crop.cpp

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#include "runtime.h"
#include "aux.h"
#include "box.h"

Value * Runtime::crop(Value * image, Value * box)
{
  // input checks
  if (image==NULL)  return NULL;
  if (box==NULL) return NULL;
  if (typeid(*image)!=typeid(ImageValue)) return NULL;
  if (typeid(*box)!=typeid(BoxValue)) return NULL;
  // convertions
  ImageValue * I = (ImageValue*)image;
  BoxValue   * B = (BoxValue*)box;
  PointValue & otl = B->tl;
  PointValue & otr = B->tr;
  PointValue & obl = B->bl;
  PointValue & obr = B->br;

  DirectPoint dtl = I->ocsToDcs(otl);
  DirectPoint dtr = I->ocsToDcs(otr);
  DirectPoint dbl = I->ocsToDcs(obl);
  DirectPoint dbr = I->ocsToDcs(obr);
  
  // final output size is the largest size we need to represent every
  // pixel
  int as = 1+(int)max(dist(dtl,dtr),dist(dbl,dbr));
  int bs = 1+(int)max(dist(dtl,dbl),dist(dtr,dbr));
  int cs = I->channelcount();
  ImageValue * O = new ImageValue(as,bs,cs);
  // we run trhough all the target pixels and fill in the values
  for(int c = 0 ; c < cs ; c++)
    for(int a = 0 ; a < as ; a++)
      for(int b = 0 ; b < bs ; b++)
        {
          int ml_x = pos(dtl.x,dbl.x,b,bs);
          int ml_y = pos(dtl.y,dbl.y,b,bs);
          int mr_x = pos(dtr.x,dbr.x,b,bs);
          int mr_y = pos(dtr.y,dbr.y,b,bs);
          int x = pos(ml_x,mr_x,a,as);
          int y = pos(ml_y,mr_y,a,as);
          O->set_direct(a,b,c,I->get_direct(x,y,c));
        }
  return O;
}

Value * Runtime::crop(vector<Value*> v)
{
  if (v.size()==2) return crop(v[0],v[1]);
  return NULL;
}

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