Pileus Git - grits/blob - src/plugin-radar.c

   1 /*
   2  * Copyright (C) 2009 Andy Spencer <spenceal@rose-hulman.edu>
   3  *
   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.
   8  *
   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.
  13  *
  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/>.
  16  */
  17
  18 #include <config.h>
  19 #include <gtk/gtk.h>
  20 #include <gtk/gtkgl.h>
  21 #include <gio/gio.h>
  22 #include <GL/gl.h>
  23 #include <math.h>
  24 #include <rsl.h>
  25
  26 #include "aweather-gui.h"
  27 #include "plugin-radar.h"
  28 #include "data.h"
  29
  30 /****************
  31  * GObject code *
  32  ****************/
  33 /* Plugin init */
  34 static void aweather_radar_plugin_init(AWeatherPluginInterface *iface);
  35 static void _aweather_radar_expose(AWeatherPlugin *_radar);
  36 G_DEFINE_TYPE_WITH_CODE(AWeatherRadar, aweather_radar, G_TYPE_OBJECT,
  37                 G_IMPLEMENT_INTERFACE(AWEATHER_TYPE_PLUGIN,
  38                         aweather_radar_plugin_init));
  39 static void aweather_radar_plugin_init(AWeatherPluginInterface *iface)
  40 {
  41         g_debug("AWeatherRadar: plugin_init");
  42         /* Add methods to the interface */
  43         iface->expose = _aweather_radar_expose;
  44 }
  45 /* Class/Object init */
  46 static void aweather_radar_init(AWeatherRadar *radar)
  47 {
  48         g_debug("AWeatherRadar: class_init");
  49         /* Set defaults */
  50         radar->gui = NULL;
  51 }
  52 static void aweather_radar_dispose(GObject *gobject)
  53 {
  54         g_debug("AWeatherRadar: dispose");
  55         AWeatherRadar *self = AWEATHER_RADAR(gobject);
  56         /* Drop references */
  57         G_OBJECT_CLASS(aweather_radar_parent_class)->dispose(gobject);
  58 }
  59 static void aweather_radar_finalize(GObject *gobject)
  60 {
  61         g_debug("AWeatherRadar: finalize");
  62         AWeatherRadar *self = AWEATHER_RADAR(gobject);
  63         /* Free data */
  64         G_OBJECT_CLASS(aweather_radar_parent_class)->finalize(gobject);
  65
  66 }
  67 static void aweather_radar_class_init(AWeatherRadarClass *klass)
  68 {
  69         g_debug("AWeatherRadar: class_init");
  70         GObjectClass *gobject_class = (GObjectClass*)klass;
  71         gobject_class->dispose  = aweather_radar_dispose;
  72         gobject_class->finalize = aweather_radar_finalize;
  73 }
  74
  75 /**************************
  76  * Data loading functions *
  77  **************************/
  78 /* Convert a sweep to an 2d array of data points */
  79 static void bscan_sweep(AWeatherRadar *self, Sweep *sweep, colormap_t *colormap,
  80                 guint8 **data, int *width, int *height)
  81 {
  82         /* Calculate max number of bins */
  83         int i, max_bins = 0;
  84         for (i = 0; i < sweep->h.nrays; i++)
  85                 max_bins = MAX(max_bins, sweep->ray[i]->h.nbins);
  86
  87         /* Allocate buffer using max number of bins for each ray */
  88         guint8 *buf = g_malloc0(sweep->h.nrays * max_bins * 4);
  89
  90         /* Fill the data */
  91         int ri, bi;
  92         for (ri = 0; ri < sweep->h.nrays; ri++) {
  93                 Ray *ray  = sweep->ray[ri];
  94                 for (bi = 0; bi < ray->h.nbins; bi++) {
  95                         /* copy RGBA into buffer */
  96                         //guint val   = dz_f(ray->range[bi]);
  97                         guint8 val   = (guint8)ray->h.f(ray->range[bi]);
  98                         guint  buf_i = (ri*max_bins+bi)*4;
  99                         buf[buf_i+0] = colormap->data[val][0];
 100                         buf[buf_i+1] = colormap->data[val][1];
 101                         buf[buf_i+2] = colormap->data[val][2];
 102                         buf[buf_i+3] = colormap->data[val][3];
 103                         if (val == BADVAL     || val == RFVAL      || val == APFLAG ||
 104                             val == NOTFOUND_H || val == NOTFOUND_V || val == NOECHO) {
