2 * Copyright (C) 2009 Andy Spencer <spenceal@rose-hulman.edu>
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/>.
18 /* Tessellation, "finding intersecting triangles" */
19 /* http://research.microsoft.com/pubs/70307/tr-2006-81.pdf */
20 /* http://www.opengl.org/wiki/Alpha_Blending */
25 #include <gdk/gdkkeysyms.h>
27 #include <gtk/gtkgl.h>
31 #include "gis-opengl.h"
33 #include "gis-object.h"
36 #define FOV_DIST 2000.0
37 #define MPPX(dist) (4*dist/FOV_DIST)
44 static void _gis_opengl_begin(GisOpenGL *self)
46 g_assert(GIS_IS_OPENGL(self));
48 GdkGLContext *glcontext = gtk_widget_get_gl_context(GTK_WIDGET(self));
49 GdkGLDrawable *gldrawable = gtk_widget_get_gl_drawable(GTK_WIDGET(self));
51 if (!gdk_gl_drawable_gl_begin(gldrawable, glcontext))
52 g_assert_not_reached();
55 static void _gis_opengl_end(GisOpenGL *self)
57 g_assert(GIS_IS_OPENGL(self));
58 GdkGLDrawable *gldrawable = gtk_widget_get_gl_drawable(GTK_WIDGET(self));
59 gdk_gl_drawable_gl_end(gldrawable);
62 static void _set_visuals(GisOpenGL *self)
64 glMatrixMode(GL_MODELVIEW);
68 double lat, lon, elev, rx, ry, rz;
69 gis_viewer_get_location(GIS_VIEWER(self), &lat, &lon, &elev);
70 gis_viewer_get_rotation(GIS_VIEWER(self), &rx, &ry, &rz);
71 glRotatef(rx, 1, 0, 0);
72 glRotatef(rz, 0, 0, 1);
76 float light_ambient[] = {0.7f, 0.7f, 0.7f, 1.0f};
77 float light_diffuse[] = {2.0f, 2.0f, 2.0f, 1.0f};
79 float light_ambient[] = {0.2f, 0.2f, 0.2f, 1.0f};
80 float light_diffuse[] = {5.0f, 5.0f, 5.0f, 1.0f};
82 float light_position[] = {-13*EARTH_R, 1*EARTH_R, 3*EARTH_R, 1.0f};
83 glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
84 glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
85 glLightfv(GL_LIGHT0, GL_POSITION, light_position);
87 glEnable(GL_LIGHTING);
89 float material_ambient[] = {0.2, 0.2, 0.2, 1.0};
90 float material_diffuse[] = {0.8, 0.8, 0.8, 1.0};
91 float material_specular[] = {0.0, 0.0, 0.0, 1.0};
92 float material_emission[] = {0.0, 0.0, 0.0, 1.0};
93 glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, material_ambient);
94 glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, material_diffuse);
95 glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, material_specular);
96 glMaterialfv(GL_FRONT_AND_BACK, GL_EMISSION, material_emission);
97 glDisable(GL_TEXTURE_2D);
98 glDisable(GL_COLOR_MATERIAL);
101 glTranslatef(0, 0, -elev2rad(elev));
102 glRotatef(lat, 1, 0, 0);
103 glRotatef(-lon, 0, 1, 0);
106 gdouble rg = MAX(0, 1-(elev/20000));
107 gdouble blue = MAX(0, 1-(elev/50000));
108 glClearColor(MIN(0.65,rg), MIN(0.65,rg), MIN(1,blue), 1.0f);
109 glColor4f(1, 1, 1, 1);
111 glDisable(GL_ALPHA_TEST);
113 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
118 glEnable(GL_CULL_FACE);
122 glDepthFunc(GL_LEQUAL);
123 glEnable(GL_DEPTH_TEST);
125 glEnable(GL_LINE_SMOOTH);
127 glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
128 //glShadeModel(GL_FLAT);
130 roam_sphere_update_view(self->sphere);
134 /********************
136 ********************/
137 static void _draw_marker(GisOpenGL *self, GisMarker *marker)
139 GisPoint *point = gis_object_center(GIS_OBJECT(marker));
141 gis_viewer_project(GIS_VIEWER(self),
