboolean _foreach_object_cb(gpointer key, gpointer value, gpointer pointers)
144 struct RenderLevel *level = value;
145 GFunc user_func = ((gpointer*)pointers)[0];
146 gpointer user_data = ((gpointer*)pointers)[1];
147 for (GList *cur = level->unsorted.next; cur; cur = cur->next)
148 user_func(cur->data, user_data);
149 for (GList *cur = level->sorted.next; cur; cur = cur->next)
150 user_func(cur->data, user_data);
154 static void _foreach_object(GritsOpenGL *opengl, GFunc func, gpointer user_data)
156 gpointer pointers[2] = {func, user_data};
157 g_tree_foreach(opengl->objects, _foreach_object_cb, pointers);
160 static void _add_object(GritsObject *object, GPtrArray *array)
162 g_ptr_array_add(array, object);
165 static GPtrArray *_objects_to_array(GritsOpenGL *opengl)
167 GPtrArray *array = g_ptr_array_new();
168 _foreach_object(opengl, (GFunc)_add_object, array);
175 static gboolean on_configure(GritsOpenGL *opengl, GdkEventConfigure *event, gpointer _)
177 g_debug("GritsOpenGL: on_configure");
179 _set_visuals(opengl);
181 g_mutex_lock(opengl->sphere_lock);
182 roam_sphere_update_errors(opengl->sphere);
183 g_mutex_unlock(opengl->sphere_lock);
189 static gboolean _draw_level(gpointer key, gpointer value, gpointer user_data)
191 GritsOpenGL *opengl = user_data;
192 glong lnum = (glong)key;
193 struct RenderLevel *level = value;
195 g_debug("GritsOpenGL: _draw_level - level=%-4ld", lnum);
196 int nsorted = 0, nunsorted = 0;
199 /* Configure individual levels */
200 if (lnum < GRITS_LEVEL_WORLD) {
201 /* Disable depth for background levels */
203 glDisable(GL_ALPHA_TEST);
204 } else if (lnum < GRITS_LEVEL_OVERLAY) {
205 /* Enable depth and alpha for world levels */
206 glEnable(GL_ALPHA_TEST);
207 glAlphaFunc(GL_GREATER, 0.1);
210 /* Disable depth for Overlay/HUD levels */
211 // This causes rendering glitches not sure why..
212 //glDepthMask(FALSE);
215 /* Draw unsorted objects without depth testing,
216 * these are polygons, etc, rather than physical objects */
217 glDisable(GL_DEPTH_TEST);
218 for (cur = level->unsorted.next; cur; cur = cur->next, nunsorted++)
219 grits_object_draw(GRITS_OBJECT(cur->data), opengl);
221 /* Draw sorted objects using depth testing
222 * These are things that are actually part of the world */
223 glEnable(GL_DEPTH_TEST);
224 for (cur = level->sorted.next; cur; cur = cur->next, nsorted++)
225 grits_object_draw(GRITS_OBJECT(cur->data), opengl);
227 /* TODO: Prune empty levels */
229 g_debug("GritsOpenGL: _draw_level - drew %d,%d objects",
234 static gboolean on_expose(GritsOpenGL *opengl, GdkEventExpose *event, gpointer _)
236 g_debug("GritsOpenGL: on_expose - begin");
238 gtk_gl_begin(GTK_WIDGET(opengl));
240 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
242 _set_visuals(opengl);
244 glColor4f(1.0, 1.0, 1.0, 1.0);
246 glDisable(GL_TEXTURE_2D);
247 glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
248 roam_sphere_draw(opengl->sphere);
250 //roam_sphere_draw_normals(opengl->sphere);
252 g_mutex_lock(opengl->objects_lock);
253 if (opengl->wireframe)
254 glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
255 g_tree_foreach(opengl->objects, _draw_level, opengl);
256 g_mutex_unlock(opengl->objects_lock);
259 gtk_gl_end(GTK_WIDGET(opengl));
261 g_debug("GritsOpenGL: on_expose - end\n");
265 static gboolean on_motion_notify(GritsOpenGL *opengl, GdkEventMotion *event, gpointer _)
267 gdouble height = GTK_WIDGET(opengl)->allocation.height;
268 gdouble gl_x = event->x;
269 gdouble gl_y = height - event->y;
273 gdouble projection[16];
274 glGetIntegerv(GL_VIEWPORT, viewport);
275 glGetDoublev(GL_PROJECTION_MATRIX, projection);
277 glMatrixMode(GL_PROJECTION);
280 gluPickMatrix(gl_x, gl_y, 2, 2, viewport);
281 glMultMatrixd(projection);
283 /* Prepare for picking */
284 guint buffer[100][4] = {};
285 glSelectBuffer(G_N_ELEMENTS(buffer), (guint*)buffer);
286 glRenderMode(GL_SELECT);
290 g_mutex_lock(opengl->objects_lock);
291 GPtrArray *objects = _objects_to_array(opengl);
292 for (guint i = 0; i < objects->len; i++) {
294 GritsObject *object = objects->pdata[i];
295 object->state.picked = FALSE;
296 grits_object_pick(object, opengl);
299 int hits = glRenderMode(GL_RENDER);
300 g_debug("GritsOpenGL: on_motion_notify - hits=%d ev=%.0lf,%.0lf",
