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/FOV_DIST);
71 double atmos = 100000;
72 double near = MAX(elev - atmos, 10); // 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)*2, 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 g_debug("GritsOpenGL: _draw_level - level=%-4ld", (glong)key);
192 GritsOpenGL *opengl = user_data;
193 struct RenderLevel *level = value;
194 int nsorted = 0, nunsorted = 0;
197 /* Draw opaque objects without sorting */
199 glClear(GL_DEPTH_BUFFER_BIT);
200 for (cur = level->unsorted.next; cur; cur = cur->next, nunsorted++)
201 grits_object_draw(GRITS_OBJECT(cur->data), opengl);
203 /* Freeze depth buffer and draw transparent objects sorted */
205 //glDepthMask(FALSE);
206 glAlphaFunc(GL_GREATER, 0.1);
207 for (cur = level->sorted.next; cur; cur = cur->next, nsorted++)
208 grits_object_draw(GRITS_OBJECT(cur->data), opengl);
210 /* TODO: Prune empty levels */
212 g_debug("GritsOpenGL: _draw_level - drew %d,%d objects",
217 static gboolean on_expose(GritsOpenGL *opengl, GdkEventExpose *event, gpointer _)
219 g_debug("GritsOpenGL: on_expose - begin");
221 gtk_gl_begin(GTK_WIDGET(opengl));
223 glClear(GL_COLOR_BUFFER_BIT);
225 _set_visuals(opengl);
227 glColor4f(1.0, 1.0, 1.0, 1.0);
229 glDisable(GL_TEXTURE_2D);
230 glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
231 roam_sphere_draw(opengl->sphere);
233 //roam_sphere_draw_normals(opengl->sphere);
235 g_mutex_lock(opengl->objects_lock);
236 g_tree_foreach(opengl->objects, _draw_level, opengl);
237 if (opengl->wireframe) {
238 glClear(GL_DEPTH_BUFFER_BIT);
239 glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
240 roam_sphere_draw(opengl->sphere);
241 g_tree_foreach(opengl->objects, _draw_level, opengl);
243 g_mutex_unlock(opengl->objects_lock);
246 gtk_gl_end(GTK_WIDGET(opengl));
248 g_debug("GritsOpenGL: on_expose - end\n");
252 static gboolean on_motion_notify(GritsOpenGL *opengl, GdkEventMotion *event, gpointer _)
254 gdouble height = GTK_WIDGET(opengl)->allocation.height;
255 gdouble gl_x = event->x;
256 gdouble gl_y = height - event->y;
260 gdouble projection[16];
261 glGetIntegerv(GL_VIEWPORT, viewport);
262 glGetDoublev(GL_PROJECTION_MATRIX, projection);
264 glMatrixMode(GL_PROJECTION);
267 gluPickMatrix(gl_x, gl_y, 2, 2, viewport);
268 glMultMatrixd(projection);
270 /* Prepare for picking */
271 guint buffer[100][4] = {};
272 glSelectBuffer(G_N_ELEMENTS(buffer), (guint*)buffer);
273 glRenderMode(GL_SELECT);
277 g_mutex_lock(opengl->objects_lock);
278 GPtrArray *objects = _objects_to_array(opengl);
279 for (guint i = 0; i < objects->len; i++) {
281 GritsObject *object = objects->pdata[i];
282 object->state.picked = FALSE;
283 grits_object_pick(object, opengl);
286 int hits = glRenderMode(GL_RENDER);
287 g_debug("GritsOpenGL: on_motion_notify - hits=%d ev=%.0lf,%.0lf",
289 for (int i = 0; i < hits; i++) {
290 //g_debug("\tHit: %d", i);
291 //g_debug("\t\tcount: %d", buffer[i][0]);
292 //g_debug("\t\tz1: %f", (float)buffer[i][1]/0x7fffffff);
293 //g_debug("\t\tz2: %f", (float)buffer[i][2]/0x7fffffff);
294 //g_debug("\t\tname: %p", (gpointer)buffer[i][3]);
295 guint index = buffer[i][3];
296 GritsObject *object = objects->pdata[index];
297 object->state.picked = TRUE;
299 for (guint i = 0; i < objects->len; i++) {
300 GritsObject *object = objects->pdata[i];
301 grits_object_set_pointer(object, object->state.picked);
303 g_ptr_array_free(objects, TRUE);
304 g_mutex_unlock(opengl->objects_lock);
307 glMatrixMode(GL_PROJECTION);