 105                                 buf[buf_i+3] = 0x00; // transparent
 106                         }
 107                 }
 108         }
 109
 110         /* set output */
 111         *width  = max_bins;
 112         *height = sweep->h.nrays;
 113         *data   = buf;
 114 }
 115
 116 /* Load a sweep as the active texture */
 117 static void load_sweep(AWeatherRadar *self, Sweep *sweep)
 118 {
 119         aweather_gui_gl_begin(self->gui);
 120         self->cur_sweep = sweep;
 121         int height, width;
 122         guint8 *data;
 123         bscan_sweep(self, sweep, self->cur_colormap, &data, &width, &height);
 124         glDeleteTextures(1, &self->cur_sweep_tex);
 125         glGenTextures(1, &self->cur_sweep_tex);
 126         glBindTexture(GL_TEXTURE_2D, self->cur_sweep_tex);
 127         glPixelStorei(GL_PACK_ALIGNMENT, 1);
 128         glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 129         glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 130         glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 131         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0,
 132                         GL_RGBA, GL_UNSIGNED_BYTE, data);
 133         g_free(data);
 134         aweather_gui_gl_redraw(self->gui);
 135         aweather_gui_gl_end(self->gui);
 136 }
 137
 138 static void load_colormap(AWeatherRadar *self, gchar *table)
 139 {
 140         /* Set colormap so we can draw it on expose */
 141         for (int i = 0; colormaps[i].name; i++)
 142                 if (g_str_equal(colormaps[i].name, table))
 143                         self->cur_colormap = &colormaps[i];
 144 }
 145
 146 /* Add selectors to the config area for the sweeps */
 147 static void on_sweep_clicked(GtkRadioButton *button, gpointer _self);
 148 static void load_radar_gui(AWeatherRadar *self, Radar *radar)
 149 {
 150         /* Clear existing items */
 151         GtkWidget *child = gtk_bin_get_child(GTK_BIN(self->config_body));
 152         if (child)
 153                 gtk_widget_destroy(child);
 154
 155         gdouble elev;
 156         guint rows = 1, cols = 1, cur_cols;
 157         gchar row_label_str[64], col_label_str[64], button_str[64];
 158         GtkWidget *row_label, *col_label, *button = NULL, *elev_box = NULL;
 159         GtkWidget *table = gtk_table_new(rows, cols, FALSE);
 160
 161         for (guint vi = 0; vi < radar->h.nvolumes; vi++) {
 162                 Volume *vol = radar->v[vi];
 163                 if (vol == NULL) continue;
 164                 rows++; cols = 1; elev = 0;
 165
 166                 /* Row label */
 167                 g_snprintf(row_label_str, 64, "<b>%s:</b>", vol->h.type_str);
 168                 row_label = gtk_label_new(row_label_str);
 169                 gtk_label_set_use_markup(GTK_LABEL(row_label), TRUE);
 170                 gtk_misc_set_alignment(GTK_MISC(row_label), 1, 0.5);
 171                 gtk_table_attach(GTK_TABLE(table), row_label,
 172                                 0,1, rows-1,rows, GTK_FILL,GTK_FILL, 5,0);
 173
 174                 for (guint si = 0; si < vol->h.nsweeps; si++) {
 175                         Sweep *sweep = vol->sweep[si];
 176                         if (sweep == NULL || sweep->h.elev == 0) continue;
 177                         if (sweep->h.elev != elev) {
 178                                 cols++;
 179                                 elev = sweep->h.elev;
 180
 181                                 /* Column label */
 182                                 g_object_get(table, "n-columns", &cur_cols, NULL);
 183                                 if (cols >  cur_cols) {
 184                                         g_snprintf(col_label_str, 64, "<b>%.2f°</b>", elev);
 185                                         col_label = gtk_label_new(col_label_str);
 186                                         gtk_label_set_use_markup(GTK_LABEL(col_label), TRUE);
 187                                         gtk_widget_set_size_request(col_label, 40, -1);
