text: // Copyright (c) the JPEG XL Project
  //
  // 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
  //
  //      http://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.
  
  #include <stdlib.h>
  
  #include <algorithm>
  
  #include "gtest/gtest.h"
  #include "lib/jxl/enc_gamma_correct.h"
  
  namespace jxl {
  namespace {
  
  TEST(GammaCorrectTest, TestLinearToSrgbEdgeCases) {
    EXPECT_EQ(0, LinearToSrgb8Direct(0.0));
    EXPECT_NEAR(0, LinearToSrgb8Direct(1E-6f), 2E-5);
    EXPECT_EQ(0, LinearToSrgb8Direct(-1E-6f));
    EXPECT_EQ(0, LinearToSrgb8Direct(-1E6));
    EXPECT_NEAR(1, LinearToSrgb8Direct(1 - 1E-6f), 1E-5);
    EXPECT_EQ(1, LinearToSrgb8Direct(1 + 1E-6f));
    EXPECT_EQ(1, LinearToSrgb8Direct(1E6));
  }
  
  TEST(GammaCorrectTest, TestRoundTrip) {
    // NOLINTNEXTLINE(clang-analyzer-security.FloatLoopCounter)
    for (double linear = 0.0; linear <= 1.0; linear += 1E-7) {
      const double srgb = LinearToSrgb8Direct(linear);
      const double linear2 = Srgb8ToLinearDirect(srgb);
      ASSERT_LT(std::abs(linear - linear2), 2E-13)
          << "linear = " << linear << ", linear2 = " << linear2;
    }
  }
  
  }  // namespace
  }  // namespace jxl
  