1 files changed, 56 insertions, 0 deletions
diff --git a/externals/oboe/apps/fxlab/app/src/main/cpp/effects/SingleFunctionEffects.h b/externals/oboe/apps/fxlab/app/src/main/cpp/effects/SingleFunctionEffects.h
new file mode 100644
index 0000000000..4c8f0df0fc
--- /dev/null
+++ b/externals/oboe/apps/fxlab/app/src/main/cpp/effects/SingleFunctionEffects.h
@@ -0,0 +1,56 @@
+ /*
+ * Copyright  2019 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef ANDROID_FXLAB_SINGLEFUNCTIONEFFECTS_H
+#define ANDROID_FXLAB_SINGLEFUNCTIONEFFECTS_H
+
+#include <list>
+
+ namespace SingleFunctionEffects {
+
+template<class floating>
+void _overdrive (floating &x) {
+    static constexpr double third = (1.0 / 3.0);
+    auto abs = std::abs(x);
+    if (abs <= third) {
+        x *= 2;
+    } else if (abs <= 2 * third) {
+        x = std::copysign((3 - (2 - 3 * abs) * (2 - 3 * abs)) * third, x);
+    } else {
+        x = std::copysign(1, x);
+    }
+}
+
+template <class iter_type>
+void overdrive(iter_type beg, iter_type end) {
+    for (; beg != end; ++beg){
+        _overdrive(*beg);
+    }
+}
+
+template <class floating>
+void _distortion (floating &x) {
+    x = std::copysign(-std::expm1(-std::abs(x)), x);
+}
+
+template <class iter_type>
+void distortion(iter_type beg, iter_type end) {
+    for (; beg != end; ++beg) {
+        _distortion(*beg);
+    }
+}
+
+}
+#endif //ANDROID_FXLAB_SINGLEFUNCTIONEFFECTS_H