313 static gboolean on_key_press(GritsOpenGL *opengl, GdkEventKey *event, gpointer _)
315 g_debug("GritsOpenGL: on_key_press - key=%x, state=%x, plus=%x",
316 event->keyval, event->state, GDK_plus);
318 guint kv = event->keyval;
321 opengl->wireframe = !opengl->wireframe;
322 gtk_widget_queue_draw(GTK_WIDGET(opengl));
325 else if (kv == GDK_n) roam_sphere_split_one(opengl->sphere);
326 else if (kv == GDK_p) roam_sphere_merge_one(opengl->sphere);
327 else if (kv == GDK_r) roam_sphere_split_merge(opengl->sphere);
328 else if (kv == GDK_u) roam_sphere_update_errors(opengl->sphere);
329 gtk_widget_queue_draw(GTK_WIDGET(opengl));
334 static gboolean on_chained_event(GritsOpenGL *opengl, GdkEvent *event, gpointer _)
336 _foreach_object(opengl, (GFunc)grits_object_event, event);
340 static gboolean _update_errors_cb(gpointer _opengl)
342 GritsOpenGL *opengl = _opengl;
343 g_mutex_lock(opengl->sphere_lock);
344 roam_sphere_update_errors(opengl->sphere);
345 g_mutex_unlock(opengl->sphere_lock);
346 opengl->ue_source = 0;
349 static void on_view_changed(GritsOpenGL *opengl,
350 gdouble _1, gdouble _2, gdouble _3)
352 g_debug("GritsOpenGL: on_view_changed");
353 _set_visuals(opengl);
355 if (!opengl->ue_source)
356 opengl->ue_source = g_idle_add_full(G_PRIORITY_HIGH_IDLE+30,
357 _update_errors_cb, opengl, NULL);
358 //roam_sphere_update_errors(opengl->sphere);
360 (void)_update_errors_cb;
364 static gboolean on_idle(GritsOpenGL *opengl)
366 //g_debug("GritsOpenGL: on_idle");
367 g_mutex_lock(opengl->sphere_lock);
368 if (roam_sphere_split_merge(opengl->sphere))
369 gtk_widget_queue_draw(GTK_WIDGET(opengl));
370 g_mutex_unlock(opengl->sphere_lock);
374 static void on_realize(GritsOpenGL *opengl, gpointer _)
376 g_debug("GritsOpenGL: on_realize");
377 gtk_gl_begin(GTK_WIDGET(opengl));
379 /* Connect signals and idle functions now that opengl is fully initialized */
380 gtk_widget_add_events(GTK_WIDGET(opengl), GDK_KEY_PRESS_MASK);
381 g_signal_connect(opengl, "configure-event", G_CALLBACK(on_configure), NULL);
382 g_signal_connect(opengl, "expose-event", G_CALLBACK(on_expose), NULL);
384 g_signal_connect(opengl, "key-press-event", G_CALLBACK(on_key_press), NULL);
386 g_signal_connect(opengl, "location-changed", G_CALLBACK(on_view_changed), NULL);
387 g_signal_connect(opengl, "rotation-changed", G_CALLBACK(on_view_changed), NULL);
389 g_signal_connect(opengl, "motion-notify-event", G_CALLBACK(on_motion_notify), NULL);
390 g_signal_connect_after(opengl, "key-press-event", G_CALLBACK(on_chained_event), NULL);
391 g_signal_connect_after(opengl, "key-release-event", G_CALLBACK(on_chained_event), NULL);
392 g_signal_connect_after(opengl, "button-press-event", G_CALLBACK(on_chained_event), NULL);
393 g_signal_connect_after(opengl, "button-release-event", G_CALLBACK(on_chained_event), NULL);
394 g_signal_connect_after(opengl, "motion-notify-event", G_CALLBACK(on_chained_event), NULL);
397 opengl->sm_source[0] = g_timeout_add_full(G_PRIORITY_HIGH_IDLE+30, 33, (GSourceFunc)on_idle, opengl, NULL);
398 opengl->sm_source[1] = g_timeout_add_full(G_PRIORITY_HIGH_IDLE+10, 500, (GSourceFunc)on_idle, opengl, NULL);
401 (void)_update_errors_cb;
404 /* Re-queue resize incase configure was triggered before realize */
405 gtk_widget_queue_resize(GTK_WIDGET(opengl));
408 /*********************
409 * GritsViewer methods *
410 *********************/
413 * @plugins: the plugins store to use
414 * @prefs: the preferences object to use
416 * Create a new OpenGL renderer.
