#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <math.h>
#include <assert.h>
#include "vertex.h"


/* read a vertext from a string.
 * fText says whether the vertex is textured or not
 */
int vtx_sscan(const char *s, pvertex pv, int fTex)
{
  int n;

  n = sscanf(s, "%f %f %f %d %d %d %d %f %f %f %f",
             &pv->x,&pv->y,&pv->z,&pv->a,&pv->r,&pv->g,&pv->b,
             &pv->u,&pv->v,&pv->d,&pv->w);

  return (((n == 11) && fTex) || ((n == 7) && !fTex));
}


/* assumes triangle in XY plane! */
double vtx_area(const vertex v[3])
{
  /* area tri ABC = 1/2 || (B-A) x (C-A) || */

  return fabs(((double)v[1].x - (double)v[0].x)*
              ((double)v[2].y - (double)v[0].y) -
              ((double)v[1].y - (double)v[0].y)*
              ((double)v[2].x - (double)v[0].x)) / 2.0;
}

/* assumes triangle in XY plane! */
/* always returns a number >= 1  */
double vtx_bbaspect(const vertex v[3])
{
  double x, y;

  x=vtx_bbhoriz(v);
  y=vtx_bbvert(v);
  
  if (x == 0 || y == 0)
    return 0;

  assert(x > 0 && y > 0);
  if (y > x) {
    float tmp = x;
    x = y;
    y = tmp;
  }

  return x/y;

}


double vtx_wratio(const vertex v[3]) 
{

  double minW, maxW;
  int i;

  for(i=0;i<3;i++) {
    if(i==0)
      minW=maxW=v[i].w;
    if(v[i].w>maxW)
      maxW=v[i].w;
    if(v[i].w<minW)
      minW=v[i].w;
  }

  if(minW==0) return 0;
  
  return maxW/minW;

}


double vtx_bbhoriz(const vertex v[3])
{
  register float minx, maxx;
  double x;

  minx = maxx = v[0].x;
  if (v[1].x < minx) minx = v[1].x;
  if (v[2].x < minx) minx = v[2].x;
  if (v[1].x > maxx) maxx = v[1].x;
  if (v[2].x > maxx) maxx = v[2].x;
  
  x = maxx-minx;

  return x;
  
}

double vtx_bbvert(const vertex v[3])
{
  register float miny, maxy;
  double y;

  miny = maxy = v[0].y;
  if (v[1].y < miny) miny = v[1].y;
  if (v[2].y < miny) miny = v[2].y;
  if (v[1].y > maxy) maxy = v[1].y;
  if (v[2].y > maxy) maxy = v[2].y;

  y = maxy-miny;

  return y;
  
}

double vtx_wave(const vertex v[3])
{

  double minW, maxW;
  int i;

  for(i=0;i<3;i++) {
    if(i==0)
      minW=maxW=v[i].w;
    if(v[i].w>maxW)
      maxW=v[i].w;
    if(v[i].w<minW)
      minW=v[i].w;
  }

  return (maxW+minW)/2;
}