Function TestAntiLog

tests/cpu/ops/log/LogOpCPU_tests.cpp:110–174

}

void TestAntiLog(float logBase)
{
    const float rgbaImage[32] = { 0.0367126f, 0.5f, 1.f,     0.f,
                                 0.2f,       0.f,   .99f, 128.f,
                                 qnan,       qnan, qnan,    0.f,
                                 0.f,        0.f,  0.f,     qnan,
                                 inf,        inf,  inf,     0.f,
                                 0.f,        0.f,  0.f,     inf,
                                -inf,       -inf, -inf,     0.f,
                                 0.f,        0.f,  0.f,    -inf };

    float rgba[32] = {};

    OCIO::ConstLogOpDataRcPtr logOp = std::make_shared<OCIO::LogOpData>(
        logBase, OCIO::TRANSFORM_DIR_INVERSE);

    OCIO::ConstOpCPURcPtr pRenderer = OCIO::GetLogRenderer(logOp, true);
    pRenderer->apply(rgbaImage, rgba, 8);

    // Relative error tolerance for the log2 approximation.
    const float rtol = powf(2.f, -14.f);

    for (unsigned i = 0; i < 8; ++i)
    {
        const bool isAlpha = (i % 4 == 3);

        const float result = rgba[i];
        float expected = rgbaImage[i];
        if (!isAlpha)
        {
            expected = powf(logBase, expected);
        }

        // LogOpCPU implementation uses optimized logarithm approximation
        // cannot use strict comparison.
        // Evaluating output for input rgbaImage[0-7] = { 0.0367126f, 0.5f, 1.f,     0.f,
        //                                                0.2f,       0.f,   .99f, 128.f,
        //                                                ... }
        OCIO_CHECK_ASSERT(OCIO::EqualWithSafeRelError(result, expected, rtol, 1.0f));
    }

    // Evaluating output for input rgbaImage[8-11] = {qnan, qnan, qnan, 0.}.
    OCIO_CHECK_ASSERT(OCIO::IsNan(rgba[8]));
    OCIO_CHECK_EQUAL(rgba[11], 0.0f);

    // Evaluating output for input rgbaImage[12-15] = {0., 0., 0., qnan.}.
    OCIO_CHECK_CLOSE(rgba[12], 1.0f, rtol);
    OCIO_CHECK_ASSERT(OCIO::IsNan(rgba[15]));

    // Evaluating output for input rgbaImage[16-19] = {inf, inf, inf, 0.}.
    OCIO_CHECK_EQUAL(rgba[16], inf);
    OCIO_CHECK_EQUAL(rgba[19], 0.0f);

    // Evaluating output for input rgbaImage[20-23] =  {0., 0., 0., inf}.
    OCIO_CHECK_CLOSE(rgba[20], 1.0f, rtol);
    OCIO_CHECK_EQUAL(rgba[23], inf);

    // Evaluating output for input rgbaImage[24-27] = {-inf, -inf, -inf, 0.}.