/**
* @brief Given a list of lines within the original image, compute their
* horizontal Y pixels or vertical X pixels within the rotated image.
*
* Input:
* origWidth,origHeight = width and height of original image
* portBitmap,portWidth,portHeight = rotated image
* slope = collection of line segments of equal slope
*
* Output:
* longlenverts,longlenhorzs = filled in to indicate where lat/lon lines
* are in the rotated image
*/
public static void ComputeVertHorzLatLons (Slope slope)
{
// scan through each line of the given slope
foreach (LongLine line in slope.GetLongLines ()) {
if (!line.IsValid ()) continue;
// rotate the line's endpoints from original image coords to rotated image coords
XY begRot = RotateImagePoint (line.begx, line.begy, latLonSlopeX, latLonSlopeY);
XY endRot = RotateImagePoint (line.endx, line.endy, latLonSlopeX, latLonSlopeY);
int xdiff = begRot.x - endRot.x;
int ydiff = begRot.y - endRot.y;
if (xdiff < 0) xdiff = -xdiff;
if (ydiff < 0) ydiff = -ydiff;
// small X difference means vertical
if (xdiff <= ydiff / 16) {
int xavg = (begRot.x + endRot.x) / 2;
if ((xavg >= 0) && (xavg < portWidth)) {
longlenverts[xavg] += ydiff;
}
}
// small Y difference means horizontal
if (ydiff <= xdiff / 16) {
int yavg = (begRot.y + endRot.y) / 2;
if ((yavg >= 0) && (yavg < portHeight)) {
longlenhorzs[yavg] += xdiff;
}
}
}
}
