ZamHeadX2: Fix mapping of FIR filter selection

Fixes #98 - array indices swapped.

The array indices weren't actually swapped, but
the ranges were defined incorrectly resulting in only
some of the filters being used, rather than filter
coefficients being mixed up/corrupted.

plugins/ZamHeadX2/ZamHeadX2Plugin.cpp

@@ -78,15 +78,15 @@ void ZamHeadX2Plugin::initParameter(uint32_t index, Parameter& parameter)
         parameter.symbol     = "az";
         parameter.unit       = " ";
         parameter.ranges.def = 0.0f;
-        parameter.ranges.min = -90.0f;
-        parameter.ranges.max = 270.0f;
+        parameter.ranges.min = -120.0f;
+        parameter.ranges.max = 120.0f;
         break;
     case paramElevation:
         parameter.name       = "Elevation";
         parameter.symbol     = "elev";
         parameter.unit       = " ";
         parameter.ranges.def = 0.0f;
-        parameter.ranges.min = -45.0f;
+        parameter.ranges.min = -30.0f;
         parameter.ranges.max = 90.0f;
         break;
     case paramWidth:
@@ -181,13 +181,12 @@ void ZamHeadX2Plugin::reload()
     int az = 0;
     int el = 0;
 
-    el = (int)((elevation + 45.) * 24. / 135.);
-    if (el >= 24) el = 24;
+    el = (int)((elevation + 30.) * 49. / 120.);
+    if (el >= 49) el = 49;
     if (el < 0) el = 0;
-    az = (int)((azimuth + 90.) * 49. / 360.);
-    if (az >= 49) az = 49;
+    az = (int)((azimuth + 120.) * 24. / 240.);
+    if (az >= 24) az = 24;
     if (az < 0) az = 0;
-    if (az > 24) az = 49 - az;
     snprintf(elev, 3, "%d", el);
     snprintf(azim, 3, "%d", az);
     if ((az != azold) || (el != elold)) {