NURBS.C

/* 
 * (c) Copyright 1993, Silicon Graphics, Inc. 
 *               1993-1995 Microsoft Corporation 
 * 
 * ALL RIGHTS RESERVED 
 * 
 * Please refer to OpenGL/readme.txt for additional information 
 * 
 */ 
 
/* 
 *  nurbs.c 
 *  This program shows a NURBS (Non-uniform rational B-splines) 
 *  surface, shaped like a heart. 
 */ 
#include "glos.h" 
 
#include <GL/gl.h> 
#include <GL/glu.h> 
#include <GL/glaux.h> 
 
void myinit(void); 
void CALLBACK display(void); 
void CALLBACK myReshape(GLsizei w, GLsizei h); 
 
#define S_NUMPOINTS 13 
#define S_ORDER     3    
#define S_NUMKNOTS  (S_NUMPOINTS + S_ORDER) 
#define T_NUMPOINTS 3 
#define T_ORDER     3  
#define T_NUMKNOTS  (T_NUMPOINTS + T_ORDER) 
#define SQRT2    1.41421356237309504880 
 
/* initialized local data */ 
 
GLfloat sknots[S_NUMKNOTS] = 
    {-1.0, -1.0, -1.0, 0.0, 1.0, 2.0, 3.0, 4.0, 
      4.0,  5.0,  6.0, 7.0, 8.0, 9.0, 9.0, 9.0}; 
GLfloat tknots[T_NUMKNOTS] = {1.0, 1.0, 1.0, 2.0, 2.0, 2.0}; 
 
GLfloat ctlpoints[S_NUMPOINTS][T_NUMPOINTS][4] = { 
{   {4.,2.,2.,1.},{4.,1.6,2.5,1.},{4.,2.,3.0,1.}    }, 
{   {5.,4.,2.,1.},{5.,4.,2.5,1.},{5.,4.,3.0,1.} }, 
{   {6.,5.,2.,1.},{6.,5.,2.5,1.},{6.,5.,3.0,1.} }, 
{   {SQRT2*6.,SQRT2*6.,SQRT2*2.,SQRT2}, 
    {SQRT2*6.,SQRT2*6.,SQRT2*2.5,SQRT2}, 
    {SQRT2*6.,SQRT2*6.,SQRT2*3.0,SQRT2}  }, 
{   {5.2,6.7,2.,1.},{5.2,6.7,2.5,1.},{5.2,6.7,3.0,1.}   }, 
{   {SQRT2*4.,SQRT2*6.,SQRT2*2.,SQRT2}, 
    {SQRT2*4.,SQRT2*6.,SQRT2*2.5,SQRT2}, 
    {SQRT2*4.,SQRT2*6.,SQRT2*3.0,SQRT2}  }, 
{   {4.,5.2,2.,1.},{4.,4.6,2.5,1.},{4.,5.2,3.0,1.}  }, 
{   {SQRT2*4.,SQRT2*6.,SQRT2*2.,SQRT2}, 
    {SQRT2*4.,SQRT2*6.,SQRT2*2.5,SQRT2}, 
    {SQRT2*4.,SQRT2*6.,SQRT2*3.0,SQRT2}  }, 
{   {2.8,6.7,2.,1.},{2.8,6.7,2.5,1.},{2.8,6.7,3.0,1.}   }, 
{   {SQRT2*2.,SQRT2*6.,SQRT2*2.,SQRT2}, 
    {SQRT2*2.,SQRT2*6.,SQRT2*2.5,SQRT2}, 
    {SQRT2*2.,SQRT2*6.,SQRT2*3.0,SQRT2}  }, 
{   {2.,5.,2.,1.},{2.,5.,2.5,1.},{2.,5.,3.0,1.} }, 
{   {3.,4.,2.,1.},{3.,4.,2.5,1.},{3.,4.,3.0,1.} }, 
{   {4.,2.,2.,1.},{4.,1.6,2.5,1.},{4.,2.,3.0,1.}    } 
}; 
 
GLUnurbsObj *theNurb; 
 
/*  Initialize material property, light source, lighting model,  
 *  and depth buffer. 
 */ 
void myinit(void) 
{ 
    GLfloat mat_ambient[] = { 1.0, 1.0, 1.0, 1.0 }; 
    GLfloat mat_diffuse[] = { 1.0, 0.2, 1.0, 1.0 }; 
    GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 }; 
    GLfloat mat_shininess[] = { 50.0 }; 
 
    GLfloat light0_position[] = { 1.0, 0.1, 1.0, 0.0 }; 
    GLfloat light1_position[] = { -1.0, 0.1, 1.0, 0.0 }; 
 
    GLfloat lmodel_ambient[] = { 0.3, 0.3, 0.3, 1.0 }; 
 
    glMaterialfv(GL_FRONT, GL_AMBIENT, mat_ambient); 
    glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse); 
    glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular); 
    glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess); 
    glLightfv(GL_LIGHT0, GL_POSITION, light0_position); 
    glLightfv(GL_LIGHT1, GL_POSITION, light1_position); 
    glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lmodel_ambient); 
 
    glEnable(GL_LIGHTING); 
    glEnable(GL_LIGHT0); 
    glEnable(GL_LIGHT1); 
    glDepthFunc(GL_LESS); 
    glEnable(GL_DEPTH_TEST); 
    glEnable(GL_AUTO_NORMAL); 
 
    theNurb = gluNewNurbsRenderer(); 
 
    glNewList (1, GL_COMPILE); 
    gluBeginSurface(theNurb); 
    gluNurbsProperty(theNurb, GLU_DISPLAY_MODE, GLU_FILL); 
    gluNurbsSurface(theNurb,  
        S_NUMKNOTS, sknots, 
        T_NUMKNOTS, tknots, 
        4 * T_NUMPOINTS, 
        4, 
        &ctlpoints[0][0][0],  
        S_ORDER, T_ORDER, 
        GL_MAP2_VERTEX_4); 
    gluEndSurface(theNurb); 
    glEndList (); 
 
} 
 
void CALLBACK display(void) 
{ 
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); 
    glColor3f(1.0, 1.0, 1.0); 
 
    glPushMatrix(); 
    glTranslatef (4., 4.5, 2.5); 
    glRotatef (220.0, 1., 0., 0.); 
    glRotatef (115.0, 0., 1., 0.); 
    glTranslatef (-4., -4.5, -2.5); 
    glCallList (1); 
    glPopMatrix(); 
    glFlush(); 
} 
 
void CALLBACK myReshape(GLsizei w, GLsizei h) 
{ 
    glViewport(0, 0, w, h); 
    glMatrixMode(GL_PROJECTION); 
    glLoadIdentity(); 
    glFrustum(-2.0, 2.0, -2.0, 2.0, 0.8, 10.0); 
    gluLookAt(7.0,4.5,4.0, 4.5,4.5,2.0, 6.0,-3.0,2.0); 
 
    glMatrixMode(GL_MODELVIEW); 
    glLoadIdentity(); 
} 
 
/*  Main Loop 
 *  Open window with initial window size, title bar,  
 *  RGBA display mode, and handle input events. 
 */ 
int main(int argc, char** argv) 
{ 
    auxInitDisplayMode (AUX_SINGLE | AUX_RGB | AUX_DEPTH16); 
    auxInitPosition (0, 0, 500, 500); 
    auxInitWindow ("NURBS Surface"); 
    myinit(); 
    auxReshapeFunc (myReshape); 
    auxMainLoop(display); 
    return(0); 
}