 188                                         gtk_table_attach(GTK_TABLE(table), col_label,
 189                                                         cols-1,cols, 0,1, GTK_FILL,GTK_FILL, 0,0);
 190                                 }
 191
 192                                 elev_box = gtk_hbox_new(TRUE, 0);
 193                                 gtk_table_attach(GTK_TABLE(table), elev_box,
 194                                                 cols-1,cols, rows-1,rows, GTK_FILL,GTK_FILL, 0,0);
 195                         }
 196
 197
 198                         /* Button */
 199                         g_snprintf(button_str, 64, "%3.2f", elev);
 200                         button = gtk_radio_button_new_with_label_from_widget(
 201                                         GTK_RADIO_BUTTON(button), button_str);
 202                         gtk_widget_set_size_request(button, -1, 26);
 203                         //button = gtk_radio_button_new_from_widget(GTK_RADIO_BUTTON(button));
 204                         //gtk_widget_set_size_request(button, -1, 22);
 205                         g_object_set(button, "draw-indicator", FALSE, NULL);
 206                         gtk_box_pack_end(GTK_BOX(elev_box), button, TRUE, TRUE, 0);
 207
 208                         g_object_set_data(G_OBJECT(button), "type",  vol->h.type_str);
 209                         g_object_set_data(G_OBJECT(button), "sweep", sweep);
 210                         g_signal_connect(button, "clicked", G_CALLBACK(on_sweep_clicked), self);
 211                 }
 212         }
 213         gtk_container_add(GTK_CONTAINER(self->config_body), table);
 214         gtk_widget_show_all(table);
 215 }
 216
 217 /* Load a radar from a decompressed file */
 218 static void load_radar(AWeatherRadar *self, gchar *radar_file)
 219 {
 220         char *dir  = g_path_get_dirname(radar_file);
 221         char *site = g_path_get_basename(dir);
 222         g_free(dir);
 223         g_debug("AWeatherRadar: load_radar - Loading new radar");
 224         RSL_read_these_sweeps("all", NULL);
 225         Radar *radar = self->cur_radar = RSL_wsr88d_to_radar(radar_file, site);
 226         if (radar == NULL) {
 227                 g_warning("fail to load radar: path=%s, site=%s", radar_file, site);
 228                 g_free(site);
 229                 return;
 230         }
 231         g_free(site);
 232
 233         /* Load the first sweep by default */
 234         if (radar->h.nvolumes < 1 || radar->v[0]->h.nsweeps < 1) {
 235                 g_warning("No sweeps found\n");
 236         } else {
 237                 /* load first available sweep */
 238                 for (int vi = 0; vi < radar->h.nvolumes; vi++) {
 239                         if (radar->v[vi]== NULL) continue;
 240                         for (int si = 0; si < radar->v[vi]->h.nsweeps; si++) {
 241                                 if (radar->v[vi]->sweep[si]== NULL) continue;
 242                                 load_colormap(self, radar->v[vi]->h.type_str);
 243                                 load_sweep(self, radar->v[vi]->sweep[si]);
 244                                 break;
 245                         }
 246                         break;
 247                 }
 248         }
 249
 250         load_radar_gui(self, radar);
 251 }
 252
 253 static void update_times(AWeatherRadar *self, AWeatherView *view, char *site, char **last_time)
 254 {
 255         GList *times = NULL;
 256         if (aweather_view_get_offline(view)) {
 257                 gchar *path = g_build_filename(g_get_user_cache_dir(), PACKAGE, "nexrd2", "raw", site, NULL);
 258                 GDir *dir = g_dir_open(path, 0, NULL);
 259                 if (dir) {
 260                         const gchar *name;
 261                         while ((name = g_dir_read_name(dir))) {
 262                                 times = g_list_prepend(times, g_strdup(name));
 263                         }
 264                         g_dir_close(dir);
 265                 }
 266                 g_free(path);
