3D mesh viewer More...

#include <stdio.h>
#include <stdlib.h>
#include <GL/glut.h>
#include <math.h>
#include "ViewerMesh/ViewerMesh.h"
#include "viewer/Arcball.h"
#include "bmp/RgbImage.h"

Include dependency graph for viewer.cpp:

Go to the source code of this file.

Functions
void	read_frame_buffer ()
void	setupObject (void)
void	setupEye (void)
void	setupLight ()
void	draw_mesh ()
void	display ()
void	reshape (int w, int h)
void	help ()
void	keyBoard (unsigned char key, int x, int y)
void	setupGLstate ()
void	mouseClick (int button, int state, int x, int y)
void	mouseMove (int x, int y)
void	initialize_bmp_texture ()
void	normalize_mesh (CVMesh *pMesh)
void	compute_normal (CVMesh *pMesh)
int	main (int argc, char *argv[])
Variables
int	win_width
int	win_height
int	gButton
int	startx
int	starty
int	shadeFlag = 0
CQrot	ObjRot (0, 0, 1, 0)
CPoint	ObjTrans (0, 0, 0)
CVMesh	mesh
CArcball	arcball
int	textureFlag = 2
GLuint	texName
RgbImage	image

Detailed Description

3D mesh viewer

Author:: David Gu

Date:: documented on 10/12/2010

3D triangle mesh viewer / /*!

Definition in file viewer.cpp.

Function Documentation

void compute_normal ( CVMesh * pMesh )

Compute the face normal and vertex normal

Parameters:

pMesh

the input mesh

Definition at line 471 of file viewer.cpp.

{
        //student: fill the details to compute face normal and vertex normal
};

void display ( )

display call back function

Definition at line 200 of file viewer.cpp.

{
        /* clear frame buffer */
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);       
    setupLight();
        /* transform from the eye coordinate system to the world system */
        setupEye();
        glPushMatrix();
        /* transform from the world to the ojbect coordinate system */
        setupObject();
    /* draw the mesh */
    draw_mesh();
        glPopMatrix();
        glutSwapBuffers();
}

void draw_mesh ( )

draw mesh

Definition at line 179 of file viewer.cpp.

{
          glBindTexture(GL_TEXTURE_2D, texName);
          //students: fill the details here
          //go through faces of the mesh
          //go through vertices of each face
          //specify normal, texture coordinates, vertex color and vertex position

          for (CVMesh::MeshFaceIterator fiter( &mesh ); !fiter.end(); ++ fiter )
          {
      CViewerFace * pf = *fiter;
          for( CVMesh::FaceVertexIterator fviter( pf ); !fviter.end(); ++ fviter )
      {
        CViewerVertex * v = *fviter;
      }
    }
        
}

void help ( )

helper function to remind the user about commands, hot keys

Definition at line 242 of file viewer.cpp.

{
  printf("w - Wireframe Display\n");
  printf("f  -  Flat Shading \n");
  printf("s  -  Smooth Shading\n");
  printf("t  -  Texture Mapping\n");
  printf("o  -  Save frame buffer to snap_n.bmp\n");
  printf("? -  Help Information\n");
  printf("esc - quit\n");
}

void initialize_bmp_texture ( )

initialize bitmap image texture

Definition at line 398 of file viewer.cpp.

{
        glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
        glGenTextures(1, &texName);
        glBindTexture(GL_TEXTURE_2D, texName);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,   GL_LINEAR);

        int ImageWidth  = image.GetNumCols();
        int ImageHeight = image.GetNumRows();
        GLubyte * ptr   = (GLubyte * )image.ImageData();

        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 
                                        ImageWidth,
                                                ImageHeight, 
                                        0, 
                                        GL_RGB, 
                                        GL_UNSIGNED_BYTE,
                                                ptr);

    if(textureFlag == 1)
                  glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
    else if(textureFlag == 2)
                  glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
    glEnable(GL_TEXTURE_2D);
}

void keyBoard	(	unsigned char	key,
		int	x,
		int	y
	)

Keyboard call back function

Definition at line 255 of file viewer.cpp.

