2 * Copyright (C) 2009-2010, 2012 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: Latitude/longitude overlays
22 * Each #GritsTile corresponds to a latitude/longitude box on the surface of
23 * the earth. When drawn, the #GritsTile renders an images associated with it
24 * to the surface of the earth. This is primarily used to draw ground overlays.
26 * Each GritsTile can be split into subtiles in order to draw higher resolution
27 * overlays. Pointers to subtitles are stored in the parent tile and a parent
28 * pointer is stored in each child.
30 * Each #GritsTile has a data filed which must be set by the user in order for
31 * the tile to be drawn. When used with GritsOpenGL the data must be an integer
32 * representing the OpenGL texture to use when drawing the tile.
38 #include "grits-tile.h"
40 guint grits_tile_mask = 0;
42 gchar *grits_tile_path_table[2][2] = {
49 * @parent: the parent for the tile, or NULL
50 * @n: the northern border of the tile
51 * @s: the southern border of the tile
52 * @e: the eastern border of the tile
53 * @w: the western border of the tile
55 * Create a tile associated with a particular latitude/longitude box.
57 * Returns: the new #GritsTile
59 GritsTile *grits_tile_new(GritsTile *parent,
60 gdouble n, gdouble s, gdouble e, gdouble w)
62 GritsTile *tile = g_object_new(GRITS_TYPE_TILE, NULL);
63 tile->parent = parent;
64 tile->atime = time(NULL);
65 grits_bounds_set_bounds(&tile->coords, 0, 1, 1, 0);
66 grits_bounds_set_bounds(&tile->edge, n, s, e, w);
68 tile->proj = parent->proj;
73 * grits_tile_get_path:
74 * @child: the tile to generate a path for
76 * Generate a string representation of a tiles location in a group of nested
77 * tiles. The string returned consists of groups of two digits separated by a
78 * delimiter. Each group of digits the tiles location with respect to it's
81 * Returns: the path representing the tiles's location
83 gchar *grits_tile_get_path(GritsTile *child)
85 /* This could be easily cached if necessary */
88 for (GritsTile *parent = child->parent; parent; child = parent, parent = child->parent)
89 grits_tile_foreach_index(child, x, y)
90 if (parent->children[x][y] == child)
91 parts = g_list_prepend(parts, grits_tile_path_table[x][y]);
92 GString *path = g_string_new("");
93 for (GList *cur = parts; cur; cur = cur->next)
94 g_string_append(path, cur->data);
96 return g_string_free(path, FALSE);
99 static gdouble _grits_tile_get_min_dist(GritsPoint *eye, GritsBounds *bounds)
102 pos.lat = eye->lat > bounds->n ? bounds->n :
103 eye->lat < bounds->s ? bounds->s : eye->lat;
104 pos.lon = eye->lon > bounds->e ? bounds->e :
105 eye->lon < bounds->w ? bounds->w : eye->lon;
106 //if (eye->lat == pos.lat && eye->lon == pos.lon)
107 // return elev; /* Shortcut? */
109 lle2xyz(eye->lat, eye->lon, eye->elev, a+0, a+1, a+2);
110 lle2xyz(pos.lat, pos.lon, pos.elev, b+0, b+1, b+2);
114 static gboolean _grits_tile_precise(GritsPoint *eye, GritsBounds *bounds,
115 gdouble max_res, gint width, gint height)
117 gdouble min_dist = _grits_tile_get_min_dist(eye, bounds);
118 gdouble view_res = MPPX(min_dist);
120 gdouble lat_point = bounds->n < 0 ? bounds->n :
121 bounds->s > 0 ? bounds->s : 0;
122 gdouble lon_dist = bounds->e - bounds->w;
123 gdouble tile_res = ll2m(lon_dist, lat_point)/width;
125 /* This isn't really right, but it helps with memory since we don't
126 * (yet?) test if the tile would be drawn */
127 gdouble scale = eye->elev / min_dist;
130 //view_res /= 1.4; /* make it a little nicer, not sure why this is needed */
131 //g_message("tile=(%7.2f %7.2f %7.2f %7.2f) "
132 // "eye=(%9.1f %9.1f %9.1f) "
133 // "elev=%9.1f / dist=%9.1f = %f",
134 // bounds->n, bounds->s, bounds->e, bounds->w,
135 // eye->lat, eye->lon, eye->elev,
136 // eye->elev, min_dist, scale);
138 return tile_res < max_res ||
142 static void _grits_tile_split_latlon(GritsTile *tile)
144 const gdouble rows = G_N_ELEMENTS(tile->children);
145 const gdouble cols = G_N_ELEMENTS(tile->children[0]);
146 const gdouble lat_dist = tile->edge.n - tile->edge.s;
