/* compute row, column number of true world co-ordinate
* RgetRowCol computes row, column number of true world co-ordinate.
*
* returns
* 0 if the co-ordinate is outside the map,
* 1 if inside,
* -1 in case of an error
*
* Merrno
* ILL_CELLSIZE
*/
int RgetRowCol(
const MAP *m, /* map handle */
double x, /* x of true co-ordinate */
double y, /* y of true co-ordinate */
size_t *row, /* write-only. Row number (y-pos).
* Undefined if (x,y) is outside of map
*/
size_t *col) /* write-only. Column number (x-pos).
* Undefined if (x,y) is outside of map
*/
{
double row_d,col_d;
int result;
result = Rcoords2RowCol(m,x,y,&row_d,&col_d);
if (result > 0)
{
*row = (size_t)floor(row_d);
*col = (size_t)floor(col_d);
}
return(result);
}
/* Calculates one pixel from output map, given the input maps.
* Puts all values of input pixels in a list and determines the value of
* the output pixel according to these values and the overlapping areas.
* Returns 0 if no error occurs, 1 otherwise.
*/
static int CalcPixel(
MAP *out, /* write-only output map */
MAP **in, /* read-only list input maps */
size_t nrCoverCells, /* min. nr. non-MV cells for non-MV */
size_t nrMaps, /* nr. of input maps */
double rOut, /* row number pixel */
double cOut, /* column number pixel */
BOOL aligned, /* maps are aligned */
REAL8 angle) /* angle of output map */
{
PTYPE tlX, tlY, trX, trY, brX, brY, blX, blY;
double r, c;
DATA *list = NULL; /* areas and values of input cells */
size_t i, nrList = 0; /* number of items in list */
POINT2D *outputCell; /* polygon of output cell */
size_t nr = 4; /* nr of points of cell */
CSF_VS vs; /* value scale of first input map */
if(nrCoverCells > 0 && nrMaps > 1)
raster = InitRaster(raster); /* initialize the raster */
/* Determine the four corners of output pixel */
RrowCol2Coords(out, rOut, cOut, &tlX, &tlY); /* top left */
RrowCol2Coords(out, rOut, cOut + 1, &trX, &trY); /* top right */
RrowCol2Coords(out, rOut + 1, cOut, &blX, &blY); /* bottom left */
RrowCol2Coords(out, rOut + 1, cOut + 1, &brX, &brY); /* bottom right */
outputCell = PutInPol(tlX, tlY, trX, trY, brX, brY, blX, blY);
if(outputCell == NULL)
return 1;
POSTCOND(outputCell[0].x == outputCell[nr].x);
POSTCOND(outputCell[0].y == outputCell[nr].y);
/* Get pixel on every input map */
for(i = 0; i < nrMaps; i++)
{
MAP *X = in[i]; /* input map number i */
PTYPE tlC, tlR, trC, trR, brC, brR, blC, blR;
PTYPE tlX2, tlY2, trX2, trY2, brX2, brY2, blX2, blY2;
double leftB, belowB, rightB, upperB; /* boundaries */
/* Corners: (tlX, tlY), (trX, trY), (blX, blY) and
* (brX, brY). Translate for input map.
*/
Rcoords2RowCol(X, tlX, tlY, &tlC, &tlR); /* top left */
Rcoords2RowCol(X, trX, trY, &trC, &trR); /* top right */
Rcoords2RowCol(X, blX, blY, &blC, &blR); /* bottom left */
Rcoords2RowCol(X, brX, brY, &brC, &brR); /* bottom right */
/* Boundaries in the input map */
rightB = ceil(MaxPoint(tlR, trR, blR, brR));
belowB = ceil(MaxPoint(tlC, trC, blC, brC));
leftB = floor(MinPoint(tlR, trR, blR, brR));
upperB = floor(MinPoint(tlC, trC, blC, brC));
PRECOND(upperB <= belowB);
PRECOND(leftB <= rightB);
/* Check all cells between the boundaries */
for(r = upperB; r < belowB; r++)
{
REAL8 *currRow;
if(0 <= r && r <= RgetNrRows(X))
currRow = (REAL8 *)CacheGetRow(in, i, r);
for(c = leftB; c < rightB; c++)
{ /* Cells that might be in pixel */
POINT2D *inputCell; /* polygon input cell */
if(r < 0 || RgetNrRows(X) <= r || c < 0 ||
RgetNrCols(X) <= c)
continue;
/* Top left & right, bottom left & right */
RrowCol2Coords(X, r, c, &tlX2, &tlY2);
RrowCol2Coords(X, r, c+1, &trX2, &trY2);
RrowCol2Coords(X, r+1, c, &blX2, &blY2);
RrowCol2Coords(X, r+1, c+1, &brX2, &brY2);
inputCell = PutInPol(tlX2, tlY2, trX2, trY2,
brX2, brY2, blX2, blY2);
if(inputCell == NULL)
return 1;
POSTCOND(inputCell[0].x == inputCell[nr].x);
POSTCOND(inputCell[0].y == inputCell[nr].y);
/* Add item to list for cell */
if(AddCell(&list, raster, &nrList, inputCell,
outputCell, currRow, X, nrMaps,
(size_t)c, nrCoverCells, aligned, angle))
return 1;
Free(inputCell); /* deallocate */
}
}
}
/* calculate output value of pixel according value scale */
vs = RgetValueScale(in[0]);
if(vs != VS_DIRECTION)
CalcScalarOut(out, (size_t)rOut, (size_t)cOut, nrList, list, nrCoverCells, nrMaps);
else
CalcDirectionOut(out, (size_t) rOut, (size_t) cOut, nrList, list, nrCoverCells, nrMaps);
Free(outputCell); /* deallocate */
Free(list); /* deallocate */
return 0; /* successfully terminated */
}
