Pileus Git - grits/blob - src/objects/grits-marker.c

   1 /*
   2  * Copyright (C) 2009-2011 Andy Spencer <andy753421@gmail.com>
   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 /**
  19  * SECTION:grits-marker
  20  * @short_description: Single point markers
  21  *
  22  * Each #GritsMarker represents some point on the earth with some form of
  23  * content. Commonly this is used to mark geographic features such as cities or
  24  * states.
  25  *
  26  * While markers represent a place in three dimensions somewhere on, below, or
  27  * above the surface of the earth, they are drawn in 2 dimensions so that they
  28  * look normal and readable by the user. Due to this, GritsObjects should almost
  29  * always be added to the GRITS_LEVEL_OVERLAY level so they are drawn "above" the
  30  * actual earth.
  31  */
  32
  33 #include <config.h>
  34 #include <math.h>
  35 #include "gtkgl.h"
  36 #include "grits-marker.h"
  37
  38 static void render_all(GritsMarker *marker);
  39 static void render_point(GritsMarker *marker);
  40 static void render_label(GritsMarker *marker);
  41 static void render_icon(GritsMarker *marker);
  42
  43 /**
  44  * grits_marker_new:
  45  * @label: a short description of the marker
  46  *
  47  * Create a new GritsMarker which shows the given label when drawn.
  48  *
  49  * Returns: the new #GritsMarker.
  50  */
  51 GritsMarker *grits_marker_new(const gchar *label)
  52 {
  53         GritsMarker *marker = g_object_new(GRITS_TYPE_MARKER, NULL);
  54
  55         marker->display_mask = MARKER_DMASK_POINT | MARKER_DMASK_LABEL;
  56
  57         //g_debug("GritsMarker: new - %s", label);
  58         /* specify size of point and size of surface */
  59         marker->outline =   2;
  60         marker->radius  =   3;
  61         marker->width   = 128;
  62         marker->height  =  32;
  63         marker->icon_width  = marker->radius * 2;
  64         marker->icon_height = marker->radius * 3;
  65
  66         marker->xoff  = marker->radius+marker->outline;
  67         marker->yoff  = marker->height-(marker->radius+marker->outline);
  68         marker->cairo = cairo_create(cairo_image_surface_create(
  69                         CAIRO_FORMAT_ARGB32, marker->width, marker->height));
  70
  71         marker->label = g_strdup(label);
  72
  73         render_all(marker);
  74
  75         return marker;
  76 }
  77
  78 /*
  79  * Create a new marker with a label, point, icon (png), or any
  80  * combination of the above.
  81  * label: The label to display if MARKER_DMASK_LABEL is set
  82  * filename: The filename of the icon
  83  * angle: The angle to rotate the icon (0 is north)
  84  * flip: Whether to flip the image so that it's never upside down.
  85  *       Useful for non-symmetric icons which have an "up".
  86  * display_mask: A bitmask which specifies which items to display.
  87  */
  88 GritsMarker *grits_marker_icon_new(const gchar *label, const gchar *filename,
  89     guint angle, gboolean flip, guint display_mask)
  90 {
  91         GritsMarker *marker = g_object_new(GRITS_TYPE_MARKER, NULL);
  92
  93         marker->label = g_strdup(label);
  94         marker->angle = angle;
  95         marker->flip = flip;
  96         marker->display_mask = display_mask;
  97
  98         if (display_mask & MARKER_DMASK_ICON) {
  99                 g_assert(filename != NULL);
 100                 g_debug("GritsMarker: marker_icon_new - marker image %s",
 101                         filename);
 102                 marker->icon_img = cairo_image_surface_create_from_png(filename);
 103                 if (cairo_surface_status(marker->icon_img)) {
 104                         g_warning("GritsMarker: marker_icon_new - "
 105                                   "error reading file %s", filename);
 106                         /* convert it to a point, better than nothing */
 107                         marker->display_mask &= ~MARKER_DMASK_ICON;
 108                         marker->display_mask |= MARKER_DMASK_POINT;
 109                         marker->icon_width = 4;
 110                         marker->icon_height = 8;
 111
 112                 } else {
 113                         marker->icon_width =
 114                             cairo_image_surface_get_width(marker->icon_img);
 115                         marker->icon_height =
 116                             cairo_image_surface_get_height(marker->icon_img);
 117                 }
 118         } else {
 119                 marker->icon_img = NULL;
