/*-------------------------------------------------------------------------
 * drawElements Internal Test Module
 * ---------------------------------
 *
 * Copyright 2015 The Android Open Source 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.
 *
 *//*!
 * \file
 * \brief 8-bit sRGB conversion test.
 *//*--------------------------------------------------------------------*/

#include "ditSRGB8ConversionTest.hpp"

#include "tcuFloat.hpp"
#include "tcuTestLog.hpp"
#include "tcuTextureUtil.hpp"
#include "tcuVectorUtil.hpp"

namespace dit
{
namespace
{

uint32_t calculateDiscreteFloatDistance(float a, float b)
{
    const uint32_t au = tcu::Float32(a).bits();
    const uint32_t bu = tcu::Float32(b).bits();

    const bool asign = (au & (0x1u << 31u)) != 0u;
    const bool bsign = (bu & (0x1u << 31u)) != 0u;

    const uint32_t avalue = (au & ((0x1u << 31u) - 1u));
    const uint32_t bvalue = (bu & ((0x1u << 31u) - 1u));

    if (asign != bsign)
        return avalue + bvalue + 1u;
    else if (avalue < bvalue)
        return bvalue - avalue;
    else
        return avalue - bvalue;
}

const tcu::UVec4 calculateDiscreteFloatDistance(const tcu::Vec4 &ref, const tcu::Vec4 &res)
{
    return tcu::UVec4(calculateDiscreteFloatDistance(ref[0], res[0]), calculateDiscreteFloatDistance(ref[1], res[1]),
                      calculateDiscreteFloatDistance(ref[2], res[2]), calculateDiscreteFloatDistance(ref[3], res[3]));
}

class SRGB8ConversionTest : public tcu::TestCase
{
public:
    SRGB8ConversionTest(tcu::TestContext &context) : tcu::TestCase(context, "srgb8", "SRGB8 conversion test")
    {
    }

    IterateResult iterate(void)
    {
        bool isOk         = true;
        tcu::TestLog &log = m_testCtx.getLog();

        for (int i = 0; i < 256; i++)
        {
            const tcu::UVec4 src(i);
            const tcu::Vec4 res(tcu::sRGBA8ToLinear(src));
            const tcu::Vec4 ref(tcu::sRGBToLinear(src.cast<float>() / tcu::Vec4(255.0f)));
            const tcu::Vec4 diff(res - ref);
            const tcu::UVec4 discreteFloatDiff(calculateDiscreteFloatDistance(ref, res));

            if (tcu::anyNotEqual(res, ref))
                log << tcu::TestLog::Message << i << ", Res: " << res << ", Ref: " << ref << ", Diff: " << diff
                    << ", Discrete float diff: " << discreteFloatDiff << tcu::TestLog::EndMessage;

            if (tcu::boolAny(tcu::greaterThan(discreteFloatDiff, tcu::UVec4(1u))))
                isOk = false;
        }

        if (isOk)
            m_testCtx.setTestResult(QP_TEST_RESULT_PASS, "Pass");
        else
            m_testCtx.setTestResult(QP_TEST_RESULT_FAIL, "Got ulp diffs greater than one.");

        return STOP;
    }
};

} // namespace

tcu::TestCase *createSRGB8ConversionTest(tcu::TestContext &context)
{
    return new SRGB8ConversionTest(context);
}

} // namespace dit