147 const gdouble lon_dist = tile->edge.e - tile->edge.w;
148 const gdouble lat_step = lat_dist / rows;
149 const gdouble lon_step = lon_dist / cols;
152 grits_tile_foreach_index(tile, row, col)
153 tile->children[row][col] = grits_tile_new(tile,
154 tile->edge.n - lat_step*(row+0), // north
155 tile->edge.n - lat_step*(row+1), // south
156 tile->edge.w + lon_step*(col+1), // east
157 tile->edge.w + lon_step*(col+0)); // west
160 static void _grits_tile_split_mercator(GritsTile *tile)
162 GritsTile *child = NULL;
163 GritsBounds tmp = tile->edge;
166 tile->edge.n = asinh(tan(deg2rad(tile->edge.n)));
167 tile->edge.s = asinh(tan(deg2rad(tile->edge.s)));
169 _grits_tile_split_latlon(tile);
171 /* Convert back to lat-lon */
173 grits_tile_foreach(tile, child) {
174 child->edge.n = rad2deg(atan(sinh(child->edge.n)));
175 child->edge.s = rad2deg(atan(sinh(child->edge.s)));
181 * @root: the root tile to split
182 * @eye: the point the tile is viewed from, for calculating distances
183 * @res: a maximum resolution in meters per pixel to split tiles to
184 * @width: width in pixels of the image associated with the tile
185 * @height: height in pixels of the image associated with the tile
186 * @load_func: function used to load the image when a new tile is created
187 * @user_data: user data to past to the load function
189 * Recursively split a tile into children of appropriate detail. The resolution
190 * of the tile in pixels per meter is compared to the resolution which the tile
191 * is being drawn at on the screen. If the screen resolution is insufficient
192 * the tile is recursively subdivided until a sufficient resolution is
195 void grits_tile_update(GritsTile *tile, GritsPoint *eye,
196 gdouble res, gint width, gint height,
197 GritsTileLoadFunc load_func, gpointer user_data)
199 //g_debug("GritsTile: update - %p->atime = %u",
200 // tile, (guint)tile->atime);
207 load_func(tile, user_data);
209 tile->atime = time(NULL);
211 /* Is this tile high enough resolution? */
212 if (_grits_tile_precise(eye, &tile->edge, res, width, height)) {
213 grits_tile_foreach(tile, child)
215 GRITS_OBJECT(child)->hidden = TRUE;
219 /* Split tile if needed */
220 grits_tile_foreach(tile, child) {
222 switch (tile->proj) {
223 case GRITS_PROJ_LATLON: _grits_tile_split_latlon(tile); break;
224 case GRITS_PROJ_MERCATOR: _grits_tile_split_mercator(tile); break;
229 /* Update recursively */
230 grits_tile_foreach(tile, child) {
231 GRITS_OBJECT(child)->hidden = FALSE;
232 grits_tile_update(child, eye, res, width, height,
233 load_func, user_data);
240 * @root: the root tile to search from
241 * @lat: target latitude
242 * @lon: target longitude
244 * Locate the subtile with the highest resolution which contains the given
247 * Returns: the child tile
249 GritsTile *grits_tile_find(GritsTile *root, gdouble lat, gdouble lon)
251 gint rows = G_N_ELEMENTS(root->children);
252 gint cols = G_N_ELEMENTS(root->children[0]);
254 gdouble lat_step = (root->edge.n - root->edge.s) / rows;
255 gdouble lon_step = (root->edge.e - root->edge.w) / cols;
257 gdouble lat_offset = root->edge.n - lat;;
258 gdouble lon_offset = lon - root->edge.w;
260 gint row = lat_offset / lat_step;
261 gint col = lon_offset / lon_step;
263 if (lon == 180) col--;
264 if (lat == -90) row--;
266 //if (lon == 180 || lon == -180)
267 // g_message("lat=%f,lon=%f step=%f,%f off=%f,%f row=%d/%d,col=%d/%d",
268 // lat,lon, lat_step,lon_step, lat_offset,lon_offset, row,rows,col,cols);
270 if (row < 0 || row >= rows || col < 0 || col >= cols)
272 else if (root->children[row][col] && root->children[row][col]->data)
273 return grits_tile_find(root->children[row][col], lat, lon);
280 * @root: the root tile to start garbage collection at
281 * @atime: most recent time at which tiles will be kept
282 * @free_func: function used to free the image when a new tile is collected
283 * @user_data: user data to past to the free function
285 * Garbage collect old tiles. This removes and deallocate tiles that have not
286 * been used since before @atime.