142 point->lat, point->lon, point->elev,
147 //g_debug("GisOpenGL: draw_marker - %s pz=%f ", marker->label, pz);
149 cairo_surface_t *surface = cairo_get_target(marker->cairo);
150 gdouble width = cairo_image_surface_get_width(surface);
151 gdouble height = cairo_image_surface_get_height(surface);
153 glMatrixMode(GL_PROJECTION); glLoadIdentity();
154 glMatrixMode(GL_MODELVIEW); glLoadIdentity();
155 glOrtho(0, GTK_WIDGET(self)->allocation.width,
156 0, GTK_WIDGET(self)->allocation.height, -1, 1);
157 glTranslated(px - marker->xoff,
158 py - marker->yoff, 0);
160 glDisable(GL_LIGHTING);
161 glDisable(GL_COLOR_MATERIAL);
162 glDisable(GL_DEPTH_TEST);
163 glEnable(GL_TEXTURE_2D);
164 glBindTexture(GL_TEXTURE_2D, marker->tex);
166 glTexCoord2f(1, 1); glVertex3f(width, 0 , 0);
167 glTexCoord2f(1, 0); glVertex3f(width, height, 0);
168 glTexCoord2f(0, 0); glVertex3f(0 , height, 0);
169 glTexCoord2f(0, 1); glVertex3f(0 , 0 , 0);
173 static void _draw_callback(GisOpenGL *self, GisCallback *callback)
175 callback->callback(callback, callback->user_data);
178 static void _draw_object(GisOpenGL *self, GisObject *object)
180 //g_debug("GisOpenGL: draw_object");
181 /* Skip out of range objects */
182 if (object->lod > 0) {
183 gdouble eye[3], obj[3];
184 gis_viewer_get_location(GIS_VIEWER(self), &eye[0], &eye[1], &eye[2]);
185 lle2xyz(eye[0], eye[1], eye[2], &eye[0], &eye[1], &eye[2]);
186 lle2xyz(object->center.lat, object->center.lon, object->center.elev,
187 &obj[0], &obj[1], &obj[2]);
188 gdouble dist = distd(obj, eye);
189 if (object->lod < dist)
194 glMatrixMode(GL_PROJECTION); glPushMatrix();
195 glMatrixMode(GL_MODELVIEW); glPushMatrix();
196 glPushAttrib(GL_ALL_ATTRIB_BITS);
197 switch (object->type) {
198 case GIS_TYPE_MARKER:
199 _draw_marker(self, GIS_MARKER(object));
201 case GIS_TYPE_CALLBACK:
202 _draw_callback(self, GIS_CALLBACK(object));
208 glMatrixMode(GL_PROJECTION); glPopMatrix();
209 glMatrixMode(GL_MODELVIEW); glPopMatrix();
212 static void _load_object(GisOpenGL *self, GisObject *object)
214 g_debug("GisOpenGL: load_object");
215 switch (object->type) {
216 case GIS_TYPE_MARKER: {
217 GisMarker *marker = GIS_MARKER(object);
218 cairo_surface_t *surface = cairo_get_target(marker->cairo);
219 gdouble width = cairo_image_surface_get_width(surface);
220 gdouble height = cairo_image_surface_get_height(surface);
222 _gis_opengl_begin(self);
223 glEnable(GL_TEXTURE_2D);
224 glGenTextures(1, &marker->tex);
225 glBindTexture(GL_TEXTURE_2D, marker->tex);
227 glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
228 glPixelStorei(GL_PACK_ALIGNMENT, 1);
229 glTexImage2D(GL_TEXTURE_2D, 0, 4, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE,
230 cairo_image_surface_get_data(surface));
231 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
232 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
233 g_debug("load_texture: %d", marker->tex);
234 _gis_opengl_end(self);
242 static void _unload_object(GisOpenGL *self, GisObject *object)
244 g_debug("GisOpenGL: unload_object");
245 switch (object->type) {
246 case GIS_TYPE_MARKER: {
247 GisMarker *marker = GIS_MARKER(object);
