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 relies on #GtkGlExt and requires (at least) OpenGL 2.0.
33 #include <gdk/gdkkeysyms.h>
35 #include <gtk/gtkgl.h>
39 #include "grits-opengl.h"
40 #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 */
52 static void _set_visuals(GritsOpenGL *opengl)
54 glMatrixMode(GL_MODELVIEW);
58 double lat, lon, elev, rx, ry, rz;
59 grits_viewer_get_location(GRITS_VIEWER(opengl), &lat, &lon, &elev);
60 grits_viewer_get_rotation(GRITS_VIEWER(opengl), &rx, &ry, &rz);
61 glRotatef(rx, 1, 0, 0);
62 glRotatef(rz, 0, 0, 1);
66 float light_ambient[] = {0.7f, 0.7f, 0.7f, 1.0f};
67 float light_diffuse[] = {2.0f, 2.0f, 2.0f, 1.0f};
69 float light_ambient[] = {0.2f, 0.2f, 0.2f, 1.0f};
70 float light_diffuse[] = {0.8f, 0.8f, 0.8f, 1.0f};
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);
77 glEnable(GL_LIGHTING);
79 float material_ambient[] = {1.0, 1.0, 1.0, 1.0};
80 float material_diffuse[] = {1.0, 1.0, 1.0, 1.0};
81 float material_specular[] = {0.0, 0.0, 0.0, 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);
91 glTranslatef(0, 0, -elev2rad(elev));
92 glRotatef(lat, 1, 0, 0);
93 glRotatef(-lon, 0, 1, 0);
95 glDisable(GL_ALPHA_TEST);
97 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
102 glEnable(GL_CULL_FACE);
105 glDepthFunc(GL_LEQUAL);
106 glEnable(GL_DEPTH_TEST);
109 glEnable(GL_LINE_SMOOTH);
111 glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
112 //glShadeModel(GL_FLAT);
114 g_mutex_lock(opengl->sphere_lock);
115 roam_sphere_update_view(opengl->sphere);
116 g_mutex_unlock(opengl->sphere_lock);
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 */
131 static gboolean on_configure(GritsOpenGL *opengl, GdkEventConfigure *event, gpointer _)
133 g_debug("GritsOpenGL: on_configure");
135 double width = GTK_WIDGET(opengl)->allocation.width;
136 double height = GTK_WIDGET(opengl)->allocation.height;
138 /* Setup OpenGL Window */
139 glViewport(0, 0, width, height);
140 glMatrixMode(GL_PROJECTION);
142 double ang = atan(height/FOV_DIST);
143 gluPerspective(rad2deg(ang)*2, width/height, 1000, 10*EARTH_R);
146 g_mutex_lock(opengl->sphere_lock);
147 roam_sphere_update_errors(opengl->sphere);
148 g_mutex_unlock(opengl->sphere_lock);
154 static gboolean _draw_level(gpointer key, gpointer value, gpointer user_data)
156 g_debug("GritsOpenGL: _draw_level - level=%-4d", (int)key);
157 GritsOpenGL *opengl = user_data;
158 struct RenderLevel *level = value;
159 int nsorted = 0, nunsorted = 0;
162 /* Draw opaque objects without sorting */
164 glClear(GL_DEPTH_BUFFER_BIT);
165 for (cur = level->unsorted.next; cur; cur = cur->next, nunsorted++)
166 grits_object_draw(GRITS_OBJECT(cur->data), opengl);
168 /* Freeze depth buffer and draw transparent objects sorted */
170 //glDepthMask(FALSE);
171 glAlphaFunc(GL_GREATER, 0.1);
172 for (cur = level->sorted.next; cur; cur = cur->next, nsorted++)
173 grits_object_draw(GRITS_OBJECT(cur->data), opengl);
175 /* TODO: Prune empty levels */
177 g_debug("GritsOpenGL: _draw_level - drew %d,%d objects",
182 static gboolean on_expose(GritsOpenGL *opengl, GdkEventExpose *event, gpointer _)
184 g_debug("GritsOpenGL: on_expose - begin");
186 glClear(GL_COLOR_BUFFER_BIT);
188 _set_visuals(opengl);
190 glColor4f(1.0, 1.0, 1.0, 1.0);
192 glDisable(GL_TEXTURE_2D);
193 glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
194 roam_sphere_draw(opengl->sphere);
196 //roam_sphere_draw_normals(opengl->sphere);
198 g_mutex_lock(opengl->objects_lock);
