Add conversion from installation to offline APA numbering convention.

src/pdt_pduneadjacency_mlt.cc

@@ -1,6 +1,46 @@
 #include "pdt_engines.h"
 #include "pdt/ModuleTrigger.h"
 
+/* 
+From Phil:
+
+ detid set inside FELIX_BR:
+
+ (m_fiber_no << 16) | (m_slot_no << 8) | m_crate_no
+    
+m_crate_no is the same as the "online" APA number ("Installation numbering" below):
+
+ Installation numbering:
+             APA5  APA6  APA4
+  beam -->
+             APA3  APA2  APA1
+
+  The Offline numbering:
+             APA1  APA3  APA5
+  beam -->
+             APA0  APA2  APA4
+
+So, based on David's message, the mapping is:
+
+m_crate_no	candidate[8]
+5		0
+6		1
+4		2
+
+(m_crate_no=4 will never occur in the current system, as APA 4 isn't
+instrumented with FELIX yet, but the plan is that it will be
+eventually).
+
+*/
+static
+int detid_to_offline_apa_number(int detid)
+{
+    const std::vector<int> i2o_apa_map = {-1, 4, 2, 0, 5, 1, 3};
+    const size_t inst_apa = detid & 0x000000FF;
+    if (inst_apa < 0 or inst_apa > 6) { return -1; }
+    return i2o_apa_map[inst_apa];
+}
+
 // Fixme: TPSet holds 50MHz clocks, PDT assumes 2MHz
 const int hwtick_per_internal = 25;
 
@@ -36,7 +76,14 @@ void PDUNEAdjacencyMLT_engine::ingest(const ptmp::data::TPSet& fresh)
         outbound.set_detid(fresh.detid());
     }
 
+    // ModuleTrigger() wants a 9-tuple of ints.  First eight entries
+    // are what TriggerCommand() returns.  The ninth is the *offline*
+    // APA number (not installation number).
+    // 
+    //     0         1       2       3      4      5     6    7   8
+    // (adjacency, adcpeak, adcsum, tspan, chan1, chan2, t1, t2, apanum)
     candidate_t candidate(9, 0);
+
     // Adjacency value is outside the TPSet/TrigPrim model and is
     // special to the PDT TriggerCandidate() algorithm.  We've stashed
     // it in TrigPrim.adcpeak in a final TrigPrim with .flag set to
@@ -50,13 +97,7 @@ void PDUNEAdjacencyMLT_engine::ingest(const ptmp::data::TPSet& fresh)
     // PDT works in 2MHz clock ticks, not 50MHz
     candidate[6] = special->tstart()/hwtick_per_internal;
     candidate[7] = (special->tstart() + special->tspan())/hwtick_per_internal;
-    // Phil sets detid inside FELIX_BR with:
-    //
-    // (m_fiber_no << 16) | (m_slot_no << 8) | m_crate_no
-    //
-    // FIXME: for lack of any better understanding assume PDT wants
-    // APA number same as m_crate_no:
-    candidate[8] = fresh.detid() & 0x000000FF;
+    candidate[8] = detid_to_offline_apa_number(fresh.detid());
     candidates.push_back(candidate);
 
     outbound.set_chanbeg(std::min(outbound.chanbeg(), fresh.chanbeg()));
@@ -83,11 +124,6 @@ void PDUNEAdjacencyMLT_engine::operator()(const ptmp::data::TPSet& input_tpset,
 
     // ready to process
 
-    // It is an 9-tuple of ints, with additional [8]'th entry from
-    // what TriggerCommand() returns
-    //     0         1       2       3      4      5     6    7   8
-    // (adjacency, adcpeak, adcsum, tspan, chan1, chan2, t1, t2, apanum)
-
     // fixme: does MT() need any sorting of its input candidates?
 
     int ok = ModuleTrigger(candidates);
@@ -109,6 +145,7 @@ void PDUNEAdjacencyMLT_engine::operator()(const ptmp::data::TPSet& input_tpset,
 
 void PDUNEAdjacencyMLT_engine::clear()
 {
+    // don't clear detid
     outbound.set_tstart(0);
     outbound.set_tspan(0);
     outbound.set_chanbeg(0);