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.
35 #define GL_GLEXT_PROTOTYPES
40 #include "grits-tile.h"
42 static guint grits_tile_mask = 0;
44 gchar *grits_tile_path_table[2][2] = {
51 * @parent: the parent for the tile, or NULL
52 * @n: the northern border of the tile
53 * @s: the southern border of the tile
54 * @e: the eastern border of the tile
55 * @w: the western border of the tile
57 * Create a tile associated with a particular latitude/longitude box.
59 * Returns: the new #GritsTile
61 GritsTile *grits_tile_new(GritsTile *parent,
62 gdouble n, gdouble s, gdouble e, gdouble w)
64 GritsTile *tile = g_object_new(GRITS_TYPE_TILE, NULL);
65 tile->parent = parent;
66 tile->atime = time(NULL);
67 grits_bounds_set_bounds(&tile->coords, 0, 1, 1, 0);
68 grits_bounds_set_bounds(&tile->edge, n, s, e, w);
70 tile->proj = parent->proj;
75 * grits_tile_get_path:
76 * @child: the tile to generate a path for
78 * Generate a string representation of a tiles location in a group of nested
79 * tiles. The string returned consists of groups of two digits separated by a
80 * delimiter. Each group of digits the tiles location with respect to it's
83 * Returns: the path representing the tiles's location
85 gchar *grits_tile_get_path(GritsTile *child)
87 /* This could be easily cached if necessary */
90 for (GritsTile *parent = child->parent; parent; child = parent, parent = child->parent)
91 grits_tile_foreach_index(child, x, y)
92 if (parent->children[x][y] == child)
93 parts = g_list_prepend(parts, grits_tile_path_table[x][y]);
94 GString *path = g_string_new("");
95 for (GList *cur = parts; cur; cur = cur->next)
96 g_string_append(path, cur->data);
98 return g_string_free(path, FALSE);
101 static gdouble _grits_tile_get_min_dist(GritsPoint *eye, GritsBounds *bounds)
104 pos.lat = eye->lat > bounds->n ? bounds->n :
105 eye->lat < bounds->s ? bounds->s : eye->lat;
106 pos.lon = eye->lon > bounds->e ? bounds->e :
107 eye->lon < bounds->w ? bounds->w : eye->lon;
108 //if (eye->lat == pos.lat && eye->lon == pos.lon)
109 // return elev; /* Shortcut? */
111 lle2xyz(eye->lat, eye->lon, eye->elev, a+0, a+1, a+2);
112 lle2xyz(pos.lat, pos.lon, pos.elev, b+0, b+1, b+2);
116 static gboolean _grits_tile_precise(GritsPoint *eye, GritsBounds *bounds,
117 gdouble max_res, gint width, gint height)
119 gdouble min_dist = _grits_tile_get_min_dist(eye, bounds);
120 gdouble view_res = MPPX(min_dist);
122 gdouble lat_point = bounds->n < 0 ? bounds->n :
123 bounds->s > 0 ? bounds->s : 0;
124 gdouble lon_dist = bounds->e - bounds->w;
125 gdouble tile_res = ll2m(lon_dist, lat_point)/width;
127 /* This isn't really right, but it helps with memory since we don't
128 * (yet?) test if the tile would be drawn */
129 gdouble scale = eye->elev / min_dist;
132 //view_res /= 1.4; /* make it a little nicer, not sure why this is needed */
133 //g_message("tile=(%7.2f %7.2f %7.2f %7.2f) "
134 // "eye=(%9.1f %9.1f %9.1f) "
135 // "elev=%9.1f / dist=%9.1f = %f",
136 // bounds->n, bounds->s, bounds->e, bounds->w,
137 // eye->lat, eye->lon, eye->elev,
138 // eye->elev, min_dist, scale);
140 return tile_res < max_res ||
144 static void _grits_tile_split_latlon(GritsTile *tile)
146 //g_debug("GritsTile: split - %p", tile);
147 const gdouble rows = G_N_ELEMENTS(tile->children);
148 const gdouble cols = G_N_ELEMENTS(tile->children[0]);
149 const gdouble lat_dist = tile->edge.n - tile->edge.s;
150 const gdouble lon_dist = tile->edge.e - tile->edge.w;
151 const gdouble lat_step = lat_dist / rows;
152 const gdouble lon_step = lon_dist / cols;
155 grits_tile_foreach_index(tile, row, col) {
156 if (!tile->children[row][col])
157 tile->children[row][col] =
158 grits_tile_new(tile, 0, 0, 0, 0);
159 /* Set edges aferwards so that north and south
160 * get reset for mercator projections */
161 GritsTile *child = tile->children[row][col];
162 child->edge.n = tile->edge.n - lat_step*(row+0);
