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->pixels && !tile->tex)
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);
250 * grits_tile_load_pixels:
251 * @tile: the tile to load data into
252 * @pixels: buffered pixel data
253 * @width: width of the pixel buffer (in pixels)
254 * @height: height of the pixel buffer (in pixels)
255 * @alpha: TRUE if the pixel data contains an alpha channel
257 * Load tile data from an in memory pixel buffer.
259 * This function is thread safe and my be called from outside the main thread.
261 * Ownership of the pixel buffer is passed to the tile, it should not be freed
262 * or modified after calling this function.
264 * Returns: TRUE if the image was loaded successfully
266 gboolean grits_tile_load_pixels(GritsTile *tile, guchar *pixels,
267 gint width, gint height, gint alpha)
269 g_debug("GritsTile: load_pixels - %p -> %p (%dx%d:%d)",
270 tile, pixels, width, height, alpha);
272 /* Copy pixbuf data for callback */
274 tile->height = height;
276 tile->pixels = pixels;
278 /* Queue OpenGL texture load/draw */
279 grits_object_queue_draw(GRITS_OBJECT(tile));
284 * grits_tile_load_file:
285 * @tile: the tile to load data into
286 * @file: path to an image file to load
288 * Load tile data from a GdkPixbuf
289 * This function is thread safe and my be called from outside the main thread.
291 * Returns: TRUE if the image was loaded successfully
293 gboolean grits_tile_load_pixbuf(GritsTile *tile, GdkPixbuf *pixbuf)
295 g_debug("GritsTile: load_pixbuf %p -> %p", tile, pixbuf);
297 /* Copy pixbuf data for callback */
298 tile->pixbuf = g_object_ref(pixbuf);
299 tile->width = gdk_pixbuf_get_width(pixbuf);
300 tile->height = gdk_pixbuf_get_height(pixbuf);
301 tile->alpha = gdk_pixbuf_get_has_alpha(pixbuf);
302 tile->pixels = gdk_pixbuf_get_pixels(pixbuf);
304 /* Queue OpenGL texture load/draw */
305 grits_object_queue_draw(GRITS_OBJECT(tile));
311 * grits_tile_load_file:
312 * @tile: the tile to load data into
313 * @file: path to an image file to load
315 * Load tile data from an image file
316 * This function is thread safe and my be called from outside the main thread.
318 * Returns: TRUE if the image was loaded successfully
320 gboolean grits_tile_load_file(GritsTile *tile, const gchar *file)
322 g_debug("GritsTile: load_file %p -> %s", tile, file);
325 GdkPixbuf *pixbuf = gdk_pixbuf_new_from_file(file, NULL);
329 /* Copy pixbuf data for callback */
330 tile->pixbuf = pixbuf;
331 tile->width = gdk_pixbuf_get_width(pixbuf);
332 tile->height = gdk_pixbuf_get_height(pixbuf);
333 tile->alpha = gdk_pixbuf_get_has_alpha(pixbuf);
334 tile->pixels = gdk_pixbuf_get_pixels(pixbuf);
336 /* Queue OpenGL texture load/draw */
337 grits_object_queue_draw(GRITS_OBJECT(tile));
344 * @root: the root tile to search from
345 * @lat: target latitude
346 * @lon: target longitude
348 * Locate the subtile with the highest resolution which contains the given
351 * Returns: the child tile
353 GritsTile *grits_tile_find(GritsTile *root, gdouble lat, gdouble lon)
355 gint rows = G_N_ELEMENTS(root->children);
356 gint cols = G_N_ELEMENTS(root->children[0]);
358 gdouble lat_step = (root->edge.n - root->edge.s) / rows;
359 gdouble lon_step = (root->edge.e - root->edge.w) / cols;
361 gdouble lat_offset = root->edge.n - lat;;
362 gdouble lon_offset = lon - root->edge.w;
364 gint row = lat_offset / lat_step;
365 gint col = lon_offset / lon_step;
367 if (lon == 180) col--;
368 if (lat == -90) row--;
370 //if (lon == 180 || lon == -180)
371 // g_message("lat=%f,lon=%f step=%f,%f off=%f,%f row=%d/%d,col=%d/%d",
372 // lat,lon, lat_step,lon_step, lat_offset,lon_offset, row,rows,col,cols);
374 if (row < 0 || row >= rows || col < 0 || col >= cols)
376 else if (root->children[row][col] && root->children[row][col]->data)
377 return grits_tile_find(root->children[row][col], lat, lon);
384 * @root: the root tile to start garbage collection at
385 * @atime: most recent time at which tiles will be kept
386 * @free_func: function used to free the image when a new tile is collected
387 * @user_data: user data to past to the free function
389 * Garbage collect old tiles. This removes and deallocate tiles that have not
390 * been used since before @atime.