248 g_debug("delete_texture: %d", marker->tex);
249 glDeleteTextures(1, &marker->tex);
261 /* The unsorted/sroted GLists are blank head nodes,
262 * This way us we can remove objects from the level just by fixing up links
263 * I.e. we don't need to do a lookup to remove an object if we have its GList */
269 static void on_realize(GisOpenGL *self, gpointer _)
271 g_debug("GisOpenGL: on_realize");
273 g_mutex_lock(self->sphere_lock);
274 roam_sphere_update_errors(self->sphere);
275 g_mutex_unlock(self->sphere_lock);
277 static gboolean on_configure(GisOpenGL *self, GdkEventConfigure *event, gpointer _)
279 g_debug("GisOpenGL: on_configure");
280 _gis_opengl_begin(self);
282 double width = GTK_WIDGET(self)->allocation.width;
283 double height = GTK_WIDGET(self)->allocation.height;
285 /* Setup OpenGL Window */
286 glViewport(0, 0, width, height);
287 glMatrixMode(GL_PROJECTION);
289 double ang = atan(height/FOV_DIST);
290 gluPerspective(rad2deg(ang)*2, width/height, 1, 10*EARTH_R);
293 g_mutex_lock(self->sphere_lock);
294 roam_sphere_update_errors(self->sphere);
295 g_mutex_unlock(self->sphere_lock);
298 _gis_opengl_end(self);
302 static gboolean _draw_level(gpointer key, gpointer value, gpointer user_data)
304 g_debug("GisOpenGL: _draw_level - level=%-4d", (int)key);
305 GisOpenGL *self = user_data;
306 struct RenderLevel *level = value;
307 int nsorted = 0, nunsorted = 0;
310 /* Draw opaque objects without sorting */
312 glClear(GL_DEPTH_BUFFER_BIT);
313 for (cur = level->unsorted.next; cur; cur = cur->next, nunsorted++)
314 _draw_object(self, GIS_OBJECT(cur->data));
316 /* Freeze depth buffer and draw transparent objects sorted */
319 for (cur = level->sorted.next; cur; cur = cur->next, nsorted++)
320 _draw_object(self, GIS_OBJECT(cur->data));
322 /* TODO: Prune empty levels */
324 g_debug("GisOpenGL: _draw_level - drew %d,%d objects",
329 static gboolean on_expose(GisOpenGL *self, GdkEventExpose *event, gpointer _)
331 g_debug("GisOpenGL: on_expose - begin");
332 _gis_opengl_begin(self);
334 glClear(GL_COLOR_BUFFER_BIT);
338 glColor4f(0.0, 0.0, 9.0, 0.6);
339 glDisable(GL_TEXTURE_2D);
340 glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
341 roam_sphere_draw(self->sphere);
342 //roam_sphere_draw_normals(self->sphere);
344 g_tree_foreach(self->objects, _draw_level, self);
345 if (self->wireframe) {
346 glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
347 roam_sphere_draw(self->sphere);
351 GdkGLDrawable *gldrawable = gtk_widget_get_gl_drawable(GTK_WIDGET(self));
352 gdk_gl_drawable_swap_buffers(gldrawable);
354 _gis_opengl_end(self);
355 g_debug("GisOpenGL: on_expose - end\n");
359 static gboolean on_key_press(GisOpenGL *self, GdkEventKey *event, gpointer _)
361 g_debug("GisOpenGL: on_key_press - key=%x, state=%x, plus=%x",
362 event->keyval, event->state, GDK_plus);
364 guint kv = event->keyval;
368 self->wireframe = !self->wireframe;
369 gtk_widget_queue_draw(GTK_WIDGET(self));
372 else if (kv == GDK_n) roam_sphere_split_one(self->sphere);
373 else if (kv == GDK_p) roam_sphere_merge_one(self->sphere);
374 else if (kv == GDK_r) roam_sphere_split_merge(self->sphere);
375 else if (kv == GDK_u) roam_sphere_update_errors(self->sphere);
