geo/tcObserver.cpp

   1 /***************************************************************************
   2  *   This file is part of Tecorrec.                                        *
   3  *   Copyright 2008 James Hogan <james@albanarts.com>                      *
   4  *                                                                         *
   5  *   Tecorrec is free software: you can redistribute it and/or modify      *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation, either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   Tecorrec is distributed in the hope that it will be useful,           *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with Tecorrec.  If not, write to the Free Software Foundation,  *
  17  *   Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.   *
  18  ***************************************************************************/
  19
  20 /**
  21  * @file tcObserver.cpp
  22  * @brief Viewing information for an observer.
  23  */
  24
  25 #include "tcObserver.h"
  26 #include <glMatrix.h>
  27
  28 #include <GL/gl.h>
  29
  30 #include <cmath>
  31
  32 /*
  33  * Constructors + destructor
  34  */
  35
  36 /// Primary constructor.
  37 tcObserver::tcObserver()
  38 : m_focus(0.0, 0.0)
  39 , m_focusAltitude(1000e3)
  40 , m_view(0, M_PI/2)
  41 , m_range(100e3)
  42 {
  43 }
  44
  45 /// Destructor.
  46 tcObserver::~tcObserver()
  47 {
  48 }
  49
  50 /*
  51  * Main interface
  52  */
  53
  54 /// Set up the OpenGL projection matrix for this observer.
  55 void tcObserver::setupProjection(double aspect) const
  56 {
  57   glMatrixMode(GL_PROJECTION);
  58   glLoadIdentity();
  59   #define SIZE 120.0
  60   glFrustum(-SIZE*aspect, SIZE*aspect, -SIZE, SIZE, 100.0, 20000e3);
  61   glMatrixMode(GL_MODELVIEW);
  62 }
  63
  64 void drawAxes(float size)
  65 {
  66   glPushMatrix();
  67   glScalef(size, size, size);
  68   glBegin(GL_LINES);
  69   {
  70     glColor3f(1.0f, 1.0f, 1.0f);
  71     glVertex3f(0.0f, 0.0f, 0.0f);
  72     glColor3f(0.0f, 1.0f, 1.0f);
  73     glVertex3f(1.0f, 0.0f, 0.0f);
  74
  75     glColor3f(1.0f, 1.0f, 1.0f);
  76     glVertex3f(0.0f, 0.0f, 0.0f);
  77     glColor3f(1.0f, 0.0f, 1.0f);
  78     glVertex3f(0.0f, 1.0f, 0.0f);
  79
  80     glColor3f(1.0f, 1.0f, 1.0f);
  81     glVertex3f(0.0f, 0.0f, 0.0f);
  82     glColor3f(1.0f, 1.0f, 0.0f);
  83     glVertex3f(0.0f, 0.0f, 1.0f);
  84   }
  85   glEnd();
  86
  87   glPointSize(5);
  88   glEnable(GL_POINT_SMOOTH);
  89   glBegin(GL_POINTS);
  90   {
  91     glColor3f(1.0f, 1.0f, 1.0f);
  92     glVertex3f(0.0f, 0.0f, 0.0f);
  93
  94     glColor3f(0.0f, 1.0f, 1.0f);
  95     glVertex3f(1.0f, 0.0f, 0.0f);
  96
  97     glColor3f(1.0f, 0.0f, 1.0f);
  98     glVertex3f(0.0f, 1.0f, 0.0f);
  99
 100     glColor3f(1.0f, 1.0f, 0.0f);
 101     glVertex3f(0.0f, 0.0f, 1.0f);
 102   }
 103   glEnd();
 104   glPointSize(1);
 105   glPopMatrix();
 106 }
 107
 108 /// Set up the OpenGL modelview matrix for this observer.
 109 void tcObserver::setupModelView() const
 110 {
 111   glLoadIdentity();
 112
 113   // Translate to focus
 114   glTranslatef(0.0f, 0.0f, -m_range);
 115
 116   //drawAxes(50e3f);
 117
 118   // Rotate to surface space
 119   glMultMatrix(m_view);
 120
 121   //drawAxes(50e3f);
 122
 123   // Translate to origin
 124   glTranslatef(0.0f, 0.0f, -m_focusAltitude);
 125
 126   // Rotate to model space
 127   glMultMatrix(m_focus);
 128
 129   //drawAxes(1000e3f);
 130 }
 131
 132 /*
 133  * Mutators
 134  */
 135
 136 /// Adjust the focus directly.
 137 void tcObserver::setFocus(const tcGeo& focus, double altitude)
 138 {
 139   m_focus = focus;
 140   m_focusAltitude = altitude;
 141 }
 142
 143 /// Adjust the focus altitude.
 144 void tcObserver::setFocusAltitude(double altitude)
 145 {
 146   m_focusAltitude = altitude;
 147 }
 148
 149 /// Make a local transformation of the focus.
 150 void tcObserver::moveFocusRelative(double dx, double dy)
 151 {
 152   dx *= 2.0 * m_range / m_focusAltitude;
 153   dy *= 2.0 * m_range / m_focusAltitude;
 154   m_focus.setLat(m_focus.lat() - sin(m_view.azim()) * dx
 155                                + cos(m_view.azim()) * dy);
 156   m_focus.setLon(m_focus.lon() - cos(m_view.azim()) * dx
 157                                - sin(m_view.azim()) * dy);
 158 }
 159
 160 /// Adjust the range exponentially.
 161 void tcObserver::adjustRange(double x)
 162 {
 163   m_range *= exp(x);
 164 }
 165
 166 /// Adjust the azimuth in radians.
 167 void tcObserver::adjustAzimuth(double daz)
 168 {
 169   m_view.setAzim(m_view.azim() + daz);
 170 }
 171
 172 /// Adjust the elevation in radians.
 173 void tcObserver::adjustElevation(double del)
 174 {
 175   m_view.setElev(m_view.elev() + del);
 176 }
 177
 178 /*
 179  * Accessors
 180  */
 181
 182 /// Get the current focus position.
 183 tcGeo tcObserver::focus() const
 184 {
 185   return m_focus;
 186 }