163 child->edge.s = tile->edge.n - lat_step*(row+1);
164 child->edge.e = tile->edge.w + lon_step*(col+1);
165 child->edge.w = tile->edge.w + lon_step*(col+0);
169 static void _grits_tile_split_mercator(GritsTile *tile)
171 GritsTile *child = NULL;
172 GritsBounds tmp = tile->edge;
175 tile->edge.n = asinh(tan(deg2rad(tile->edge.n)));
176 tile->edge.s = asinh(tan(deg2rad(tile->edge.s)));
178 _grits_tile_split_latlon(tile);
180 /* Convert back to lat-lon */
182 grits_tile_foreach(tile, child) {
183 child->edge.n = rad2deg(atan(sinh(child->edge.n)));
184 child->edge.s = rad2deg(atan(sinh(child->edge.s)));
190 * @root: the root tile to split
191 * @eye: the point the tile is viewed from, for calculating distances
192 * @res: a maximum resolution in meters per pixel to split tiles to
193 * @width: width in pixels of the image associated with the tile
194 * @height: height in pixels of the image associated with the tile
195 * @load_func: function used to load the image when a new tile is created
196 * @user_data: user data to past to the load function
198 * Recursively split a tile into children of appropriate detail. The resolution
199 * of the tile in pixels per meter is compared to the resolution which the tile
200 * is being drawn at on the screen. If the screen resolution is insufficient
201 * the tile is recursively subdivided until a sufficient resolution is
204 void grits_tile_update(GritsTile *tile, GritsPoint *eye,
205 gdouble res, gint width, gint height,
206 GritsTileLoadFunc load_func, gpointer user_data)
213 //g_debug("GritsTile: update - %p->atime = %u",
214 // tile, (guint)tile->atime);
216 /* Is the parent tile's texture high enough
217 * resolution for this part? */
218 gint xs = G_N_ELEMENTS(tile->children);
219 gint ys = G_N_ELEMENTS(tile->children[0]);
220 if (tile->parent && _grits_tile_precise(eye, &tile->edge,
221 res, width/xs, height/ys)) {
222 GRITS_OBJECT(tile)->hidden = TRUE;
227 if (!tile->load && !tile->data && !tile->tex && !tile->pixels && !tile->pixbuf)
228 load_func(tile, user_data);
229 tile->atime = time(NULL);
231 GRITS_OBJECT(tile)->hidden = FALSE;
233 /* Split tile if needed */
234 grits_tile_foreach(tile, child) {
236 switch (tile->proj) {
237 case GRITS_PROJ_LATLON: _grits_tile_split_latlon(tile); break;
238 case GRITS_PROJ_MERCATOR: _grits_tile_split_mercator(tile); break;
243 /* Update recursively */
244 grits_tile_foreach(tile, child)
245 grits_tile_update(child, eye, res, width, height,
246 load_func, user_data);
249 static void _grits_tile_queue_draw(GritsTile *tile)
251 while (!GRITS_OBJECT(tile)->viewer && tile->parent)
253 grits_object_queue_draw(GRITS_OBJECT(tile));
257 * grits_tile_load_pixels:
258 * @tile: the tile to load data into
259 * @pixels: buffered pixel data
260 * @width: width of the pixel buffer (in pixels)
261 * @height: height of the pixel buffer (in pixels)
262 * @alpha: TRUE if the pixel data contains an alpha channel
264 * Load tile data from an in memory pixel buffer.
266 * This function is thread safe and my be called from outside the main thread.
268 * Ownership of the pixel buffer is passed to the tile, it should not be freed
269 * or modified after calling this function.
271 * Returns: TRUE if the image was loaded successfully
273 gboolean grits_tile_load_pixels(GritsTile *tile, guchar *pixels,
274 gint width, gint height, gint alpha)
276 g_debug("GritsTile: load_pixels - %p -> %p (%dx%d:%d)",
277 tile, pixels, width, height, alpha);
279 /* Copy pixbuf data for callback */
281 tile->height = height;
283 tile->pixels = pixels;
285 /* Queue OpenGL texture load/draw */
286 _grits_tile_queue_draw(tile);
292 * grits_tile_load_file:
293 * @tile: the tile to load data into
294 * @file: path to an image file to load
296 * Load tile data from a GdkPixbuf
297 * This function is thread safe and my be called from outside the main thread.
