Add some heuristics to deal with shorter initial sync periods.

[c64tapwav] / interpolate.h

diff --git a/interpolate.h b/interpolate.h
index 55bc61cc3ca146147e0ba31b68c303e8b387493f..f9aeb110060a0501b1e79255fa0edbab2a156ecb 100644 (file)
--- a/interpolate.h
+++ b/interpolate.h
@@ -26,13 +26,13 @@ inline double lanczos_weight(double x)
        return sinc(M_PI * x) * sinc(M_PI * x / LANCZOS_RADIUS);
 }
 
-extern double lanczos_table[(LANCZOS_RADIUS * 2) * LANCZOS_RESOLUTION];
+extern double lanczos_table[LANCZOS_RADIUS * LANCZOS_RESOLUTION];
 void make_lanczos_weight_table();
 
 inline double lanczos_weight_table(double x)
 {
-       int table_id = lrintf((x + LANCZOS_RADIUS) * LANCZOS_RESOLUTION);
-       if (table_id < 0 || table_id >= (LANCZOS_RADIUS * 2) * LANCZOS_RESOLUTION) {
+       int table_id = lrintf(fabs(x) * LANCZOS_RESOLUTION);
+       if (table_id >= LANCZOS_RADIUS * LANCZOS_RESOLUTION) {
                return 0.0;
        }
        return lanczos_table[table_id];