288 * Returns: a pointer to the original tile, or NULL if it was garbage collected
290 GritsTile *grits_tile_gc(GritsTile *root, time_t atime,
291 GritsTileFreeFunc free_func, gpointer user_data)
295 gboolean has_children = FALSE;
297 grits_tile_foreach_index(root, x, y) {
298 root->children[x][y] = grits_tile_gc(
299 root->children[x][y], atime,
300 free_func, user_data);
301 if (root->children[x][y])
304 //g_debug("GritsTile: gc - %p->atime=%u < atime=%u",
305 // root, (guint)root->atime, (guint)atime);
306 if (!has_children && root->atime < atime && root->data) {
307 free_func(root, user_data);
308 g_object_unref(root);
314 /* Use GObject for this */
317 * @root: the root tile to free
318 * @free_func: function used to free the image when a new tile is collected
319 * @user_data: user data to past to the free function
321 * Recursively free a tile and all it's children.
323 void grits_tile_free(GritsTile *root, GritsTileFreeFunc free_func, gpointer user_data)
328 grits_tile_foreach(root, child)
329 grits_tile_free(child, free_func, user_data);
331 free_func(root, user_data);
332 g_object_unref(root);
335 /* Load texture mask so we can draw a texture to just a part of a triangle */
336 static guint _grits_tile_load_mask(void)
340 glGenTextures(1, &tex);
341 glBindTexture(GL_TEXTURE_2D, tex);
343 glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, 1, 1, 0,
344 GL_ALPHA, GL_UNSIGNED_BYTE, &byte);
346 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
347 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
349 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
350 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
354 /* Draw a single tile */
355 static void grits_tile_draw_one(GritsTile *tile, GritsOpenGL *opengl, GList *triangles)
357 if (!tile || !tile->data)
360 g_warning("GritsOpenGL: _draw_tiles - No triangles to draw: edges=%f,%f,%f,%f",
361 tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
362 if (!grits_tile_mask)
363 grits_tile_mask = _grits_tile_load_mask();
365 //g_message("drawing %4d triangles for tile edges=%7.2f,%7.2f,%7.2f,%7.2f",
366 // g_list_length(triangles), tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
367 tile->atime = time(NULL);
369 gdouble n = tile->edge.n;
370 gdouble s = tile->edge.s;
371 gdouble e = tile->edge.e;
372 gdouble w = tile->edge.w;
374 gdouble londist = e - w;
375 gdouble latdist = n - s;
377 gdouble xscale = tile->coords.e - tile->coords.w;
378 gdouble yscale = tile->coords.s - tile->coords.n;
380 for (GList *cur = triangles; cur; cur = cur->next) {
381 RoamTriangle *tri = cur->data;
383 gdouble lat[3] = {tri->p.r->lat, tri->p.m->lat, tri->p.l->lat};
384 gdouble lon[3] = {tri->p.r->lon, tri->p.m->lon, tri->p.l->lon};
386 if (lon[0] < -90 || lon[1] < -90 || lon[2] < -90) {
387 if (lon[0] > 90) lon[0] -= 360;
388 if (lon[1] > 90) lon[1] -= 360;
389 if (lon[2] > 90) lon[2] -= 360;
393 {(lon[0]-w)/londist, 1-(lat[0]-s)/latdist},
394 {(lon[1]-w)/londist, 1-(lat[1]-s)/latdist},
395 {(lon[2]-w)/londist, 1-(lat[2]-s)/latdist},
398 //if ((lat[0] == 90 && (xy[0][0] < 0 || xy[0][0] > 1)) ||
399 // (lat[1] == 90 && (xy[1][0] < 0 || xy[1][0] > 1)) ||
400 // (lat[2] == 90 && (xy[2][0] < 0 || xy[2][0] > 1)))
401 // g_message("w,e=%4.f,%4.f "