299 * Returns: TRUE if the image was loaded successfully
301 gboolean grits_tile_load_pixbuf(GritsTile *tile, GdkPixbuf *pixbuf)
303 g_debug("GritsTile: load_pixbuf %p -> %p", tile, pixbuf);
305 /* Copy pixbuf data for callback */
306 tile->pixbuf = g_object_ref(pixbuf);
307 tile->width = gdk_pixbuf_get_width(pixbuf);
308 tile->height = gdk_pixbuf_get_height(pixbuf);
309 tile->alpha = gdk_pixbuf_get_has_alpha(pixbuf);
311 /* Queue OpenGL texture load/draw */
312 _grits_tile_queue_draw(tile);
318 * grits_tile_load_file:
319 * @tile: the tile to load data into
320 * @file: path to an image file to load
322 * Load tile data from an image file
323 * This function is thread safe and my be called from outside the main thread.
325 * Returns: TRUE if the image was loaded successfully
327 gboolean grits_tile_load_file(GritsTile *tile, const gchar *file)
329 g_debug("GritsTile: load_file %p -> %s", tile, file);
331 /* Copy pixbuf data for callback */
332 tile->pixbuf = gdk_pixbuf_new_from_file(file, NULL);
335 tile->width = gdk_pixbuf_get_width(tile->pixbuf);
336 tile->height = gdk_pixbuf_get_height(tile->pixbuf);
337 tile->alpha = gdk_pixbuf_get_has_alpha(tile->pixbuf);
339 /* Queue OpenGL texture load/draw */
340 _grits_tile_queue_draw(tile);
347 * @root: the root tile to search from
348 * @lat: target latitude
349 * @lon: target longitude
351 * Locate the subtile with the highest resolution which contains the given
354 * Returns: the child tile
356 GritsTile *grits_tile_find(GritsTile *root, gdouble lat, gdouble lon)
358 gint rows = G_N_ELEMENTS(root->children);
359 gint cols = G_N_ELEMENTS(root->children[0]);
361 gdouble lat_step = (root->edge.n - root->edge.s) / rows;
362 gdouble lon_step = (root->edge.e - root->edge.w) / cols;
364 gdouble lat_offset = root->edge.n - lat;;
365 gdouble lon_offset = lon - root->edge.w;
367 gint row = lat_offset / lat_step;
368 gint col = lon_offset / lon_step;
370 if (lon == 180) col--;
371 if (lat == -90) row--;
373 //if (lon == 180 || lon == -180)
374 // g_message("lat=%f,lon=%f step=%f,%f off=%f,%f row=%d/%d,col=%d/%d",
375 // lat,lon, lat_step,lon_step, lat_offset,lon_offset, row,rows,col,cols);
377 if (row < 0 || row >= rows || col < 0 || col >= cols)
379 else if (root->children[row][col] && root->children[row][col]->data)
380 return grits_tile_find(root->children[row][col], lat, lon);
387 * @root: the root tile to start garbage collection at
388 * @atime: most recent time at which tiles will be kept
389 * @free_func: function used to free the image when a new tile is collected
390 * @user_data: user data to past to the free function
392 * Garbage collect old tiles. This removes and deallocate tiles that have not
393 * been used since before @atime.
395 * Returns: a pointer to the original tile, or NULL if it was garbage collected
397 GritsTile *grits_tile_gc(GritsTile *root, time_t atime,
398 GritsTileFreeFunc free_func, gpointer user_data)
402 gboolean has_children = FALSE;
404 grits_tile_foreach_index(root, x, y) {
405 root->children[x][y] = grits_tile_gc(
406 root->children[x][y], atime,
407 free_func, user_data);
408 if (root->children[x][y])
411 //g_debug("GritsTile: gc - %p kids=%d time=%d data=%d load=%d",
412 // root, !!has_children, root->atime < atime, !!root->data, !!root->load);
413 int thread_safe = !root->load || root->data || root->tex || root->pixels || root->pixbuf;
414 if (root->parent && !has_children && root->atime < atime && thread_safe) {
415 //g_debug("GritsTile: gc/free - %p", root);
417 g_object_unref(root->pixbuf);
419 g_free(root->pixels);
421 glDeleteTextures(1, &root->tex);
424 free_func(root, user_data);
428 g_object_unref(root);
434 /* Use GObject for this */
437 * @root: the root tile to free
438 * @free_func: function used to free the image when a new tile is collected
439 * @user_data: user data to past to the free function
441 * Recursively free a tile and all it's children.