199 g_tree_foreach(opengl->objects, _draw_level, opengl);
200 if (opengl->wireframe) {
201 glClear(GL_DEPTH_BUFFER_BIT);
202 glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
203 roam_sphere_draw(opengl->sphere);
204 g_tree_foreach(opengl->objects, _draw_level, opengl);
206 g_mutex_unlock(opengl->objects_lock);
209 GdkGLDrawable *gldrawable = gtk_widget_get_gl_drawable(GTK_WIDGET(opengl));
210 gdk_gl_drawable_swap_buffers(gldrawable);
212 g_debug("GritsOpenGL: on_expose - end\n");
216 static gboolean on_key_press(GritsOpenGL *opengl, GdkEventKey *event, gpointer _)
218 g_debug("GritsOpenGL: on_key_press - key=%x, state=%x, plus=%x",
219 event->keyval, event->state, GDK_plus);
221 guint kv = event->keyval;
224 opengl->wireframe = !opengl->wireframe;
225 gtk_widget_queue_draw(GTK_WIDGET(opengl));
228 else if (kv == GDK_n) roam_sphere_split_one(opengl->sphere);
229 else if (kv == GDK_p) roam_sphere_merge_one(opengl->sphere);
230 else if (kv == GDK_r) roam_sphere_split_merge(opengl->sphere);
231 else if (kv == GDK_u) roam_sphere_update_errors(opengl->sphere);
232 gtk_widget_queue_draw(GTK_WIDGET(opengl));
237 static gboolean _update_errors_cb(gpointer _opengl)
239 GritsOpenGL *opengl = _opengl;
240 g_mutex_lock(opengl->sphere_lock);
241 roam_sphere_update_errors(opengl->sphere);
242 g_mutex_unlock(opengl->sphere_lock);
243 opengl->ue_source = 0;
246 static void on_view_changed(GritsOpenGL *opengl,
247 gdouble _1, gdouble _2, gdouble _3)
249 g_debug("GritsOpenGL: on_view_changed");
250 _set_visuals(opengl);
252 if (!opengl->ue_source)
253 opengl->ue_source = g_idle_add_full(G_PRIORITY_HIGH_IDLE+30,
254 _update_errors_cb, opengl, NULL);
255 //roam_sphere_update_errors(opengl->sphere);
257 (void)_update_errors_cb;
261 static gboolean on_idle(GritsOpenGL *opengl)
263 //g_debug("GritsOpenGL: on_idle");
264 g_mutex_lock(opengl->sphere_lock);
265 if (roam_sphere_split_merge(opengl->sphere))
266 gtk_widget_queue_draw(GTK_WIDGET(opengl));
267 g_mutex_unlock(opengl->sphere_lock);
271 static void on_realize(GritsOpenGL *opengl, gpointer _)
273 g_debug("GritsOpenGL: on_realize");
276 GdkGLContext *glcontext = gtk_widget_get_gl_context(GTK_WIDGET(opengl));
277 GdkGLDrawable *gldrawable = gtk_widget_get_gl_drawable(GTK_WIDGET(opengl));
278 if (!gdk_gl_drawable_gl_begin(gldrawable, glcontext))
279 g_assert_not_reached();
281 /* Connect signals and idle functions now that opengl is fully initialized */
282 gtk_widget_add_events(GTK_WIDGET(opengl), GDK_KEY_PRESS_MASK);
283 g_signal_connect(opengl, "configure-event", G_CALLBACK(on_configure), NULL);
284 g_signal_connect(opengl, "expose-event", G_CALLBACK(on_expose), NULL);
286 g_signal_connect(opengl, "key-press-event", G_CALLBACK(on_key_press), NULL);
288 g_signal_connect(opengl, "location-changed", G_CALLBACK(on_view_changed), NULL);
289 g_signal_connect(opengl, "rotation-changed", G_CALLBACK(on_view_changed), NULL);
292 opengl->sm_source[0] = g_timeout_add_full(G_PRIORITY_HIGH_IDLE+30, 33, (GSourceFunc)on_idle, opengl, NULL);
293 opengl->sm_source[1] = g_timeout_add_full(G_PRIORITY_HIGH_IDLE+10, 500, (GSourceFunc)on_idle, opengl, NULL);
296 (void)_update_errors_cb;
299 /* Re-queue resize incase configure was triggered before realize */
300 gtk_widget_queue_resize(GTK_WIDGET(opengl));
303 /*********************
304 * GritsViewer methods *
305 *********************/
308 * @plugins: the plugins store to use
309 * @prefs: the preferences object to use
311 * Create a new OpenGL renderer.
