path.c

来自「FreeFem++可以生成高质量的有限元网格。可以用于流体力学」· C语言 代码 · 共 189 行

#include "medit.h"
#include "extern.h"
#include "sproto.h"

#define MAX_PATH    1024
#define IMG_PER_SEC   25

/* add point to path */
int pathAdd(pScene sc,int x,int y) {
  GLdouble    modelmat[16],projmat[16];
  GLdouble    ptx,pty,ptz;
  GLint       viewport[4];
  Trajet     *path;
  pMesh       mesh;
  pTransform  view;
  float      *p,*p1,*a;
  int         k;

  if ( ddebug )  fprintf(stdout,"pathAdd");
  path = &sc->path;
  mesh = cv.mesh[sc->idmesh];
  view = sc->view;
  if ( path->np == MAX_PATH ) return(0); 

  /* memory alloc */
  if ( !path->np ) {
    path->pt = (float*)calloc(mesh->dim*(MAX_PATH+1),sizeof(float));
    if ( !path->pt ) {
      fprintf(stderr,"   Not enough memory to store path.\n");
      return(0);
    }
    path->tg = (float*)calloc(mesh->dim*(MAX_PATH+1),sizeof(float));
    if ( !path->tg ) {
      fprintf(stderr,"   Not enough memory to store tangents.\n");
      return(0);
    }
  }
  else if ( path->np > MAX_PATH-1 ) return(0);

  /* get 3D point */
  glGetDoublev(GL_PROJECTION_MATRIX,projmat);
  glGetIntegerv(GL_VIEWPORT,viewport);
  for (k=0; k<16; k++) modelmat[k] = view->matrix[k];
  gluUnProject(x,y,-100,modelmat,projmat,viewport,&ptx,&pty,&ptz);

  /* store point coords */
  ++path->np;
  p = &path->pt[mesh->dim*path->np];
  p[0] = ptx;
  p[1] = pty;
  p[2] = ptz;

  /* compute tangent at point-1 */
  if ( path->np > 2 ) {
    p1 = &path->pt[mesh->dim*(path->np-2)];
    a  = &path->tg[mesh->dim*path->np];
    a[0] = 0.5 * (p[0] - p1[0]);
    a[1] = 0.5 * (p[1] - p1[1]);
    a[2] = 0.5 * (p[2] - p1[2]);
  }
  
  if ( ddebug ) printf(" Point %d: (%f %f %f) added\n",path->np,p[0],p[1],p[2]);
  return(1);
}

/* build list of points */
GLuint pathList(pScene sc) {
  Trajet   path;
  pMesh    mesh;
  GLuint   dlist;
  float   *p;
  int      k;
  static GLfloat green[3] = {0.2, 1.0, 0.2};
  /*static GLfloat orang[3] = {1.0, 0.7, 0.1};*/

  if ( ddebug )  fprintf(stdout,"pathList");
  path = sc->path;
  mesh = cv.mesh[sc->idmesh];

  /* build display list */
  dlist = glGenLists(1);
  glNewList(dlist,GL_COMPILE);
  if ( glGetError() )  return(0);

  /* node positions */
  glPointSize(5);
  glColor3f(1.0,0.3,0.3);
  glBegin(GL_POINTS);
  for (k=1; k<=path.np; k++) {
    p = &path.pt[mesh->dim*k];
    glVertex3fv(p);
  }
  glEnd();

  /* straight path */
  glLineWidth(2.0);
  glColor3fv(green);
  glBegin(GL_LINE_STRIP);
  for (k=1; k<=path.np; k++) {
    p = &path.pt[mesh->dim*k];
    glVertex3fv(p);
  }
  glEnd();
  glLineWidth(1.0);

  /* curvilinear path */
  /*
  glBegin(GL_LINE_STRIP);
  glColor3fv(orang);
  glEnd();
  */

  glEndList();
  return(dlist);  
}

/* follow path */
void pathFollow(pScene sc) {
  Trajet  path;
  int     nbp;

  if ( !sc->path.np ) return;
  if ( ddebug )  fprintf(stdout,"pathFollow %d\n",sc->path.np);
  path = sc->path;
  if ( sc->path.sec < 0 )
    nbp = sc->path.np;
  else
    nbp = (sc->path.sec*IMG_PER_SEC);
}

int pathLoad(char *file,pScene sc) {
  FILE      *in;
  char      *ptr,data[256];

  strcpy(data,file);
  ptr = (char *)strstr(data,".mesh");
  if ( ptr )  *ptr = '\0';
  if ( !strstr(data,".path") )
    strcat(data,".path");
  in = fopen(data,"r");
  if ( !in ) {
    sscanf(data,"DEFAULT.path");
    in = fopen(data,"r");
    if ( !in )  return(0);
  }
  if ( !quiet )  fprintf(stdout,"  Loading %s\n",data);

  return(1);
}

int pathSave(char *file,pScene sc) {
  FILE      *out;
  pMesh      mesh;
  time_t     timeptr;
  float     *p;
  int        i,k;
  char      *ptr,data[256];

  strcpy(data,file);
  ptr = (char *)strstr(data,".mesh");
  if ( ptr )  *ptr = '\0';
  if ( !strstr(data,".path") )
    strcat(data,".path");

  out = fopen(data,"w");
  if ( !out ) {
	fprintf(stdout,"  ## Unable to open file\n");;
    return(0);
  }
  if ( !quiet )  fprintf(stdout,"  Writing %s\n",data);

  /* create standard path file */
  fprintf(out,"#  File created with Medit %s\n",ME_VER);
  fprintf(out,"#  Release %s\n",ME_REL);
  time(&timeptr);
  fprintf(out,"# Created: %s",ctime(&timeptr));

  mesh = cv.mesh[sc->idmesh];
  fprintf(out,"NbPoints\n%d\n",sc->path.np);
  for (k=1; k<=sc->path.np; k++) {
    p = &sc->path.pt[mesh->dim*k];
    for (i=0; i<mesh->dim; i++)
      fprintf(out,"%f ",p[i]);
    fprintf(out,"\n");
  }
  fclose(out); 
  return(1);
}