1 /* 2 * Copyright 2014 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #ifndef SkHalf_DEFINED 9 #define SkHalf_DEFINED 10 11 #include <cstdint> 12 13 // 16-bit floating point value 14 // format is 1 bit sign, 5 bits exponent, 10 bits mantissa 15 // only used for storage 16 using SkHalf = uint16_t; 17 18 static constexpr uint16_t SK_HalfNaN = 0x7c01; // a NaN value, not all possible NaN values 19 static constexpr uint16_t SK_HalfInfinity = 0x7c00; 20 static constexpr uint16_t SK_HalfMin = 0x0400; // 2^-14 (minimum positive normal value) 21 static constexpr uint16_t SK_HalfMax = 0x7bff; // 65504 (maximum positive normal value) 22 static constexpr uint16_t SK_HalfEpsilon = 0x1400; // 2^-10 23 static constexpr uint16_t SK_Half1 = 0x3C00; // 1 24 25 // Convert between half and single precision floating point. Vectorized functions 26 // skvx::from_half and skvx::to_half are also available. Unlike skvx::to_half, this will 27 // correctly handle float NaN -> half NaN. 28 float SkHalfToFloat(SkHalf h); 29 SkHalf SkFloatToHalf(float f); 30 31 #endif 32