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"
41 #define GL_GLEXT_PROTOTYPES
45 guint grits_tile_mask = 0;
47 gchar *grits_tile_path_table[2][2] = {
54 * @parent: the parent for the tile, or NULL
55 * @n: the northern border of the tile
56 * @s: the southern border of the tile
57 * @e: the eastern border of the tile
58 * @w: the western border of the tile
60 * Create a tile associated with a particular latitude/longitude box.
62 * Returns: the new #GritsTile
64 GritsTile *grits_tile_new(GritsTile *parent,
65 gdouble n, gdouble s, gdouble e, gdouble w)
67 GritsTile *tile = g_object_new(GRITS_TYPE_TILE, NULL);
68 tile->parent = parent;
69 tile->atime = time(NULL);
70 grits_bounds_set_bounds(&tile->coords, 0, 1, 1, 0);
71 grits_bounds_set_bounds(&tile->edge, n, s, e, w);
73 tile->proj = parent->proj;
78 * grits_tile_get_path:
79 * @child: the tile to generate a path for
81 * Generate a string representation of a tiles location in a group of nested
82 * tiles. The string returned consists of groups of two digits separated by a
83 * delimiter. Each group of digits the tiles location with respect to it's
86 * Returns: the path representing the tiles's location
88 gchar *grits_tile_get_path(GritsTile *child)
90 /* This could be easily cached if necessary */
93 for (GritsTile *parent = child->parent; parent; child = parent, parent = child->parent)
94 grits_tile_foreach_index(child, x, y)
95 if (parent->children[x][y] == child)
96 parts = g_list_prepend(parts, grits_tile_path_table[x][y]);
97 GString *path = g_string_new("");
98 for (GList *cur = parts; cur; cur = cur->next)
99 g_string_append(path, cur->data);
101 return g_string_free(path, FALSE);
104 static gdouble _grits_tile_get_min_dist(GritsPoint *eye, GritsBounds *bounds)
107 pos.lat = eye->lat > bounds->n ? bounds->n :
108 eye->lat < bounds->s ? bounds->s : eye->lat;
109 pos.lon = eye->lon > bounds->e ? bounds->e :
110 eye->lon < bounds->w ? bounds->w : eye->lon;
111 //if (eye->lat == pos.lat && eye->lon == pos.lon)
112 // return elev; /* Shortcut? */
114 lle2xyz(eye->lat, eye->lon, eye->elev, a+0, a+1, a+2);
115 lle2xyz(pos.lat, pos.lon, pos.elev, b+0, b+1, b+2);
119 static gboolean _grits_tile_precise(GritsPoint *eye, GritsBounds *bounds,
120 gdouble max_res, gint width, gint height)
122 gdouble min_dist = _grits_tile_get_min_dist(eye, bounds);
123 gdouble view_res = MPPX(min_dist);
125 gdouble lat_point = bounds->n < 0 ? bounds->n :
126 bounds->s > 0 ? bounds->s : 0;
127 gdouble lon_dist = bounds->e - bounds->w;
128 gdouble tile_res = ll2m(lon_dist, lat_point)/width;
130 /* This isn't really right, but it helps with memory since we don't
131 * (yet?) test if the tile would be drawn */
132 gdouble scale = eye->elev / min_dist;
135 //view_res /= 1.4; /* make it a little nicer, not sure why this is needed */
136 //g_message("tile=(%7.2f %7.2f %7.2f %7.2f) "
137 // "eye=(%9.1f %9.1f %9.1f) "
138 // "elev=%9.1f / dist=%9.1f = %f",
139 // bounds->n, bounds->s, bounds->e, bounds->w,
140 // eye->lat, eye->lon, eye->elev,
141 // eye->elev, min_dist, scale);
143 return tile_res < max_res ||
147 static void _grits_tile_split_latlon(GritsTile *tile)
149 //g_debug("GritsTile: split - %p", tile);
150 const gdouble rows = G_N_ELEMENTS(tile->children);
151 const gdouble cols = G_N_ELEMENTS(tile->children[0]);
152 const gdouble lat_dist = tile->edge.n - tile->edge.s;
153 const gdouble lon_dist = tile->edge.e - tile->edge.w;
154 const gdouble lat_step = lat_dist / rows;
155 const gdouble lon_step = lon_dist / cols;
158 grits_tile_foreach_index(tile, row, col) {
159 if (!tile->children[row][col])
160 tile->children[row][col] =
161 grits_tile_new(tile, 0, 0, 0, 0);
162 /* Set edges aferwards so that north and south
163 * get reset for mercator projections */
164 GritsTile *child = tile->children[row][col];
165 child->edge.n = tile->edge.n - lat_step*(row+0);
