Function msProjectRectAsPolygon

mapproject.c:756–868

/************************************************************************/

static int 
msProjectRectAsPolygon(projectionObj *in, projectionObj *out, 
                       rectObj *rect) 
{
#ifdef USE_PROJ
  shapeObj polygonObj;
  lineObj  ring;
//  pointObj ringPoints[NUMBER_OF_SAMPLE_POINTS*4+4];
  pointObj *ringPoints;
  int     ix, iy;

  double dx, dy;

  ringPoints = (pointObj*) calloc(sizeof(pointObj),NUMBER_OF_SAMPLE_POINTS*4+4);
  ring.point = ringPoints;
  ring.numpoints = 0;

  msInitShape( &polygonObj );
  polygonObj.type = MS_SHAPE_POLYGON;

/* -------------------------------------------------------------------- */
/*      Build polygon as steps around the source rectangle.             */
/* -------------------------------------------------------------------- */
  dx = (rect->maxx - rect->minx)/NUMBER_OF_SAMPLE_POINTS;
  dy = (rect->maxy - rect->miny)/NUMBER_OF_SAMPLE_POINTS;

  /* sample along top */
  if(dx != 0) {
    for(ix = 0; ix <= NUMBER_OF_SAMPLE_POINTS; ix++ )
    {
      ringPoints[ring.numpoints].x = rect->minx + ix * dx;
      ringPoints[ring.numpoints++].y = rect->miny;
    }
  }

  /* sample on along right side */
  if(dy != 0) {
    for(iy = 1; iy <= NUMBER_OF_SAMPLE_POINTS; iy++ )
    {
      ringPoints[ring.numpoints].x = rect->maxx;
      ringPoints[ring.numpoints++].y = rect->miny + iy * dy;
    }
  }

  /* sample along bottom */
  if(dx != 0) {
    for(ix = NUMBER_OF_SAMPLE_POINTS-1; ix >= 0; ix-- )
    {
      ringPoints[ring.numpoints].x = rect->minx + ix * dx;
      ringPoints[ring.numpoints++].y = rect->maxy;
    }
  }

  /* sample on along left side */
  if(dy != 0) {
    for(iy = NUMBER_OF_SAMPLE_POINTS-1; iy >= 0; iy-- )
    {
      ringPoints[ring.numpoints].x = rect->minx;