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 "src/base/SkVx.h" 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 typedef uint16_t SkHalf; 17 18 static constexpr uint16_t SK_HalfMin = 0x0400; // 2^-14 (minimum positive normal value) 19 static constexpr uint16_t SK_HalfMax = 0x7bff; // 65504 20 static constexpr uint16_t SK_HalfEpsilon = 0x1400; // 2^-10 21 static constexpr uint16_t SK_Half1 = 0x3C00; // 1 22 23 // convert between half and single precision floating point 24 float SkHalfToFloat(SkHalf h); 25 SkHalf SkFloatToHalf(float f); 26 27 // Convert between half and single precision floating point, 28 // assuming inputs and outputs are both finite, and may 29 // flush values which would be denormal half floats to zero. SkHalfToFloat_finite_ftz(uint64_t rgba)30static inline skvx::float4 SkHalfToFloat_finite_ftz(uint64_t rgba) { 31 return skvx::from_half(skvx::half4::Load(&rgba)); 32 } SkFloatToHalf_finite_ftz(const skvx::float4 & c)33static inline skvx::half4 SkFloatToHalf_finite_ftz(const skvx::float4& c) { 34 return skvx::to_half(c); 35 } 36 37 #endif 38