166 child->edge.s = tile->edge.n - lat_step*(row+1);
167 child->edge.e = tile->edge.w + lon_step*(col+1);
168 child->edge.w = tile->edge.w + lon_step*(col+0);
172 static void _grits_tile_split_mercator(GritsTile *tile)
174 GritsTile *child = NULL;
175 GritsBounds tmp = tile->edge;
178 tile->edge.n = asinh(tan(deg2rad(tile->edge.n)));
179 tile->edge.s = asinh(tan(deg2rad(tile->edge.s)));
181 _grits_tile_split_latlon(tile);
183 /* Convert back to lat-lon */
185 grits_tile_foreach(tile, child) {
186 child->edge.n = rad2deg(atan(sinh(child->edge.n)));
187 child->edge.s = rad2deg(atan(sinh(child->edge.s)));
193 * @root: the root tile to split
194 * @eye: the point the tile is viewed from, for calculating distances
195 * @res: a maximum resolution in meters per pixel to split tiles to
196 * @width: width in pixels of the image associated with the tile
197 * @height: height in pixels of the image associated with the tile
198 * @load_func: function used to load the image when a new tile is created
199 * @user_data: user data to past to the load function
201 * Recursively split a tile into children of appropriate detail. The resolution
202 * of the tile in pixels per meter is compared to the resolution which the tile
203 * is being drawn at on the screen. If the screen resolution is insufficient
204 * the tile is recursively subdivided until a sufficient resolution is
207 void grits_tile_update(GritsTile *tile, GritsPoint *eye,
208 gdouble res, gint width, gint height,
209 GritsTileLoadFunc load_func, gpointer user_data)
216 //g_debug("GritsTile: update - %p->atime = %u",
217 // tile, (guint)tile->atime);
219 /* Is the parent tile's texture high enough
220 * resolution for this part? */
221 gint xs = G_N_ELEMENTS(tile->children);
222 gint ys = G_N_ELEMENTS(tile->children[0]);
223 if (tile->parent && _grits_tile_precise(eye, &tile->edge,
224 res, width/xs, height/ys)) {
225 GRITS_OBJECT(tile)->hidden = TRUE;
230 if (!tile->load && !tile->data)
231 load_func(tile, user_data);
232 tile->atime = time(NULL);
234 GRITS_OBJECT(tile)->hidden = FALSE;
236 /* Split tile if needed */
237 grits_tile_foreach(tile, child) {
239 switch (tile->proj) {
240 case GRITS_PROJ_LATLON: _grits_tile_split_latlon(tile); break;
241 case GRITS_PROJ_MERCATOR: _grits_tile_split_mercator(tile); break;
246 /* Update recursively */
247 grits_tile_foreach(tile, child)
248 grits_tile_update(child, eye, res, width, height,
249 load_func, user_data);
254 * @root: the root tile to search from
255 * @lat: target latitude
256 * @lon: target longitude
258 * Locate the subtile with the highest resolution which contains the given
261 * Returns: the child tile
263 GritsTile *grits_tile_find(GritsTile *root, gdouble lat, gdouble lon)
265 gint rows = G_N_ELEMENTS(root->children);
266 gint cols = G_N_ELEMENTS(root->children[0]);
268 gdouble lat_step = (root->edge.n - root->edge.s) / rows;
269 gdouble lon_step = (root->edge.e - root->edge.w) / cols;
271 gdouble lat_offset = root->edge.n - lat;;
272 gdouble lon_offset = lon - root->edge.w;
274 gint row = lat_offset / lat_step;
275 gint col = lon_offset / lon_step;
277 if (lon == 180) col--;
278 if (lat == -90) row--;
280 //if (lon == 180 || lon == -180)
281 // g_message("lat=%f,lon=%f step=%f,%f off=%f,%f row=%d/%d,col=%d/%d",
282 // lat,lon, lat_step,lon_step, lat_offset,lon_offset, row,rows,col,cols);
284 if (row < 0 || row >= rows || col < 0 || col >= cols)
286 else if (root->children[row][col] && root->children[row][col]->data)
287 return grits_tile_find(root->children[row][col], lat, lon);
294 * @root: the root tile to start garbage collection at
295 * @atime: most recent time at which tiles will be kept
296 * @free_func: function used to free the image when a new tile is collected
297 * @user_data: user data to past to the free function
299 * Garbage collect old tiles. This removes and deallocate tiles that have not
300 * been used since before @atime.