377 gtk_widget_queue_draw(GTK_WIDGET(self));
384 static gboolean _update_errors_cb(gpointer sphere)
386 roam_sphere_update_errors(sphere);
389 static void on_view_changed(GisOpenGL *self,
390 gdouble _1, gdouble _2, gdouble _3)
392 g_debug("GisOpenGL: on_view_changed");
394 _gis_opengl_begin(self);
397 g_idle_add_full(G_PRIORITY_HIGH_IDLE+30, _update_errors_cb, self->sphere, NULL);
398 //roam_sphere_update_errors(self->sphere);
400 _gis_opengl_end(self);
404 static gboolean on_idle(GisOpenGL *self)
406 //g_debug("GisOpenGL: on_idle");
408 _gis_opengl_begin(self);
409 g_mutex_lock(self->sphere_lock);
410 if (roam_sphere_split_merge(self->sphere))
411 gtk_widget_queue_draw(GTK_WIDGET(self));
412 g_mutex_unlock(self->sphere_lock);
413 _gis_opengl_end(self);
419 /*********************
420 * GisViewer methods *
421 *********************/
422 GisViewer *gis_opengl_new(GisPlugins *plugins)
424 g_debug("GisOpenGL: new");
425 GisViewer *self = g_object_new(GIS_TYPE_OPENGL, NULL);
426 self->plugins = plugins;
430 static void gis_opengl_center_position(GisViewer *_self, gdouble lat, gdouble lon, gdouble elev)
432 GisOpenGL *self = GIS_OPENGL(_self);
433 glRotatef(lon, 0, 1, 0);
434 glRotatef(-lat, 1, 0, 0);
435 glTranslatef(0, 0, elev2rad(elev));
438 static void gis_opengl_project(GisViewer *_self,
439 gdouble lat, gdouble lon, gdouble elev,
440 gdouble *px, gdouble *py, gdouble *pz)
442 GisOpenGL *self = GIS_OPENGL(_self);
444 lle2xyz(lat, lon, elev, &x, &y, &z);
446 self->sphere->view->model,
447 self->sphere->view->proj,
448 self->sphere->view->view,
452 static void gis_opengl_render_tile(GisViewer *_self, GisTile *tile)
454 GisOpenGL *self = GIS_OPENGL(_self);
455 if (!tile || !tile->data)
457 GList *triangles = roam_sphere_get_intersect(self->sphere, FALSE,
458 tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
460 g_warning("GisOpenGL: render_tiles - No triangles to draw: edges=%f,%f,%f,%f",
461 tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
462 //g_message("rendering %4d triangles for tile edges=%7.2f,%7.2f,%7.2f,%7.2f",
463 // g_list_length(triangles), tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
464 for (GList *cur = triangles; cur; cur = cur->next) {
465 RoamTriangle *tri = cur->data;
467 gdouble lat[3] = {tri->p.r->lat, tri->p.m->lat, tri->p.l->lat};
468 gdouble lon[3] = {tri->p.r->lon, tri->p.m->lon, tri->p.l->lon};
470 if (lon[0] < -90 || lon[1] < -90 || lon[2] < -90) {
471 if (lon[0] > 90) lon[0] -= 360;
472 if (lon[1] > 90) lon[1] -= 360;
473 if (lon[2] > 90) lon[2] -= 360;
476 gdouble n = tile->edge.n;
477 gdouble s = tile->edge.s;
478 gdouble e = tile->edge.e;
479 gdouble w = tile->edge.w;
481 gdouble londist = e - w;
482 gdouble latdist = n - s;
485 {(lon[0]-w)/londist, 1-(lat[0]-s)/latdist},
486 {(lon[1]-w)/londist, 1-(lat[1]-s)/latdist},
487 {(lon[2]-w)/londist, 1-(lat[2]-s)/latdist},
490 glEnable(GL_TEXTURE_2D);
491 glBindTexture(GL_TEXTURE_2D, *(guint*)tile->data);
492 glBegin(GL_TRIANGLES);
493 glNormal3dv(tri->p.r->norm); glTexCoord2dv(xy[0]); glVertex3dv((double*)tri->p.r);
494 glNormal3dv(tri->p.m->norm); glTexCoord2dv(xy[1]); glVertex3dv((double*)tri->p.m);
