1 /* 2 * Copyright 2020 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef FLOWGRAPH_UTILITIES_H 18 #define FLOWGRAPH_UTILITIES_H 19 20 #include <unistd.h> 21 22 using namespace FLOWGRAPH_OUTER_NAMESPACE::flowgraph; 23 24 class FlowgraphUtilities { 25 public: 26 // This was copied from audio_utils/primitives.h 27 /** 28 * Convert a single-precision floating point value to a Q0.31 integer value. 29 * Rounds to nearest, ties away from 0. 30 * 31 * Values outside the range [-1.0, 1.0) are properly clamped to -2147483648 and 2147483647, 32 * including -Inf and +Inf. NaN values are considered undefined, and behavior may change 33 * depending on hardware and future implementation of this function. 34 */ clamp32FromFloat(float f)35static int32_t clamp32FromFloat(float f) 36 { 37 static const float scale = (float)(1UL << 31); 38 static const float limpos = 1.; 39 static const float limneg = -1.; 40 41 if (f <= limneg) { 42 return INT32_MIN; 43 } else if (f >= limpos) { 44 return INT32_MAX; 45 } 46 f *= scale; 47 /* integer conversion is through truncation (though int to float is not). 48 * ensure that we round to nearest, ties away from 0. 49 */ 50 return f > 0 ? f + 0.5 : f - 0.5; 51 } 52 53 }; 54 55 #endif // FLOWGRAPH_UTILITIES_H 56