302 * Returns: a pointer to the original tile, or NULL if it was garbage collected
304 GritsTile *grits_tile_gc(GritsTile *root, time_t atime,
305 GritsTileFreeFunc free_func, gpointer user_data)
309 gboolean has_children = FALSE;
311 grits_tile_foreach_index(root, x, y) {
312 root->children[x][y] = grits_tile_gc(
313 root->children[x][y], atime,
314 free_func, user_data);
315 if (root->children[x][y])
318 //g_debug("GritsTile: gc - %p kids=%d time=%d data=%d load=%d",
319 // root, !!has_children, root->atime < atime, !!root->data, !!root->load);
320 if (root->parent && !has_children && root->atime < atime &&
321 (root->data || !root->load)) {
322 //g_debug("GritsTile: gc/free - %p", root);
324 free_func(root, user_data);
325 g_object_unref(root);
331 /* Use GObject for this */
334 * @root: the root tile to free
335 * @free_func: function used to free the image when a new tile is collected
336 * @user_data: user data to past to the free function
338 * Recursively free a tile and all it's children.
340 void grits_tile_free(GritsTile *root, GritsTileFreeFunc free_func, gpointer user_data)
345 grits_tile_foreach(root, child)
346 grits_tile_free(child, free_func, user_data);
348 free_func(root, user_data);
349 g_object_unref(root);
352 /* Load texture mask so we can draw a texture to just a part of a triangle */
353 static guint _grits_tile_load_mask(void)
357 glGenTextures(1, &tex);
358 glBindTexture(GL_TEXTURE_2D, tex);
360 glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, 1, 1, 0,
361 GL_ALPHA, GL_UNSIGNED_BYTE, &byte);
363 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
364 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
366 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
367 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
371 /* Draw a single tile */
372 static void grits_tile_draw_one(GritsTile *tile, GritsOpenGL *opengl, GList *triangles)
374 if (!tile || !tile->data)
377 g_warning("GritsOpenGL: _draw_tiles - No triangles to draw: edges=%f,%f,%f,%f",
378 tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
380 //g_message("drawing %4d triangles for tile edges=%7.2f,%7.2f,%7.2f,%7.2f",
381 // g_list_length(triangles), tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
382 tile->atime = time(NULL);
384 gdouble n = tile->edge.n;
385 gdouble s = tile->edge.s;
386 gdouble e = tile->edge.e;
387 gdouble w = tile->edge.w;
389 gdouble londist = e - w;
390 gdouble latdist = n - s;
392 gdouble xscale = tile->coords.e - tile->coords.w;
393 gdouble yscale = tile->coords.s - tile->coords.n;
395 glPolygonOffset(0, -tile->zindex);
397 for (GList *cur = triangles; cur; cur = cur->next) {
398 RoamTriangle *tri = cur->data;
400 gdouble lat[3] = {tri->p.r->lat, tri->p.m->lat, tri->p.l->lat};
401 gdouble lon[3] = {tri->p.r->lon, tri->p.m->lon, tri->p.l->lon};
403 if (lon[0] < -90 || lon[1] < -90 || lon[2] < -90) {
404 if (lon[0] > 90) lon[0] -= 360;
405 if (lon[1] > 90) lon[1] -= 360;
406 if (lon[2] > 90) lon[2] -= 360;
410 {(lon[0]-w)/londist, 1-(lat[0]-s)/latdist},
411 {(lon[1]-w)/londist, 1-(lat[1]-s)/latdist},
412 {(lon[2]-w)/londist, 1-(lat[2]-s)/latdist},
415 //if ((lat[0] == 90 && (xy[0][0] < 0 || xy[0][0] > 1)) ||
416 // (lat[1] == 90 && (xy[1][0] < 0 || xy[1][0] > 1)) ||