 120                 marker->icon_width = 4; /* room for the point if there is one */
 121                 marker->icon_height = 8;
 122         }
 123         g_debug("GritsMarker: marker_icon_new - width = %d, height = %d",
 124                 marker->icon_width, marker->icon_height);
 125
 126         marker->outline =   2;
 127         marker->radius  =   3;
 128         /* this is the surface size, a guess really */
 129         marker->width   = marker->icon_width  + 128;
 130         marker->height  = marker->icon_height + 64;
 131
 132         marker->xoff  = marker->width/2;
 133         marker->yoff  = marker->height/2;
 134         marker->cairo = cairo_create(cairo_image_surface_create(
 135                         CAIRO_FORMAT_ARGB32, marker->width, marker->height));
 136         /* clear the surface just in case */
 137         cairo_set_operator(marker->cairo, CAIRO_OPERATOR_SOURCE);
 138         //cairo_set_source_rgba(marker->cairo, 1.0, 0.0, 0.0, 0.3); // debug
 139         cairo_set_source_rgba(marker->cairo, 1.0, 0.0, 0.0, 0.0);
 140         cairo_paint(marker->cairo);
 141         cairo_set_operator(marker->cairo, CAIRO_OPERATOR_OVER);
 142
 143         render_all(marker);
 144
 145         if (marker->icon_img) {
 146                 cairo_surface_destroy(marker->icon_img);
 147         }
 148
 149         return marker;
 150 }
 151
 152 static void render_all(GritsMarker *marker)
 153 {
 154         g_assert(marker);
 155         if (marker->display_mask & MARKER_DMASK_ICON) {
 156                 render_icon(marker);
 157         }
 158         if (marker->display_mask & MARKER_DMASK_POINT) {
 159                 render_point(marker);
 160         }
 161         if (marker->display_mask & MARKER_DMASK_LABEL) {
 162                 render_label(marker);
 163         }
 164
 165         /* Load GL texture */
 166         glEnable(GL_TEXTURE_2D);
 167         glGenTextures(1, &marker->tex);
 168         glBindTexture(GL_TEXTURE_2D, marker->tex);
 169         glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 170         glPixelStorei(GL_PACK_ALIGNMENT, 1);
 171         glTexImage2D(GL_TEXTURE_2D, 0, 4, marker->width, marker->height,
 172                 0, GL_BGRA, GL_UNSIGNED_BYTE,
 173                 cairo_image_surface_get_data(cairo_get_target(marker->cairo)));
 174         glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 175         glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 176 }
 177
 178
 179 static void render_point(GritsMarker *marker)
 180 {
 181         /* Draw outline */
 182         cairo_set_source_rgba(marker->cairo, 0, 0, 0, 1);
 183         cairo_set_line_width(marker->cairo, marker->outline*2);
 184
 185         cairo_arc(marker->cairo, marker->xoff, marker->yoff, marker->radius,
 186                   0, 2*G_PI);
 187         cairo_stroke(marker->cairo);
 188
 189         /* Draw filler */
 190         cairo_set_source_rgba(marker->cairo, 1, 1, 1, 1);
 191
 192         cairo_arc(marker->cairo, marker->xoff, marker->yoff, marker->radius,
 193                   0, 2*G_PI);
 194         cairo_fill(marker->cairo);
 195 }
 196
 197 static void render_label(GritsMarker *marker)
 198 {
 199         g_assert(marker->label);
 200
 201         cairo_set_source_rgba(marker->cairo, 0, 0, 0, 1);
 202         cairo_select_font_face(marker->cairo, "sans-serif",
 203                         CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_BOLD);
 204         cairo_set_font_size(marker->cairo, 13);
 205         cairo_move_to(marker->cairo, marker->xoff + (marker->icon_width  / 2),
 206                                      marker->yoff - (marker->icon_height / 2));
 207         cairo_text_path(marker->cairo, marker->label);
 208         cairo_stroke(marker->cairo);
 209
 210         /* Draw filler */
 211         cairo_set_source_rgba(marker->cairo, 1, 1, 1, 1);
 212         cairo_move_to(marker->cairo, marker->xoff + (marker->icon_width  / 2),
 213                                      marker->yoff - (marker->icon_height / 2));
 214         cairo_show_text(marker->cairo, marker->label);
 215 }
 216
 217 static void render_icon(GritsMarker *marker)
 218 {
 219         g_assert(marker->icon_img != NULL);
 220
 221         /* This code assumes the icon is an image pointing toward 0 degrees
 222         * (ie. north/up).  If marker->flip is set, then it will rotate the
 223         * icon appropriately then reflect it across the vertical axis so
 224         * it's never upside down.
