2 * Copyright (C) 2009-2010 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>
38 #include "grits-opengl.h"
39 #include "grits-util.h"
45 /* Tessellation, "finding intersecting triangles" */
46 /* http://research.microsoft.com/pubs/70307/tr-2006-81.pdf */
47 /* http://www.opengl.org/wiki/Alpha_Blending */
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 */
60 static void _set_visuals(GritsOpenGL *opengl)
62 glMatrixMode(GL_MODELVIEW);
66 double lat, lon, elev, rx, ry, rz;
67 grits_viewer_get_location(GRITS_VIEWER(opengl), &lat, &lon, &elev);
68 grits_viewer_get_rotation(GRITS_VIEWER(opengl), &rx, &ry, &rz);
69 glRotatef(rx, 1, 0, 0);
70 glRotatef(rz, 0, 0, 1);
74 float light_ambient[] = {0.7f, 0.7f, 0.7f, 1.0f};
75 float light_diffuse[] = {2.0f, 2.0f, 2.0f, 1.0f};
77 float light_ambient[] = {0.2f, 0.2f, 0.2f, 1.0f};
78 float light_diffuse[] = {0.8f, 0.8f, 0.8f, 1.0f};
80 float light_position[] = {-13*EARTH_R, 1*EARTH_R, 3*EARTH_R, 1.0f};
81 glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
82 glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
83 glLightfv(GL_LIGHT0, GL_POSITION, light_position);
85 glEnable(GL_LIGHTING);
87 float material_ambient[] = {1.0, 1.0, 1.0, 1.0};
88 float material_diffuse[] = {1.0, 1.0, 1.0, 1.0};
89 float material_specular[] = {0.0, 0.0, 0.0, 1.0};
90 float material_emission[] = {0.0, 0.0, 0.0, 1.0};
91 glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, material_ambient);
92 glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, material_diffuse);
93 glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, material_specular);
94 glMaterialfv(GL_FRONT_AND_BACK, GL_EMISSION, material_emission);
95 glDisable(GL_TEXTURE_2D);
96 glDisable(GL_COLOR_MATERIAL);
99 glTranslatef(0, 0, -elev2rad(elev));
100 glRotatef(lat, 1, 0, 0);
101 glRotatef(-lon, 0, 1, 0);
103 glDisable(GL_ALPHA_TEST);
105 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
110 glEnable(GL_CULL_FACE);
113 glDepthFunc(GL_LEQUAL);
114 glEnable(GL_DEPTH_TEST);
117 glEnable(GL_LINE_SMOOTH);
119 glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
120 //glShadeModel(GL_FLAT);
122 g_mutex_lock(opengl->sphere_lock);
123 roam_sphere_update_view(opengl->sphere);
124 g_mutex_unlock(opengl->sphere_lock);
127 static gboolean _foreach_object_cb(gpointer key, gpointer value, gpointer pointers)
129 struct RenderLevel *level = value;
130 GFunc user_func = ((gpointer*)pointers)[0];
131 gpointer user_data = ((gpointer*)pointers)[1];
132 for (GList *cur = level->unsorted.next; cur; cur = cur->next)
133 user_func(cur->data, user_data);
134 for (GList *cur = level->sorted.next; cur; cur = cur->next)
135 user_func(cur->data, user_data);
139 static void _foreach_object(GritsOpenGL *opengl, GFunc func, gpointer user_data)
141 gpointer pointers[2] = {func, user_data};
142 g_tree_foreach(opengl->objects, _foreach_object_cb, pointers);
148 static gboolean on_configure(GritsOpenGL *opengl, GdkEventConfigure *event, gpointer _)
150 g_debug("GritsOpenGL: on_configure");
152 double width = GTK_WIDGET(opengl)->allocation.width;
153 double height = GTK_WIDGET(opengl)->allocation.height;
155 /* Setup OpenGL Window */
156 glViewport(0, 0, width, height);
157 glMatrixMode(GL_PROJECTION);
159 double ang = atan(height/FOV_DIST);
160 gluPerspective(rad2deg(ang)*2, width/height, 10, 100*EARTH_R);
163 g_mutex_lock(opengl->sphere_lock);
164 roam_sphere_update_errors(opengl->sphere);
165 g_mutex_unlock(opengl->sphere_lock);
171 static gboolean _draw_level(gpointer key, gpointer value, gpointer user_data)
173 g_debug("GritsOpenGL: _draw_level - level=%-4d", (int)key);
174 GritsOpenGL *opengl = user_data;
175 struct RenderLevel *level = value;
176 int nsorted = 0, nunsorted = 0;
179 /* Draw opaque objects without sorting */
181 glClear(GL_DEPTH_BUFFER_BIT);