417 // (lat[2] == 90 && (xy[2][0] < 0 || xy[2][0] > 1)))
418 // g_message("w,e=%4.f,%4.f "
420 // "%4.1f,%4.0f,%4.2f,%4.2f "
421 // "%4.1f,%4.0f,%4.2f,%4.2f "
422 // "%4.1f,%4.0f,%4.2f,%4.2f ",
424 // lat[0], lon[0], xy[0][0], xy[0][1],
425 // lat[1], lon[1], xy[1][0], xy[1][1],
426 // lat[2], lon[2], xy[2][0], xy[2][1]);
429 if (lat[0] == 90 || lat[0] == -90) xy[0][0] = 0.5;
430 if (lat[1] == 90 || lat[1] == -90) xy[1][0] = 0.5;
431 if (lat[2] == 90 || lat[2] == -90) xy[2][0] = 0.5;
433 /* Scale to tile coords */
434 for (int i = 0; i < 3; i++) {
435 xy[i][0] = tile->coords.w + xy[i][0]*xscale;
436 xy[i][1] = tile->coords.n + xy[i][1]*yscale;
440 glBindTexture(GL_TEXTURE_2D, *(guint*)tile->data);
441 glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
442 glBegin(GL_TRIANGLES);
443 glNormal3dv(tri->p.r->norm); glMultiTexCoord2dv(GL_TEXTURE0, xy[0]); glMultiTexCoord2dv(GL_TEXTURE1, xy[0]); glVertex3dv((double*)tri->p.r);
444 glNormal3dv(tri->p.m->norm); glMultiTexCoord2dv(GL_TEXTURE0, xy[1]); glMultiTexCoord2dv(GL_TEXTURE1, xy[1]); glVertex3dv((double*)tri->p.m);
445 glNormal3dv(tri->p.l->norm); glMultiTexCoord2dv(GL_TEXTURE0, xy[2]); glMultiTexCoord2dv(GL_TEXTURE1, xy[2]); glVertex3dv((double*)tri->p.l);
451 static gboolean grits_tile_draw_rec(GritsTile *tile, GritsOpenGL *opengl)
453 //g_debug("GritsTile: draw_rec - tile=%p, data=%d, load=%d, hide=%d", tile,
454 // tile ? !!tile->data : 0,
455 // tile ? !!tile->load : 0,
456 // tile ? !!GRITS_OBJECT(tile)->hidden : 0);
458 if (!tile || !tile->data || GRITS_OBJECT(tile)->hidden)
461 GritsTile *child = NULL;
463 /* Draw child tiles */
464 gboolean draw_parent = FALSE;
465 grits_tile_foreach(tile, child)
466 if (!grits_tile_draw_rec(child, opengl))
469 /* Draw parent tile underneath using depth test */
471 GList *triangles = roam_sphere_get_intersect(opengl->sphere, FALSE,
472 tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
473 grits_tile_draw_one(tile, opengl, triangles);
474 g_list_free(triangles);
480 static void grits_tile_draw(GritsObject *tile, GritsOpenGL *opengl)
482 glEnable(GL_DEPTH_TEST);
483 glDepthFunc(GL_LESS);
484 glEnable(GL_ALPHA_TEST);
485 glAlphaFunc(GL_GREATER, 0.1);
486 glEnable(GL_POLYGON_OFFSET_FILL);
489 /* Setup texture mask */
490 if (!grits_tile_mask)
491 grits_tile_mask = _grits_tile_load_mask();
492 glActiveTexture(GL_TEXTURE1);
493 glEnable(GL_TEXTURE_2D);
494 glBindTexture(GL_TEXTURE_2D, grits_tile_mask);
495 glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
498 glActiveTexture(GL_TEXTURE0);
499 glEnable(GL_TEXTURE_2D);
501 /* Hack to show maps tiles with better color */
502 if (GRITS_TILE(tile)->proj == GRITS_PROJ_MERCATOR) {
503 float material_emission[] = {0.5, 0.5, 0.5, 1.0};
504 glMaterialfv(GL_FRONT_AND_BACK, GL_EMISSION, material_emission);
508 grits_tile_draw_rec(GRITS_TILE(tile), opengl);
510 /* Disable texture mask */
511 glActiveTexture(GL_TEXTURE1);
512 glDisable(GL_TEXTURE_2D);
513 glActiveTexture(GL_TEXTURE0);
518 G_DEFINE_TYPE(GritsTile, grits_tile, GRITS_TYPE_OBJECT);
519 static void grits_tile_init(GritsTile *tile)
523 static void grits_tile_class_init(GritsTileClass *klass)
525 g_debug("GritsTile: class_init");
526 GritsObjectClass *object_class = GRITS_OBJECT_CLASS(klass);
527 object_class->draw = grits_tile_draw;