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/>.
20 * @short_description: OpenGL based virtual globe
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.
27 * GisOpenGL relies on #GtkGlExt and requires (at least) OpenGL 2.0.
33 #include <gdk/gdkkeysyms.h>
35 #include <gtk/gtkgl.h>
39 #include "gis-opengl.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(GisOpenGL *opengl)
54 glMatrixMode(GL_MODELVIEW);
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);
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[] = {5.0f, 5.0f, 5.0f, 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[] = {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);
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);
106 glDepthFunc(GL_LEQUAL);
107 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(GisOpenGL *opengl, GdkEventConfigure *event, gpointer _)
133 g_debug("GisOpenGL: 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 void on_realize(GisOpenGL *opengl, gpointer _)
156 g_debug("GisOpenGL: on_realize");
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();
163 _set_visuals(opengl);
164 on_configure(opengl, NULL, NULL);
167 static gboolean _draw_level(gpointer key, gpointer value, gpointer user_data)
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;
175 /* Draw opaque objects without sorting */
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);
181 /* Freeze depth buffer and draw transparent objects sorted */
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);
188 /* TODO: Prune empty levels */
190 g_debug("GisOpenGL: _draw_level - drew %d,%d objects",
195 static gboolean on_expose(GisOpenGL *opengl, GdkEventExpose *event, gpointer _)
197 g_debug("GisOpenGL: on_expose - begin");
199 glClear(GL_COLOR_BUFFER_BIT);
201 _set_visuals(opengl);
203 glColor4f(0.0, 0.0, 9.0, 0.6);
204 glDisable(GL_TEXTURE_2D);
205 glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
206 roam_sphere_draw(opengl->sphere);
207 //roam_sphere_draw_normals(opengl->sphere);
209 g_mutex_lock(opengl->objects_lock);
210 g_tree_foreach(opengl->objects, _draw_level, opengl);
211 g_mutex_unlock(opengl->objects_lock);
212 if (opengl->wireframe) {
213 glClear(GL_DEPTH_BUFFER_BIT);
214 glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
215 roam_sphere_draw(opengl->sphere);
219 GdkGLDrawable *gldrawable = gtk_widget_get_gl_drawable(GTK_WIDGET(opengl));
220 gdk_gl_drawable_swap_buffers(gldrawable);
222 g_debug("GisOpenGL: on_expose - end\n");
226 static gboolean on_key_press(GisOpenGL *opengl, GdkEventKey *event, gpointer _)
228 g_debug("GisOpenGL: on_key_press - key=%x, state=%x, plus=%x",
229 event->keyval, event->state, GDK_plus);
231 guint kv = event->keyval;
234 opengl->wireframe = !opengl->wireframe;
235 gtk_widget_queue_draw(GTK_WIDGET(opengl));
238 else if (kv == GDK_n) roam_sphere_split_one(opengl->sphere);
239 else if (kv == GDK_p) roam_sphere_merge_one(opengl->sphere);
240 else if (kv == GDK_r) roam_sphere_split_merge(opengl->sphere);
241 else if (kv == GDK_u) roam_sphere_update_errors(opengl->sphere);
242 gtk_widget_queue_draw(GTK_WIDGET(opengl));
247 static gboolean _update_errors_cb(gpointer _opengl)
249 GisOpenGL *opengl = _opengl;
250 g_mutex_lock(opengl->sphere_lock);
251 roam_sphere_update_errors(opengl->sphere);
252 g_mutex_unlock(opengl->sphere_lock);
253 opengl->ue_source = 0;
256 static void on_view_changed(GisOpenGL *opengl,
257 gdouble _1, gdouble _2, gdouble _3)
259 g_debug("GisOpenGL: on_view_changed");
260 _set_visuals(opengl);
262 if (!opengl->ue_source)
263 opengl->ue_source = g_idle_add_full(G_PRIORITY_HIGH_IDLE+30,
264 _update_errors_cb, opengl, NULL);
265 //roam_sphere_update_errors(opengl->sphere);
269 static gboolean on_idle(GisOpenGL *opengl)
271 //g_debug("GisOpenGL: on_idle");
272 g_mutex_lock(opengl->sphere_lock);
273 if (roam_sphere_split_merge(opengl->sphere))
274 gtk_widget_queue_draw(GTK_WIDGET(opengl));
275 g_mutex_unlock(opengl->sphere_lock);
280 /*********************
281 * GisViewer methods *
282 *********************/
285 * @plugins: the plugins store to use
286 * @prefs: the preferences object to use
288 * Create a new OpenGL renderer.