182 for (cur = level->unsorted.next; cur; cur = cur->next, nunsorted++)
183 grits_object_draw(GRITS_OBJECT(cur->data), opengl);
185 /* Freeze depth buffer and draw transparent objects sorted */
187 //glDepthMask(FALSE);
188 glAlphaFunc(GL_GREATER, 0.1);
189 for (cur = level->sorted.next; cur; cur = cur->next, nsorted++)
190 grits_object_draw(GRITS_OBJECT(cur->data), opengl);
192 /* TODO: Prune empty levels */
194 g_debug("GritsOpenGL: _draw_level - drew %d,%d objects",
199 static gboolean on_expose(GritsOpenGL *opengl, GdkEventExpose *event, gpointer _)
201 g_debug("GritsOpenGL: on_expose - begin");
203 glClear(GL_COLOR_BUFFER_BIT);
205 _set_visuals(opengl);
207 glColor4f(1.0, 1.0, 1.0, 1.0);
209 glDisable(GL_TEXTURE_2D);
210 glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
211 roam_sphere_draw(opengl->sphere);
213 //roam_sphere_draw_normals(opengl->sphere);
215 g_mutex_lock(opengl->objects_lock);
216 g_tree_foreach(opengl->objects, _draw_level, opengl);
217 if (opengl->wireframe) {
218 glClear(GL_DEPTH_BUFFER_BIT);
219 glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
220 roam_sphere_draw(opengl->sphere);
221 g_tree_foreach(opengl->objects, _draw_level, opengl);
223 g_mutex_unlock(opengl->objects_lock);
226 gtk_gl_end(GTK_WIDGET(opengl));
228 g_debug("GritsOpenGL: on_expose - end\n");
232 static gboolean on_motion_notify(GritsOpenGL *opengl, GdkEventMotion *event, gpointer _)
234 gdouble height = GTK_WIDGET(opengl)->allocation.height;
235 gdouble gl_x = event->x;
236 gdouble gl_y = height - event->y;
240 gdouble projection[16];
241 glGetIntegerv(GL_VIEWPORT, viewport);
242 glGetDoublev(GL_PROJECTION_MATRIX, projection);
244 glMatrixMode(GL_PROJECTION);
247 gluPickMatrix(gl_x, gl_y, 2, 2, viewport);
248 glMultMatrixd(projection);
250 /* Prepare for picking */
251 guint buffer[100][4] = {};
252 glSelectBuffer(G_N_ELEMENTS(buffer), (guint*)buffer);
253 glRenderMode(GL_SELECT);
257 g_mutex_lock(opengl->objects_lock);
258 _foreach_object(opengl, (GFunc)grits_object_pick_begin, opengl);
259 int hits = glRenderMode(GL_RENDER);
260 g_debug("GritsOpenGL: on_motion_notify - hits=%d ev=%.0lf,%.0lf",
262 for (int i = 0; i < hits; i++) {
263 //g_debug("\tHit: %d", i);
264 //g_debug("\t\tcount: %d", buffer[i][0]);
265 //g_debug("\t\tz1: %f", (float)buffer[i][1]/0x7fffffff);
266 //g_debug("\t\tz2: %f", (float)buffer[i][2]/0x7fffffff);
267 //g_debug("\t\tname: %p", (gpointer)buffer[i][3]);
268 GritsObject *object = GRITS_OBJECT(buffer[i][3]);
269 grits_object_pick_pointer(object, gl_x, gl_y);
271 _foreach_object(opengl, (GFunc)grits_object_pick_end, NULL);
272 g_mutex_unlock(opengl->objects_lock);
275 glMatrixMode(GL_PROJECTION);
281 static gboolean on_key_press(GritsOpenGL *opengl, GdkEventKey *event, gpointer _)
283 g_debug("GritsOpenGL: on_key_press - key=%x, state=%x, plus=%x",
284 event->keyval, event->state, GDK_plus);
286 guint kv = event->keyval;
289 opengl->wireframe = !opengl->wireframe;
290 gtk_widget_queue_draw(GTK_WIDGET(opengl));
293 else if (kv == GDK_n) roam_sphere_split_one(opengl->sphere);
294 else if (kv == GDK_p) roam_sphere_merge_one(opengl->sphere);
295 else if (kv == GDK_r) roam_sphere_split_merge(opengl->sphere);
296 else if (kv == GDK_u) roam_sphere_update_errors(opengl->sphere);
297 gtk_widget_queue_draw(GTK_WIDGET(opengl));
302 static gboolean _update_errors_cb(gpointer _opengl)
304 GritsOpenGL *opengl = _opengl;
305 g_mutex_lock(opengl->sphere_lock);
306 roam_sphere_update_errors(opengl->sphere);
307 g_mutex_unlock(opengl->sphere_lock);
308 opengl->ue_source = 0;
311 static void on_view_changed(GritsOpenGL *opengl,
312 gdouble _1, gdouble _2, gdouble _3)
314 g_debug("GritsOpenGL: on_view_changed");
315 _set_visuals(opengl);
317 if (!opengl->ue_source)
318 opengl->ue_source = g_idle_add_full(G_PRIORITY_HIGH_IDLE+30,
319 _update_errors_cb, opengl, NULL);