403 // "%4.1f,%4.0f,%4.2f,%4.2f "
404 // "%4.1f,%4.0f,%4.2f,%4.2f "
405 // "%4.1f,%4.0f,%4.2f,%4.2f ",
407 // lat[0], lon[0], xy[0][0], xy[0][1],
408 // lat[1], lon[1], xy[1][0], xy[1][1],
409 // lat[2], lon[2], xy[2][0], xy[2][1]);
412 if (lat[0] == 90 || lat[0] == -90) xy[0][0] = 0.5;
413 if (lat[1] == 90 || lat[1] == -90) xy[1][0] = 0.5;
414 if (lat[2] == 90 || lat[2] == -90) xy[2][0] = 0.5;
416 /* Scale to tile coords */
417 for (int i = 0; i < 3; i++) {
418 xy[i][0] = tile->coords.w + xy[i][0]*xscale;
419 xy[i][1] = tile->coords.n + xy[i][1]*yscale;
423 glEnable(GL_POLYGON_OFFSET_FILL);
424 glPolygonOffset(0, -tile->zindex);
427 glActiveTexture(GL_TEXTURE0);
428 glEnable(GL_TEXTURE_2D);
429 glBindTexture(GL_TEXTURE_2D, *(guint*)tile->data);
430 glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
432 /* Enable texture mask */
433 if (tile->proj == GRITS_PROJ_MERCATOR) {
434 glActiveTexture(GL_TEXTURE1);
435 glEnable(GL_TEXTURE_2D);
436 glBindTexture(GL_TEXTURE_2D, grits_tile_mask);
437 glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
439 /* Hack to show maps tiles with better color */
440 float material_emission[] = {0.5, 0.5, 0.5, 1.0};
441 glMaterialfv(GL_FRONT_AND_BACK, GL_EMISSION, material_emission);
447 glBegin(GL_TRIANGLES);
448 glNormal3dv(tri->p.r->norm); glMultiTexCoord2dv(GL_TEXTURE0, xy[0]); glMultiTexCoord2dv(GL_TEXTURE1, xy[0]); glVertex3dv((double*)tri->p.r);
449 glNormal3dv(tri->p.m->norm); glMultiTexCoord2dv(GL_TEXTURE0, xy[1]); glMultiTexCoord2dv(GL_TEXTURE1, xy[1]); glVertex3dv((double*)tri->p.m);
450 glNormal3dv(tri->p.l->norm); glMultiTexCoord2dv(GL_TEXTURE0, xy[2]); glMultiTexCoord2dv(GL_TEXTURE1, xy[2]); glVertex3dv((double*)tri->p.l);
453 /* Disable texture mask */
454 glDisable(GL_TEXTURE_2D);
455 glActiveTexture(GL_TEXTURE0);
460 static gboolean grits_tile_draw_rec(GritsTile *tile, GritsOpenGL *opengl)
462 if (!tile || !tile->data || GRITS_OBJECT(tile)->hidden)
465 GritsTile *child = NULL;
466 gboolean done = FALSE;
468 /* Only draw children if possible */
469 gboolean draw_parent = FALSE;
470 grits_tile_foreach(tile, child)
471 if (!child || !child->data || GRITS_OBJECT(child)->hidden)
474 /* Draw parent tile underneath */
476 GList *triangles = roam_sphere_get_intersect(opengl->sphere, FALSE,
477 tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
478 grits_tile_draw_one(tile, opengl, triangles);
479 g_list_free(triangles);
482 /* Draw child tiles */
483 gboolean drew_all_children = TRUE;
484 grits_tile_foreach(tile, child)
485 if (!grits_tile_draw_rec(child, opengl))
486 drew_all_children = FALSE;
488 /* Check if tiles were hidden by a thread while drawing */
489 done = draw_parent || drew_all_children;
494 static void grits_tile_draw(GritsObject *tile, GritsOpenGL *opengl)
496 glEnable(GL_DEPTH_TEST);
497 glDepthFunc(GL_LESS);
498 glEnable(GL_ALPHA_TEST);
499 glAlphaFunc(GL_GREATER, 0.1);
500 grits_tile_draw_rec(GRITS_TILE(tile), opengl);
505 G_DEFINE_TYPE(GritsTile, grits_tile, GRITS_TYPE_OBJECT);
506 static void grits_tile_init(GritsTile *tile)
510 static void grits_tile_class_init(GritsTileClass *klass)
512 g_debug("GritsTile: class_init");
513 GritsObjectClass *object_class = GRITS_OBJECT_CLASS(klass);
514 object_class->draw = grits_tile_draw;