///////////////////////////////////////////////////////////////////////////

//

// Copyright (c) 2009-2014 DreamWorks Animation LLC. 

//

// All rights reserved.

//

// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions are

// met:

// *       Redistributions of source code must retain the above copyright

// notice, this list of conditions and the following disclaimer.

// *       Redistributions in binary form must reproduce the above

// copyright notice, this list of conditions and the following disclaimer

// in the documentation and/or other materials provided with the

// distribution.

// *       Neither the name of DreamWorks Animation nor the names of

// its contributors may be used to endorse or promote products derived

// from this software without specific prior written permission.

//

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

//

///////////////////////////////////////////////////////////////////////////

#include <math.h>

#include <assert.h>

#include "half.h"

#include "compareDwa.h"

using namespace OPENEXR_IMF_NAMESPACE;

using namespace std;

//

// Convert from linear to a nonlinear representation,

//

half

toNonlinear(half linear)

{

    float sign    = 1;

    float logBase = pow(2.7182818, 2.2);

    if ((float)linear < 0) {

        sign = -1;

    } 

    if ((linear.bits() & 0x7c00) == 0x7c00) {

        return (half)0.0;                   

    }

    if ( fabs( (float)linear ) <= 1.0f) {

        return (half)(sign * pow(fabs((float)linear), 1.f/2.2f));

    } else {

        return (half)(sign * ( log(fabs((float)linear)) / log(logBase) + 1.0f) );

    }

    return (half)0.0f;

}

void

compareDwa(int width, 

           int height,

           const Array2D<Rgba> &src,

           const Array2D<Rgba> &test,

           RgbaChannels channels)

{

    half  srcNonlin, testNonlin;

    float relError;

    for (int y=0; y

        for (int x=0; x

            for (int comp=0; comp<3; ++comp) {

                switch (comp) {

                    case 0:

                        if (!(channels & WRITE_R)) continue;

                        srcNonlin  = toNonlinear(src[y][x].r);

                        testNonlin = toNonlinear(test[y][x].r);

                        break;

                    case 1:

                        if (!(channels & WRITE_G)) continue;

                        srcNonlin  = toNonlinear(src[y][x].g);

                        testNonlin = toNonlinear(test[y][x].g);

                        break;

                    case 2:

                        if (!(channels & WRITE_B)) continue;

                        srcNonlin  = toNonlinear(src[y][x].b);

                        testNonlin = toNonlinear(test[y][x].b);

                        break;

                }

                //

                // Try to compare with relative error. This breaks down

                // for small numbers, which could be quantiezed to 0 

                // giving 100% error. 

                //

                if (srcNonlin.bits() != 0x00) {

                    relError = fabs( (float)srcNonlin - (float)testNonlin ) /

                                    fabs((float)srcNonlin);

                    if (fabs(srcNonlin) < .1) continue;

                    if (fabs(srcNonlin) < .25) {

                        assert( relError < .25);

                    } else {

                        assert( relError < .1);

                    }

                } else {

                    assert( srcNonlin != testNonlin );

                }

            }

        }

    }

    //

    // Test alpha, if necessary

    //

    if (channels & WRITE_A) {

        for (int y=0; y

            for (int x=0; x

                assert( src[y][x].a == test[y][x].a );

            }

        }

    }

}