320 //roam_sphere_update_errors(opengl->sphere);
322 (void)_update_errors_cb;
326 static gboolean on_idle(GritsOpenGL *opengl)
328 //g_debug("GritsOpenGL: on_idle");
329 g_mutex_lock(opengl->sphere_lock);
330 if (roam_sphere_split_merge(opengl->sphere))
331 gtk_widget_queue_draw(GTK_WIDGET(opengl));
332 g_mutex_unlock(opengl->sphere_lock);
336 static void on_realize(GritsOpenGL *opengl, gpointer _)
338 g_debug("GritsOpenGL: on_realize");
339 gtk_gl_begin(GTK_WIDGET(opengl));
341 /* Connect signals and idle functions now that opengl is fully initialized */
342 gtk_widget_add_events(GTK_WIDGET(opengl), GDK_KEY_PRESS_MASK);
343 g_signal_connect(opengl, "configure-event", G_CALLBACK(on_configure), NULL);
344 g_signal_connect(opengl, "expose-event", G_CALLBACK(on_expose), NULL);
346 g_signal_connect(opengl, "key-press-event", G_CALLBACK(on_key_press), NULL);
348 g_signal_connect(opengl, "location-changed", G_CALLBACK(on_view_changed), NULL);
349 g_signal_connect(opengl, "rotation-changed", G_CALLBACK(on_view_changed), NULL);
351 g_signal_connect(opengl, "motion-notify-event", G_CALLBACK(on_motion_notify), NULL);
353 opengl->sm_source[0] = g_timeout_add_full(G_PRIORITY_HIGH_IDLE+30, 33, (GSourceFunc)on_idle, opengl, NULL);
354 opengl->sm_source[1] = g_timeout_add_full(G_PRIORITY_HIGH_IDLE+10, 500, (GSourceFunc)on_idle, opengl, NULL);
357 (void)_update_errors_cb;
360 /* Re-queue resize incase configure was triggered before realize */
361 gtk_widget_queue_resize(GTK_WIDGET(opengl));
364 /*********************
365 * GritsViewer methods *
366 *********************/
369 * @plugins: the plugins store to use
370 * @prefs: the preferences object to use
372 * Create a new OpenGL renderer.
374 * Returns: the new #GritsOpenGL
376 GritsViewer *grits_opengl_new(GritsPlugins *plugins, GritsPrefs *prefs)
378 g_debug("GritsOpenGL: new");
379 GritsViewer *opengl = g_object_new(GRITS_TYPE_OPENGL, NULL);
380 grits_viewer_setup(opengl, plugins, prefs);
384 static void grits_opengl_center_position(GritsViewer *_opengl, gdouble lat, gdouble lon, gdouble elev)
386 glRotatef(lon, 0, 1, 0);
387 glRotatef(-lat, 1, 0, 0);
388 glTranslatef(0, 0, elev2rad(elev));
391 static void grits_opengl_project(GritsViewer *_opengl,
392 gdouble lat, gdouble lon, gdouble elev,
393 gdouble *px, gdouble *py, gdouble *pz)
395 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
397 lle2xyz(lat, lon, elev, &x, &y, &z);
399 opengl->sphere->view->model,
400 opengl->sphere->view->proj,
401 opengl->sphere->view->view,
405 static void grits_opengl_set_height_func(GritsViewer *_opengl, GritsBounds *bounds,
406 RoamHeightFunc height_func, gpointer user_data, gboolean update)
408 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
409 /* TODO: get points? */
410 g_mutex_lock(opengl->sphere_lock);
411 GList *triangles = roam_sphere_get_intersect(opengl->sphere, TRUE,
412 bounds->n, bounds->s, bounds->e, bounds->w);
413 for (GList *cur = triangles; cur; cur = cur->next) {
414 RoamTriangle *tri = cur->data;
415 RoamPoint *points[] = {tri->p.l, tri->p.m, tri->p.r, tri->split};
416 for (int i = 0; i < G_N_ELEMENTS(points); i++) {
417 if (bounds->n >= points[i]->lat && points[i]->lat >= bounds->s &&
418 bounds->e >= points[i]->lon && points[i]->lon >= bounds->w) {
419 points[i]->height_func = height_func;
420 points[i]->height_data = user_data;
421 roam_point_update_height(points[i]);
425 g_list_free(triangles);
426 g_mutex_unlock(opengl->sphere_lock);
429 static void _grits_opengl_clear_height_func_rec(RoamTriangle *root)
433 RoamPoint *points[] = {root->p.l, root->p.m, root->p.r, root->split};
434 for (int i = 0; i < G_N_ELEMENTS(points); i++) {
435 points[i]->height_func = NULL;
436 points[i]->height_data = NULL;
437 roam_point_update_height(points[i]);
439 _grits_opengl_clear_height_func_rec(root->kids[0]);
