/*
*
* Demonstrates how to load and display an Wavefront OBJ file.
* Using triangles and normals as static object. No texture mapping.
*
* OBJ files must be triangulated!!!
* Non triangulated objects wont work!
* You can use Blender to triangulate
*
*/
/*works olny with blender file*/
#include <iostream>
#include <fstream>
#include <stdio.h>
#include <string.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glut.h>
#include <iostream>
#include <sstream>
#include <fstream>
#include <string>
#include <vector>
#include <cmath>
#define KEY_ESCAPE 27
using namespace std;
/************************************************************************
Window
************************************************************************/
typedef struct {
int width;
int height;
char * title;
float field_of_view_angle;
float z_near;
float z_far;
} glutWindow;
/***************************************************************************
OBJ Loading
***************************************************************************/
class Model_OBJ
{
public:
Model_OBJ();
float * calculateNormal( float * coord1, float * coord2, float * coord3 );
int Load( char * filename ); // Loads the model
void Draw(); // Draws the model on the screen
void Release(); // Release the model
float * normals; // Stores the normals
float * Faces_Triangles; // Stores the triangles
float * vertexBuffer; // Stores the points which make the object
long TotalConnectedPoints; // Stores the total number of connected verteces
long TotalConnectedTriangles; // Stores the total number of connected triangles
};
#define POINTS_PER_VERTEX 3
#define TOTAL_FLOATS_IN_TRIANGLE 9
using namespace std;
Model_OBJ::Model_OBJ()
{
this->TotalConnectedTriangles = 0;
this->TotalConnectedPoints = 0;
}
float * Model_OBJ::calculateNormal( float * coord1, float * coord2, float * coord3 )
{
/* calculate Vector1 and Vector2 */
float va[ 3 ], vb[ 3 ], vr[ 3 ], val;
va[ 0 ] = coord1[ 0 ] - coord2[ 0 ];
va[ 1 ] = coord1[ 1 ] - coord2[ 1 ];
va[ 2 ] = coord1[ 2 ] - coord2[ 2 ];
vb[ 0 ] = coord1[ 0 ] - coord3[ 0 ];
vb[ 1 ] = coord1[ 1 ] - coord3[ 1 ];
vb[ 2 ] = coord1[ 2 ] - coord3[ 2 ];
/* cross product */
vr[ 0 ] = va[ 1 ] * vb[ 2 ] - vb[ 1 ] * va[ 2 ];
vr[ 1 ] = vb[ 0 ] * va[ 2 ] - va[ 0 ] * vb[ 2 ];
vr[ 2 ] = va[ 0 ] * vb[ 1 ] - vb[ 0 ] * va[ 1 ];
/* normalization factor */
val = sqrt( vr[ 0 ] * vr[ 0 ] + vr[ 1 ] * vr[ 1 ] + vr[ 2 ] * vr[ 2 ] );
float norm[ 3 ];
norm[ 0 ] = vr[ 0 ] / val;
norm[ 1 ] = vr[ 1 ] / val;
norm[ 2 ] = vr[ 2 ] / val;
return norm;
}
int Model_OBJ::Load( char * filename )
{
string line;
ifstream objFile( filename );
if( objFile.is_open() ) // If obj file is open, continue
{
objFile.seekg( 0, ios::end ); // Go to end of the file,
long fileSize = objFile.tellg(); // get file size
objFile.seekg( 0, ios::beg ); // we'll use this to register memory for our 3d model
vertexBuffer =( float * ) malloc( fileSize ); // Allocate memory for the verteces
Faces_Triangles =( float * ) malloc( fileSize * sizeof( float ) ); // Allocate memory for the triangles
normals =( float * ) malloc( fileSize * sizeof( float ) ); // Allocate memory for the normals
int triangle_index = 0; // Set triangle index to zero
int normal_index = 0; // Set normal index to zero
while( !objFile.eof() ) // Start reading file data
{
getline( objFile, line ); // Get line from file
if( line.c_str()[ 0 ] == 'v' ) // The first character is a v: on this line is a vertex stored.
{
line[ 0 ] = ' '; // Set first character to 0. This will allow us to use sscanf
sscanf( line.c_str(), "%f %f %f ", // Read floats from the line: v X Y Z
& vertexBuffer[ TotalConnectedPoints ],
& vertexBuffer[ TotalConnectedPoints + 1 ],
& vertexBuffer[ TotalConnectedPoints + 2 ] );
TotalConnectedPoints += POINTS_PER_VERTEX; // Add 3 to the total connected points
}
if( line.c_str()[ 0 ] == 'f' ) // The first character is an 'f': on this line is a point stored
{
line[ 0 ] = ' '; // Set first character to 0. This will allow us to use sscanf
int vertexNumber[ 4 ] = { 0, 0, 0 };
sscanf( line.c_str(), "%i%i%i", // Read integers from the line: f 1 2 3
& vertexNumber[ 0 ], // First point of our triangle. This is an
& vertexNumber[ 1 ], // pointer to our vertexBuffer list
& vertexNumber[ 2 ] ); // each point represents an X,Y,Z.
vertexNumber[ 0 ] -= 1; // OBJ file starts counting from 1
vertexNumber[ 1 ] -= 1; // OBJ file starts counting from 1
vertexNumber[ 2 ] -= 1; // OBJ file starts counting from 1
/********************************************************************
* Create triangles (f 1 2 3) from points: (v X Y Z) (v X Y Z) (v X Y Z).