{
        //students: fill the details in the following
        switch( key )
        {
        case 'f':
                //Flat Shading
                //set shadeFlag 
                break;
        case 's':
                //Smooth Shading
                //set shadeFlag 
                break;
        case 'w':
                //Wireframe mode
                break;
  case 't':
    textureFlag = (textureFlag +1 )%3;
    switch( textureFlag )
    {
    case 0:
        //disable texture mapping
        break;
    case 1:
        //enable texture mapping
                //replace mode
        break;
    case 2:
        //enable texture mapping
                //modulate mode
       break;
    }
    break;
  case '?':
    help();
    break;


  case 'o':
          read_frame_buffer();
          break;

  case 27:
                exit(0);
                break;
        }
  glutPostRedisplay();  
}

int main	(	int	argc,
		char *	argv[]
	)

main function for viewer

Definition at line 478 of file viewer.cpp.

{
        if( argc < 3 ) 
        {
                printf("Usage: %s mesh_name bmp_name\n");
                return -1;
        }

        std::string mesh_name( argv[1] );
        if( strutil::endsWith( mesh_name, ".obj" ) )
        {
                mesh.read_obj( argv[1] );
        }

        if( strutil::endsWith( mesh_name, ".m" ) )
        {
                mesh.read_m( argv[1] );
        }
                
        
        image.LoadBmpFile( argv[2] );

        normalize_mesh( &mesh );
        compute_normal( &mesh );

        /* glut stuff */
        glutInit(&argc, argv);                /* Initialize GLUT */
        glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH );
        glutInitWindowSize(800, 800);
        glutCreateWindow("Mesh Viewer");        /* Create window with given title */
        glViewport(0,0,800,800 );

        glutDisplayFunc(display);             /* Set-up callback functions */
        glutReshapeFunc(reshape);
        glutMouseFunc(mouseClick);
        glutMotionFunc(mouseMove);
        glutKeyboardFunc(keyBoard);
        setupGLstate();
        initialize_bmp_texture();

        glutMainLoop();                       /* Start GLUT event-processing loop */

        return 0;
}

void mouseClick	(	int	button,
		int	state,
		int	x,
		int	y
	)

mouse click call back function

Definition at line 331 of file viewer.cpp.

                                                      {

  
  /* set up an arcball around the Eye's center
          switch y coordinates to right handed system  */

  if (button == GLUT_LEFT_BUTTON && state == GLUT_DOWN) 
  { 
      gButton = GLUT_LEFT_BUTTON;  
          //student: fill the details to initialize Arcball
  }
  
  if (button == GLUT_MIDDLE_BUTTON && state == GLUT_DOWN) {
      startx = x;
      starty = y;
      gButton = GLUT_MIDDLE_BUTTON;
   }
  
  if (button == GLUT_RIGHT_BUTTON && state == GLUT_DOWN) {
      startx = x;
      starty = y;
      gButton = GLUT_RIGHT_BUTTON;
   }
  return ;
}

void mouseMove	(	int	x,
		int	y
	)

mouse motion call back function

Definition at line 359 of file viewer.cpp.

{
  CPoint trans;
  CQrot       rot;
  
  /* rotation, call arcball */
  if (gButton == GLUT_LEFT_BUTTON ) 
  {
          //student: fill the details to update the Arcball
          //update the ObjRot   
      glutPostRedisplay();
  }
  
  /*xy translation */
  if (gButton == GLUT_MIDDLE_BUTTON) 
  {
          double scale = 10./win_height;
      trans =  CPoint(scale*(x-startx), scale*(starty-y), 0  );
            startx = x;
            starty = y;
      ObjTrans = ObjTrans + trans;
      glutPostRedisplay();
  }
  
  /* zoom in and out */
  if (gButton == GLUT_RIGHT_BUTTON ) {
      double scale = 10./win_height;
      trans =  CPoint(0,0, scale*(starty-y)   );
            startx = x;
            starty = y;
      ObjTrans = ObjTrans+trans;
      glutPostRedisplay();
  }
  
}

void normalize_mesh ( CVMesh * pMesh )

Normalize mesh

Parameters:

pMesh

the input mesh

Definition at line 430 of file viewer.cpp.