302 for (int i = 0; i < hits; i++) {
303 //g_debug("\tHit: %d", i);
304 //g_debug("\t\tcount: %d", buffer[i][0]);
305 //g_debug("\t\tz1: %f", (float)buffer[i][1]/0x7fffffff);
306 //g_debug("\t\tz2: %f", (float)buffer[i][2]/0x7fffffff);
307 //g_debug("\t\tname: %p", (gpointer)buffer[i][3]);
308 guint index = buffer[i][3];
309 GritsObject *object = objects->pdata[index];
310 object->state.picked = TRUE;
312 for (guint i = 0; i < objects->len; i++) {
313 GritsObject *object = objects->pdata[i];
314 grits_object_set_pointer(object, object->state.picked);
316 g_ptr_array_free(objects, TRUE);
317 g_mutex_unlock(opengl->objects_lock);
320 gdouble lat, lon, elev;
321 grits_viewer_unproject(GRITS_VIEWER(opengl),
322 gl_x, gl_y, -1, &lat, &lon, &elev);
325 glMatrixMode(GL_PROJECTION);
331 static gboolean on_key_press(GritsOpenGL *opengl, GdkEventKey *event, gpointer _)
333 g_debug("GritsOpenGL: on_key_press - key=%x, state=%x, plus=%x",
334 event->keyval, event->state, GDK_plus);
336 guint kv = event->keyval;
339 opengl->wireframe = !opengl->wireframe;
340 gtk_widget_queue_draw(GTK_WIDGET(opengl));
343 else if (kv == GDK_n) roam_sphere_split_one(opengl->sphere);
344 else if (kv == GDK_p) roam_sphere_merge_one(opengl->sphere);
345 else if (kv == GDK_r) roam_sphere_split_merge(opengl->sphere);
346 else if (kv == GDK_u) roam_sphere_update_errors(opengl->sphere);
347 gtk_widget_queue_draw(GTK_WIDGET(opengl));
352 static gboolean on_chained_event(GritsOpenGL *opengl, GdkEvent *event, gpointer _)
354 _foreach_object(opengl, (GFunc)grits_object_event, event);
358 static gboolean _update_errors_cb(gpointer _opengl)
360 GritsOpenGL *opengl = _opengl;
361 g_mutex_lock(opengl->sphere_lock);
362 roam_sphere_update_errors(opengl->sphere);
363 g_mutex_unlock(opengl->sphere_lock);
364 opengl->ue_source = 0;
367 static void on_view_changed(GritsOpenGL *opengl,
368 gdouble _1, gdouble _2, gdouble _3)
370 g_debug("GritsOpenGL: on_view_changed");
371 _set_visuals(opengl);
373 if (!opengl->ue_source)
374 opengl->ue_source = g_idle_add_full(G_PRIORITY_HIGH_IDLE+30,
375 _update_errors_cb, opengl, NULL);
376 //roam_sphere_update_errors(opengl->sphere);
378 (void)_update_errors_cb;
382 static gboolean on_idle(GritsOpenGL *opengl)
384 //g_debug("GritsOpenGL: on_idle");
385 g_mutex_lock(opengl->sphere_lock);
386 if (roam_sphere_split_merge(opengl->sphere))
387 gtk_widget_queue_draw(GTK_WIDGET(opengl));
388 g_mutex_unlock(opengl->sphere_lock);
392 static void on_realize(GritsOpenGL *opengl, gpointer _)
394 g_debug("GritsOpenGL: on_realize");
395 gtk_gl_begin(GTK_WIDGET(opengl));
397 /* Connect signals and idle functions now that opengl is fully initialized */
398 gtk_widget_add_events(GTK_WIDGET(opengl), GDK_KEY_PRESS_MASK);
399 g_signal_connect(opengl, "configure-event", G_CALLBACK(on_configure), NULL);
400 g_signal_connect(opengl, "expose-event", G_CALLBACK(on_expose), NULL);
402 g_signal_connect(opengl, "key-press-event", G_CALLBACK(on_key_press), NULL);
404 g_signal_connect(opengl, "location-changed", G_CALLBACK(on_view_changed), NULL);
405 g_signal_connect(opengl, "rotation-changed", G_CALLBACK(on_view_changed), NULL);
407 g_signal_connect(opengl, "motion-notify-event", G_CALLBACK(on_motion_notify), NULL);
408 g_signal_connect_after(opengl, "key-press-event", G_CALLBACK(on_chained_event), NULL);
409 g_signal_connect_after(opengl, "key-release-event", G_CALLBACK(on_chained_event), NULL);
410 g_signal_connect_after(opengl, "button-press-event", G_CALLBACK(on_chained_event), NULL);
411 g_signal_connect_after(opengl, "button-release-event", G_CALLBACK(on_chained_event), NULL);
412 g_signal_connect_after(opengl, "motion-notify-event", G_CALLBACK(on_chained_event), NULL);
415 opengl->sm_source[0] = g_timeout_add_full(G_PRIORITY_HIGH_IDLE+30, 33, (GSourceFunc)on_idle, opengl, NULL);
416 opengl->sm_source[1] = g_timeout_add_full(G_PRIORITY_HIGH_IDLE+10, 500, (GSourceFunc)on_idle, opengl, NULL);
419 (void)_update_errors_cb;
422 /* Re-queue resize incase configure was triggered before realize */
423 gtk_widget_queue_resize(GTK_WIDGET(opengl));
426 /*********************
427 * GritsViewer methods *
428 *********************/
431 * @plugins: the plugins store to use
432 * @prefs: the preferences object to use
434 * Create a new OpenGL renderer.