 267         } else {
 268                 gchar *data;
 269                 gsize length;
 270                 GError *error = NULL;
 271
 272                 char *list_uri = g_strdup_printf("http://mesonet.agron.iastate.edu/data/nexrd2/raw/%s/dir.list", site);
 273                 GFile *list = g_file_new_for_uri(list_uri);
 274                 g_file_load_contents(list, NULL, &data, &length, NULL, &error);
 275                 if (error) {
 276                         g_warning("Error loading list for %s: %s", site, error->message);
 277                         g_error_free(error);
 278                 } else {
 279                         gchar **lines = g_strsplit(data, "\n", -1);
 280                         for (int i = 0; lines[i] && lines[i][0]; i++) {
 281                                 char **parts = g_strsplit(lines[i], " ", 2);
 282                                 times = g_list_prepend(times, parts[1]);
 283                                 g_strfreev(parts);
 284                         }
 285                         g_strfreev(lines);
 286                         g_free(data);
 287                 }
 288
 289                 g_free(list_uri);
 290                 g_object_unref(list);
 291         }
 292
 293         GRegex *regex = g_regex_new("^[A-Z]{4}_([0-9]{8}_[0-9]{4})$", 0, 0, NULL); // KLSX_20090622_2113
 294         GMatchInfo *info;
 295
 296         GtkTreeView  *tview  = GTK_TREE_VIEW(aweather_gui_get_widget(self->gui, "time"));
 297         GtkListStore *lstore = GTK_LIST_STORE(gtk_tree_view_get_model(tview));
 298         gtk_list_store_clear(lstore);
 299         GtkTreeIter iter;
 300         times = g_list_reverse(times);
 301         for (GList *cur = times; cur; cur = cur->next) {
 302                 g_message("trying time %s", (gchar*)cur->data);
 303                 if (g_regex_match(regex, cur->data, 0, &info)) {
 304                         gchar *time = g_match_info_fetch(info, 1);
 305                         g_message("adding time %s", (gchar*)cur->data);
 306                         gtk_list_store_insert(lstore, &iter, 0);
 307                         gtk_list_store_set(lstore, &iter, 0, time, -1);
 308                         if (last_time)
 309                                 *last_time = time;
 310                 }
 311         }
 312
 313         g_regex_unref(regex);
 314         g_list_foreach(times, (GFunc)g_free, NULL);
 315         g_list_free(times);
 316 }
 317
 318 /*****************
 319  * ASync helpers *
 320  *****************/
 321 typedef struct {
 322         AWeatherRadar *self;
 323         gchar *radar_file;
 324 } decompressed_t;
 325
 326 static void decompressed_cb(GPid pid, gint status, gpointer _udata)
 327 {
 328         decompressed_t *udata = _udata;
 329         if (status != 0) {
 330                 g_warning("wsr88ddec exited with status %d", status);
 331                 return;
 332         }
 333         load_radar(udata->self, udata->radar_file);
 334         g_spawn_close_pid(pid);
 335         g_free(udata->radar_file);
 336         g_free(udata);
 337 }
 338
 339 static void cached_cb(char *path, gboolean updated, gpointer _self)
 340 {
 341         AWeatherRadar *self = AWEATHER_RADAR(_self);
 342         char *decompressed = g_strconcat(path, ".raw", NULL);
 343         if (!updated) {
 344                 load_radar(self, decompressed);
 345                 return;
 346         }
 347
 348         decompressed_t *udata = g_malloc(sizeof(decompressed_t));
 349         udata->self       = self;
 350         udata->radar_file = decompressed;
 351         g_debug("AWeatherRadar: cached_cb - File updated, decompressing..");
 352         char *argv[] = {"wsr88ddec", path, decompressed, NULL};
 353         GPid pid;
 354         GError *error = NULL;
 355         g_spawn_async(
 356                 NULL,    // const gchar *working_directory,
 357                 argv,    // gchar **argv,
 358                 NULL,    // gchar **envp,
 359                 G_SPAWN_SEARCH_PATH|