495 glNormal3dv(tri->p.l->norm); glTexCoord2dv(xy[2]); glVertex3dv((double*)tri->p.l);
498 g_list_free(triangles);
501 static void gis_opengl_render_tiles(GisViewer *_self, GisTile *tile)
503 GisOpenGL *self = GIS_OPENGL(_self);
504 /* Only render children if possible */
505 gboolean has_children = TRUE;
507 gis_tile_foreach(tile, child)
508 if (!child || !child->data)
509 has_children = FALSE;
511 /* Only render children */
512 gis_tile_foreach(tile, child)
513 gis_opengl_render_tiles(_self, child);
515 /* No children, render this tile */
516 gis_opengl_render_tile(_self, tile);
519 static void gis_opengl_set_height_func(GisViewer *_self, GisTile *tile,
520 RoamHeightFunc height_func, gpointer user_data, gboolean update)
522 GisOpenGL *self = GIS_OPENGL(_self);
525 /* TODO: get points? */
526 g_mutex_lock(self->sphere_lock);
527 GList *triangles = roam_sphere_get_intersect(self->sphere, TRUE,
528 tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
529 for (GList *cur = triangles; cur; cur = cur->next) {
530 RoamTriangle *tri = cur->data;
531 RoamPoint *points[] = {tri->p.l, tri->p.m, tri->p.r, tri->split};
532 for (int i = 0; i < G_N_ELEMENTS(points); i++) {
533 if (tile->edge.n >= points[i]->lat && points[i]->lat >= tile->edge.s &&
534 tile->edge.e >= points[i]->lon && points[i]->lon >= tile->edge.w) {
535 points[i]->height_func = height_func;
536 points[i]->height_data = user_data;
537 roam_point_update_height(points[i]);
541 g_list_free(triangles);
542 g_mutex_unlock(self->sphere_lock);
545 static void _gis_opengl_clear_height_func_rec(RoamTriangle *root)
549 RoamPoint *points[] = {root->p.l, root->p.m, root->p.r, root->split};
550 for (int i = 0; i < G_N_ELEMENTS(points); i++) {
551 points[i]->height_func = NULL;
552 points[i]->height_data = NULL;
553 roam_point_update_height(points[i]);
555 _gis_opengl_clear_height_func_rec(root->kids[0]);
556 _gis_opengl_clear_height_func_rec(root->kids[1]);
559 static void gis_opengl_clear_height_func(GisViewer *_self)
561 GisOpenGL *self = GIS_OPENGL(_self);
562 for (int i = 0; i < G_N_ELEMENTS(self->sphere->roots); i++)
563 _gis_opengl_clear_height_func_rec(self->sphere->roots[i]);
566 static void gis_opengl_begin(GisViewer *_self)
568 g_assert(GIS_IS_OPENGL(_self));
569 _gis_opengl_begin(GIS_OPENGL(_self));
572 static void gis_opengl_end(GisViewer *_self)
574 g_assert(GIS_IS_OPENGL(_self));
575 _gis_opengl_end(GIS_OPENGL(_self));
578 static gpointer gis_opengl_add(GisViewer *_self, GisObject *object,
579 gint key, gboolean sort)
581 g_assert(GIS_IS_OPENGL(_self));
582 GisOpenGL *self = GIS_OPENGL(_self);
583 _load_object(self, object);
584 struct RenderLevel *level = g_tree_lookup(self->objects, (gpointer)key);
586 level = g_new0(struct RenderLevel, 1);
587 g_tree_insert(self->objects, (gpointer)key, level);
589 GList *list = sort ? &level->sorted : &level->unsorted;
590 list->next = g_list_prepend(list->next, object);
594 static void gis_opengl_remove(GisViewer *_self, gpointer _link)
596 g_assert(GIS_IS_OPENGL(_self));
598 GisOpenGL *self = GIS_OPENGL(_self);
599 _unload_object(self, link->data);
600 /* Just unlink and free it (blowup link to avoid warnings) */