436 * Returns: the new #GritsOpenGL
438 GritsViewer *grits_opengl_new(GritsPlugins *plugins, GritsPrefs *prefs)
440 g_debug("GritsOpenGL: new");
441 GritsViewer *opengl = g_object_new(GRITS_TYPE_OPENGL, NULL);
442 grits_viewer_setup(opengl, plugins, prefs);
446 static void grits_opengl_center_position(GritsViewer *_opengl, gdouble lat, gdouble lon, gdouble elev)
448 glRotatef(lon, 0, 1, 0);
449 glRotatef(-lat, 1, 0, 0);
450 glTranslatef(0, 0, elev2rad(elev));
453 static void grits_opengl_project(GritsViewer *_opengl,
454 gdouble lat, gdouble lon, gdouble elev,
455 gdouble *px, gdouble *py, gdouble *pz)
457 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
459 lle2xyz(lat, lon, elev, &x, &y, &z);
461 opengl->sphere->view->model,
462 opengl->sphere->view->proj,
463 opengl->sphere->view->view,
467 static void grits_opengl_unproject(GritsViewer *_opengl,
468 gdouble px, gdouble py, gdouble pz,
469 gdouble *lat, gdouble *lon, gdouble *elev)
471 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
475 glReadPixels(px, py, 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &tmp);
478 gluUnProject(px, py, pz,
479 opengl->sphere->view->model,
480 opengl->sphere->view->proj,
481 opengl->sphere->view->view,
483 xyz2lle(x, y, z, lat, lon, elev);
484 //g_message("GritsOpenGL: unproject - "
485 // "%4.0lf,%4.0lf,(%5.3lf) -> "
486 // "%8.0lf,%8.0lf,%8.0lf -> "
487 // "%6.2lf,%7.2lf,%4.0lf",
488 // px, py, pz, x, y, z, *lat, *lon, *elev);
491 static void grits_opengl_set_height_func(GritsViewer *_opengl, GritsBounds *bounds,
492 RoamHeightFunc height_func, gpointer user_data, gboolean update)
494 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
495 /* TODO: get points? */
496 g_mutex_lock(opengl->sphere_lock);
497 GList *triangles = roam_sphere_get_intersect(opengl->sphere, TRUE,
498 bounds->n, bounds->s, bounds->e, bounds->w);
499 for (GList *cur = triangles; cur; cur = cur->next) {
500 RoamTriangle *tri = cur->data;
501 RoamPoint *points[] = {tri->p.l, tri->p.m, tri->p.r, tri->split};
502 for (int i = 0; i < G_N_ELEMENTS(points); i++) {
503 if (bounds->n >= points[i]->lat && points[i]->lat >= bounds->s &&
504 bounds->e >= points[i]->lon && points[i]->lon >= bounds->w) {
505 points[i]->height_func = height_func;
506 points[i]->height_data = user_data;
507 roam_point_update_height(points[i]);
511 g_list_free(triangles);
512 g_mutex_unlock(opengl->sphere_lock);
515 static void _grits_opengl_clear_height_func_rec(RoamTriangle *root)
519 RoamPoint *points[] = {root->p.l, root->p.m, root->p.r, root->split};
520 for (int i = 0; i < G_N_ELEMENTS(points); i++) {
521 points[i]->height_func = NULL;
522 points[i]->height_data = NULL;
523 roam_point_update_height(points[i]);
525 _grits_opengl_clear_height_func_rec(root->kids[0]);
526 _grits_opengl_clear_height_func_rec(root->kids[1]);
529 static void grits_opengl_clear_height_func(GritsViewer *_opengl)
531 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
532 for (int i = 0; i < G_N_ELEMENTS(opengl->sphere->roots); i++)
533 _grits_opengl_clear_height_func_rec(opengl->sphere->roots[i]);
536 static gpointer grits_opengl_add(GritsViewer *_opengl, GritsObject *object,
537 gint key, gboolean sort)
539 g_assert(GRITS_IS_OPENGL(_opengl));
540 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
541 g_mutex_lock(opengl->objects_lock);