 360                 G_SPAWN_DO_NOT_REAP_CHILD,
 361                          // GSpawnFlags flags,
 362                 NULL,    // GSpawnChildSetupFunc child_setup,
 363                 NULL,    // gpointer user_data,
 364                 &pid,    // GPid *child_pid,
 365                 &error); // GError **error
 366         if (error) {
 367                 g_warning("failed to decompress WSR88D data: %s",
 368                                 error->message);
 369                 g_error_free(error);
 370         }
 371         g_child_watch_add(pid, decompressed_cb, udata);
 372 }
 373
 374 /*************
 375  * Callbacks *
 376  *************/
 377 static void on_sweep_clicked(GtkRadioButton *button, gpointer _self)
 378 {
 379         AWeatherRadar *self = AWEATHER_RADAR(_self);
 380         load_colormap(self, g_object_get_data(G_OBJECT(button), "type" ));
 381         load_sweep   (self, g_object_get_data(G_OBJECT(button), "sweep"));
 382 }
 383
 384 static void on_time_changed(AWeatherView *view, const char *time, gpointer _self)
 385 {
 386         AWeatherRadar *self = AWEATHER_RADAR(_self);
 387         g_debug("AWeatherRadar: on_time_changed - setting time=%s", time);
 388         // format: http://mesonet.agron.iastate.edu/data/nexrd2/raw/KABR/KABR_20090510_0323
 389         char *site = aweather_view_get_site(view);
 390         char *base = "http://mesonet.agron.iastate.edu/data/";
 391         char *path = g_strdup_printf("nexrd2/raw/%s/%s_%s", site, site, time);
 392
 393         /* Clear out children */
 394         GtkWidget *child = gtk_bin_get_child(GTK_BIN(self->config_body));
 395         if (child)
 396                 gtk_widget_destroy(child);
 397         gtk_container_add(GTK_CONTAINER(self->config_body),
 398                 gtk_label_new("Loading radar..."));
 399         gtk_widget_show_all(self->config_body);
 400         if (self->cur_radar)
 401                 RSL_free_radar(self->cur_radar);
 402         self->cur_radar = NULL;
 403         self->cur_sweep = NULL;
 404         aweather_gui_gl_redraw(self->gui);
 405
 406         /* Start loading the new radar */
 407         if (aweather_view_get_offline(view))
 408                 cache_file(base, path, AWEATHER_ONCE, cached_cb, self);
 409         else
 410                 cache_file(base, path, AWEATHER_UPDATE, cached_cb, self);
 411         g_free(path);
 412 }
 413
 414 static void on_site_changed(AWeatherView *view, char *site, gpointer _self)
 415 {
 416         AWeatherRadar *self = AWEATHER_RADAR(_self);
 417         g_debug("AWeatherRadar: on_site_changed - Loading wsr88d list for %s", site);
 418         char *time = NULL;
 419         update_times(self, view, site, &time);
 420         aweather_view_set_time(view, time);
 421
 422         g_free(time);
 423 }
 424
 425 static void on_refresh(AWeatherView *view, gpointer _self)
 426 {
 427         AWeatherRadar *self = AWEATHER_RADAR(_self);
 428         char *site = aweather_view_get_site(view);
 429         char *time = NULL;
 430         update_times(self, view, site, &time);
 431         aweather_view_set_time(view, time);
 432         g_free(time);
 433 }
 434
 435 /***********
 436  * Methods *
 437  ***********/
 438 AWeatherRadar *aweather_radar_new(AWeatherGui *gui)
 439 {
 440         g_debug("AWeatherRadar: new");
 441         AWeatherRadar *self = g_object_new(AWEATHER_TYPE_RADAR, NULL);
 442         self->gui = gui;
 443
 444         GtkWidget    *config  = aweather_gui_get_widget(gui, "tabs");
 445         AWeatherView *view    = aweather_gui_get_view(gui);
 446
 447         /* Add configuration tab */
 448         self->config_body = gtk_alignment_new(0, 0, 1, 1);
 449         gtk_container_set_border_width(GTK_CONTAINER(self->config_body), 5);
 450         gtk_container_add(GTK_CONTAINER(self->config_body), gtk_label_new("No radar loaded"));
 451         gtk_notebook_prepend_page(GTK_NOTEBOOK(config), self->config_body, gtk_label_new("Radar"));
 452