440 _grits_opengl_clear_height_func_rec(root->kids[1]);
443 static void grits_opengl_clear_height_func(GritsViewer *_opengl)
445 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
446 for (int i = 0; i < G_N_ELEMENTS(opengl->sphere->roots); i++)
447 _grits_opengl_clear_height_func_rec(opengl->sphere->roots[i]);
450 static gpointer grits_opengl_add(GritsViewer *_opengl, GritsObject *object,
451 gint key, gboolean sort)
453 g_assert(GRITS_IS_OPENGL(_opengl));
454 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
455 g_mutex_lock(opengl->objects_lock);
456 struct RenderLevel *level = g_tree_lookup(opengl->objects, (gpointer)key);
458 level = g_new0(struct RenderLevel, 1);
459 g_tree_insert(opengl->objects, (gpointer)key, level);
461 GList *list = sort ? &level->sorted : &level->unsorted;
462 /* Put the link in the list */
463 GList *link = g_new0(GList, 1);
466 link->next = list->next;
468 list->next->prev = link;
470 g_mutex_unlock(opengl->objects_lock);
474 static GritsObject *grits_opengl_remove(GritsViewer *_opengl, gpointer _link)
476 g_assert(GRITS_IS_OPENGL(_opengl));
477 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
479 g_mutex_lock(opengl->objects_lock);
480 GritsObject *object = link->data;
481 /* Just unlink and free it, link->prev is assured */
482 link->prev->next = link->next;
484 link->next->prev = link->prev;
485 g_mutex_unlock(opengl->objects_lock);
487 g_object_unref(object);
494 static int _objects_cmp(gconstpointer _a, gconstpointer _b, gpointer _)
496 gint a = (int)_a, b = (int)_b;
500 static void _objects_free(gpointer value)
502 struct RenderLevel *level = value;
503 if (level->sorted.next)
504 g_list_free(level->sorted.next);
505 if (level->unsorted.next)
506 g_list_free(level->unsorted.next);
510 G_DEFINE_TYPE(GritsOpenGL, grits_opengl, GRITS_TYPE_VIEWER);
511 static void grits_opengl_init(GritsOpenGL *opengl)
513 g_debug("GritsOpenGL: init");
514 opengl->objects = g_tree_new_full(_objects_cmp, NULL, NULL, _objects_free);
515 opengl->objects_lock = g_mutex_new();
516 opengl->sphere = roam_sphere_new(opengl);
517 opengl->sphere_lock = g_mutex_new();
518 gtk_gl_enable(GTK_WIDGET(opengl));
519 g_signal_connect(opengl, "realize", G_CALLBACK(on_realize), NULL);
521 static void grits_opengl_dispose(GObject *_opengl)
523 g_debug("GritsOpenGL: dispose");
524 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
525 if (opengl->sm_source[0]) {
526 g_source_remove(opengl->sm_source[0]);
527 opengl->sm_source[0] = 0;
529 if (opengl->sm_source[1]) {
530 g_source_remove(opengl->sm_source[1]);
531 opengl->sm_source[1] = 0;
533 if (opengl->ue_source) {
534 g_source_remove(opengl->ue_source);
535 opengl->ue_source = 0;
537 G_OBJECT_CLASS(grits_opengl_parent_class)->dispose(_opengl);
539 static void grits_opengl_finalize(GObject *_opengl)
541 g_debug("GritsOpenGL: finalize");
542 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
543 roam_sphere_free(opengl->sphere);
544 g_tree_destroy(opengl->objects);
545 g_mutex_free(opengl->objects_lock);
546 g_mutex_free(opengl->sphere_lock);
547 G_OBJECT_CLASS(grits_opengl_parent_class)->finalize(_opengl);
549 static void grits_opengl_class_init(GritsOpenGLClass *klass)
551 g_debug("GritsOpenGL: class_init");
552 GObjectClass *gobject_class = G_OBJECT_CLASS(klass);
553 gobject_class->finalize = grits_opengl_finalize;
554 gobject_class->dispose = grits_opengl_dispose;
556 GritsViewerClass *viewer_class = GRITS_VIEWER_CLASS(klass);
557 viewer_class->center_position = grits_opengl_center_position;
558 viewer_class->project = grits_opengl_project;
559 viewer_class->clear_height_func = grits_opengl_clear_height_func;
560 viewer_class->set_height_func = grits_opengl_set_height_func;
561 viewer_class->add = grits_opengl_add;
562 viewer_class->remove = grits_opengl_remove;