Dummy: fix sine/square frequency sweep

diff --git a/libs/backends/dummy/dummy_audiobackend.cc b/libs/backends/dummy/dummy_audiobackend.cc
index 1428dc28a22b8a1528f67f890ebca28030d552cf..050e99435c87253b85c5df829455008e7e39864c 100644 (file)
--- a/libs/backends/dummy/dummy_audiobackend.cc
+++ b/libs/backends/dummy/dummy_audiobackend.cc
@@ -1621,7 +1621,7 @@ void DummyAudioPort::setup_generator (GeneratorType const g, float const sampler
 #else
                                        const double phase = a * exp (b * j) - a;
 #endif
-                                       _wavetable[i] = (float)sin (2. * M_PI * (phase - floor (phase)));
+                                       _wavetable[i] = -(float)sin (2. * M_PI * (phase - floor (phase)));
                                }
                                if (_gen_type == SquareSweep) {
                                        for (uint32_t i = 0 ; i < _gen_period; ++i) {