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

   1 /*
   2  * Copyright (C) 2009-2010 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:gis-marker
  20  * @short_description: Single point markers
  21  *
  22  * Each #GisMarker 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, GisObjects should almost
  29  * always be added to the GIS_LEVEL_OVERLAY level so they are drawn "above" the
  30  * actual earth.
  31  */
  32
  33 #include <config.h>
  34 #include <GL/gl.h>
  35 #include "grits-marker.h"
  36
  37 /**
  38  * gis_marker_new:
  39  * @label: a short description of the marker
  40  *
  41  * Create a new GisMarker which shows the given label when drawn.
  42  *
  43  * Returns: the new #GisMarker.
  44  */
  45 GisMarker *gis_marker_new(const gchar *label)
  46 {
  47         //g_debug("GisMarker: new - %s", label);
  48         static const gdouble OUTLINE =   2;
  49         static const gdouble RADIUS  =   3;
  50         static const gdouble WIDTH   = 128;
  51         static const gdouble HEIGHT  =  32;
  52
  53         GisMarker *marker = g_object_new(GIS_TYPE_MARKER, NULL);
  54         marker->xoff  = RADIUS+OUTLINE;
  55         marker->yoff  = HEIGHT-(RADIUS+OUTLINE);
  56         marker->label = g_strdup(label);
  57         marker->cairo = cairo_create(cairo_image_surface_create(
  58                         CAIRO_FORMAT_ARGB32, WIDTH, HEIGHT));
  59
  60         cairo_select_font_face(marker->cairo, "sans-serif",
  61                         CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_BOLD);
  62         cairo_set_font_size(marker->cairo, 13);
  63
  64         /* Draw outline */
  65         cairo_set_source_rgba(marker->cairo, 0, 0, 0, 1);
  66         cairo_set_line_width(marker->cairo, OUTLINE*2);
  67
  68         cairo_arc(marker->cairo, marker->xoff, marker->yoff, RADIUS, 0, 2*G_PI);
  69         cairo_stroke(marker->cairo);
  70
  71         cairo_move_to(marker->cairo, marker->xoff+4, marker->yoff-8);
  72         cairo_text_path(marker->cairo, marker->label);
  73         cairo_stroke(marker->cairo);
  74
  75         /* Draw filler */
  76         cairo_set_source_rgba(marker->cairo, 1, 1, 1, 1);
  77
  78         cairo_arc(marker->cairo, marker->xoff, marker->yoff, RADIUS, 0, 2*G_PI);
  79         cairo_fill(marker->cairo);
  80
  81         cairo_move_to(marker->cairo, marker->xoff+4, marker->yoff-8);
  82         cairo_show_text(marker->cairo, marker->label);
  83
  84         /* Load GL texture */
  85         glEnable(GL_TEXTURE_2D);
  86         glGenTextures(1, &marker->tex);
  87         glBindTexture(GL_TEXTURE_2D, marker->tex);
  88         glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  89         glPixelStorei(GL_PACK_ALIGNMENT, 1);
  90         glTexImage2D(GL_TEXTURE_2D, 0, 4, WIDTH, HEIGHT, 0, GL_RGBA, GL_UNSIGNED_BYTE,
  91                         cairo_image_surface_get_data(cairo_get_target(marker->cairo)));
  92         glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  93         glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  94
  95         return marker;
  96 }
  97
  98 /* Drawing */
  99 static void gis_marker_draw(GisObject *_marker, GisOpenGL *opengl)
 100 {
 101         GisMarker *marker = GIS_MARKER(_marker);
 102         GisPoint *point = gis_object_center(marker);
 103         gdouble px, py, pz;
 104         gis_viewer_project(GIS_VIEWER(opengl),
 105                         point->lat, point->lon, point->elev,
 106                         &px, &py, &pz);
 107
 108         gint win_width  = GTK_WIDGET(opengl)->allocation.width;
 109         gint win_height = GTK_WIDGET(opengl)->allocation.height;
 110         py = win_height - py;
 111         if (pz > 1)
 112                 return;
 113
 114         //g_debug("GisOpenGL: draw_marker - %s pz=%f ", marker->label, pz);
 115
 116         cairo_surface_t *surface = cairo_get_target(marker->cairo);
 117         gdouble width  = cairo_image_surface_get_width(surface);
 118         gdouble height = cairo_image_surface_get_height(surface);
 119
 120         glMatrixMode(GL_PROJECTION); glLoadIdentity();
 121         glMatrixMode(GL_MODELVIEW);  glLoadIdentity();
 122         glOrtho(0, win_width, win_height, 0, -1, 1);
 123         glTranslated(px - marker->xoff,
 124                      py - marker->yoff, 0);
 125
 126         glDisable(GL_LIGHTING);
 127         glDisable(GL_COLOR_MATERIAL);
 128         glDisable(GL_DEPTH_TEST);
 129         glEnable(GL_TEXTURE_2D);
 130         glBindTexture(GL_TEXTURE_2D, marker->tex);
 131         glDisable(GL_CULL_FACE);
 132         glBegin(GL_QUADS);
 133         glTexCoord2f(1, 0); glVertex3f(width, 0     , 0);
 134         glTexCoord2f(1, 1); glVertex3f(width, height, 0);
 135         glTexCoord2f(0, 1); glVertex3f(0    , height, 0);
 136         glTexCoord2f(0, 0); glVertex3f(0    , 0     , 0);
 137         glEnd();
 138 }
 139
 140 /* GObject code */
 141 G_DEFINE_TYPE(GisMarker, gis_marker, GIS_TYPE_OBJECT);
 142 static void gis_marker_init(GisMarker *marker)
 143 {
 144 }
 145
 146 static void gis_marker_finalize(GObject *_marker)
 147 {
 148         //g_debug("GisMarker: finalize - %s", marker->label);
 149         GisMarker *marker = GIS_MARKER(_marker);
 150         glDeleteTextures(1, &marker->tex);
 151         cairo_surface_t *surface = cairo_get_target(marker->cairo);
 152         cairo_surface_destroy(surface);
 153         cairo_destroy(marker->cairo);
 154         g_free(marker->label);
 155 }
 156
 157 static void gis_marker_class_init(GisMarkerClass *klass)
 158 {
 159         g_debug("GisMarker: class_init");
 160         GObjectClass *gobject_class = G_OBJECT_CLASS(klass);
 161         gobject_class->finalize = gis_marker_finalize;
 162
 163         GisObjectClass *object_class = GIS_OBJECT_CLASS(klass);
 164         object_class->draw = gis_marker_draw;
 165 }