542 struct RenderLevel *level = g_tree_lookup(opengl->objects, (gpointer)(gintptr)key);
544 level = g_new0(struct RenderLevel, 1);
545 g_tree_insert(opengl->objects, (gpointer)(gintptr)key, level);
547 GList *list = sort ? &level->sorted : &level->unsorted;
548 /* Put the link in the list */
549 GList *link = g_new0(GList, 1);
552 link->next = list->next;
554 list->next->prev = link;
556 g_mutex_unlock(opengl->objects_lock);
560 static GritsObject *grits_opengl_remove(GritsViewer *_opengl, GritsObject *object)
562 g_assert(GRITS_IS_OPENGL(_opengl));
563 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
564 GList *link = object->ref;
565 g_mutex_lock(opengl->objects_lock);
566 /* Just unlink and free it, link->prev is assured */
567 link->prev->next = link->next;
569 link->next->prev = link->prev;
570 g_mutex_unlock(opengl->objects_lock);
572 object->viewer = NULL;
574 g_object_unref(object);
581 static int _objects_cmp(gconstpointer _a, gconstpointer _b, gpointer _)
583 gintptr a = (gintptr)_a, b = (gintptr)_b;
587 static void _objects_free(gpointer value)
589 struct RenderLevel *level = value;
590 if (level->sorted.next)
591 g_list_free(level->sorted.next);
592 if (level->unsorted.next)
593 g_list_free(level->unsorted.next);
597 G_DEFINE_TYPE(GritsOpenGL, grits_opengl, GRITS_TYPE_VIEWER);
598 static void grits_opengl_init(GritsOpenGL *opengl)
600 g_debug("GritsOpenGL: init");
601 opengl->objects = g_tree_new_full(_objects_cmp, NULL, NULL, _objects_free);
602 opengl->objects_lock = g_mutex_new();
603 opengl->sphere = roam_sphere_new(opengl);
604 opengl->sphere_lock = g_mutex_new();
605 gtk_gl_enable(GTK_WIDGET(opengl));
606 gtk_widget_add_events(GTK_WIDGET(opengl), GDK_KEY_PRESS_MASK);
607 g_signal_connect(opengl, "map", G_CALLBACK(on_realize), NULL);
609 static void grits_opengl_dispose(GObject *_opengl)
611 g_debug("GritsOpenGL: dispose");
612 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
613 if (opengl->sm_source[0]) {
614 g_source_remove(opengl->sm_source[0]);
615 opengl->sm_source[0] = 0;
617 if (opengl->sm_source[1]) {
618 g_source_remove(opengl->sm_source[1]);
619 opengl->sm_source[1] = 0;
621 if (opengl->ue_source) {
622 g_source_remove(opengl->ue_source);
623 opengl->ue_source = 0;
625 G_OBJECT_CLASS(grits_opengl_parent_class)->dispose(_opengl);
627 static void grits_opengl_finalize(GObject *_opengl)
629 g_debug("GritsOpenGL: finalize");
630 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
631 roam_sphere_free(opengl->sphere);
632 g_tree_destroy(opengl->objects);
633 g_mutex_free(opengl->objects_lock);
634 g_mutex_free(opengl->sphere_lock);
635 G_OBJECT_CLASS(grits_opengl_parent_class)->finalize(_opengl);
637 static void grits_opengl_class_init(GritsOpenGLClass *klass)
639 g_debug("GritsOpenGL: class_init");
640 GObjectClass *gobject_class = G_OBJECT_CLASS(klass);
641 gobject_class->finalize = grits_opengl_finalize;
642 gobject_class->dispose = grits_opengl_dispose;
644 GritsViewerClass *viewer_class = GRITS_VIEWER_CLASS(klass);
645 viewer_class->center_position = grits_opengl_center_position;
646 viewer_class->project = grits_opengl_project;
647 viewer_class->unproject = grits_opengl_unproject;
648 viewer_class->clear_height_func = grits_opengl_clear_height_func;
649 viewer_class->set_height_func = grits_opengl_set_height_func;
650 viewer_class->add = grits_opengl_add;
651 viewer_class->remove = grits_opengl_remove;