1 /* 2 * Copyright (c) 2021-2023 Huawei Device Co., Ltd. 3 * Licensed under the Apache License, Version 2.0 (the "License"); 4 * you may not use this file except in compliance with the License. 5 * You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software 10 * distributed under the License is distributed on an "AS IS" BASIS, 11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 * See the License for the specific language governing permissions and 13 * limitations under the License. 14 */ 15 16 #ifndef SCALAR_H 17 #define SCALAR_H 18 19 #include <cmath> 20 #include <limits> 21 22 namespace OHOS { 23 namespace Rosen { 24 namespace Drawing { 25 typedef float scalar; 26 static const scalar BLUR_SIGMA_SCALE = 0.57735f; 27 static const scalar FLOAT_PI = 3.14159265f; 28 IsScalarAlmostEqual(scalar a,scalar b)29inline bool IsScalarAlmostEqual(scalar a, scalar b) 30 { 31 return fabs(a - b) < std::numeric_limits<scalar>::min(); 32 } 33 ConvertRadiusToSigma(scalar radius)34inline scalar ConvertRadiusToSigma(scalar radius) 35 { 36 return radius > 0 ? BLUR_SIGMA_SCALE * radius + 0.5f : 0.0f; 37 } 38 ConvertSigmaToRadius(scalar sigma)39inline scalar ConvertSigmaToRadius(scalar sigma) 40 { 41 return sigma > 0.5f ? (sigma - 0.5f) / BLUR_SIGMA_SCALE : 0.0f; 42 } 43 44 /* 45 * @param radians Radians values. 46 * @return Return degrees values. 47 */ ConvertRadiansToDegrees(scalar radians)48inline scalar ConvertRadiansToDegrees(scalar radians) 49 { 50 return radians * (180 / FLOAT_PI); 51 } 52 } // namespace Drawing 53 } // namespace Rosen 54 } // namespace OHOS 55 #endif 56