290 * Returns: the new #GisOpenGL
292 GisViewer *gis_opengl_new(GisPlugins *plugins, GisPrefs *prefs)
294 g_debug("GisOpenGL: new");
295 GisViewer *opengl = g_object_new(GIS_TYPE_OPENGL, NULL);
296 gis_viewer_setup(opengl, plugins, prefs);
300 static void gis_opengl_center_position(GisViewer *_opengl, gdouble lat, gdouble lon, gdouble elev)
302 glRotatef(lon, 0, 1, 0);
303 glRotatef(-lat, 1, 0, 0);
304 glTranslatef(0, 0, elev2rad(elev));
307 static void gis_opengl_project(GisViewer *_opengl,
308 gdouble lat, gdouble lon, gdouble elev,
309 gdouble *px, gdouble *py, gdouble *pz)
311 GisOpenGL *opengl = GIS_OPENGL(_opengl);
313 lle2xyz(lat, lon, elev, &x, &y, &z);
315 opengl->sphere->view->model,
316 opengl->sphere->view->proj,
317 opengl->sphere->view->view,
321 static void gis_opengl_set_height_func(GisViewer *_opengl, GisBounds *bounds,
322 RoamHeightFunc height_func, gpointer user_data, gboolean update)
324 GisOpenGL *opengl = GIS_OPENGL(_opengl);
325 /* TODO: get points? */
326 g_mutex_lock(opengl->sphere_lock);
327 GList *triangles = roam_sphere_get_intersect(opengl->sphere, TRUE,
328 bounds->n, bounds->s, bounds->e, bounds->w);
329 for (GList *cur = triangles; cur; cur = cur->next) {
330 RoamTriangle *tri = cur->data;
331 RoamPoint *points[] = {tri->p.l, tri->p.m, tri->p.r, tri->split};
332 for (int i = 0; i < G_N_ELEMENTS(points); i++) {
333 if (bounds->n >= points[i]->lat && points[i]->lat >= bounds->s &&
334 bounds->e >= points[i]->lon && points[i]->lon >= bounds->w) {
335 points[i]->height_func = height_func;
336 points[i]->height_data = user_data;
337 roam_point_update_height(points[i]);
341 g_list_free(triangles);
342 g_mutex_unlock(opengl->sphere_lock);
345 static void _gis_opengl_clear_height_func_rec(RoamTriangle *root)
349 RoamPoint *points[] = {root->p.l, root->p.m, root->p.r, root->split};
350 for (int i = 0; i < G_N_ELEMENTS(points); i++) {
351 points[i]->height_func = NULL;
352 points[i]->height_data = NULL;
353 roam_point_update_height(points[i]);
355 _gis_opengl_clear_height_func_rec(root->kids[0]);
356 _gis_opengl_clear_height_func_rec(root->kids[1]);
359 static void gis_opengl_clear_height_func(GisViewer *_opengl)
361 GisOpenGL *opengl = GIS_OPENGL(_opengl);
362 for (int i = 0; i < G_N_ELEMENTS(opengl->sphere->roots); i++)
363 _gis_opengl_clear_height_func_rec(opengl->sphere->roots[i]);
366 static gpointer gis_opengl_add(GisViewer *_opengl, GisObject *object,
367 gint key, gboolean sort)
369 g_assert(GIS_IS_OPENGL(_opengl));
370 GisOpenGL *opengl = GIS_OPENGL(_opengl);
371 g_mutex_lock(opengl->objects_lock);
372 struct RenderLevel *level = g_tree_lookup(opengl->objects, (gpointer)key);
374 level = g_new0(struct RenderLevel, 1);
375 g_tree_insert(opengl->objects, (gpointer)key, level);
377 GList *list = sort ? &level->sorted : &level->unsorted;
378 /* Put the link in the list */
379 GList *link = g_new0(GList, 1);
382 link->next = list->next;
384 list->next->prev = link;
386 g_mutex_unlock(opengl->objects_lock);
390 static GisObject *gis_opengl_remove(GisViewer *_opengl, gpointer _link)
392 g_assert(GIS_IS_OPENGL(_opengl));
393 GisOpenGL *opengl = GIS_OPENGL(_opengl);
394 g_mutex_lock(opengl->objects_lock);
396 GisObject *object = link->data;
397 /* Just unlink and free it, link->prev is assured */
398 link->prev->next = link->next;
400 link->next->prev = link->prev;
402 g_object_unref(object);
