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/****************************************************************************
Copyright (C) 2002-2007 Gilles Debunne (Gilles.Debunne@imag.fr)
This file is part of the QGLViewer library.
Version 2.2.6-3, released on August 28, 2007.
http://artis.imag.fr/Members/Gilles.Debunne/QGLViewer
libQGLViewer is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
libQGLViewer is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with libQGLViewer; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*****************************************************************************/
#include "drawLight.h"
#include <math.h>
using namespace std;
using namespace qglviewer;
void Viewer::draw()
{
float pos[4] = {1.0, 0.5, 1.0, 0.0};
// Directionnal light
glLightfv(GL_LIGHT0, GL_POSITION, pos);
pos[3] = 1.0;
// Spot light
light1->getPosition(pos[0], pos[1], pos[2]);
glLightfv(GL_LIGHT1, GL_POSITION, pos);
glLightfv(GL_LIGHT1, GL_SPOT_DIRECTION, light1->inverseTransformOf(Vec(0,0,1)));
// Point light
light2->getPosition(pos[0], pos[1], pos[2]);
glLightfv(GL_LIGHT2, GL_POSITION, pos);
// Draws the spiral
const float nbSteps = 200.0;
glBegin(GL_QUAD_STRIP);
for (float i=0; i<nbSteps; ++i)
{
float ratio = i/nbSteps;
float angle = 21.0*ratio;
float c = cos(angle);
float s = sin(angle);
float r1 = 1.0 - 0.8*ratio;
float r2 = 0.8 - 0.8*ratio;
float alt = ratio - 0.5;
const float nor = .5;
const float up = sqrt(1.0-nor*nor);
glColor3f(1-ratio, .2 , ratio);
glNormal3f(nor*c, up, nor*s);
glVertex3f(r1*c, alt, r1*s);
glVertex3f(r2*c, alt+0.05, r2*s);
}
glEnd();
drawLight(GL_LIGHT0);
if (light1->grabsMouse())
drawLight(GL_LIGHT1, 1.2);
else
drawLight(GL_LIGHT1);
if (light2->grabsMouse())
drawLight(GL_LIGHT2, 1.2);
else
drawLight(GL_LIGHT2);
}
void Viewer::init()
{
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
// Light0 is the default ambient light
glEnable(GL_LIGHT0);
// Light1 is a spot light
glEnable(GL_LIGHT1);
const GLfloat light_ambient[4] = {0.8, 0.2, 0.2, 1.0};
const GLfloat light_diffuse[4] = {1.0, 0.4, 0.4, 1.0};
const GLfloat light_specular[4] = {1.0, 0.0, 0.0, 1.0};
glLightf( GL_LIGHT1, GL_SPOT_EXPONENT, 3.0);
glLightf( GL_LIGHT1, GL_SPOT_CUTOFF, 20.0);
glLightf( GL_LIGHT1, GL_CONSTANT_ATTENUATION, 0.5);
glLightf( GL_LIGHT1, GL_LINEAR_ATTENUATION, 1.0);
glLightf( GL_LIGHT1, GL_QUADRATIC_ATTENUATION, 1.5);
glLightfv(GL_LIGHT1, GL_AMBIENT, light_ambient);
glLightfv(GL_LIGHT1, GL_SPECULAR, light_specular);
glLightfv(GL_LIGHT1, GL_DIFFUSE, light_diffuse);
// Light2 is a classical directionnal light
glEnable(GL_LIGHT2);
const GLfloat light_ambient2[4] = {0.2, 0.2, 2.0, 1.0};
const GLfloat light_diffuse2[4] = {0.8, 0.8, 1.0, 1.0};
const GLfloat light_specular2[4] = {0.0, 0.0, 1.0, 1.0};
glLightfv(GL_LIGHT2, GL_AMBIENT, light_ambient2);
glLightfv(GL_LIGHT2, GL_SPECULAR, light_specular2);
glLightfv(GL_LIGHT2, GL_DIFFUSE, light_diffuse2);
light1 = new ManipulatedFrame();
light2 = new ManipulatedFrame();
setMouseTracking(true);
light1->setPosition(0.5, 0.5, 0);
// Align z axis with -position direction : look at scene center
light1->setOrientation(Quaternion(Vec(0,0,1), -light1->position()));
light2->setPosition(-0.5, 0.5, 0);
restoreStateFromFile();
help();
}
QString Viewer::helpString() const
{
QString text("<h2>D r a w L i g h t</h2>");
text += "The <i>drawLight()</i> function displays a representation of the OpenGL lights ";
text += "of your scene. This is convenient for debugging your light setup.<br><br>";
text += "This scene features a directionnal ligth (arrow), a spot light (cone) and a point ";
text += "light source (sphere). The representation color, position and shape matches the light setup.<br><br>";
text += "Hover over the point light or the spot light to manipulate it using the mouse (right ";
text += "button translates and left button rotates).";
return text;
}
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