418 * Returns: the new #GritsOpenGL
420 GritsViewer *grits_opengl_new(GritsPlugins *plugins, GritsPrefs *prefs)
422 g_debug("GritsOpenGL: new");
423 GritsViewer *opengl = g_object_new(GRITS_TYPE_OPENGL, NULL);
424 grits_viewer_setup(opengl, plugins, prefs);
428 static void grits_opengl_center_position(GritsViewer *_opengl, gdouble lat, gdouble lon, gdouble elev)
430 glRotatef(lon, 0, 1, 0);
431 glRotatef(-lat, 1, 0, 0);
432 glTranslatef(0, 0, elev2rad(elev));
435 static void grits_opengl_project(GritsViewer *_opengl,
436 gdouble lat, gdouble lon, gdouble elev,
437 gdouble *px, gdouble *py, gdouble *pz)
439 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
441 lle2xyz(lat, lon, elev, &x, &y, &z);
443 opengl->sphere->view->model,
444 opengl->sphere->view->proj,
445 opengl->sphere->view->view,
449 static void grits_opengl_set_height_func(GritsViewer *_opengl, GritsBounds *bounds,
450 RoamHeightFunc height_func, gpointer user_data, gboolean update)
452 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
453 /* TODO: get points? */
454 g_mutex_lock(opengl->sphere_lock);
455 GList *triangles = roam_sphere_get_intersect(opengl->sphere, TRUE,
456 bounds->n, bounds->s, bounds->e, bounds->w);
457 for (GList *cur = triangles; cur; cur = cur->next) {
458 RoamTriangle *tri = cur->data;
459 RoamPoint *points[] = {tri->p.l, tri->p.m, tri->p.r, tri->split};
460 for (int i = 0; i < G_N_ELEMENTS(points); i++) {
461 if (bounds->n >= points[i]->lat && points[i]->lat >= bounds->s &&
462 bounds->e >= points[i]->lon && points[i]->lon >= bounds->w) {
463 points[i]->height_func = height_func;
464 points[i]->height_data = user_data;
465 roam_point_update_height(points[i]);
469 g_list_free(triangles);
470 g_mutex_unlock(opengl->sphere_lock);
473 static void _grits_opengl_clear_height_func_rec(RoamTriangle *root)
477 RoamPoint *points[] = {root->p.l, root->p.m, root->p.r, root->split};
478 for (int i = 0; i < G_N_ELEMENTS(points); i++) {
479 points[i]->height_func = NULL;
480 points[i]->height_data = NULL;
481 roam_point_update_height(points[i]);
483 _grits_opengl_clear_height_func_rec(root->kids[0]);
484 _grits_opengl_clear_height_func_rec(root->kids[1]);
487 static void grits_opengl_clear_height_func(GritsViewer *_opengl)
489 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
490 for (int i = 0; i < G_N_ELEMENTS(opengl->sphere->roots); i++)
491 _grits_opengl_clear_height_func_rec(opengl->sphere->roots[i]);
494 static gpointer grits_opengl_add(GritsViewer *_opengl, GritsObject *object,
495 gint key, gboolean sort)
497 g_assert(GRITS_IS_OPENGL(_opengl));
498 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
499 g_mutex_lock(opengl->objects_lock);
500 struct RenderLevel *level = g_tree_lookup(opengl->objects, (gpointer)(gintptr)key);
502 level = g_new0(struct RenderLevel, 1);
503 g_tree_insert(opengl->objects, (gpointer)(gintptr)key, level);
505 GList *list = sort ? &level->sorted : &level->unsorted;
506 /* Put the link in the list */
507 GList *link = g_new0(GList, 1);