392 * Returns: a pointer to the original tile, or NULL if it was garbage collected
394 GritsTile *grits_tile_gc(GritsTile *root, time_t atime,
395 GritsTileFreeFunc free_func, gpointer user_data)
399 gboolean has_children = FALSE;
401 grits_tile_foreach_index(root, x, y) {
402 root->children[x][y] = grits_tile_gc(
403 root->children[x][y], atime,
404 free_func, user_data);
405 if (root->children[x][y])
408 //g_debug("GritsTile: gc - %p kids=%d time=%d data=%d load=%d",
409 // root, !!has_children, root->atime < atime, !!root->data, !!root->load);
410 if (root->parent && !has_children && root->atime < atime &&
411 (root->data || !root->load)) {
412 //g_debug("GritsTile: gc/free - %p", root);
414 glDeleteTextures(1, &root->tex);
419 free_func(root, user_data);
424 g_object_unref(root);
430 /* Use GObject for this */
433 * @root: the root tile to free
434 * @free_func: function used to free the image when a new tile is collected
435 * @user_data: user data to past to the free function
437 * Recursively free a tile and all it's children.
439 void grits_tile_free(GritsTile *root, GritsTileFreeFunc free_func, gpointer user_data)
444 grits_tile_foreach(root, child)
445 grits_tile_free(child, free_func, user_data);
447 free_func(root, user_data);
448 g_object_unref(root);
451 /* Load texture mask so we can draw a texture to just a part of a triangle */
452 static guint _grits_tile_load_mask(void)
455 const int width = 256, height = 256;
456 guint8 *bytes = g_malloc(width*height);
457 memset(bytes, 0xff, width*height);
458 glGenTextures(1, &tex);
459 glBindTexture(GL_TEXTURE_2D, tex);
461 glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, width, height, 0,
462 GL_ALPHA, GL_UNSIGNED_BYTE, bytes);
464 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
465 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
467 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
468 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
473 /* Load the texture from saved pixel data */
474 static gboolean _grits_tile_load_tex(GritsTile *tile)
476 /* Abort for null tiles */
480 /* Defer loading of hidden tiles */
481 if (GRITS_OBJECT(tile)->hidden)
484 /* If we're already done loading the text stop */
488 /* Check if the tile has data yet */
493 g_debug("GritsTile: load_tex");
494 glGenTextures(1, &tile->tex);
495 glBindTexture(GL_TEXTURE_2D, tile->tex);
497 glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
498 glPixelStorei(GL_PACK_ALIGNMENT, 1);
499 glTexImage2D(GL_TEXTURE_2D, 0, 4, tile->width, tile->height, 0,
500 (tile->alpha ? GL_RGBA : GL_RGB), GL_UNSIGNED_BYTE, tile->pixels);
501 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
502 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
503 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
504 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
508 g_object_unref(tile->pixbuf);
510 g_free(tile->pixels);
518 /* Draw a single tile */
519 static void grits_tile_draw_one(GritsTile *tile, GritsOpenGL *opengl, GList *triangles)
521 if (!tile || !tile->tex)
524 g_warning("GritsOpenGL: _draw_tiles - No triangles to draw: edges=%f,%f,%f,%f",
525 tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
527 //g_message("drawing %4d triangles for tile edges=%7.2f,%7.2f,%7.2f,%7.2f",
528 // g_list_length(triangles), tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
529 tile->atime = time(NULL);
531 gdouble n = tile->edge.n;
532 gdouble s = tile->edge.s;
533 gdouble e = tile->edge.e;
534 gdouble w = tile->edge.w;
536 gdouble londist = e - w;
537 gdouble latdist = n - s;
539 gdouble xscale = tile->coords.e - tile->coords.w;
540 gdouble yscale = tile->coords.s - tile->coords.n;
542 glPolygonOffset(0, -tile->zindex);
544 for (GList *cur = triangles; cur; cur = cur->next) {
545 RoamTriangle *tri = cur->data;