443 void grits_tile_free(GritsTile *root, GritsTileFreeFunc free_func, gpointer user_data)
448 grits_tile_foreach(root, child)
449 grits_tile_free(child, free_func, user_data);
451 free_func(root, user_data);
452 g_object_unref(root);
455 /* Load texture mask so we can draw a texture to just a part of a triangle */
456 static guint _grits_tile_load_mask(void)
459 const int width = 256, height = 256;
460 guint8 *bytes = g_malloc(width*height);
461 memset(bytes, 0xff, width*height);
462 glGenTextures(1, &tex);
463 glBindTexture(GL_TEXTURE_2D, tex);
465 glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, width, height, 0,
466 GL_ALPHA, GL_UNSIGNED_BYTE, bytes);
468 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
469 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
471 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
472 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
477 /* Load the texture from saved pixel data */
478 static gboolean _grits_tile_load_tex(GritsTile *tile)
480 /* Abort for null tiles */
484 /* Defer loading of hidden tiles */
485 if (GRITS_OBJECT(tile)->hidden)
488 /* If we're already done loading the text stop */
492 /* Check if the tile has data yet */
493 if (!tile->pixels && !tile->pixbuf)
496 /* Get correct pixel buffer */
497 guchar *pixels = tile->pixels ?:
498 gdk_pixbuf_get_pixels(tile->pixbuf);
501 g_debug("GritsTile: load_tex");
502 glGenTextures(1, &tile->tex);
503 glBindTexture(GL_TEXTURE_2D, tile->tex);
505 glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
506 glPixelStorei(GL_PACK_ALIGNMENT, 1);
507 glTexImage2D(GL_TEXTURE_2D, 0, 4, tile->width, tile->height, 0,
508 (tile->alpha ? GL_RGBA : GL_RGB), GL_UNSIGNED_BYTE, pixels);
509 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
510 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
511 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
512 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
516 g_object_unref(tile->pixbuf);
520 g_free(tile->pixels);
528 /* Draw a single tile */
529 static void grits_tile_draw_one(GritsTile *tile, GritsOpenGL *opengl, GList *triangles)
531 if (!tile || !tile->tex)
534 g_warning("GritsOpenGL: _draw_tiles - No triangles to draw: edges=%f,%f,%f,%f",
535 tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
537 //g_message("drawing %4d triangles for tile edges=%7.2f,%7.2f,%7.2f,%7.2f",
538 // g_list_length(triangles), tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
539 tile->atime = time(NULL);
541 gdouble n = tile->edge.n;
542 gdouble s = tile->edge.s;
543 gdouble e = tile->edge.e;
544 gdouble w = tile->edge.w;
546 gdouble londist = e - w;
547 gdouble latdist = n - s;
549 gdouble xscale = tile->coords.e - tile->coords.w;
550 gdouble yscale = tile->coords.s - tile->coords.n;
552 glPolygonOffset(0, -tile->zindex);
554 for (GList *cur = triangles; cur; cur = cur->next) {
555 RoamTriangle *tri = cur->data;
557 gdouble lat[3] = {tri->p.r->lat, tri->p.m->lat, tri->p.l->lat};
558 gdouble lon[3] = {tri->p.r->lon, tri->p.m->lon, tri->p.l->lon};
560 if (lon[0] < -90 || lon[1] < -90 || lon[2] < -90) {
561 if (lon[0] > 90) lon[0] -= 360;
562 if (lon[1] > 90) lon[1] -= 360;
563 if (lon[2] > 90) lon[2] -= 360;
567 {(lon[0]-w)/londist, 1-(lat[0]-s)/latdist},
568 {(lon[1]-w)/londist, 1-(lat[1]-s)/latdist},
569 {(lon[2]-w)/londist, 1-(lat[2]-s)/latdist},
