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//=============================================================================
//
// Glagen : a planet sized landscape generator
// Copyright (C) 2002 Julien Guertault, Hugues Hiegel, Meng-Tih Lam
//
// This program 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.
//
// This program 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 this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
//
//=============================================================================
//
// Glagen : GPL LAndscape GENerator
//
// triangle.cc for Glagen : made by Zavie (Julien Guertault)
//
// www.glagen.org
//
//=============================================================================
#ifndef DARWIN
# include <GL/gl.h>
# include <GL/glu.h>
#else
# include <gl.h>
# include <glu.h>
#endif
#include "data_glagen.hh"
#include "dot.hh"
#include "triangle.hh"
//
// Manage the T-case (when the has a 4th point)
//
bool Triangle :: T_case (const unsigned int id)
{
Dot *middle;
Triangle *child1;
Triangle *child2;
// Is there a triangle on this side ?
if (_neighbor_ab != NULL)
// Then is it split ?
if (_neighbor_ab->Is_split ())
{
// Find the dangling vertex
child1 = _neighbor_ab->Child (_a);
child2 = _neighbor_ab->Child (_b);
if (child1->B () == child2->C ())
middle = child1->B ();
else
middle = child1->C ();
// Display two triangles instead of just one
glBegin (GL_TRIANGLES);
_b->Display (id);
_c->Display (id);
middle->Display (id);
_c->Display (id);
_a->Display (id);
middle->Display (id);
glEnd ();
// The T case is fixed
return true;
}
if (_neighbor_bc != NULL)
if (_neighbor_bc->Is_split ())
{
child1 = _neighbor_bc->Child (_b);
child2 = _neighbor_bc->Child (_c);
if (child1->B () == child2->C ())
middle = child1->B ();
else
middle = child1->C ();
glBegin (GL_TRIANGLES);
_a->Display (id);
_b->Display (id);
middle->Display (id);
_c->Display (id);
_a->Display (id);
middle->Display (id);
glEnd ();
return true;
}
if (_neighbor_ca != NULL)
if (_neighbor_ca->Is_split ())
{
child1 = _neighbor_ca->Child (_c);
child2 = _neighbor_ca->Child (_a);
if (child1->B () == child2->C ())
middle = child1->B ();
else
middle = child1->C ();
glBegin (GL_TRIANGLES);
_b->Display (id);
_c->Display (id);
middle->Display (id);
_a->Display (id);
_b->Display (id);
middle->Display (id);
glEnd ();
return true;
}
// In fact there's no T-case for this triangle
return false;
}
//
// Display the faces included in the triangle (general case)
//
void Triangle :: Display (const unsigned int id)
{
// Test if this triangle has been visited yet
if (step == glagen.step)
return;
step = glagen.step;
if (glagen.display_all == true || _visible == true)
{
// If the triangle has childs, we visit them instead
if (_child_center != NULL)
{
_child_a->Display (id);
_child_b->Display (id);
_child_c->Display (id);
_child_center->Display (id);
}
else
{
// T-case managment
if (false == T_case (id))
{
if (glagen.display_normal == true)
{
float x = (_a->x () + _b->x () + _c->x ()) / 3;
float y = (_a->y () + _b->y () + _c->y ()) / 3;
float z = (_a->z () + _b->z () + _c->z ()) / 3;
// Display the normal vector
if (glagen.light)
glDisable(GL_LIGHTING);
glBegin (GL_LINES);
glColor3f(1.0, 0.2, 0.0);
glVertex3f(x, y, z);
glVertex3f(x + _normal_real.X () / 100,
y + _normal_real.Y () / 100,
z + _normal_real.Z () / 100);
glEnd ();
if (glagen.light)
glEnable(GL_LIGHTING);
}
// Could it be more simple ?
glBegin (GL_TRIANGLES);
_a->Display (id);
_b->Display (id);
_c->Display (id);
glEnd ();
}
}
}
// Recursive call at the top of the three
if (NULL == Father ())
{
_neighbor_ab->Display (id);
_neighbor_bc->Display (id);
_neighbor_ca->Display (id);
}
}
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