547 gdouble lat[3] = {tri->p.r->lat, tri->p.m->lat, tri->p.l->lat};
548 gdouble lon[3] = {tri->p.r->lon, tri->p.m->lon, tri->p.l->lon};
550 if (lon[0] < -90 || lon[1] < -90 || lon[2] < -90) {
551 if (lon[0] > 90) lon[0] -= 360;
552 if (lon[1] > 90) lon[1] -= 360;
553 if (lon[2] > 90) lon[2] -= 360;
557 {(lon[0]-w)/londist, 1-(lat[0]-s)/latdist},
558 {(lon[1]-w)/londist, 1-(lat[1]-s)/latdist},
559 {(lon[2]-w)/londist, 1-(lat[2]-s)/latdist},
562 //if ((lat[0] == 90 && (xy[0][0] < 0 || xy[0][0] > 1)) ||
563 // (lat[1] == 90 && (xy[1][0] < 0 || xy[1][0] > 1)) ||
564 // (lat[2] == 90 && (xy[2][0] < 0 || xy[2][0] > 1)))
565 // g_message("w,e=%4.f,%4.f "
567 // "%4.1f,%4.0f,%4.2f,%4.2f "
568 // "%4.1f,%4.0f,%4.2f,%4.2f "
569 // "%4.1f,%4.0f,%4.2f,%4.2f ",
571 // lat[0], lon[0], xy[0][0], xy[0][1],
572 // lat[1], lon[1], xy[1][0], xy[1][1],
573 // lat[2], lon[2], xy[2][0], xy[2][1]);
576 if (lat[0] == 90 || lat[0] == -90) xy[0][0] = 0.5;
577 if (lat[1] == 90 || lat[1] == -90) xy[1][0] = 0.5;
578 if (lat[2] == 90 || lat[2] == -90) xy[2][0] = 0.5;
580 /* Scale to tile coords */
581 for (int i = 0; i < 3; i++) {
582 xy[i][0] = tile->coords.w + xy[i][0]*xscale;
583 xy[i][1] = tile->coords.n + xy[i][1]*yscale;
587 glBindTexture(GL_TEXTURE_2D, tile->tex);
588 glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
589 glBegin(GL_TRIANGLES);
590 glNormal3dv(tri->p.r->norm); glMultiTexCoord2dv(GL_TEXTURE0, xy[0]); glMultiTexCoord2dv(GL_TEXTURE1, xy[0]); glVertex3dv((double*)tri->p.r);
591 glNormal3dv(tri->p.m->norm); glMultiTexCoord2dv(GL_TEXTURE0, xy[1]); glMultiTexCoord2dv(GL_TEXTURE1, xy[1]); glVertex3dv((double*)tri->p.m);
592 glNormal3dv(tri->p.l->norm); glMultiTexCoord2dv(GL_TEXTURE0, xy[2]); glMultiTexCoord2dv(GL_TEXTURE1, xy[2]); glVertex3dv((double*)tri->p.l);
598 static gboolean grits_tile_draw_rec(GritsTile *tile, GritsOpenGL *opengl)
600 //g_debug("GritsTile: draw_rec - tile=%p, data=%d, load=%d, hide=%d", tile,
601 // tile ? !!tile->data : 0,
602 // tile ? !!tile->load : 0,
603 // tile ? !!GRITS_OBJECT(tile)->hidden : 0);
605 if (!_grits_tile_load_tex(tile))
608 GritsTile *child = NULL;
610 /* Draw child tiles */
611 gboolean draw_parent = FALSE;
612 grits_tile_foreach(tile, child)
613 if (!grits_tile_draw_rec(child, opengl))
616 /* Draw parent tile underneath using depth test */
618 GList *triangles = roam_sphere_get_intersect(opengl->sphere, FALSE,
619 tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
620 grits_tile_draw_one(tile, opengl, triangles);
621 g_list_free(triangles);
627 static void grits_tile_draw(GritsObject *tile, GritsOpenGL *opengl)
629 glEnable(GL_DEPTH_TEST);
630 glDepthFunc(GL_LESS);
631 glEnable(GL_ALPHA_TEST);
632 glAlphaFunc(GL_GREATER, 0.1);
633 glEnable(GL_POLYGON_OFFSET_FILL);
636 /* Setup texture mask */
637 if (!grits_tile_mask)
638 grits_tile_mask = _grits_tile_load_mask();
639 glActiveTexture(GL_TEXTURE1);
640 glEnable(GL_TEXTURE_2D);
641 glBindTexture(GL_TEXTURE_2D, grits_tile_mask);
642 glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
645 glActiveTexture(GL_TEXTURE0);
646 glEnable(GL_TEXTURE_2D);
648 /* Hack to show maps tiles with better color */
649 if (GRITS_TILE(tile)->proj == GRITS_PROJ_MERCATOR) {
650 float material_emission[] = {0.5, 0.5, 0.5, 1.0};
651 glMaterialfv(GL_FRONT_AND_BACK, GL_EMISSION, material_emission);
655 grits_tile_draw_rec(GRITS_TILE(tile), opengl);
657 /* Disable texture mask */
658 glActiveTexture(GL_TEXTURE1);
659 glDisable(GL_TEXTURE_2D);
660 glActiveTexture(GL_TEXTURE0);
665 G_DEFINE_TYPE(GritsTile, grits_tile, GRITS_TYPE_OBJECT);
666 static void grits_tile_init(GritsTile *tile)
670 static void grits_tile_class_init(GritsTileClass *klass)
672 g_debug("GritsTile: class_init");
673 GritsObjectClass *object_class = GRITS_OBJECT_CLASS(klass);
674 object_class->draw = grits_tile_draw;