313 * Returns: the new #GritsOpenGL
315 GritsViewer *grits_opengl_new(GritsPlugins *plugins, GritsPrefs *prefs)
317 g_debug("GritsOpenGL: new");
318 GritsViewer *opengl = g_object_new(GRITS_TYPE_OPENGL, NULL);
319 grits_viewer_setup(opengl, plugins, prefs);
323 static void grits_opengl_center_position(GritsViewer *_opengl, gdouble lat, gdouble lon, gdouble elev)
325 glRotatef(lon, 0, 1, 0);
326 glRotatef(-lat, 1, 0, 0);
327 glTranslatef(0, 0, elev2rad(elev));
330 static void grits_opengl_project(GritsViewer *_opengl,
331 gdouble lat, gdouble lon, gdouble elev,
332 gdouble *px, gdouble *py, gdouble *pz)
334 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
336 lle2xyz(lat, lon, elev, &x, &y, &z);
338 opengl->sphere->view->model,
339 opengl->sphere->view->proj,
340 opengl->sphere->view->view,
344 static void grits_opengl_set_height_func(GritsViewer *_opengl, GritsBounds *bounds,
345 RoamHeightFunc height_func, gpointer user_data, gboolean update)
347 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
348 /* TODO: get points? */
349 g_mutex_lock(opengl->sphere_lock);
350 GList *triangles = roam_sphere_get_intersect(opengl->sphere, TRUE,
351 bounds->n, bounds->s, bounds->e, bounds->w);
352 for (GList *cur = triangles; cur; cur = cur->next) {
353 RoamTriangle *tri = cur->data;
354 RoamPoint *points[] = {tri->p.l, tri->p.m, tri->p.r, tri->split};
355 for (int i = 0; i < G_N_ELEMENTS(points); i++) {
356 if (bounds->n >= points[i]->lat && points[i]->lat >= bounds->s &&
357 bounds->e >= points[i]->lon && points[i]->lon >= bounds->w) {
358 points[i]->height_func = height_func;
359 points[i]->height_data = user_data;
360 roam_point_update_height(points[i]);
364 g_list_free(triangles);
365 g_mutex_unlock(opengl->sphere_lock);
368 static void _grits_opengl_clear_height_func_rec(RoamTriangle *root)
372 RoamPoint *points[] = {root->p.l, root->p.m, root->p.r, root->split};
373 for (int i = 0; i < G_N_ELEMENTS(points); i++) {
374 points[i]->height_func = NULL;
375 points[i]->height_data = NULL;
376 roam_point_update_height(points[i]);
378 _grits_opengl_clear_height_func_rec(root->kids[0]);
379 _grits_opengl_clear_height_func_rec(root->kids[1]);
382 static void grits_opengl_clear_height_func(GritsViewer *_opengl)
384 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
385 for (int i = 0; i < G_N_ELEMENTS(opengl->sphere->roots); i++)
386 _grits_opengl_clear_height_func_rec(opengl->sphere->roots[i]);
389 static gpointer grits_opengl_add(GritsViewer *_opengl, GritsObject *object,
390 gint key, gboolean sort)
392 g_assert(GRITS_IS_OPENGL(_opengl));
393 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
394 g_mutex_lock(opengl->objects_lock);
395 struct RenderLevel *level = g_tree_lookup(opengl->objects, (gpointer)key);
397 level = g_new0(struct RenderLevel, 1);
398 g_tree_insert(opengl->objects, (gpointer)key, level);
400 GList *list = sort ? &level->sorted : &level->unsorted;
401 /* Put the link in the list */
402 GList *link = g_new0(GList, 1);
405 link->next = list->next;
407 list->next->prev = link;
409 g_mutex_unlock(opengl->objects_lock);
413 static GritsObject *grits_opengl_remove(GritsViewer *_opengl, gpointer _link)