{
    CPoint s(0,0,0);
        for( CVMesh::MeshVertexIterator viter( pMesh ); !viter.end(); ++ viter )
    {
      CViewerVertex * v = *viter;
      s = s + v->point();
    }

    s = s / pMesh->numVertices();
        for( CVMesh::MeshVertexIterator viter( pMesh ); !viter.end(); ++ viter )
    {
      CViewerVertex * v = *viter;
      CPoint p = v->point();
      p = p-s;
      v->point() = p;
    }
    double d = 0;

        for( CVMesh::MeshVertexIterator viter( pMesh ); !viter.end(); ++ viter )
    {
      CViewerVertex * v = *viter;
      CPoint p = v->point();
      for( int k = 0; k < 3; k ++ )
      {
        d = ( d > fabs(p[k]) )?d: fabs(p[k]);
      }
    }

        for( CVMesh::MeshVertexIterator viter( pMesh ); !viter.end(); ++ viter )
    {
      CViewerVertex * v = *viter;
      CPoint p = v->point();
      p = p/d;
      v->point() = p;
    }
};

void read_frame_buffer ( )

save frame buffer to an image "snap_k.bmp"

Definition at line 123 of file viewer.cpp.

{
        static int id = 0;

        GLfloat * buffer = new GLfloat[win_width * win_height*3];
        assert( buffer );
        glReadBuffer(GL_FRONT_LEFT);
        glReadPixels( 0, 0, win_width, win_height, GL_RGB, GL_FLOAT, buffer);

        RgbImage  image(win_height,win_width);

        for( int i = 0; i < win_height; i ++ )
        for( int j = 0; j < win_width;j ++ )
        {
                float r = buffer[(i*win_width + j)*3+0];
                float g = buffer[(i*win_width + j)*3+1];
                float b = buffer[(i*win_width + j)*3+2];

                image.SetRgbPixelf( i,j, r,g,b);
        }
        delete []buffer;

        char name[256];
        std::ostringstream os(name);
        os << "snape_"<< id++ << ".bmp";
        image.WriteBmpFile( os.str().c_str() );

}

void reshape	(	int	w,
		int	h
	)

Called when a "resize" event is received by the window.

Definition at line 218 of file viewer.cpp.

{
  float ar;

  win_width=w;
  win_height=h;

  ar = (float)(w)/h;
  glViewport(0, 0, w, h);               /* Set Viewport */
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity(); 

  // magic imageing commands
  gluPerspective( 40.0, /* field of view in degrees */
                  ar, /* aspect ratio */
                  1.0, /* Z near */ 
                  100.0 /* Z far */);

  glMatrixMode(GL_MODELVIEW);
  
  glutPostRedisplay();
}

void setupEye ( void )

the eye is always fixed at world z = +5

Definition at line 165 of file viewer.cpp.

                   {
  glLoadIdentity();
  gluLookAt( 0,0, 5,0,0,0,0,1,0);
}

void setupGLstate ( )

setup GL states

Definition at line 305 of file viewer.cpp.

                   {

  GLfloat lightOneColor[] = {1, 1, 1, 1};
  GLfloat globalAmb[] = {.1, .1, .1, 1};
  GLfloat lightOnePosition[] = {.0,  .0, 1, 0.0};

  glEnable(GL_CULL_FACE);
  glFrontFace(GL_CCW);      
  glEnable(GL_DEPTH_TEST);
  glClearColor(0,0,0,0);
  glShadeModel(GL_SMOOTH);


  glEnable(GL_LIGHT1);
  glEnable(GL_LIGHTING);
  glEnable(GL_NORMALIZE);
  glEnable(GL_COLOR_MATERIAL);

  glLightfv(GL_LIGHT1, GL_DIFFUSE, lightOneColor);
  glLightModelfv(GL_LIGHT_MODEL_AMBIENT, globalAmb);
  glColorMaterial(GL_FRONT, GL_AMBIENT_AND_DIFFUSE);

  glLightfv(GL_LIGHT1, GL_POSITION, lightOnePosition);
}

void setupLight ( )

setup light

Definition at line 171 of file viewer.cpp.

{
  CPoint position(0,0,1);
  GLfloat lightOnePosition[4]={position[0], position[1], position[2], 0};
  glLightfv(GL_LIGHT1, GL_POSITION, lightOnePosition);
}

void setupObject ( void )

setup the object, transform from the world to the object coordinate system

Definition at line 154 of file viewer.cpp.

{
    double rot[16];

    glTranslated( ObjTrans[0], ObjTrans[1], ObjTrans[2]);
    ObjRot.convert( rot );
    glMultMatrixd(( GLdouble *)  rot ); 
}