572 //if ((lat[0] == 90 && (xy[0][0] < 0 || xy[0][0] > 1)) ||
573 // (lat[1] == 90 && (xy[1][0] < 0 || xy[1][0] > 1)) ||
574 // (lat[2] == 90 && (xy[2][0] < 0 || xy[2][0] > 1)))
575 // g_message("w,e=%4.f,%4.f "
577 // "%4.1f,%4.0f,%4.2f,%4.2f "
578 // "%4.1f,%4.0f,%4.2f,%4.2f "
579 // "%4.1f,%4.0f,%4.2f,%4.2f ",
581 // lat[0], lon[0], xy[0][0], xy[0][1],
582 // lat[1], lon[1], xy[1][0], xy[1][1],
583 // lat[2], lon[2], xy[2][0], xy[2][1]);
586 if (lat[0] == 90 || lat[0] == -90) xy[0][0] = 0.5;
587 if (lat[1] == 90 || lat[1] == -90) xy[1][0] = 0.5;
588 if (lat[2] == 90 || lat[2] == -90) xy[2][0] = 0.5;
590 /* Scale to tile coords */
591 for (int i = 0; i < 3; i++) {
592 xy[i][0] = tile->coords.w + xy[i][0]*xscale;
593 xy[i][1] = tile->coords.n + xy[i][1]*yscale;
597 glBindTexture(GL_TEXTURE_2D, tile->tex);
598 glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
599 glBegin(GL_TRIANGLES);
600 glNormal3dv(tri->p.r->norm); glMultiTexCoord2dv(GL_TEXTURE0, xy[0]); glMultiTexCoord2dv(GL_TEXTURE1, xy[0]); glVertex3dv((double*)tri->p.r);
601 glNormal3dv(tri->p.m->norm); glMultiTexCoord2dv(GL_TEXTURE0, xy[1]); glMultiTexCoord2dv(GL_TEXTURE1, xy[1]); glVertex3dv((double*)tri->p.m);
602 glNormal3dv(tri->p.l->norm); glMultiTexCoord2dv(GL_TEXTURE0, xy[2]); glMultiTexCoord2dv(GL_TEXTURE1, xy[2]); glVertex3dv((double*)tri->p.l);
608 static gboolean grits_tile_draw_rec(GritsTile *tile, GritsOpenGL *opengl)
610 //g_debug("GritsTile: draw_rec - tile=%p, data=%d, load=%d, hide=%d", tile,
611 // tile ? !!tile->data : 0,
612 // tile ? !!tile->load : 0,
613 // tile ? !!GRITS_OBJECT(tile)->hidden : 0);
615 if (!_grits_tile_load_tex(tile))
618 GritsTile *child = NULL;
620 /* Draw child tiles */
621 gboolean draw_parent = FALSE;
622 grits_tile_foreach(tile, child)
623 if (!grits_tile_draw_rec(child, opengl))
626 /* Draw parent tile underneath using depth test */
628 GList *triangles = roam_sphere_get_intersect(opengl->sphere, FALSE,
629 tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
630 grits_tile_draw_one(tile, opengl, triangles);
631 g_list_free(triangles);
637 static void grits_tile_draw(GritsObject *tile, GritsOpenGL *opengl)
639 glEnable(GL_DEPTH_TEST);
640 glDepthFunc(GL_LESS);
641 glEnable(GL_ALPHA_TEST);
642 glAlphaFunc(GL_GREATER, 0.1);
643 glEnable(GL_POLYGON_OFFSET_FILL);
646 /* Setup texture mask */
647 if (!grits_tile_mask)
648 grits_tile_mask = _grits_tile_load_mask();
649 glActiveTexture(GL_TEXTURE1);
650 glEnable(GL_TEXTURE_2D);
651 glBindTexture(GL_TEXTURE_2D, grits_tile_mask);
652 glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
655 glActiveTexture(GL_TEXTURE0);
656 glEnable(GL_TEXTURE_2D);
658 /* Hack to show maps tiles with better color */
659 if (GRITS_TILE(tile)->proj == GRITS_PROJ_MERCATOR) {
660 float material_emission[] = {0.5, 0.5, 0.5, 1.0};
661 glMaterialfv(GL_FRONT_AND_BACK, GL_EMISSION, material_emission);
665 grits_tile_draw_rec(GRITS_TILE(tile), opengl);
667 /* Disable texture mask */
668 glActiveTexture(GL_TEXTURE1);
669 glDisable(GL_TEXTURE_2D);
670 glActiveTexture(GL_TEXTURE0);
675 G_DEFINE_TYPE(GritsTile, grits_tile, GRITS_TYPE_OBJECT);
676 static void grits_tile_init(GritsTile *tile)
680 static void grits_tile_class_init(GritsTileClass *klass)
682 g_debug("GritsTile: class_init");
683 GritsObjectClass *object_class = GRITS_OBJECT_CLASS(klass);
684 object_class->draw = grits_tile_draw;