1 files changed, 72 insertions, 0 deletions
diff --git a/libs/fluidsynth/src/fluid_lfo.h b/libs/fluidsynth/src/fluid_lfo.h
new file mode 100644
index 0000000000..e9440cf526
--- /dev/null
+++ b/libs/fluidsynth/src/fluid_lfo.h
@@ -0,0 +1,72 @@
+/* FluidSynth - A Software Synthesizer
+ *
+ * Copyright (C) 2003  Peter Hanappe and others.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public License
+ * as published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA
+ */
+
+#ifndef _FLUID_LFO_H
+#define _FLUID_LFO_H
+
+#include "fluidsynth_priv.h"
+
+typedef struct _fluid_lfo_t fluid_lfo_t;
+
+struct _fluid_lfo_t {
+	fluid_real_t val;          /* the current value of the LFO */
+	unsigned int delay;       /* the delay of the lfo in samples */
+	fluid_real_t increment;         /* the lfo frequency is converted to a per-buffer increment */
+};
+
+static inline void 
+fluid_lfo_reset(fluid_lfo_t* lfo)
+{
+  lfo->val = 0.0f;
+}
+
+// These two cannot be inlined since they're used by event_dispatch
+void fluid_lfo_set_incr(fluid_lfo_t* lfo, fluid_real_t increment);
+void fluid_lfo_set_delay(fluid_lfo_t* lfo, unsigned int delay);
+
+static inline fluid_real_t
+fluid_lfo_get_val(fluid_lfo_t* lfo)
+{
+  return lfo->val;
+}
+
+static inline void 
+fluid_lfo_calc(fluid_lfo_t* lfo, unsigned int cur_delay)
+{
+  if (cur_delay < lfo->delay) 
+    return;
+  
+  lfo->val += lfo->increment;
+  
+  if (lfo->val > (fluid_real_t) 1.0)
+  {
+    lfo->increment = -lfo->increment;
+    lfo->val = (fluid_real_t) 2.0 - lfo->val;
+  }
+  else if (lfo->val < (fluid_real_t) -1.0)
+  {
+    lfo->increment = -lfo->increment;
+    lfo->val = (fluid_real_t) -2.0 - lfo->val;
+  }
+
+}
+
+#endif
+