F2-OI: Discrepancy between OT Patrol field and valid TCS demands

[iarriagada]

It appears that the F2OI patrol field displayed by the OT is flipped in the X-axis.
Targets selected in the lower area, yield to TCS Demands with negative y-coordinates (for more details, see FR-41353 comment)

According to the following line in the code

ocs/bundle/edu.gemini.pot/src/main/java/edu/gemini/spModel/gemini/flamingos2/Flamingos2OiwfsGuideProbe.java

Line 52 in c33af32

180, 180, Arc2D.CHORD);

The lower area has a larger radius, but according to the mechanical specs, the larger radius area covers the +Y coordinates.
I think the Arc should start at 0 degrees and cover 180 degrees

[iarriagada]

I was wrong. The patrol field is defined correctly following the specs in the pdf found in REL-285. The issue is that F2OPC defines the following constraint as well

xTarget = (xTarget - xOffset)*PROBE_POSITION_SCALING_FACTOR;
yTarget = -(yTarget - yOffset)*PROBE_POSITION_SCALING_FACTOR;

 /*
     * Convert from instrument coordinates to base coordinates
     * which use the axis of rotation of the base arm as the origin.
     * First subtract the {IC} to {B} origin offsets then negate since
     * both X & Y axis go in opposite directions compared to {IC}.
     */
x_prime = -(xTarget - IC_X);
y_prime = -(yTarget - IC_Y);

/*
     *  Compute distance from the target to the axis of base arm.
     */
r = sqrt(SQR(x_prime) + SQR(y_prime));

/*  If the target is too far from (or too close to) the axis of
     *  the base arm, then the target cannot be reached by the
     *  probe.
     */
if (r > B_X + P_X)
{
return -1; /* cannot reach with both axes fully extended */
}
else if (r < P_X - B_X)
    {
        return -1; /* cannot reach with pickoff folded back completely */
    }

This effectively adds another constraint to the patrol field. Please refer to the the fault report posted in the original comment for a deeper analysis.