* The vertexBuffer contains all verteces
* The triangles will be created using the verteces we read previously
*/
int tCounter = 0;
for( int i = 0; i < POINTS_PER_VERTEX; i++ )
{
Faces_Triangles[ triangle_index + tCounter ] = vertexBuffer[ 3 * vertexNumber[ i ] ];
Faces_Triangles[ triangle_index + tCounter + 1 ] = vertexBuffer[ 3 * vertexNumber[ i ] + 1 ];
Faces_Triangles[ triangle_index + tCounter + 2 ] = vertexBuffer[ 3 * vertexNumber[ i ] + 2 ];
tCounter += POINTS_PER_VERTEX;
}
/*********************************************************************
* Calculate all normals, used for lighting
*/
float coord1[ 3 ] = { Faces_Triangles[ triangle_index ], Faces_Triangles[ triangle_index + 1 ], Faces_Triangles[ triangle_index + 2 ] };
float coord2[ 3 ] = { Faces_Triangles[ triangle_index + 3 ], Faces_Triangles[ triangle_index + 4 ], Faces_Triangles[ triangle_index + 5 ] };
float coord3[ 3 ] = { Faces_Triangles[ triangle_index + 6 ], Faces_Triangles[ triangle_index + 7 ], Faces_Triangles[ triangle_index + 8 ] };
float * norm = this->calculateNormal( coord1, coord2, coord3 );
tCounter = 0;
for( int i = 0; i < POINTS_PER_VERTEX; i++ )
{
normals[ normal_index + tCounter ] = norm[ 0 ];
normals[ normal_index + tCounter + 1 ] = norm[ 1 ];
normals[ normal_index + tCounter + 2 ] = norm[ 2 ];
tCounter += POINTS_PER_VERTEX;
}
triangle_index += TOTAL_FLOATS_IN_TRIANGLE;
normal_index += TOTAL_FLOATS_IN_TRIANGLE;
TotalConnectedTriangles += TOTAL_FLOATS_IN_TRIANGLE;
}
}
objFile.close(); // Close OBJ file
}
else
{
cout << "Unable to open file";
}
return 0;
}
void Model_OBJ::Release()
{
free( this->Faces_Triangles );
free( this->normals );
free( this->vertexBuffer );
}
void Model_OBJ::Draw()
{
glEnableClientState( GL_VERTEX_ARRAY ); // Enable vertex arrays
glEnableClientState( GL_NORMAL_ARRAY ); // Enable normal arrays
glVertexPointer( 3, GL_FLOAT, 0, Faces_Triangles ); // Vertex Pointer to triangle array
glNormalPointer( GL_FLOAT, 0, normals ); // Normal pointer to normal array
glDrawArrays( GL_TRIANGLES,0, TotalConnectedTriangles ); // Draw the triangles
glDisableClientState( GL_VERTEX_ARRAY ); // Disable vertex arrays
glDisableClientState( GL_NORMAL_ARRAY ); // Disable normal arrays
}
/***************************************************************************
* Program code
***************************************************************************/
Model_OBJ obj;
float g_rotation;
glutWindow win;
void display()
{
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glLoadIdentity();
gluLookAt( 0, 1, 4, 0, 0, 0, 0, - 100, - 100 );
glPushMatrix();
glRotatef( g_rotation, 0, 1, 0 );
glRotatef( 90, 0, 1, 0 );
g_rotation++;
obj.Draw();
glPopMatrix();
glutSwapBuffers();
}
void initialize()
{
glMatrixMode( GL_PROJECTION );
glViewport( 0, 0, win.width, win.height );
GLfloat aspect =( GLfloat ) win.width / win.height;
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
gluPerspective( win.field_of_view_angle, aspect, win.z_near, win.z_far );
glMatrixMode( GL_MODELVIEW );
glShadeModel( GL_SMOOTH );
glClearColor( 0.0f, 0.1f, 0.0f, 0.5f );
glClearDepth( 1.0f );
glEnable( GL_DEPTH_TEST );
glDepthFunc( GL_LEQUAL );
glHint( GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST );
GLfloat amb_light[] = { 0.1, 0.1, 0.1, 1.0 };
GLfloat diffuse[] = { 0.6, 0.6, 0.6, 1 };
GLfloat specular[] = { 0.7, 0.7, 0.3, 1 };
glLightModelfv( GL_LIGHT_MODEL_AMBIENT, amb_light );
glLightfv( GL_LIGHT0, GL_DIFFUSE, diffuse );
glLightfv( GL_LIGHT0, GL_SPECULAR, specular );
glEnable( GL_LIGHT0 );
glEnable( GL_COLOR_MATERIAL );
glShadeModel( GL_SMOOTH );
glLightModeli( GL_LIGHT_MODEL_TWO_SIDE, GL_FALSE );
glDepthFunc( GL_LEQUAL );
glEnable( GL_DEPTH_TEST );
glEnable( GL_LIGHTING );
glEnable( GL_LIGHT0 );
}
void keyboard( unsigned char key, int x, int y )
{
switch( key ) {
case KEY_ESCAPE:
exit( 0 );
break;
default:
break;
}
}
int main( int argc, char ** argv )
{
// set window values
win.width = 640;
win.height = 480;
win.title = "OpenGL/GLUT OBJ Loader.";
win.field_of_view_angle = 45;
win.z_near = 1.0f;
win.z_far = 500.0f;
// initialize and run program
glutInit( & argc, argv ); // GLUT initialization
glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH ); // Display Mode
glutInitWindowSize( win.width, win.height ); // set window size
glutCreateWindow( win.title ); // create Window
glutDisplayFunc( display ); // register Display Function
glutIdleFunc( display ); // register Idle Function
glutKeyboardFunc( keyboard ); // register Keyboard Handler
initialize();
obj.Load( "untitled.obj" );
glutMainLoop(); // run GLUT mainloop
return 0;
}
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