510 link->next = list->next;
512 list->next->prev = link;
514 g_mutex_unlock(opengl->objects_lock);
518 static GritsObject *grits_opengl_remove(GritsViewer *_opengl, GritsObject *object)
520 g_assert(GRITS_IS_OPENGL(_opengl));
521 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
522 GList *link = object->ref;
523 g_mutex_lock(opengl->objects_lock);
524 /* Just unlink and free it, link->prev is assured */
525 link->prev->next = link->next;
527 link->next->prev = link->prev;
528 g_mutex_unlock(opengl->objects_lock);
530 object->viewer = NULL;
532 g_object_unref(object);
539 static int _objects_cmp(gconstpointer _a, gconstpointer _b, gpointer _)
541 gintptr a = (gintptr)_a, b = (gintptr)_b;
545 static void _objects_free(gpointer value)
547 struct RenderLevel *level = value;
548 if (level->sorted.next)
549 g_list_free(level->sorted.next);
550 if (level->unsorted.next)
551 g_list_free(level->unsorted.next);
555 G_DEFINE_TYPE(GritsOpenGL, grits_opengl, GRITS_TYPE_VIEWER);
556 static void grits_opengl_init(GritsOpenGL *opengl)
558 g_debug("GritsOpenGL: init");
559 opengl->objects = g_tree_new_full(_objects_cmp, NULL, NULL, _objects_free);
560 opengl->objects_lock = g_mutex_new();
561 opengl->sphere = roam_sphere_new(opengl);
562 opengl->sphere_lock = g_mutex_new();
563 gtk_gl_enable(GTK_WIDGET(opengl));
564 gtk_widget_add_events(GTK_WIDGET(opengl), GDK_KEY_PRESS_MASK);
565 g_signal_connect(opengl, "map", G_CALLBACK(on_realize), NULL);
567 static void grits_opengl_dispose(GObject *_opengl)
569 g_debug("GritsOpenGL: dispose");
570 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
571 if (opengl->sm_source[0]) {
572 g_source_remove(opengl->sm_source[0]);
573 opengl->sm_source[0] = 0;
575 if (opengl->sm_source[1]) {
576 g_source_remove(opengl->sm_source[1]);
577 opengl->sm_source[1] = 0;
579 if (opengl->ue_source) {
580 g_source_remove(opengl->ue_source);
581 opengl->ue_source = 0;
583 G_OBJECT_CLASS(grits_opengl_parent_class)->dispose(_opengl);
585 static void grits_opengl_finalize(GObject *_opengl)
587 g_debug("GritsOpenGL: finalize");
588 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
589 roam_sphere_free(opengl->sphere);
590 g_tree_destroy(opengl->objects);
591 g_mutex_free(opengl->objects_lock);
592 g_mutex_free(opengl->sphere_lock);
593 G_OBJECT_CLASS(grits_opengl_parent_class)->finalize(_opengl);
595 static void grits_opengl_class_init(GritsOpenGLClass *klass)
597 g_debug("GritsOpenGL: class_init");
598 GObjectClass *gobject_class = G_OBJECT_CLASS(klass);
599 gobject_class->finalize = grits_opengl_finalize;
600 gobject_class->dispose = grits_opengl_dispose;
602 GritsViewerClass *viewer_class = GRITS_VIEWER_CLASS(klass);
603 viewer_class->center_position = grits_opengl_center_position;
604 viewer_class->project = grits_opengl_project;
605 viewer_class->clear_height_func = grits_opengl_clear_height_func;
606 viewer_class->set_height_func = grits_opengl_set_height_func;
607 viewer_class->add = grits_opengl_add;
608 viewer_class->remove = grits_opengl_remove;