601 link = g_list_delete_link(NULL, link);
607 static int _objects_cmp(gconstpointer _a, gconstpointer _b)
609 gint a = (int)_a, b = (int)_b;
614 G_DEFINE_TYPE(GisOpenGL, gis_opengl, GIS_TYPE_VIEWER);
615 static void gis_opengl_init(GisOpenGL *self)
617 g_debug("GisOpenGL: init");
619 GdkGLConfig *glconfig = gdk_gl_config_new_by_mode(
620 GDK_GL_MODE_RGBA | GDK_GL_MODE_DEPTH |
621 GDK_GL_MODE_DOUBLE | GDK_GL_MODE_ALPHA);
623 g_error("Failed to create glconfig");
624 if (!gtk_widget_set_gl_capability(GTK_WIDGET(self),
625 glconfig, NULL, TRUE, GDK_GL_RGBA_TYPE))
626 g_error("GL lacks required capabilities");
627 g_object_unref(glconfig);
629 gtk_widget_set_size_request(GTK_WIDGET(self), 600, 550);
630 gtk_widget_set_events(GTK_WIDGET(self),
631 GDK_BUTTON_PRESS_MASK |
632 GDK_ENTER_NOTIFY_MASK |
634 g_object_set(self, "can-focus", TRUE, NULL);
636 self->objects = g_tree_new(_objects_cmp);
637 self->sphere = roam_sphere_new(self);
638 self->sphere_lock = g_mutex_new();
641 self->sm_source[0] = g_timeout_add_full(G_PRIORITY_HIGH_IDLE+30, 33, (GSourceFunc)on_idle, self, NULL);
642 self->sm_source[1] = g_timeout_add_full(G_PRIORITY_HIGH_IDLE+10, 500, (GSourceFunc)on_idle, self, NULL);
645 g_signal_connect(self, "realize", G_CALLBACK(on_realize), NULL);
646 g_signal_connect(self, "configure-event", G_CALLBACK(on_configure), NULL);
647 g_signal_connect(self, "expose-event", G_CALLBACK(on_expose), NULL);
649 g_signal_connect(self, "key-press-event", G_CALLBACK(on_key_press), NULL);
651 g_signal_connect(self, "location-changed", G_CALLBACK(on_view_changed), NULL);
652 g_signal_connect(self, "rotation-changed", G_CALLBACK(on_view_changed), NULL);
654 static void gis_opengl_dispose(GObject *_self)
656 g_debug("GisOpenGL: dispose");
657 GisOpenGL *self = GIS_OPENGL(_self);
658 if (self->sm_source[0]) {
659 g_source_remove(self->sm_source[0]);
660 self->sm_source[0] = 0;
662 if (self->sm_source[1]) {
663 g_source_remove(self->sm_source[1]);
664 self->sm_source[1] = 0;
667 roam_sphere_free(self->sphere);
670 /* TODO: Cleanup/free objects tree */
671 G_OBJECT_CLASS(gis_opengl_parent_class)->dispose(_self);
673 static void gis_opengl_finalize(GObject *_self)
675 g_debug("GisViewer: finalize");
676 GisOpenGL *self = GIS_OPENGL(_self);
677 g_mutex_free(self->sphere_lock);
678 G_OBJECT_CLASS(gis_opengl_parent_class)->finalize(_self);
680 static void gis_opengl_class_init(GisOpenGLClass *klass)
682 g_debug("GisOpenGL: class_init");
683 GObjectClass *gobject_class = G_OBJECT_CLASS(klass);
684 gobject_class->dispose = gis_opengl_dispose;
686 GisViewerClass *viewer_class = GIS_VIEWER_CLASS(klass);
687 viewer_class->center_position = gis_opengl_center_position;
688 viewer_class->project = gis_opengl_project;
689 viewer_class->clear_height_func = gis_opengl_clear_height_func;
690 viewer_class->set_height_func = gis_opengl_set_height_func;
691 viewer_class->render_tile = gis_opengl_render_tile;
692 viewer_class->render_tiles = gis_opengl_render_tiles;
693 viewer_class->begin = gis_opengl_begin;
694 viewer_class->end = gis_opengl_end;
695 viewer_class->add = gis_opengl_add;
696 viewer_class->remove = gis_opengl_remove;