403 g_mutex_unlock(opengl->objects_lock);
410 static int _objects_cmp(gconstpointer _a, gconstpointer _b, gpointer _)
412 gint a = (int)_a, b = (int)_b;
416 static void _objects_free(gpointer value)
418 struct RenderLevel *level = value;
419 if (level->sorted.next)
420 g_list_free(level->sorted.next);
421 if (level->unsorted.next)
422 g_list_free(level->unsorted.next);
426 G_DEFINE_TYPE(GisOpenGL, gis_opengl, GIS_TYPE_VIEWER);
427 static void gis_opengl_init(GisOpenGL *opengl)
429 g_debug("GisOpenGL: init");
431 GdkGLConfig *glconfig = gdk_gl_config_new_by_mode(
432 GDK_GL_MODE_RGBA | GDK_GL_MODE_DEPTH |
433 GDK_GL_MODE_DOUBLE | GDK_GL_MODE_ALPHA);
435 g_error("Failed to create glconfig");
436 if (!gtk_widget_set_gl_capability(GTK_WIDGET(opengl),
437 glconfig, NULL, TRUE, GDK_GL_RGBA_TYPE))
438 g_error("GL lacks required capabilities");
439 g_object_unref(glconfig);
441 opengl->objects = g_tree_new_full(_objects_cmp, NULL, NULL, _objects_free);
442 opengl->objects_lock = g_mutex_new();
443 opengl->sphere = roam_sphere_new(opengl);
444 opengl->sphere_lock = g_mutex_new();
447 opengl->sm_source[0] = g_timeout_add_full(G_PRIORITY_HIGH_IDLE+30, 33, (GSourceFunc)on_idle, opengl, NULL);
448 opengl->sm_source[1] = g_timeout_add_full(G_PRIORITY_HIGH_IDLE+10, 500, (GSourceFunc)on_idle, opengl, NULL);
451 gtk_widget_add_events(GTK_WIDGET(opengl), GDK_KEY_PRESS_MASK);
452 g_signal_connect(opengl, "realize", G_CALLBACK(on_realize), NULL);
453 g_signal_connect(opengl, "configure-event", G_CALLBACK(on_configure), NULL);
454 g_signal_connect(opengl, "expose-event", G_CALLBACK(on_expose), NULL);
456 g_signal_connect(opengl, "key-press-event", G_CALLBACK(on_key_press), NULL);
458 g_signal_connect(opengl, "location-changed", G_CALLBACK(on_view_changed), NULL);
459 g_signal_connect(opengl, "rotation-changed", G_CALLBACK(on_view_changed), NULL);
461 static void gis_opengl_dispose(GObject *_opengl)
463 g_debug("GisOpenGL: dispose");
464 GisOpenGL *opengl = GIS_OPENGL(_opengl);
465 if (opengl->sm_source[0]) {
466 g_source_remove(opengl->sm_source[0]);
467 opengl->sm_source[0] = 0;
469 if (opengl->sm_source[1]) {
470 g_source_remove(opengl->sm_source[1]);
471 opengl->sm_source[1] = 0;
473 if (opengl->ue_source) {
474 g_source_remove(opengl->ue_source);
475 opengl->ue_source = 0;
477 G_OBJECT_CLASS(gis_opengl_parent_class)->dispose(_opengl);
479 static void gis_opengl_finalize(GObject *_opengl)
481 g_debug("GisOpenGL: finalize");
482 GisOpenGL *opengl = GIS_OPENGL(_opengl);
483 roam_sphere_free(opengl->sphere);
484 g_tree_destroy(opengl->objects);
485 g_mutex_free(opengl->objects_lock);
486 g_mutex_free(opengl->sphere_lock);
487 G_OBJECT_CLASS(gis_opengl_parent_class)->finalize(_opengl);
489 static void gis_opengl_class_init(GisOpenGLClass *klass)
491 g_debug("GisOpenGL: class_init");
492 GObjectClass *gobject_class = G_OBJECT_CLASS(klass);
493 gobject_class->finalize = gis_opengl_finalize;
494 gobject_class->dispose = gis_opengl_dispose;
496 GisViewerClass *viewer_class = GIS_VIEWER_CLASS(klass);
497 viewer_class->center_position = gis_opengl_center_position;
498 viewer_class->project = gis_opengl_project;
499 viewer_class->clear_height_func = gis_opengl_clear_height_func;
500 viewer_class->set_height_func = gis_opengl_set_height_func;
501 viewer_class->add = gis_opengl_add;
502 viewer_class->remove = gis_opengl_remove;