415 g_assert(GRITS_IS_OPENGL(_opengl));
416 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
418 g_mutex_lock(opengl->objects_lock);
419 GritsObject *object = link->data;
420 /* Just unlink and free it, link->prev is assured */
421 link->prev->next = link->next;
423 link->next->prev = link->prev;
424 g_mutex_unlock(opengl->objects_lock);
426 g_object_unref(object);
433 static int _objects_cmp(gconstpointer _a, gconstpointer _b, gpointer _)
435 gint a = (int)_a, b = (int)_b;
439 static void _objects_free(gpointer value)
441 struct RenderLevel *level = value;
442 if (level->sorted.next)
443 g_list_free(level->sorted.next);
444 if (level->unsorted.next)
445 g_list_free(level->unsorted.next);
449 G_DEFINE_TYPE(GritsOpenGL, grits_opengl, GRITS_TYPE_VIEWER);
450 static void grits_opengl_init(GritsOpenGL *opengl)
452 g_debug("GritsOpenGL: init");
453 opengl->objects = g_tree_new_full(_objects_cmp, NULL, NULL, _objects_free);
454 opengl->objects_lock = g_mutex_new();
455 opengl->sphere = roam_sphere_new(opengl);
456 opengl->sphere_lock = g_mutex_new();
458 /* Set OpenGL before "realize" */
459 GdkGLConfig *glconfig = gdk_gl_config_new_by_mode(
460 GDK_GL_MODE_RGBA | GDK_GL_MODE_DEPTH |
461 GDK_GL_MODE_DOUBLE | GDK_GL_MODE_ALPHA);
463 g_error("Failed to create glconfig");
464 if (!gtk_widget_set_gl_capability(GTK_WIDGET(opengl),
465 glconfig, NULL, TRUE, GDK_GL_RGBA_TYPE))
466 g_error("GL lacks required capabilities");
467 g_object_unref(glconfig);
469 /* Finish OpenGL init after it's realized */
470 g_signal_connect(opengl, "realize", G_CALLBACK(on_realize), NULL);
472 static void grits_opengl_dispose(GObject *_opengl)
474 g_debug("GritsOpenGL: dispose");
475 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
476 if (opengl->sm_source[0]) {
477 g_source_remove(opengl->sm_source[0]);
478 opengl->sm_source[0] = 0;
480 if (opengl->sm_source[1]) {
481 g_source_remove(opengl->sm_source[1]);
482 opengl->sm_source[1] = 0;
484 if (opengl->ue_source) {
485 g_source_remove(opengl->ue_source);
486 opengl->ue_source = 0;
488 G_OBJECT_CLASS(grits_opengl_parent_class)->dispose(_opengl);
490 static void grits_opengl_finalize(GObject *_opengl)
492 g_debug("GritsOpenGL: finalize");
493 GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
494 roam_sphere_free(opengl->sphere);
495 g_tree_destroy(opengl->objects);
496 g_mutex_free(opengl->objects_lock);
497 g_mutex_free(opengl->sphere_lock);
498 G_OBJECT_CLASS(grits_opengl_parent_class)->finalize(_opengl);
500 static void grits_opengl_class_init(GritsOpenGLClass *klass)
502 g_debug("GritsOpenGL: class_init");
503 GObjectClass *gobject_class = G_OBJECT_CLASS(klass);
504 gobject_class->finalize = grits_opengl_finalize;
505 gobject_class->dispose = grits_opengl_dispose;
507 GritsViewerClass *viewer_class = GRITS_VIEWER_CLASS(klass);
508 viewer_class->center_position = grits_opengl_center_position;
509 viewer_class->project = grits_opengl_project;
510 viewer_class->clear_height_func = grits_opengl_clear_height_func;
511 viewer_class->set_height_func = grits_opengl_set_height_func;
512 viewer_class->add = grits_opengl_add;
513 viewer_class->remove = grits_opengl_remove;