 453         /* Set up OpenGL Stuff */
 454         g_signal_connect(view,    "site-changed", G_CALLBACK(on_site_changed), self);
 455         g_signal_connect(view,    "time-changed", G_CALLBACK(on_time_changed), self);
 456         g_signal_connect(view,    "refresh",      G_CALLBACK(on_refresh),      self);
 457
 458         return self;
 459 }
 460
 461 static void _aweather_radar_expose(AWeatherPlugin *_self)
 462 {
 463         AWeatherRadar *self = AWEATHER_RADAR(_self);
 464         g_debug("AWeatherRadar: expose");
 465         if (self->cur_sweep == NULL)
 466                 return;
 467         Sweep *sweep = self->cur_sweep;
 468
 469         /* Draw the rays */
 470
 471         glMatrixMode(GL_MODELVIEW);
 472         glPushMatrix();
 473         glBindTexture(GL_TEXTURE_2D, self->cur_sweep_tex);
 474         glEnable(GL_TEXTURE_2D);
 475         glDisable(GL_ALPHA_TEST);
 476         glColor4f(1,1,1,1);
 477         glBegin(GL_QUAD_STRIP);
 478         for (int ri = 0; ri <= sweep->h.nrays; ri++) {
 479                 Ray  *ray = NULL;
 480                 double angle = 0;
 481                 if (ri < sweep->h.nrays) {
 482                         ray = sweep->ray[ri];
 483                         angle = ((ray->h.azimuth - ((double)ray->h.beam_width/2.))*M_PI)/180.0;
 484                 } else {
 485                         /* Do the right side of the last sweep */
 486                         ray = sweep->ray[ri-1];
 487                         angle = ((ray->h.azimuth + ((double)ray->h.beam_width/2.))*M_PI)/180.0;
 488                 }
 489
 490                 double lx = sin(angle);
 491                 double ly = cos(angle);
 492
 493                 double near_dist = ray->h.range_bin1;
 494                 double far_dist  = ray->h.nbins*ray->h.gate_size + ray->h.range_bin1;
 495
 496                 /* (find middle of bin) / scale for opengl */
 497                 // near left
 498                 glTexCoord2f(0.0, (double)ri/sweep->h.nrays-0.01);
 499                 glVertex3f(lx*near_dist, ly*near_dist, 2.0);
 500
 501                 // far  left
 502                 glTexCoord2f(1.0, (double)ri/sweep->h.nrays-0.01);
 503                 glVertex3f(lx*far_dist,  ly*far_dist,  2.0);
 504         }
 505         //g_print("ri=%d, nr=%d, bw=%f\n", _ri, sweep->h.nrays, sweep->h.beam_width);
 506         glEnd();
 507         glPopMatrix();
 508
 509         /* Texture debug */
 510         //glBegin(GL_QUADS);
 511         //glTexCoord2d( 0.,  0.); glVertex3f(-500.,   0., 0.); // bot left
 512         //glTexCoord2d( 0.,  1.); glVertex3f(-500., 500., 0.); // top left
 513         //glTexCoord2d( 1.,  1.); glVertex3f( 0.,   500., 3.); // top right
 514         //glTexCoord2d( 1.,  0.); glVertex3f( 0.,     0., 3.); // bot right
 515         //glEnd();
 516
 517         /* Print the color table */
 518         glDisable(GL_TEXTURE_2D);
 519         glDisable(GL_DEPTH_TEST);
 520         glMatrixMode(GL_MODELVIEW ); glPushMatrix(); glLoadIdentity();
 521         glMatrixMode(GL_PROJECTION); glPushMatrix(); glLoadIdentity();
 522         glBegin(GL_QUADS);
 523         int i;
 524         for (i = 0; i < 256; i++) {
 525                 glColor4ub(self->cur_colormap->data[i][0],
 526                            self->cur_colormap->data[i][1],
 527                            self->cur_colormap->data[i][2],
 528                            self->cur_colormap->data[i][3]);
 529                 glVertex3f(-1.0, (float)((i  ) - 256/2)/(256/2), 0.0); // bot left
 530                 glVertex3f(-1.0, (float)((i+1) - 256/2)/(256/2), 0.0); // top left
 531                 glVertex3f(-0.9, (float)((i+1) - 256/2)/(256/2), 0.0); // top right
 532                 glVertex3f(-0.9, (float)((i  ) - 256/2)/(256/2), 0.0); // bot right
 533         }
 534         glEnd();
 535         glEnable(GL_DEPTH_TEST);
 536         glEnable(GL_ALPHA_TEST);
 537         glMatrixMode(GL_PROJECTION); glPopMatrix();
 538         glMatrixMode(GL_MODELVIEW ); glPopMatrix();
 539 }