 225         */
 226         gdouble flip = 1.0;
 227         gdouble angle = marker->angle % 360;
 228         if (marker->flip && (angle < 360 && angle > 180)) {
 229                 /* if icon rotates to the left half it will be upside down */
 230                 flip = -1.0; /* flip horizontally */
 231         }
 232
 233         cairo_save(marker->cairo);
 234
 235         /* move to marker location */
 236         cairo_translate(marker->cairo, marker->xoff, marker->yoff);
 237
 238         /* perform rotation and flip in one transformation */
 239         gdouble C = cos(angle*(M_PI/180.0));
 240         gdouble S = sin(angle*(M_PI/180.0));
 241         gdouble fx = flip;
 242         gdouble fy = 1.0;
 243         gdouble tx = 0.0;
 244         gdouble ty = 0.0;
 245         cairo_matrix_t matrix;
 246         cairo_matrix_init(&matrix,
 247                 fx*C, fx*S,
 248                 -S*fy, C*fy,
 249                 C*tx*(1-fx)-S*ty*(fy-1)+tx-C*tx+S*ty,
 250                 S*tx*(1-fx)+C*ty*(fy-1)+ty-S*tx-C*ty);
 251         cairo_transform(marker->cairo, &matrix);
 252
 253         /* center image */
 254         cairo_translate(marker->cairo, -marker->icon_width/2,
 255                                        -marker->icon_height/2);
 256
 257         cairo_set_source_surface(marker->cairo, marker->icon_img, 0, 0);
 258
 259         cairo_paint(marker->cairo);
 260         cairo_restore(marker->cairo);
 261 }
 262
 263 /* Drawing */
 264 static void grits_marker_draw(GritsObject *_marker, GritsOpenGL *opengl)
 265 {
 266         GritsMarker *marker = GRITS_MARKER(_marker);
 267         GritsPoint  *point  = grits_object_center(marker);
 268         gdouble px, py, pz;
 269         grits_viewer_project(GRITS_VIEWER(opengl),
 270                         point->lat, point->lon, point->elev,
 271                         &px, &py, &pz);
 272
 273         gint win_width  = GTK_WIDGET(opengl)->allocation.width;
 274         gint win_height = GTK_WIDGET(opengl)->allocation.height;
 275         py = win_height - py;
 276         if (pz > 1)
 277                 return;
 278
 279         //g_debug("GritsOpenGL: draw_marker - %s pz=%f ", marker->label, pz);
 280
 281         cairo_surface_t *surface = cairo_get_target(marker->cairo);
 282         gdouble width  = cairo_image_surface_get_width(surface);
 283         gdouble height = cairo_image_surface_get_height(surface);
 284
 285         glMatrixMode(GL_PROJECTION); glLoadIdentity();
 286         glMatrixMode(GL_MODELVIEW);  glLoadIdentity();
 287         glOrtho(0, win_width, win_height, 0, -1, 1);
 288         glTranslated(px - marker->xoff,
 289                      py - marker->yoff, 0);
 290
 291         glDisable(GL_LIGHTING);
 292         glDisable(GL_COLOR_MATERIAL);
 293         glDisable(GL_DEPTH_TEST);
 294         glEnable(GL_TEXTURE_2D);
 295         glBindTexture(GL_TEXTURE_2D, marker->tex);
 296         glDisable(GL_CULL_FACE);
 297         glBegin(GL_QUADS);
 298         glTexCoord2f(1, 0); glVertex3f(width, 0     , 0);
 299         glTexCoord2f(1, 1); glVertex3f(width, height, 0);
 300         glTexCoord2f(0, 1); glVertex3f(0    , height, 0);
 301         glTexCoord2f(0, 0); glVertex3f(0    , 0     , 0);
 302         glEnd();
 303 }
 304
 305
 306 /* GObject code */
 307 G_DEFINE_TYPE(GritsMarker, grits_marker, GRITS_TYPE_OBJECT);
 308 static void grits_marker_init(GritsMarker *marker)
 309 {
 310 }
 311
 312 static void grits_marker_finalize(GObject *_marker)
 313 {
 314         //g_debug("GritsMarker: finalize - %s", marker->label);
 315         GritsMarker *marker = GRITS_MARKER(_marker);
 316         glDeleteTextures(1, &marker->tex);
 317         cairo_surface_t *surface = cairo_get_target(marker->cairo);
 318         cairo_surface_destroy(surface);
 319         cairo_destroy(marker->cairo);
 320         g_free(marker->label);
 321         glDeleteTextures(1, &marker->tex);
 322 }
 323
 324 static void grits_marker_class_init(GritsMarkerClass *klass)
 325 {
 326         g_debug("GritsMarker: class_init");
 327         GObjectClass *gobject_class = G_OBJECT_CLASS(klass);
 328         gobject_class->finalize = grits_marker_finalize;
 329
 330         GritsObjectClass *object_class = GRITS_OBJECT_CLASS(klass);
 331         object_class->draw = grits_marker_draw;
 332 }